Develop Reference

How to get H2 database filesystem with java

I want to use H2 database filesystem in my Java project. But I don't know how to implement by using properties file in java.

There is some code that you can refer to. I am currently using this and this is working like a charm:
package group.demo.custMgmt.common;
import java.util.Properties;
import javax.sql.DataSource;
import org.apache.commons.dbcp.BasicDataSource;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.core.env.Environment;
import org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor;
import org.springframework.orm.hibernate5.HibernateTransactionManager;
import org.springframework.orm.hibernate5.LocalSessionFactoryBean;
import org.springframework.transaction.annotation.EnableTransactionManagement;
#Configuration
#EnableTransactionManagement
#PropertySource({ "classpath:group/demo/custMgmt/resources/persistence-sql.properties" })
#ComponentScan({ "group.*" })
public class HibernateConfig {
#Autowired
private Environment env;
#Bean
public LocalSessionFactoryBean sessionFactory() {
LocalSessionFactoryBean sessionFactory = new LocalSessionFactoryBean();
sessionFactory.setDataSource(restDataSource());
sessionFactory.setPackagesToScan("*");
sessionFactory.setHibernateProperties(hibernateProperties());
sessionFactory.setMappingResources("Model.hbm.xml");
return sessionFactory;
}
#Bean(destroyMethod="close")
public DataSource restDataSource() {
BasicDataSource dataSource = new BasicDataSource();
dataSource.setDriverClassName(env.getProperty("jdbc.driverClassName"));
dataSource.setUrl(env.getProperty("jdbc.url"));
dataSource.setUsername(env.getProperty("jdbc.username"));
dataSource.setPassword(env.getProperty("jdbc.password"));
return dataSource;
}
#Bean
#Autowired
public HibernateTransactionManager transactionManager(SessionFactory sessionFactory) {
HibernateTransactionManager txManager = new HibernateTransactionManager();
txManager.setSessionFactory(sessionFactory);
return txManager;
}
#Bean
public PersistenceExceptionTranslationPostProcessor exceptionTranslation() {
return new PersistenceExceptionTranslationPostProcessor();
}
Properties hibernateProperties() {
return new Properties() {
/**
*
*/
private static final long serialVersionUID = -7570975785205994647L;
{
setProperty("hibernate.hbm2ddl.auto", env.getProperty("hibernate.hbm2ddl.auto"));
setProperty("hibernate.dialect", env.getProperty("hibernate.dialect"));
setProperty("hibernate.globally_quoted_identifiers", "true");
setProperty("hibernate.show_sql",env.getProperty("hibernate.show_sql"));
}
};
}
}
persistence-sql.properties
`spring.h2.console.enabled=true
jdbc.driverClassName =org.h2.Driver
jdbc.url =jdbc:h2:tcp://localhost:9092/~/test
jdbc.username =sa
jdbc.password =
hibernate.dialect =org.hibernate.dialect.H2Dialect
hibernate.hbm2ddl.auto=create
hibernate.show_sql=true`
maven dependency
<dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
<version>1.4.196</version>
<scope>runtime</scope>
</dependency>

No mapping found for HTTP request with URI [/proj/] in DispatcherServlet with name 'dispatcher'

I am following "Spring in action - Craig Walls" book and encountered the below error message. Lot of the issues were mentioned in relation to web.xml. I am using Java config and not web.xml.
Controller in spitter.web package:
package spitter.web;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
#Controller
public class HomeController {
#RequestMapping(value="/", method = RequestMethod.GET)
public String home(){
return "home";
}
}
Dispatcher servlet configuration in spittr.config package:
package spittr.config;
import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;
public class SpittrWebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {
#Override
protected String[] getServletMappings() {
return new String[] {"/"};
}
#Override
protected Class<?>[] getRootConfigClasses() {
//return new Class<?>[] {RootConfig.Class};
return null;
}
#Override
protected Class<?>[] getServletConfigClasses() {
//return new Class<?>[] {WebConfig.Class};
return null;
}
}
Rootconfig in same package:
package spittr.config;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.ComponentScan.Filter;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.FilterType;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
#Configuration
#ComponentScan(basePackages={"spitter"}, excludeFilters={#Filter(type=FilterType.ANNOTATION, value=EnableWebMvc.class)})
public class RootConfig {
}
WebConfig:
package spittr.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
#Configuration
#EnableWebMvc
#ComponentScan("spitter.web")
public class WebConfig extends WebMvcConfigurerAdapter{
#Bean
public ViewResolver viewResolver(){
InternalResourceViewResolver resolver = new InternalResourceViewResolver();
resolver.setPrefix("/WebContent/WEB-INF/views/");
resolver.setSuffix(".jsp");
resolver.setExposeContextBeansAsAttributes(true);
return resolver;
}
#Override
public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer){
configurer.enable();
}
}
I am using Maven to resolving dependencies and Tomcat 9 within eclipse to run.
Sep 17, 2016 4:46:48 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 5007 ms Sep 17, 2016 4:46:49 PM
org.springframework.web.servlet.PageNotFound noHandlerFound WARNING:
No mapping found for HTTP request with URI [/SpringMVC/] in
DispatcherServlet with name 'dispatcher'
My view home.jsp is in WebContent/WEB-INF/views/home.jsp.

Thanks for your help. I made the below changes and it is working now.
I move the web.config to the same package as my constructor. Then created the war file and deployed in Apache Tomcat. Now i am able to access the website.

Failed to load ApplicationContext in my Test (Junit with Hibernate)

I have a problem... Well, when I start my test, I throw me the following error, and can not find that he is doing wrong. Agrege corresponding to the "Application-context" where is the notation hibernate settings, but I can not perform my test successfully
"WebAppInitializer":
package com.checkwork.conf;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.WebApplicationInitializer;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.servlet.DispatcherServlet;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRegistration;
public class WebAppInitializer implements WebApplicationInitializer {
private static final Logger logger = LoggerFactory.getLogger(WebAppInitializer.class);
#Override
public void onStartup(ServletContext servletContext) throws ServletException {
logger.info("Initializing web application with context configuration class {}", WebAppConfigurer.class.getCanonicalName());
//WebApplication Param-Value (Web.XML)
AnnotationConfigWebApplicationContext webAppContext = new AnnotationConfigWebApplicationContext();
webAppContext.register(WebAppConfigurer.class);
//Crea Servlet y mapea las peticiones con "/" sin extensiones.
ServletRegistration.Dynamic dispatcher = servletContext.addServlet("dispatcher",
new DispatcherServlet(webAppContext));
dispatcher.setLoadOnStartup(1);
dispatcher.addMapping("/");
}
}
"WebAppConfigurer":
package com.checkwork.conf;
import com.checkwork.model.Empleado;
import java.util.Properties;
import javax.sql.DataSource;
import org.apache.commons.dbcp.BasicDataSource;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.*;
import org.springframework.orm.hibernate4.HibernateTransactionManager;
import org.springframework.orm.hibernate4.LocalSessionFactoryBuilder;
import org.springframework.transaction.annotation.EnableTransactionManagement;
import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
#Configuration
#EnableTransactionManagement /** Gestor de transacciones que permiten habilitar los componentes para la conexion a la BD */
#EnableWebMvc
#ComponentScan(basePackages = {"com.checkwork"})
public class WebAppConfigurer extends WebMvcConfigurerAdapter {
#Override
public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
configurer.enable();
}
#Bean(name = "dataSource")
public DataSource getDataSource() {
BasicDataSource dataSource = new BasicDataSource();
dataSource.setDriverClassName("com.mysql.jdbc.Driver");
dataSource.setUrl("jdbc:mysql://localhost:3306/module");
dataSource.setUsername("root");
dataSource.setPassword("root");
return dataSource;
}
private Properties getHibernateProperties() {
Properties properties = new Properties();
properties.put("hibernate.show_sql", "true");
properties.put("hibernate.dialect", "org.hibernate.dialect.MySQLDialect");
return properties;
}
#Autowired
#Bean(name = "sessionFactory")
public SessionFactory getSessionFactory(DataSource dataSource) {
LocalSessionFactoryBuilder sessionBuilder = new LocalSessionFactoryBuilder(dataSource);
sessionBuilder.addProperties(getHibernateProperties());
sessionBuilder.addAnnotatedClasses(Empleado.class);
return sessionBuilder.buildSessionFactory();
}
#Autowired
#Bean(name = "transactionManager")
public HibernateTransactionManager getTransactionManager(
SessionFactory sessionFactory) {
HibernateTransactionManager transactionManager = new HibernateTransactionManager(
sessionFactory);
return transactionManager;
}
/**
* Agrega al Caché la librería OpenUI5 en tiempo de ejecución {WEB-INF/lib}
*/
#Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
registry.addResourceHandler("/resources/**").addResourceLocations("classpath:/resources/", "/resources/**")
.setCachePeriod(31556926);
}
}
Test:
package com.checkwork.service;
import static org.junit.Assert.*;
import javax.transaction.Transactional;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import com.checkwork.conf.WebAppConfigurer;
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(classes = WebAppConfigurer.class)
public class EmpleadoServiceTest {
private EmpleadoService empleadoService;
#Before
public void setUp() throws Exception{
empleadoService = new EmpleadoService();
}
#Test
#Transactional
public void getAllTest(){
assertNotNull(empleadoService.getAll());
}
}
Error console - Junit:
SEVERE: Caught exception while allowing TestExecutionListener [org.springframework.test.context.support.DependencyInjectionTestExecutionListener#1761de10] to prepare test instance [com.checkwork.service.EmpleadoServiceTest#22df874e]
java.lang.IllegalStateException: Failed to load ApplicationContext...

Change
#ContextConfiguration(classes = WebAppConfigurer.class)
to
#ContextConfiguration(classes = WebAppConfigurer.class, initializers=WebAppInitializer.class)
update
Also include #WebIntegrationTest below #ContextConfiguration

Spring MVC 4 configuration not finding my controllers

Hi I am new to Spring MVC 4 I am trying to do the java configuration setup but it seems Spring is not finding my Controller it is running fine no errors on startup I can even explicitly call a jsp but if I try to call my controller it does nothing
e.g.
localhost:8080/apollo/hello.jsp <-- this renders fine if I put my JSP in the webapp directory
What I want is to call my login.jsp using my controller
My project structure is
com
+apollo
-WebAppInitializer.java
-WebConfig.java
src
+main
+webapp
-**hello.jsp**
+WEB-INF
+view
-**login.jsp**
here is my Configuration
package com.apollo;
import java.util.Locale;
import org.springframework.context.MessageSource;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.support.ResourceBundleMessageSource;
import org.springframework.web.servlet.LocaleResolver;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.i18n.LocaleChangeInterceptor;
import org.springframework.web.servlet.i18n.SessionLocaleResolver;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
#Configuration
#EnableWebMvc
#ComponentScan(basePackages = "com.apollo")
public class WebConfig extends WebMvcConfigurerAdapter {
#Bean
public MessageSource messageSource() {
ResourceBundleMessageSource messageSource = new ResourceBundleMessageSource();
messageSource.setBasename("messages");
return messageSource;
}
#Bean
public InternalResourceViewResolver getInternalResourceViewResolver() {
InternalResourceViewResolver resolver = new InternalResourceViewResolver();
resolver.setPrefix("/WEB-INF/view/");
resolver.setSuffix(".jsp");
return resolver;
}
#Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
/*registry.addResourceHandler("/pdfs/**").addResourceLocations("/WEB-INF/pdf/");
registry.addResourceHandler("/css/**").addResourceLocations("/WEB-INF/css/");*/
registry.addResourceHandler("/static/**").addResourceLocations("/static/");
}
}
Here is my Initializer Class
package com.apollo;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRegistration;
import org.springframework.web.WebApplicationInitializer;
import org.springframework.web.context.ContextLoaderListener;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.servlet.DispatcherServlet;
public class WebAppInitializer implements WebApplicationInitializer {
#Override
public void onStartup(ServletContext servletContext) throws ServletException {
WebApplicationContext context = getContext();
servletContext.addListener(new ContextLoaderListener(context));
ServletRegistration.Dynamic dispatcher = servletContext.addServlet("DispatcherServlet", new DispatcherServlet(context));
dispatcher.setLoadOnStartup(1);
dispatcher.addMapping("*.html");
}
private AnnotationConfigWebApplicationContext getContext() {
AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
context.register(WebConfig.class);
return context;
}
}
here is my Controller
package com.apollo.controller;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
#Controller
public class LoginController {
#RequestMapping(value="/login")
public String greeting (Model model){
System.out.println("controller???");
model.addAttribute("greeting" , "Hello World");
return "login";
}
}

The basePackages mean the package contains the controller
Here is the problem:
#ComponentScan(basePackages = "com.apollo")
You should change to
#ComponentScan(basePackages = "com.apollo.controller")
If you put controller to modules, you should scan like this
#ComponentScan(basePackages = "com.apollo.**.controller")

No mapping found for HTTP request with URI… in DispatcherServlet with name

When performing a request to http://localhost:8080/SquirrelAuth/api/groups/.json I get this error:
Mar 24, 2015 5:55:52 PM org.springframework.web.servlet.PageNotFound noHandlerFound
WARNING: No mapping found for HTTP request with URI [/SquirrelAuth/api/groups/.json] in DispatcherServlet with name 'dispatcher'
I've been spinning on this one forever and can't seem to find any answers out there that work for me. Can anyone help me through this?
Pom Dependencies/Properties
<properties>
<spring.version>4.1.5.RELEASE</spring.version>
<oauth.version>2.0.7.RELEASE</oauth.version>
<taglibs.version>3.2.6.RELEASE</taglibs.version>
<hibernate.version>4.3.5.Final</hibernate.version>
<log4j.version>2.2</log4j.version>
<jdk.version>1.7</jdk.version>
<jackson.version>2.5.1</jackson.version>
<jstl.version>1.2</jstl.version>
<mysql.version>5.1.6</mysql.version>
<liquibase.version>3.3.2</liquibase.version>
<javax.version>3.1.0</javax.version>
<mavenWar.version>2.6</mavenWar.version>
<mavenCompiler.version>3.2</mavenCompiler.version>
</properties>
<dependencies>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
<version>${log4j.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.security.oauth</groupId>
<artifactId>spring-security-oauth2</artifactId>
<version>${oauth.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.security</groupId>
<artifactId>spring-security-taglibs</artifactId>
<version>${taglibs.version}</version>
</dependency>
<dependency>
<groupId>jstl</groupId>
<artifactId>jstl</artifactId>
<version>${jstl.version}</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>${jackson.version}</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-annotations</artifactId>
<version>${jackson.version}</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>${mysql.version}</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<version>${hibernate.version}</version>
</dependency>
<dependency>
<groupId>org.liquibase</groupId>
<artifactId>liquibase-core</artifactId>
<version>${liquibase.version}</version>
<type>jar</type>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>${javax.version}</version>
</dependency>
</dependencies>
Web Application Intializer
public class WebInitializer implements WebApplicationInitializer {
public void onStartup(ServletContext servletContext) throws ServletException {
WebApplicationContext context = getContext();
servletContext.addListener(new ContextLoaderListener(context));
Dynamic servlet = servletContext.addServlet("dispatcher", new DispatcherServlet(context));
servlet.addMapping("/");
servlet.setLoadOnStartup(1);
}
private AnnotationConfigWebApplicationContext getContext() {
AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
context.setConfigLocation("com.squirrels.config");
return context;
}
}
PersistenceJPAConfig
import java.util.Properties;
import javax.persistence.EntityManagerFactory;
import javax.sql.DataSource;
import liquibase.integration.spring.SpringLiquibase;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.core.env.Environment;
import org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor;
import org.springframework.jdbc.datasource.DriverManagerDataSource;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.JpaVendorAdapter;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;
#Configuration
#EnableTransactionManagement
#ComponentScan({ "com.squirrels.controller", "com.squirrels.services", "com.squirrels.persistence.dao" })
#PropertySource(value = { "classpath:squirrel.properties" })
public class PersistenceJPAConfig {
#Autowired
private Environment environment;
#Bean
public SpringLiquibase liquibase() {
SpringLiquibase liquibase = new SpringLiquibase();
liquibase.setDataSource(dataSource());
liquibase.setDefaultSchema(environment.getRequiredProperty("db_schema"));
liquibase.setChangeLog("classpath:/db/changelog/db.changelog-master.xml");
return liquibase;
}
#Bean
public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
em.setDataSource(dataSource());
em.setPackagesToScan(new String[] { "com.squirrels.persistence.model" });
JpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
em.setJpaVendorAdapter(vendorAdapter);
em.setJpaProperties(additionalProperties());
return em;
}
#Bean
public DataSource dataSource() {
DriverManagerDataSource dataSource = new DriverManagerDataSource();
dataSource.setDriverClassName(environment.getRequiredProperty("db_driverClass"));
dataSource.setUrl(environment.getRequiredProperty("db_jdbcUrl"));
dataSource.setUsername(environment.getRequiredProperty("db_user"));
dataSource.setPassword(environment.getRequiredProperty("db_password"));
return dataSource;
}
#Bean
public PlatformTransactionManager transactionManager(EntityManagerFactory emf) {
JpaTransactionManager transactionManager = new JpaTransactionManager();
transactionManager.setEntityManagerFactory(emf);
return transactionManager;
}
#Bean
public PersistenceExceptionTranslationPostProcessor exceptionTranslation() {
return new PersistenceExceptionTranslationPostProcessor();
}
Properties additionalProperties() {
Properties properties = new Properties();
properties.setProperty("hibernate.dialect", environment.getRequiredProperty("db_hibernateDialect"));
return properties;
}
}
Groups Controller
package com.squirrels.controller;
import java.util.List;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import com.squirrels.dto.GroupDTO;
import com.squirrels.services.GroupUtil;
#Controller
public class GroupsController {
#Autowired
GroupUtil groupUtil;
static final Logger logger = LogManager.getLogger(GroupsController.class);
#RequestMapping(value = "/api/groups/", method = RequestMethod.GET)
public #ResponseBody List<GroupDTO> getGroups() {
List<GroupDTO> groupList = null;
try {
groupList = groupUtil.getAll();
} catch (Exception e) {
e.printStackTrace();
}
return groupList;
}
}
WebMvcConfig
package com.squirrels.config;
import java.util.ArrayList;
import java.util.List;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.MediaType;
import org.springframework.web.accept.ContentNegotiationManager;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.ContentNegotiationConfigurer;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.ContentNegotiatingViewResolver;
#Configuration
#EnableWebMvc
public class WebMvcConfig extends WebMvcConfigurerAdapter {
/*
* Configure ContentNegotiationManager
*/
#Override
public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
configurer.ignoreAcceptHeader(true).defaultContentType(MediaType.TEXT_HTML);
}
/*
* Configure ContentNegotiatingViewResolver
*/
#Bean
public ViewResolver contentNegotiatingViewResolver(ContentNegotiationManager manager) {
ContentNegotiatingViewResolver resolver = new ContentNegotiatingViewResolver();
resolver.setContentNegotiationManager(manager);
// Define all possible view resolvers
List<ViewResolver> resolvers = new ArrayList<ViewResolver>();
resolvers.add(jsonViewResolver());
resolver.setViewResolvers(resolvers);
return resolver;
}
/*
* Configure View resolver to provide JSON output using JACKSON library to
* convert object in JSON format.
*/
#Bean
public ViewResolver jsonViewResolver() {
return new JsonViewResolver();
}
}

The RequestMappingHandlerMapping that spring uses to resolve #RequestMapping annotations has a property alwaysUseFullPath which defaults to false. This means that the mappings you set on handlers (i.e. your #RequestMapping annotations) are resolved relative to the dispatcher servlet mapping which in your case is /api .
Seems that you have not overriden it so make the base mapping path of the controller /groups instead of /api/groups
see reference for details

I ended up solving it finally last night.
I added this to the WebMvcConfig class and all is well.
#Override
public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
configurer.enable();
};