I am trying to recast my SpringBoot application to functional bean registration form for faster application start up times as mentioned in the Spring documentation for Spring Cloud Functions. Below is the code referenced in the documentation:
#SpringBootConfiguration
public class DemoApplication implements ApplicationContextInitializer<GenericApplicationContext> {
public static void main(String[] args) {
FunctionalSpringApplication.run(DemoApplication.class, args);
}
public Function<String, String> uppercase() {
return value -> value.toUpperCase();
}
#Override
public void initialize(GenericApplicationContext context) {
context.registerBean("demo", FunctionRegistration.class,
() -> new FunctionRegistration<>(uppercase())
.type(FunctionType.from(String.class).to(String.class)));
}
}
Here is my code attempting to follow the above exaple. The main difference is that my function is a separate class that implements the Java 8 function interface.
import com.example.functions.RockPaperScissors;
import com.example.model.Game;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringBootConfiguration;
import org.springframework.cloud.function.context.FunctionRegistration;
import org.springframework.cloud.function.context.FunctionType;
import org.springframework.cloud.function.context.FunctionalSpringApplication;
import org.springframework.context.ApplicationContextInitializer;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.support.GenericApplicationContext;
#Slf4j
#ComponentScan
#SpringBootConfiguration
public class Application implements ApplicationContextInitializer<GenericApplicationContext> {
private RockPaperScissors rockPaperScissors;
public static void main(String[] args) {
FunctionalSpringApplication.run(Application.class, args);
}
#Override
public void initialize(GenericApplicationContext applicationContext) {
applicationContext.registerBean(
"rpsFunction",
FunctionRegistration.class,
() ->
new FunctionRegistration<>(this.rockPaperScissors)
.type(FunctionType.from(Game.class).to(String.class)));
}
#Autowired
public void setRpsFunction(RockPaperScissors rockPaperScissors) {
this.rockPaperScissors = rockPaperScissors;
}
}
The issue I am having is java.lang.IllegalArgumentException: 'target' must not be null. I know this is due to no application context being found but not sure why FunctionalSpringApplication.run(DemoApplication.class, args); isn't creating that context.
Related
I have a random class in a random package that is loaded through reflection after the app launches, is there a way for it to be registered as a component under springboot and have annotations such as #Autowired and #Value etc work for that class.
It works when it is in the same package at launch time, but if introduce it thorough another jar at runtime (same package or not) it doesn't work.
Below are samples that don't work even if it is in the same jar. I can't change the app's configuration - it would defeat the "random package/random class" objective.
Code in Spring boot application package
package sample.app
#SpringBootApplication
public class Application {
public static void main(String[] args) {
// Code that starts app
//
//
try {
Thread.sleep(7000);
Class test = Class.forName("test.Test", true, Application.class.getClassLoader());
System.out.println(test.getMethod("getName").invoke(null)); //NPE
System.out.println(test.getMethod("getProfiles").invoke(null)); //NPE
} catch (Throwable t) {
t.printStackTrace();
}
}
}
Test.java
package test;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.DependsOn;
import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.Map;
#DependsOn("blaaaaaaaah")
#ComponentScan
public class Test {
#DependsOn("blaaaaaaaah")
public static String getName() {
return SpringGetter.instance.getApplicationName();
}
#DependsOn("blaaaaaaaah")
public static String[] getProfiles() {
String[] profiles = SpringGetter.instance.getEnv().getActiveProfiles();
if (profiles == null || profiles.length == 0) {
profiles = SpringGetter.instance.getEnv().getDefaultProfiles();
}
return profiles;
}
}
SpringGetter.java
package test;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.env.Environment;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;
#Component("blaaaaaaaah")
public class SpringGetter implements InitializingBean {
public static SpringGetter instance;
#Value("${spring.application.name}")
private String applicationName;
#Autowired
private Environment env;
public SpringGetter() {
System.out.println("consASFJEFWEFJWDNFWJVNJSBVJWNCJWBVJNVJNVJSNJSNCSDJVNSVJtruct");
}
public String getApplicationName() {
return applicationName;
}
public void setApplicationName(String applicationName) {
this.applicationName = applicationName;
}
public Environment getEnv() {
return env;
}
public void setEnv(Environment env) {
this.env = env;
}
#PostConstruct
public void setInstance() {
instance = this;
}
#Override
public void afterPropertiesSet() throws Exception {
instance = this;
}
}
EDIT:
I managed to dynamically create the SpringGetter class as part of the same package as the Application class(the one with the #SpringBootApplication). I got Test.java to point to that dynamic class and yet no luck.
To simply inject fields into a POJO as if it were a Spring-managed bean, you can use something like the following:
#Component
public class BeanInitializer implements ApplicationContextAware {
private AutowireCapableBeanFactory beanFactory;
#Override
public void setApplicationContext(final ApplicationContext applicationContext) {
beanFactory = applicationContext.getAutowireCapableBeanFactory();
}
public void initializeObject(Object pojo) {
beanFactory.autowireBean(pojo);
}
}
Note, however, that this only injects fields marked as #Autowired or #Injected. It does not create proxies that honor method interception strategies based on e.g. #Transactional, #Async, etc.
If you're using Spring 5, have a look at the registerBean() method from GenericApplicationContext. You can find an example here: https://www.baeldung.com/spring-5-functional-beans
The issue in your Test class may also be that you're not loading the Spring Boot context from the main class. You can use the SpringBootTest annotation for this.
I have these classes. when I debug I see that the spring creates the service object in constructor and called the constructors in both classes but when I want to use the fields, they are null. What's the problem?! (type1Processor, type2Processor and type3Processor are null)
import com.vali.ReactiveSocketServer.service.ReceivedDataService;
import org.springframework.stereotype.Component;
public abstract class Processor {
public ReceivedDataService receivedDataService;
public Processor(ReceivedDataService receivedDataService) {
this.receivedDataService = receivedDataService;
}
public abstract void readStream(String stream);
}
and this is its subclass
import com.vali.ReactiveSocketServer.model.ReceivedData;
import com.vali.ReactiveSocketServer.service.ReceivedDataService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
#Component
public class Type1Processor extends Processor {
#Autowired
public Type1Processor(ReceivedDataService receivedDataService) {
super(receivedDataService);
}
#Override
public void readStream(String stream) {
System.out.println("readStream "+ getClass().getSimpleName() + "-" + stream);
receivedDataService.add(new ReceivedData(stream.getBytes()));
}
}
and this is its usage:
import com.vali.ReactiveSocketServer.processor.Processor;
import com.vali.ReactiveSocketServer.processor.Type1Processor;
import com.vali.ReactiveSocketServer.processor.Type2Processor;
import com.vali.ReactiveSocketServer.processor.Type3Processor;
import com.vali.ReactiveSocketServer.receivers.AppServer;
import com.vali.ReactiveSocketServer.socket.ClientHandler;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import java.util.HashMap;
import java.util.Map;
#SpringBootApplication
public class ReactiveSocketServerApplication {
private AppServer appServer;
#Autowired
Type1Processor type1Processor;
#Autowired
Type2Processor type2Processor;
#Autowired
Type3Processor type3Processor;
public static void main(String[] args) {
SpringApplication.run(ReactiveSocketServerApplication.class, args);
ReactiveSocketServerApplication reactiveSocketServerApplication = new ReactiveSocketServerApplication();
reactiveSocketServerApplication.Start();
}
public void Start(){
appServer = AppServer.getInstance();
Map<Integer, Processor> processorMap = new HashMap<>();
processorMap.put(7001, type1Processor);
processorMap.put(7002, type2Processor);
processorMap.put(7003, type3Processor);
appServer.initialize(processorMap);
new ClientHandler(7001, 1000);
new ClientHandler(7002, 5000);
}
}
You are instantiating ReactiveSocketServerApplication yourself.
So spring can't inject the #Autowired annotated beans, because the instance was created outside of it's life cycle.
Remove this completly:
ReactiveSocketServerApplication reactiveSocketServerApplication = new ReactiveSocketServerApplication();
reactiveSocketServerApplication.Start();
And annotate your Start() with #PostConstruct:
#PostConstruct
public void Start() { ... }
You are missing #Component in the abstract class ReceivedDataService.
This mean when you create the subclases using :
#Autowired
public Type1Processor(ReceivedDataService receivedDataService) {
super(receivedDataService);
}
Can't inject ReceivedDataService and get the default value(null)
I am new to Spring AOP and annotations. I tried to write a simple program that uses Aspect. I am unable to figure out where I went wrong. Its doesn't print the what I have in my Aspect.
package com.business.main;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.EnableAspectJAutoProxy;
#EnableAspectJAutoProxy
#Configuration
public class PrintMain {
public static void main(String[] args) {
// Do I always need to have this. Can't I just use #Autowired to get beans
ApplicationContext ctx = new AnnotationConfigApplicationContext(PrintMain.class);
CheckService ck = (CheckService)ctx.getBean("service");
ck.print();
}
#Bean(name="service")
public CheckService service(){
return new CheckService();
}
}
package com.business.main;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.stereotype.Component;
#Aspect
#Component
public class SimpleAspect {
#Around("execution(* com.business.main.CheckService.*(..))")
public void applyAdvice(){
System.out.println("Aspect executed");
}
}
package com.business.main;
import org.springframework.stereotype.Component;
#Component
public class CheckService{
public void print(){
System.out.println("Executed service method");
}
}
Output: Executed service method
I expect to print what I have in my Aspect
I think your #Component isn't work!
Maybe, you need the #ComponentScan
#EnableAspectJAutoProxy
#ComponentScan
#Configuration
public class PrintMain {
public static void main(String[] args) {
// Do I always need to have this. Can't I just use #Autowired to get beans
ApplicationContext ctx = new AnnotationConfigApplicationContext(TNGPrintMain.class);
CheckService ck = (CheckService)ctx.getBean("service");
ck.print();
}
#Bean(name="service")
public CheckService service(){
return new CheckService();
}
}
AppConfig contains Java Configuration.
package com.wh;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.EnableLoadTimeWeaving;
import org.springframework.context.annotation.EnableLoadTimeWeaving.AspectJWeaving;
import org.springframework.context.annotation.Lazy;
import org.springframework.context.annotation.aspectj.EnableSpringConfigured;
#Configuration
#EnableSpringConfigured
#EnableLoadTimeWeaving(aspectjWeaving=AspectJWeaving.ENABLED)
public class AppConfig {
#Bean
#Lazy
public EchoService echoService(){
return new EchoService();
}
#Bean
public InstrumentationLoadTimeWeaver loadTimeWeaver() throws Throwable {
InstrumentationLoadTimeWeaver loadTimeWeaver = new InstrumentationLoadTimeWeaver();
return loadTimeWeaver;
}
}
Service Class
package com.wh;
import org.springframework.stereotype.Service;
#Service
public class EchoService {
public void echo( String s ) {
System.out.println( s );
}
}
EchoDelegateService is the Non Bean class in which we have Autowired The required Bean.
We expect that the EchoService should get autowired.
Problem : EchoService not getting autowired. Gives an Null Pointer exception.
package com.wh;
import org.springframework.beans.factory.annotation.Autowire;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Configurable;
#Configurable( preConstruction = true, autowire = Autowire.BY_TYPE, dependencyCheck = false )
public class EchoDelegateService {
#Autowired
private EchoService echoService;
public void echo( String s ) {
echoService.echo( s );
}
}
Main Class where we are calling method of NonBean Class.
package com.wh;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
public class MainApp {
public static void main(String[] args) {
ApplicationContext ctx =
new AnnotationConfigApplicationContext(AppConfig.class);
new EchoDelegateService().echo("hihi, it works...");
}
}
Your question already includes the answer: "... in a non-bean class". This simply does not work. All the autowiring, aspect resolving and whatever is to that, only works for beans. Thus, you definitely need to construct your EchoDelegateService via the spring factory:
EchoDelegateService myService = ctx.getBean(EchoDelegateService.class);
myService.echo("this should really work now");
I have been trying to add spring validators to a spring-data-rest project.
I followed along and setup the "getting started" application via this link: http://spring.io/guides/gs/accessing-data-rest/
...and now I am trying to add a custom PeopleValidator by following the documents here:
http://docs.spring.io/spring-data/rest/docs/2.1.0.RELEASE/reference/html/validation-chapter.html
My custom PeopleValidator looks like
package hello;
import org.springframework.validation.Errors;
import org.springframework.validation.Validator;
public class PeopleValidator implements Validator {
#Override
public boolean supports(Class<?> clazz) {
return true;
}
#Override
public void validate(Object target, Errors errors) {
errors.reject("DIE");
}
}
...and my Application.java class now looks like this
package hello;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.data.rest.webmvc.config.RepositoryRestMvcConfiguration;
#Configuration
#EnableJpaRepositories
#Import(RepositoryRestMvcConfiguration.class)
#EnableAutoConfiguration
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
#Bean
public PeopleValidator beforeCreatePeopleValidator() {
return new PeopleValidator();
}
}
I would expect that POSTing to the http://localhost:8080/people URL would result in an error of some kind since the PeopleValidator is rejecting everything. However, no error is thrown, and the validator is never called.
I have also tried manually setting up the validator as shown in section 5.1 of the spring-data-rest documentation.
What am I missing?
So it appears that the before/after "save" events only fire on PUT and PATCH. When POSTing, the before/after "create" events fire.
I tried it the manual way again using the configureValidatingRepositoryEventListener override and it worked. I'm not sure what I'm doing differently at work than here at home. I'll have to look tomorrow.
I sure would love to hear if others have suggestions on why it wouldn't work.
For the record, here is what the new Application.java class looks like.
package hello;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.data.rest.core.event.ValidatingRepositoryEventListener;
import org.springframework.data.rest.webmvc.config.RepositoryRestMvcConfiguration;
#Configuration
#EnableJpaRepositories
#Import(RepositoryRestMvcConfiguration.class)
#EnableAutoConfiguration
public class Application extends RepositoryRestMvcConfiguration {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
#Override
protected void configureValidatingRepositoryEventListener(ValidatingRepositoryEventListener validatingListener) {
validatingListener.addValidator("beforeCreate", new PeopleValidator());
}
}
Looks like the feature is currently not implemented (2.3.0), unluckily there are no constants for the event names otherwise the solution below would not be that fragile.
The Configuration adds all properly named Validator beans to ValidatingRepositoryEventListener using the right event.
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.ListableBeanFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.rest.core.event.ValidatingRepositoryEventListener;
import org.springframework.validation.Validator;
#Configuration
public class ValidatorRegistrar implements InitializingBean {
private static final List<String> EVENTS;
static {
List<String> events = new ArrayList<String>();
events.add("beforeCreate");
events.add("afterCreate");
events.add("beforeSave");
events.add("afterSave");
events.add("beforeLinkSave");
events.add("afterLinkSave");
events.add("beforeDelete");
events.add("afterDelete");
EVENTS = Collections.unmodifiableList(events);
}
#Autowired
ListableBeanFactory beanFactory;
#Autowired
ValidatingRepositoryEventListener validatingRepositoryEventListener;
#Override
public void afterPropertiesSet() throws Exception {
Map<String, Validator> validators = beanFactory.getBeansOfType(Validator.class);
for (Map.Entry<String, Validator> entry : validators.entrySet()) {
EVENTS.stream().filter(p -> entry.getKey().startsWith(p)).findFirst()
.ifPresent(p -> validatingRepositoryEventListener.addValidator(p, entry.getValue()));
}
}
}
A bit of a stab in the dark - I've not used spring-data-rest. However, after having a read of the tutorial you're following, I think the problem is that you need a PersonValidator not a PeopleValidator. Rename everything accordingly:
PersonValidator
package hello;
import org.springframework.validation.Errors;
import org.springframework.validation.Validator;
public class PersonValidator implements Validator {
#Override
public boolean supports(Class<?> clazz) {
return true;
}
#Override
public void validate(Object target, Errors errors) {
errors.reject("DIE");
}
}
Application
package hello;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.data.rest.webmvc.config.RepositoryRestMvcConfiguration;
#Configuration
#EnableJpaRepositories
#Import(RepositoryRestMvcConfiguration.class)
#EnableAutoConfiguration
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
#Bean
public PersonValidator beforeCreatePersonValidator() {
return new PersonValidator();
}
}
Another way of doing it is to use annotated handlers as specified here
http://docs.spring.io/spring-data/rest/docs/2.1.0.RELEASE/reference/html/events-chapter.html#d5e443
Here is an example of how to use annotated handlers:
import gr.bytecode.restapp.model.Agent;
import org.springframework.data.rest.core.annotation.HandleBeforeCreate;
import org.springframework.data.rest.core.annotation.HandleBeforeSave;
import org.springframework.data.rest.core.annotation.RepositoryEventHandler;
import org.springframework.stereotype.Component;
#Component
#RepositoryEventHandler(Agent.class)
public class AgentEventHandler {
public static final String NEW_NAME = "**modified**";
#HandleBeforeCreate
public void handleBeforeCreates(Agent agent) {
agent.setName(NEW_NAME);
}
#HandleBeforeSave
public void handleBeforeSave(Agent agent) {
agent.setName(NEW_NAME + "..update");
}
}
Example is from github edited for brevity.