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Spring Elasticsearch: Adding fields to working POJO class causes IllegalArgumentException: null is not a Map

currently we add a dashboard in our spring application with information from our elastic. We use the documented approach via RestHighLevelClient.. The request and mapping does work pretty good. However, when we tried to add a few additional fields we expected to get the corresponding values. Instead,we got the following stacktrace:
java.lang.IllegalArgumentException: null is not a Map.
at org.springframework.data.elasticsearch.core.convert.MappingElasticsearchConverter$MapValueAccessor.getAsMap(MappingElasticsearchConverter.java:941) ~[spring-data-elasticsearch-4.1.1.jar!/:4.1.1]
at org.springframework.data.elasticsearch.core.convert.MappingElasticsearchConverter$MapValueAccessor.get(MappingElasticsearchConverter.java:911) ~[spring-data-elasticsearch-4.1.1.jar!/:4.1.1]
at org.springframework.data.elasticsearch.core.convert.MappingElasticsearchConverter$ElasticsearchPropertyValueProvider.getPropertyValue(MappingElasticsearchConverter.java:956) ~[spring-data-elasticsearch-4.1.1.jar!/:4.1.1]
at org.springframework.data.elasticsearch.core.convert.MappingElasticsearchConverter.readProperties(MappingElasticsearchConverter.java:266) ~[spring-data-elasticsearch-4.1.1.jar!/:4.1.1]
at org.springframework.data.elasticsearch.core.convert.MappingElasticsearchConverter.readEntity(MappingElasticsearchConverter.java:197) ~[spring-data-elasticsearch-4.1.1.jar!/:4.1.1]
at org.springframework.data.elasticsearch.core.convert.MappingElasticsearchConverter.read(MappingElasticsearchConverter.java:177) ~[spring-data-elasticsearch-4.1.1.jar!/:4.1.1]
at org.springframework.data.elasticsearch.core.convert.MappingElasticsearchConverter.read(MappingElasticsearchConverter.java:77) ~[spring-data-elasticsearch-4.1.1.jar!/:4.1.1]
at org.springframework.data.elasticsearch.core.AbstractElasticsearchTemplate$ReadDocumentCallback.doWith(AbstractElasticsearchTemplate.java:714) ~[spring-data-elasticsearch-4.1.1.jar!/:4.1.1]
at java.base/java.util.stream.ReferencePipeline$3$1.accept(Unknown Source) ~[na:na]
at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(Unknown Source) ~[na:na]
at java.base/java.util.stream.AbstractPipeline.copyInto(Unknown Source) ~[na:na]
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(Unknown Source) ~[na:na]
at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(Unknown Source) ~[na:na]
at java.base/java.util.stream.AbstractPipeline.evaluate(Unknown Source) ~[na:na]
at java.base/java.util.stream.ReferencePipeline.collect(Unknown Source) ~[na:na]
at org.springframework.data.elasticsearch.core.AbstractElasticsearchTemplate$ReadSearchDocumentResponseCallback.doWith(AbstractElasticsearchTemplate.java:738) ~[spring-data-elasticsearch-4.1.1.jar!/:4.1.1]
at org.springframework.data.elasticsearch.core.AbstractElasticsearchTemplate$ReadSearchDocumentResponseCallback.doWith(AbstractElasticsearchTemplate.java:724) ~[spring-data-elasticsearch-4.1.1.jar!/:4.1.1]
at org.springframework.data.elasticsearch.core.ElasticsearchRestTemplate.search(ElasticsearchRestTemplate.java:276) ~[spring-data-elasticsearch-4.1.1.jar!/:4.1.1]
at org.springframework.data.elasticsearch.repository.query.ElasticsearchPartQuery.execute(ElasticsearchPartQuery.java:120) ~[spring-data-elasticsearch-4.1.1.jar!/:4.1.1]
at org.springframework.data.repository.core.support.RepositoryMethodInvoker.doInvoke(RepositoryMethodInvoker.java:137) ~[spring-data-commons-2.4.1.jar!/:2.4.1]
at org.springframework.data.repository.core.support.RepositoryMethodInvoker.invoke(RepositoryMethodInvoker.java:121) ~[spring-data-commons-2.4.1.jar!/:2.4.1]
at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.doInvoke(QueryExecutorMethodInterceptor.java:152) ~[spring-data-commons-2.4.1.jar!/:2.4.1]
at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.invoke(QueryExecutorMethodInterceptor.java:131) ~[spring-data-commons-2.4.1.jar!/:2.4.1]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.1.jar!/:5.3.1]
at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:80) ~[spring-data-commons-2.4.1.jar!/:2.4.1]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.1.jar!/:5.3.1]
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:97) ~[spring-aop-5.3.1.jar!/:5.3.1]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.1.jar!/:5.3.1]
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:215) ~[spring-aop-5.3.1.jar!/:5.3.1]
at com.sun.proxy.$Proxy85.findByFooInfo(Unknown Source) ~[na:na]
at org.foo.bar.casper.web.InitialConfigurationDashboardController.getInitialConfigurationDashboardPage(InitialConfigurationDashboardController.java:69) ~[classes!/:0.0.1-191]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[na:na]
at java.base/java.lang.reflect.Method.invoke(Unknown Source) ~[na:na]
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:197) ~[spring-web-5.3.1.jar!/:5.3.1]
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:141) ~[spring-web-5.3.1.jar!/:5.3.1]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106) ~[spring-webmvc-5.3.1.jar!/:5.3.1]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:893) ~[spring-webmvc-5.3.1.jar!/:5.3.1]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:807) ~[spring-webmvc-5.3.1.jar!/:5.3.1]
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.3.1.jar!/:5.3.1]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1061) ~[spring-webmvc-5.3.1.jar!/:5.3.1]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:961) ~[spring-webmvc-5.3.1.jar!/:5.3.1]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.3.1.jar!/:5.3.1]
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909) ~[spring-webmvc-5.3.1.jar!/:5.3.1]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:652) ~[tomcat-embed-core-9.0.39.jar!/:4.0.FR]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.3.1.jar!/:5.3.1]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:733) ~[tomcat-embed-core-9.0.39.jar!/:4.0.FR]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.39.jar!/:9.0.39]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.3.1.jar!/:5.3.1]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.1.jar!/:5.3.1]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.3.1.jar!/:5.3.1]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.1.jar!/:5.3.1]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:93) ~[spring-boot-actuator-2.4.0.jar!/:2.4.0]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.1.jar!/:5.3.1]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.3.1.jar!/:5.3.1]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.1.jar!/:5.3.1]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at org.apache.catalina.valves.RemoteIpValve.invoke(RemoteIpValve.java:747) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1590) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) ~[na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) ~[na:na]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.39.jar!/:9.0.39]
at java.base/java.lang.Thread.run(Unknown Source) ~[na:na]
The new fields look as follows:
package org.foo.bar.casper.datascraping;
import org.springframework.data.annotation.Id;
import org.springframework.data.elasticsearch.annotations.Document;
import org.springframework.data.elasticsearch.annotations.Field;
import lombok.Data;
import lombok.NoArgsConstructor;
#Data
#Document(indexName = "foo-data")
#NoArgsConstructor
public class ElasticInitialConfiguration {
#Id
#Field(name = "_id")
private String id;
#Field(name = "_meta.isConfigurable.result")
private String configurable;
#Field(name = "_meta.isConfigurable.error.message")
private String errorMessage;
#Field(name = "_meta.configurationContext.fooInfo")
private String fooInfo;
...
}
package org.foo.bar.casper.datascraping;
import org.springframework.data.domain.Page;
import org.springframework.data.elasticsearch.annotations.Query;
import org.springframework.data.elasticsearch.repository.ElasticsearchRepository;
import org.springframework.data.domain.Pageable;
public interface DataScrapingRepository extends ElasticsearchRepository<ElasticInitialConfiguration, String> {
Page<ElasticInitialConfiguration> findByFooInfo(String fooInfo, Pageable pageable);
}
package org.foo.bar.casper.datascraping;
import lombok.NoArgsConstructor;
import org.elasticsearch.client.RestHighLevelClient;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.elasticsearch.client.ClientConfiguration;
import org.springframework.data.elasticsearch.client.RestClients;
import org.springframework.data.elasticsearch.core.ElasticsearchOperations;
import org.springframework.data.elasticsearch.core.ElasticsearchRestTemplate;
import org.springframework.data.elasticsearch.repository.config.EnableElasticsearchRepositories;
#Configuration
#NoArgsConstructor
#EnableElasticsearchRepositories(basePackages = "org.foo.bar.casper.datascraping")
public class DatascrapingConfiguration {
#Value("${elastic.username}")
private String user;
#Value("${elastic.password}")
private String password;
#Value("${elastic.url}")
private String url;
#Bean
public RestHighLevelClient client() {
ClientConfiguration clientConfiguration = ClientConfiguration.builder()
.connectedTo(url)
.usingSsl()
.withBasicAuth(user, password)
.build();
return RestClients.create(clientConfiguration).rest();
}
#Bean
public ElasticsearchOperations elasticsearchTemplate() {
return new ElasticsearchRestTemplate(client());
}
}
The new fields are the ones above info, which was always working. The newly added field values are sometimes null, which leads in our opinion to the exception.
We tried already some fixes, like adding #Nullable to the fields. Another was adding ** #Mapping(mappingPath = "elastic/null_mapping.json")
** with the following json under resources/elastic:
{
"type": "string",
"index": "analyzed",
"analyzer": "word_analyzer",
"fields": {
"raw": {
"type": "string",
"index": "not_analyzed",
"null_value": "NULL"
}
}
}
We do not know if the json is correct though.
The error seems to be pretty uncommon. We neither found it in the web nor were we able to get at least a different one. So any suggestions are welcome here. It is not an option not to get the fields.
Thank you for your time

Exception Handler in Spring boot v 2.2.2.RELEASE not working?

I am implementing global error handling in my project using Spring boot. I am throwing a "FileStorageException " when my "File" object is "null". But the Spring exception handler is not catching it.
FileRestService class:
package com.file.web;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import javax.annotation.processing.FilerException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.servlet.mvc.support.RedirectAttributes;
import com.file.entities.FileRepository;
import com.file.service.FileService;
#CrossOrigin("*")
#RestController
public class FileRestService {
#Autowired
FileRepository fileRepository;
#Autowired
FileService fileService;
#RequestMapping(value="/upload/file",method=RequestMethod.POST)
public ResponseEntity<Object> uploadFile(#RequestParam("file") MultipartFile file) throws FilerException {
fileService.uploadFile(file);
return new ResponseEntity<Object>("file is uploaded successfuly",HttpStatus.OK);
}
}
AppExceptionHandeller class
package com.file.web.exeception;
import java.util.ArrayList;
import java.util.List;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.context.request.WebRequest;
#ControllerAdvice
public class AppExceptionHandeller {
#ExceptionHandler(FileException.class)
public ResponseEntity<Object> etExcetion(FileStorageException ex, WebRequest request) {
List<String> errors = new ArrayList<String>();
errors.add("session exipred");
ApiError apiError = new ApiError(HttpStatus.BAD_REQUEST, ex.getLocalizedMessage(), errors);
return new ResponseEntity<Object>(apiError, new HttpHeaders(), apiError.getStatus());
}
}
FileServiceImp class
package com.file.service;
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardCopyOption;
import org.springframework.stereotype.Service;
import org.springframework.util.StringUtils;
import org.springframework.web.multipart.MultipartFile;
import com.file.web.exeception.FileStorageException;
#Service
public class FileServiceImp implements FileService {
public String uploadDir="/Users/mac/Desktop/upload";
#Override
public void uploadFile(MultipartFile file) {
//StringUtils.cleanPath(file.getOriginalFil);
Path copyLocation=Paths.get(uploadDir + File.separator + StringUtils.cleanPath(file.getOriginalFilename())); ;
try {
Files.copy(file.getInputStream(), copyLocation, StandardCopyOption.REPLACE_EXISTING);
} catch (IOException e) {
// TODO Auto-generated catch block
System.out.println("empty file ...");
throw new FileStorageException("Could not store file " + file.getOriginalFilename()
+ ". Please try again!");
//e.printStackTrace();
}
}
#Override
public void DownloadFile() {
}
}
FileStorageException class
package com.file.web.exeception;
public class FileStorageException extends RuntimeException {
private static final long serialVersionUID = 1L;
private String msg;
public FileStorageException(String msg) {
this.msg = msg;
}
public String getMsg() {
return msg;
}
}
observe the FileRestService class. When I get a request for a file , if the file is not present it throws
exception. By default this needs to be catched by the ExceptionHandler. But instead of this I am getting the stackTrace like following. Please help me in catching this exception globally.
I followed this tuto (https://devwithus.com/exception-handling-for-rest-api-with-spring-boot/)
and this (Exception Handler in Spring boot not working?)
I can’t find the solution I’m starting in spring
javax.annotation.processing.FilerException: Could not store file . Please try again!
at com.file.service.FileServiceImp.uploadFile(FileServiceImp.java:34) ~[classes/:na]
at com.file.web.FileRestService.uploadFile(FileRestService.java:41) ~[classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_212]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_212]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_212]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_212]
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) ~[spring-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:888) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:660) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.29.jar:9.0.29]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:526) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:367) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:860) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1591) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.29.jar:9.0.29]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_212]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_212]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.29.jar:9.0.29]
at java.lang.Thread.run(Thread.java:748) [na:1.8.0_212]

I find solution just replaces FileException by FileStorageException
in FileRestService(throws FilerException... by throws FileStorageException)
in AppExceptionHandeller (#ExceptionHandler(FileException.class) by #ExceptionHandler(FileStorageException.class))

org.hibernate.property.access.spi.PropertyAccessException: Error accessing field [private java.lang.Integer

I just tried out setting up a demo CRUD api in hibernate and I've been unable to resolve the issue with this. I've tried this with multiple versions of Hibernate but none seem to work. I keep getting the error message "Error accessing field [private java.lang.Integer com.webapp.firstwebapp.Models.UserModel.id] by reflection for persistent property [com.webapp.firstwebapp.Models.UserModel#id] : com.webapp.firstwebapp.Models.UserModel#1bc31512",
"path": "/create/user", but everything seems fine. Here's the code for it:
FirstWebApp.java
package com.webapp.firstwebapp;
import java.io.File;
import com.webapp.firstwebapp.Models.UserModel;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.boot.MetadataSources;
import org.hibernate.boot.registry.StandardServiceRegistry;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
#SpringBootApplication
#RestController
public class FirstwebappApplication {
public static void main(String[] args) {
SpringApplication.run(FirstwebappApplication.class, args);
}
#GetMapping("/create/user")
public UserModel doSomething() throws Exception{
File file = new File("hibernate.cfg.xml");
UserModel userModel = new UserModel(122, "Jane Doe", "jane_doe");
StandardServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().configure(file).build();
SessionFactory sessionFactory = new MetadataSources(serviceRegistry).addAnnotatedClass(UserModel.class).buildMetadata().buildSessionFactory();
Session session = sessionFactory.openSession();
Transaction transaction = session.beginTransaction();
try{
session.save(userModel);
transaction.commit();
}catch(Exception e){
System.out.println(e);
StandardServiceRegistryBuilder.destroy(serviceRegistry);
throw e;
}
return userModel;
}
}
UserModel.java
package com.webapp.firstwebapp.Models;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
#Entity
#Table(name="users")
public class UserModel {
#Id
#Column(name="id", nullable = false, unique = true)
public Integer id;
#Column(name="name", nullable = false, unique = false)
public String name;
#Column(name="username", nullable = false, unique = true)
public String username;
// #OneToMany(mappedBy = "user")
public UserModel(){
}
public UserModel(Integer id, String name, String username){
this.id = id;
this.username= username;
this.name = name;
}
public void setId(Integer id){
this.id = id;
}
public Integer getId(){
return id;
}
public void setName(String name){
this.name = name;
}
public String getName(){
return name;
}
public void setUsername(String username){
this.username = username;
}
public String getUsername(){
return username;
}
}
Is there something I'm missing or am I doing something wrong? Here is the full log report I'm getting on the console:
ERROR 11976 --- [nio-8080-exec-3] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.hibernate.property.access.spi.PropertyAccessException: Error accessing field [private java.lang.Integer com.webapp.firstwebapp.Models.UserModel.id] by reflection for persistent property [com.webapp.firstwebapp.Models.UserModel#id] : com.webapp.firstwebapp.Models.UserModel#1bc31512] with root cause
java.lang.IllegalArgumentException: Can not set java.lang.Integer field com.webapp.firstwebapp.Models.UserModel.id to com.webapp.firstwebapp.Models.UserModel
at java.base/jdk.internal.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:167) ~[na:na]
at java.base/jdk.internal.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:171) ~[na:na]
at java.base/jdk.internal.reflect.UnsafeFieldAccessorImpl.ensureObj(UnsafeFieldAccessorImpl.java:58)
~[na:na]
at java.base/jdk.internal.reflect.UnsafeObjectFieldAccessorImpl.get(UnsafeObjectFieldAccessorImpl.java:36) ~[na:na]
at java.base/java.lang.reflect.Field.get(Field.java:418) ~[na:na]
at org.hibernate.property.access.spi.GetterFieldImpl.get(GetterFieldImpl.java:71) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.tuple.entity.AbstractEntityTuplizer.getIdentifier(AbstractEntityTuplizer.java:230) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.persister.entity.AbstractEntityPersister.getIdentifier(AbstractEntityPersister.java:5150) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.id.Assigned.generate(Assigned.java:31) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:115) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:194) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:38) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:179) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:32) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:75) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.event.service.internal.EventListenerGroupImpl.fireEventOnEachListener(EventListenerGroupImpl.java:102) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:637) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.internal.SessionImpl.save(SessionImpl.java:630) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.internal.SessionImpl.save(SessionImpl.java:625) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at com.webapp.firstwebapp.FirstwebappApplication.doSomething(FirstwebappApplication.java:39) ~[classes/:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na]
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) ~[spring-web-5.3.0-SNAPSHOT.jar:5.3.0-SNAPSHOT]
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.3.0-SNAPSHOT.jar:5.3.0-SNAPSHOT]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:105) ~[spring-webmvc-5.3.0-SNAPSHOT.jar:5.3.0-SNAPSHOT]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:888) ~[spring-webmvc-5.3.0-SNAPSHOT.jar:5.3.0-SNAPSHOT]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:802) ~[spring-webmvc-5.3.0-SNAPSHOT.jar:5.3.0-SNAPSHOT]
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.3.0-SNAPSHOT.jar:5.3.0-SNAPSHOT]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1061) ~[spring-webmvc-5.3.0-SNAPSHOT.jar:5.3.0-SNAPSHOT]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:961) ~[spring-webmvc-5.3.0-SNAPSHOT.jar:5.3.0-SNAPSHOT]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.3.0-SNAPSHOT.jar:5.3.0-SNAPSHOT]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.3.0-SNAPSHOT.jar:5.3.0-SNAPSHOT]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:626) ~[tomcat-embed-core-9.0.37.jar:4.0.FR]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.3.0-SNAPSHOT.jar:5.3.0-SNAPSHOT]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:733) ~[tomcat-embed-core-9.0.37.jar:4.0.FR]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
~[tomcat-embed-core-9.0.37.jar:9.0.37]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.37.jar:9.0.37]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
~[tomcat-embed-core-9.0.37.jar:9.0.37]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.3.0-SNAPSHOT.jar:5.3.0-SNAPSHOT]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.0-SNAPSHOT.jar:5.3.0-SNAPSHOT]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
~[tomcat-embed-core-9.0.37.jar:9.0.37]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.3.0-SNAPSHOT.jar:5.3.0-SNAPSHOT]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.0-SNAPSHOT.jar:5.3.0-SNAPSHOT]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
~[tomcat-embed-core-9.0.37.jar:9.0.37]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.3.0-SNAPSHOT.jar:5.3.0-SNAPSHOT]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.0-SNAPSHOT.jar:5.3.0-SNAPSHOT]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
~[tomcat-embed-core-9.0.37.jar:9.0.37]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:373) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1589) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[na:na] at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[na:na] at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
at java.base/java.lang.Thread.run(Thread.java:834) ~[na:na]
2020-09-06 19:00:23.731 INFO 11976 --- [ Thread-5] o.s.s.concurrent.ThreadPoolTaskExecutor : Shutting down ExecutorService 'applicationTaskExecutor'

AS the error says "Error accessing field [private java.lang.Integer com.webapp.firstwebapp.Models.UserModel.id]
This is related to the scope for the attributes of UserModel entity
You have to make public access modifiers for attributes of UserModel Entity

Retrieve data from two table parent table Id one-to-many relation Spring boot using JPQL JpaRepository

how to retrieve data from two table one to many relationship based on parent table id.
I have to Entity Credit and Debit. Credit is parent Entity and Debit is child Entity.
In Credit
cid camount copening cbusiness ctotal
1 50 60 90 200
2 10 20 30 60
3 5 4 3 12
In Debit
did damount ddescription
1 100 market
2 200 invest
3 20 nothing
4 500 marker
in third table i have store there reference id of that above two table using one to many relation
This below table is automatically created
credit_debit
c_cid d_did
1 1
1 2
2 3
2 4
How to retrieve data by id when i passing cid to JPQL query
I have try to write JPQL Query but they will show Error.
Like this query
#Query(value= "select c,d from Credit as c, Debit as d where c.cid=c.cid")
1.Credit.java
package com.rajesh.model;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.List;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import org.springframework.core.annotation.Order;
import org.springframework.format.annotation.DateTimeFormat;
#Entity
#Table(name="credit")
public class Credit extends BaseEntity{
#Id
#GeneratedValue(strategy=GenerationType.AUTO)
#Column
private long cid;
#Column #Order
private long openingbalance;
#Column
#DateTimeFormat(pattern = "yyyy-MM-dd")
private Date date;
#Column #Order
private long debittotal;
#Column #Order
private long drawertotal;
#Column #Order
private long debittotalplusdrawertotal;
#Column #Order
private long todaybusiness;
#OneToMany(cascade={CascadeType.ALL})
#JoinTable(name="credit_debit",
joinColumns=#JoinColumn(name="c_id"),
inverseJoinColumns=#JoinColumn(name="d_id"))
private List<Debit> debits = new ArrayList<Debit>(Arrays.asList());
2.Debit.java
package com.rajesh.model;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
#Entity
#Table(name="debit")
public class Debit {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column
private long did;
#Column
private String amount;
#Column
private String description;
3.CreditDebitRepository.java
package com.rajesh.repository;
import org.hibernate.validator.constraints.UniqueElements;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Query;
import org.springframework.stereotype.Repository;
import com.rajesh.model.Credit;
#Repository
public interface CreditDebitRepository extends JpaRepository<Credit, Long>{
#UniqueElements
#Query(value= "select c,d from Credit as c, Debit as d where c.cid=c.cid")
long findById(long cid);
}
4.CreditDebitService.java
package com.rajesh.service;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import com.rajesh.model.Credit;
import com.rajesh.repository.CreditDebitRepository;
#Service
public class CreditDebitService {
#Autowired
CreditDebitRepository creditDebitRepository;
public void save(Credit credit) {
creditDebitRepository.save(credit);
}
public List<Credit> getAllCreditList() {
return creditDebitRepository.findAll();
}
public long getCreditDebitById(long cid) {
cid = creditDebitRepository.findById(cid);
return cid;
}
CreditDebirController.java
package com.rajesh.controller;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import com.rajesh.model.Credit;
import com.rajesh.model.Debit;
import com.rajesh.model.User;
import com.rajesh.service.CreditDebitService;
#Controller
public class CreditDebitController {
#Autowired
CreditDebitService creditDebitService;
#GetMapping("/user/getCreditDebit/{cid}")
#ResponseBody
public String getCreditDebitById(#PathVariable("cid") long cid, #ModelAttribute("command") Credit credit, HttpSession session, HttpServletRequest request, BindingResult result) {
creditDebitService.getCreditDebitById(cid);
return "userdashboard";
}
javax.persistence.NonUniqueResultException: query did not return a unique result: 640
at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:123) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:157) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
at org.hibernate.query.internal.AbstractProducedQuery.getSingleResult(AbstractProducedQuery.java:1471) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final]
at org.springframework.data.jpa.repository.query.JpaQueryExecution$SingleEntityExecution.doExecute(JpaQueryExecution.java:214) ~[spring-data-jpa-2.0.9.RELEASE.jar:2.0.9.RELEASE]
at org.springframework.data.jpa.repository.query.JpaQueryExecution.execute(JpaQueryExecution.java:91) ~[spring-data-jpa-2.0.9.RELEASE.jar:2.0.9.RELEASE]
at org.springframework.data.jpa.repository.query.AbstractJpaQuery.doExecute(AbstractJpaQuery.java:136) ~[spring-data-jpa-2.0.9.RELEASE.jar:2.0.9.RELEASE]
at org.springframework.data.jpa.repository.query.AbstractJpaQuery.execute(AbstractJpaQuery.java:125) ~[spring-data-jpa-2.0.9.RELEASE.jar:2.0.9.RELEASE]
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:590) ~[spring-data-commons-2.0.9.RELEASE.jar:2.0.9.RELEASE]
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:578) ~[spring-data-commons-2.0.9.RELEASE.jar:2.0.9.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:59) ~[spring-data-commons-2.0.9.RELEASE.jar:2.0.9.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:294) ~[spring-tx-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:98) ~[spring-tx-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:139) ~[spring-tx-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:135) ~[spring-data-jpa-2.0.9.RELEASE.jar:2.0.9.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92) ~[spring-aop-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.data.repository.core.support.SurroundingTransactionDetectorMethodInterceptor.invoke(SurroundingTransactionDetectorMethodInterceptor.java:61) ~[spring-data-commons-2.0.9.RELEASE.jar:2.0.9.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212) ~[spring-aop-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at com.sun.proxy.$Proxy156.findById(Unknown Source) ~[na:na]
at com.rajesh.service.CreditDebitService.getCreditDebitById(CreditDebitService.java:21) ~[classes/:na]
at com.rajesh.controller.CreditDebitController.getCreditDebitById(CreditDebitController.java:78) ~[classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_191]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_191]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_191]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_191]
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:635) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.5.32.jar:8.5.32]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.32.jar:8.5.32]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:493) [tomcat-embed-core-8.5.32.jar:8.5.32]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.32.jar:8.5.32]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) [tomcat-embed-core-8.5.32.jar:8.5.32]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.32.jar:8.5.32]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) [tomcat-embed-core-8.5.32.jar:8.5.32]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:800) [tomcat-embed-core-8.5.32.jar:8.5.32]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.32.jar:8.5.32]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:800) [tomcat-embed-core-8.5.32.jar:8.5.32]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1471) [tomcat-embed-core-8.5.32.jar:8.5.32]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.32.jar:8.5.32]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_191]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_191]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.32.jar:8.5.32]
at java.lang.Thread.run(Thread.java:748) [na:1.8.0_191]

I has to try with as per given solution by JB Nizet It is solved

I can't call JpaReposistory api in a Vaadin Component

I am while new to Vaadin and Spring Boot and I am trying to make a small app that can do all CRUD methods. I am making this Form that will take in all the data from fields, save it to a model object and save that to my database but it won't let me.
StudentRepo
package com.vinh.vaadin.allinone.repo;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;
import com.vinh.vaadin.allinone.entity.Student;
#Repository
public interface StudentRepo extends JpaRepository<Student, Long>{
}
StudentForm
package com.vinh.vaadin.allinone.vaadin;
import org.springframework.beans.factory.annotation.Autowired;
import com.vaadin.data.Binder;
import com.vaadin.data.ValidationException;
import com.vaadin.spring.annotation.SpringComponent;
import com.vaadin.ui.Button;
import com.vaadin.ui.FormLayout;
import com.vaadin.ui.HorizontalLayout;
import com.vaadin.ui.TextField;
import com.vinh.vaadin.allinone.entity.Student;
import com.vinh.vaadin.allinone.repo.StudentRepo;
#SpringComponent
public class StudentForm extends FormLayout{
#Autowired
StudentRepo repo;
Student student = new Student();
private TextField firstName = new TextField("First Name");
private TextField lastName = new TextField("Last Name");
private TextField email = new TextField("Email");
private Button save = new Button("Save");
private Button delete = new Button("Delete");
private Binder<Student> binder = new Binder<>(Student.class);
public StudentForm() {
HorizontalLayout buttons = new HorizontalLayout(save, delete);
addComponents(firstName, lastName, email, buttons);
binder.bindInstanceFields(this);
binder.setBean(student);
setSizeUndefined();
save.addClickListener(event -> {
try {
binder.writeBean(student);
} catch (ValidationException e) {
e.printStackTrace();
} finally {
saveStudent(student);
}
});
}
private void saveStudent(Student theStudent) {
repo.save(theStudent);
}
}
MainContent where StudentForm get call
package com.vinh.vaadin.allinone.vaadin;
import java.util.ArrayList;
import java.util.List;
import javax.annotation.PostConstruct;
import org.assertj.core.util.Lists;
import org.springframework.beans.factory.annotation.Autowired;
import com.vaadin.icons.VaadinIcons;
import com.vaadin.spring.annotation.SpringComponent;
import com.vaadin.ui.Alignment;
import com.vaadin.ui.Button;
import com.vaadin.ui.CssLayout;
import com.vaadin.ui.Grid;
import com.vaadin.ui.HorizontalLayout;
import com.vaadin.ui.TextField;
import com.vaadin.ui.VerticalLayout;
import com.vaadin.ui.themes.ValoTheme;
import com.vinh.vaadin.allinone.entity.Student;
import com.vinh.vaadin.allinone.repo.StudentRepo;
import javassist.expr.NewArray;
#SpringComponent
public class MainContent extends VerticalLayout {
#Autowired
private Student student;
#Autowired
StudentRepo repo;
private StudentForm studentForm = new StudentForm();
private CssLayout filterLayout;
private TextField filterText;
private Button filterBtn;
private HomeUI homeUI;
private Grid<Student> studentGrid;
#PostConstruct
void init() {
setStudents(repo.findAll());
}
private void setStudents(List<Student> findAll) {
studentGrid.setItems(findAll);
}
public MainContent() {
addFilter();
addMainContent();
}
private void addMainContent() {
HorizontalLayout main = new HorizontalLayout();
studentGrid = new Grid<>(Student.class);
studentGrid.setColumns("firstName", "lastName", "email");
main.addComponentsAndExpand(studentGrid);
main.addComponents(studentForm);
studentGrid.setSizeFull();
addComponents(main);
}
private void addFilter() {
filterLayout = new CssLayout();
filterLayout.addStyleName(ValoTheme.LAYOUT_COMPONENT_GROUP);
filterText = new TextField();
filterText.setPlaceholder("filter by name...");
filterBtn = new Button(VaadinIcons.CLOSE);
filterLayout.addComponents(filterText, filterBtn);
HorizontalLayout toolbar = new HorizontalLayout(filterLayout);
addComponent(toolbar);
}
}
In Summary, I have the MainContent component which display a grid to the left then display StudentForm on the right.
All is fine until I try to repo.save(theStudent) inside the StudentForm,and I got this error
java.lang.NullPointerException: null
at com.vinh.vaadin.allinone.vaadin.StudentForm.lambda$0(StudentForm.java:44) ~[classes/:na]
at sun.reflect.GeneratedMethodAccessor309.invoke(Unknown Source) ~[na:na]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_171]
at java.lang.reflect.Method.invoke(Unknown Source) ~[na:1.8.0_171]
at com.vaadin.event.ListenerMethod.receiveEvent(ListenerMethod.java:499) ~[vaadin-server-8.4.1.jar:8.4.1]
at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:273) ~[vaadin-server-8.4.1.jar:8.4.1]
at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:237) ~[vaadin-server-8.4.1.jar:8.4.1]
at com.vaadin.server.AbstractClientConnector.fireEvent(AbstractClientConnector.java:1014) ~[vaadin-server-8.4.1.jar:8.4.1]
at com.vaadin.ui.Button.fireClick(Button.java:384) ~[vaadin-server-8.4.1.jar:8.4.1]
at com.vaadin.ui.Button$1.click(Button.java:57) ~[vaadin-server-8.4.1.jar:8.4.1]
at sun.reflect.GeneratedMethodAccessor308.invoke(Unknown Source) ~[na:na]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_171]
at java.lang.reflect.Method.invoke(Unknown Source) ~[na:1.8.0_171]
at com.vaadin.server.ServerRpcManager.applyInvocation(ServerRpcManager.java:155) ~[vaadin-server-8.4.1.jar:8.4.1]
at com.vaadin.server.ServerRpcManager.applyInvocation(ServerRpcManager.java:116) ~[vaadin-server-8.4.1.jar:8.4.1]
at com.vaadin.server.communication.ServerRpcHandler.handleInvocation(ServerRpcHandler.java:445) [vaadin-server-8.4.1.jar:8.4.1]
at com.vaadin.server.communication.ServerRpcHandler.handleInvocations(ServerRpcHandler.java:410) [vaadin-server-8.4.1.jar:8.4.1]
at com.vaadin.server.communication.ServerRpcHandler.handleRpc(ServerRpcHandler.java:274) [vaadin-server-8.4.1.jar:8.4.1]
at com.vaadin.server.communication.UidlRequestHandler.synchronizedHandleRequest(UidlRequestHandler.java:90) [vaadin-server-8.4.1.jar:8.4.1]
at com.vaadin.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:40) [vaadin-server-8.4.1.jar:8.4.1]
at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1601) [vaadin-server-8.4.1.jar:8.4.1]
at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:445) [vaadin-server-8.4.1.jar:8.4.1]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) [tomcat-embed-core-8.5.31.jar:8.5.31]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) [tomcat-embed-core-8.5.31.jar:8.5.31]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.31.jar:8.5.31]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) [tomcat-embed-websocket-8.5.31.jar:8.5.31]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.31.jar:8.5.31]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.31.jar:8.5.31]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) [spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.31.jar:8.5.31]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.31.jar:8.5.31]
at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109) [spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.31.jar:8.5.31]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.31.jar:8.5.31]
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93) [spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.31.jar:8.5.31]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.31.jar:8.5.31]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) [spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.31.jar:8.5.31]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.31.jar:8.5.31]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) [tomcat-embed-core-8.5.31.jar:8.5.31]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.31.jar:8.5.31]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496) [tomcat-embed-core-8.5.31.jar:8.5.31]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.31.jar:8.5.31]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) [tomcat-embed-core-8.5.31.jar:8.5.31]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.31.jar:8.5.31]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) [tomcat-embed-core-8.5.31.jar:8.5.31]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803) [tomcat-embed-core-8.5.31.jar:8.5.31]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.31.jar:8.5.31]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790) [tomcat-embed-core-8.5.31.jar:8.5.31]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1468) [tomcat-embed-core-8.5.31.jar:8.5.31]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.31.jar:8.5.31]
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [na:1.8.0_171]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [na:1.8.0_171]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.31.jar:8.5.31]
at java.lang.Thread.run(Unknown Source) [na:1.8.0_171]
However, if I put repo.save() inside a saveStudent() method in the MainContent, pass that MainContent to the StudentForm then call saveStudent() method from there then it will work. why?
Another question I have is in the MainContent, I have to add repo.findAll() in the #PostConstruct for it to work, if I put it any where else that is not #PostConstruct, then it won't work, why is this?

Your StudentRepo class should be annotated with #Component since you are creating its bean in the StudentForm class.
When the bean of the StudentForm is created it requires the bean of the StudentRepo class which is not created because you have not marked it as #Component. So when you try to access the methods of the StudentRepo a null pointer exception is thrown
#Component
public interface StudentRepo extends JpaRepository<Student, Long> {
}
You can also use #Repository annotation to specify this is a dao layer class.
#Repository extends from #Component and is used only to keep the naming consistent.
So both the annotations will work

You are calling bindInstanceFields, but you have not annotated your Fields with #PropertyId(..) annotations. Hence it probably does nothing, and your edits are never bound to your Student bean. See JavaDoc
https://vaadin.com/download/release/8.4/8.4.4/docs/api/com/vaadin/data/Binder.html#bindInstanceFields-java.lang.Object-