Spring 3 JavaConfig - Problems Injecting DataSource

Question

I'm new to Spring and I'm trying to my DataSource injection to work. I'm getting a "Property 'dataSource' is required" error. Been stumped on this for a while. Thanks in advance for your help!

WebConfig.java

import javax.sql.DataSource;
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.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.InternalResourceViewResolver;

@Configuration
@EnableWebMvc
@ComponentScan(basePackages = "com.test")
public class WebConfig extends WebMvcConfigurerAdapter {

@Autowired
DataSource Source;

@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
    System.out.println("addResourceHandlers :: init");
    registry.addResourceHandler("/resources/**").addResourceLocations(
            "/resources/");
}

@Bean
public InternalResourceViewResolver viewResolver() {
    System.out.println("viewResolver :: init");
    InternalResourceViewResolver resolver = new InternalResourceViewResolver();
    resolver.setPrefix("/WEB-INF/views/");
    resolver.setSuffix(".jsp");
    return resolver;
}

}

AppConfig.java

import javax.sql.DataSource;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.jdbc.datasource.DriverManagerDataSource;

@Configuration
@ComponentScan(basePackages = { "com.test" })
public class AppConfig {

@Bean
public DataSource dataSource() {
    System.out.println("userDBDatasource :: init");
    DriverManagerDataSource dataSource = new DriverManagerDataSource();
    dataSource.setDriverClassName("com.mysql.jdbc.Driver");
    dataSource.setUrl("jdbc:mysql://localhost:3306/test");
    dataSource.setUsername("foo");
    dataSource.setPassword("foo");
    return dataSource;
}

}

JDBCUserDaoImpl.java

package com.test.foo;

import java.util.ArrayList;
import java.util.List;
import javax.sql.DataSource;
import org.apache.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;

@Repository
public class JDBCUserDAOImpl implements JDBCUserDAO {

private Logger logger = Logger.getRootLogger();
private JdbcTemplate jdbcTemplate;
private DataSource dataSource;

@Autowired
public void setDataSource(DataSource dataSource) {
    logger.debug("setDataSource :: called");
    this.dataSource = dataSource;
}

public List<UserBean> getUsers() {
    logger.info("Getting List of Users!");
    List<UserBean> userBeans = new ArrayList<UserBean>();
    String sql = "SELECT * FROM users";
    jdbcTemplate = new JdbcTemplate(dataSource);
    userBeans = jdbcTemplate.query(sql, new UserBeanRowMapper());
    return userBeans;
}
}

Error

Dec 07, 2013 10:46:53 AM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [main] in context with path [/springmvc] threw exception [Request processing failed; nested exception is java.lang.IllegalArgumentException: Property 'dataSource' is required] with root cause
java.lang.IllegalArgumentException: Property 'dataSource' is required
    at org.springframework.jdbc.support.JdbcAccessor.afterPropertiesSet(JdbcAccessor.java:134)
    at org.springframework.jdbc.core.JdbcTemplate.<init>(JdbcTemplate.java:165)
    at com.tajima.models.JDBCUserDAOImpl.getUsers(JDBCUserDAOImpl.java:42)
    at com.tajima.controllers.HomeController.loadUserList(HomeController.java:53)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:219)
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:745)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:686)
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:925)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:936)
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:827)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:812)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1023)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:744)

Answer 1

The @Import annotation provides just this kind of support, and it is the direct equivalent of the element found in Spring beans XML files.

You have missed to import AppConfig class to the WebMvcConfig class file. So, spring unable to create the bean with the name 'dataSource'.

In your WebMvcConfig class you need to import the DataSource configuration class with @Import annotation. This will helps to create dataSource bean by the spring Container.

 ex:@Configuration
    @EnableWebMvc
    @Import({AppConfig.class})
    @ComponentScan(basePackages = "com.test")
    public class WebConfig extends WebMvcConfigurerAdapter {

I hope have correctly specified webConfig class as contextConfigLocation param to the Dispatcher servlet. if it is not there specify as specified below

<servlet>
<servlet-name>mvc</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
  <param-name>contextClass</param-name>
  <param-value>org.springframework.web.context.support.AnnotationConfigWebApplicationContext</param-value>
</init-param>
<init-param>
  <param-name>contextConfigLocation</param-name>
  <param-value>yourpackage.config.WebMvcConfig</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
 <servlet-name>mvc</servlet-name>
 <url-pattern>/</url-pattern>
</servlet-mapping>

or you can specify this context class and contextConfiglocation to the ContextLoaderLister as a context param as specified below

   <listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
 <context-param>
<param-name>contextClass</param-name>
<param- value>org.springframework.web.context.support.AnnotationConfigWebApplicationC     ontext</param-value>
</context-param>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>yourpackage.WebMvcConfig</param-value>
</context-param>

Answer 2

Remove the DataSource injection from WebConfig.java