无法在ApplicationContext.xml中声明Bean

Question

Whoever answers correct will be rewarded My Implementation is as follows:

NextShipmentDaoImpl.java

public class NextShipmentDaoImpl implements NextShipmentDao{

    private DataSource dataSource;

    public DataSource getDataSource() {
        return dataSource;
    }

    public void setDataSource(DataSource dataSource) {
        this.dataSource = dataSource;
    }

LoginController.java

@Controller  
public class LoginController {  

      @Autowired
      private NextShipmentDao nextShipmentDao;

      public void setNextShipmentDao(NextShipmentDao nextShipmentDao) {
        this.nextShipmentDao = nextShipmentDao;
     }

While Creating the required above bean like this:

<bean id="nextShipmentDao" class="com.ibrahim.dao.NextShipmentDaoImpl">
<property name="dataSource" ref="dataSource"></property>
</bean>

ApplicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>  
<beans xmlns="http://www.springframework.org/schema/beans"  
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"   
 xmlns:context="http://www.springframework.org/schema/context"  
 xmlns:tx="http://www.springframework.org/schema/tx"  
 xsi:schemaLocation=" 
http://www.springframework.org/schema/beans  
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd  
http://www.springframework.org/schema/context  
http://www.springframework.org/schema/context/spring-context-3.0.xsd  
http://www.springframework.org/schema/tx  
http://www.springframework.org/schema/tx/spring-tx-3.0.xsd">

<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">  
<property name="driverClassName" value="com.mysql.jdbc.Driver" />  
<property name="url" value="jdbc:mysql://localhost:3306/board" />  
<property name="username" value="root" />  
<property name="password" value="root" />  
</bean>

<bean id="nextShipmentDao" class="com.ibrahim.dao.NextShipmentDaoImpl">
<property name="dataSource" ref="dataSource"></property>
</bean>

 <security:http auto-config="true" >  
 <security:intercept-url pattern="/index*" access="ROLE_USER" />  
 <security:form-login login-page="/login.htm" default-target-url="/index.htm"  
  authentication-failure-url="/loginerror.htm" />  
 <security:logout logout-success-url="/logout.htm" />  
 </security:http> 


<context:component-scan base-package="com.ibrahim.controller,com.ibrahim.domain,com.ibrahim.dao" />  

<bean id="jspViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">  
<property name="viewClass"  value="org.springframework.web.servlet.view.JstlView" />  
<property name="prefix" value="/WEB-INF/views/" />  
<property name="suffix" value=".jsp" />  
</bean>
</beans>

Everything works fine. But when I try to create a bean This shows the error

SEVERE: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'loginController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.ibrahim.dao.NextShipmentDao com.ibrahim.controller.LoginController.nextShipmentDao; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'nextShipmentDao' defined in ServletContext resource [/WEB-INF/board-dao.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.ibrahim.dao.NextShipmentDaoImpl]: Constructor threw exception; nested exception is java.lang.IllegalArgumentException: Property 'dataSource' is required
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:288)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1116)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:295)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:292)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:628)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:932)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:479)
    at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:389)
    at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:294)
    at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:112)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4728)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5166)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1409)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1399)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.ibrahim.dao.NextShipmentDao com.ibrahim.controller.LoginController.nextShipmentDao; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'nextShipmentDao' defined in ServletContext resource [/WEB-INF/board-dao.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.ibrahim.dao.NextShipmentDaoImpl]: Constructor threw exception; nested exception is java.lang.IllegalArgumentException: Property 'dataSource' is required
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:514)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:285)
    ... 22 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'nextShipmentDao' defined in ServletContext resource [/WEB-INF/board-dao.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.ibrahim.dao.NextShipmentDaoImpl]: Constructor threw exception; nested exception is java.lang.IllegalArgumentException: Property 'dataSource' is required
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1007)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:953)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:487)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:295)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:292)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:912)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:855)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:770)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:486)
    ... 24 more
Caused by: org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.ibrahim.dao.NextShipmentDaoImpl]: Constructor threw exception; nested exception is java.lang.IllegalArgumentException: Property 'dataSource' is required
    at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:163)
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:87)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1000)
    ... 35 more
Caused by: 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.ibrahim.dao.NextShipmentDaoImpl.<init>(NextShipmentDaoImpl.java:28)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:148)
    ... 37 more

May 07, 2015 12:21:48 PM org.apache.catalina.core.StandardContext startInternal
SEVERE: Error listenerStart
May 07, 2015 12:21:48 PM org.apache.catalina.core.StandardContext startInternal
SEVERE: Context [/13.1SecuringUrlAcces] startup failed due to previous errors
May 07, 2015 12:21:48 PM org.apache.catalina.core.ApplicationContext log
INFO: Closing Spring root WebApplicationContext
May 07, 2015 12:21:48 PM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-nio-8080"]
May 07, 2015 12:21:48 PM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["ajp-nio-8009"]
May 07, 2015 12:21:48 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 12402 ms

Here's My NextShipmentDaoImpl.java

public class NextShipmentDaoImpl implements NextShipmentDao{

    private DataSource dataSource;

    public DataSource getDataSource() {
        return dataSource;
    }

    public void setDataSource(DataSource dataSource) {
        this.dataSource = dataSource;
    }

    JdbcTemplate jdbcTemplate= new JdbcTemplate(dataSource);

    @Override
    public List<NextShipment> display() {

        String sql = "SELECT * FROM NEXTSHIPMENT";

        List<NextShipment> shipments = new ArrayList<NextShipment>();
        List<Map<String, Object>> rows = jdbcTemplate.queryForList(sql);
        for (Map row : rows) {
            NextShipment shipment = new NextShipment();
            shipment.setOid((String) row.get("OID"));
            shipment.setAddress((String) row.get("ADDRESS"));
            shipment.setPack_Date((Date) row.get("PACK_DATE"));
            shipment.setIsAvailable((Boolean) row.get("ISAVAILABLE"));
            shipment.setAssignShipper((String) row.get("ASSIGNSHIPPER"));
            shipment.setInTransit((Boolean) row.get("InTransit"));
            shipments.add(shipment);
        }
        return shipments;
    }
}

Answer 1

The times of the XML-based configuration are over.

I strongly recommend you to use Annotated Configuration

Something like this:

@Configuration
@EnableWebMvc
@EnableTransactionManagement
@ComponentScan(basePackages = "com.myapp.*")
public class AppConfiguration extends WebMvcConfigurerAdapter {

    @Bean
    public DataSource myDataSource() {

        DriverManagerDataSource dataSource = new DriverManagerDataSource();

        dataSource.setDriverClassName("<full.driver.class.name>");
        dataSource.setUrl("url");
        dataSource.setUsername("dit");
        dataSource.setPassword("pass");

        return dataSource;
    }

    [...] other Beans like TransactionManager....

}

Answer 2

The stacktrace says :

• you correctly autowire nextShipmentDAO in loginController
• but dataSource property is null is the NextShipmentDAOImpl bean
• and the exception occurs in JdbcTemplate initialization

The NextShipmentDAOImpl gives the cause : you correctly inject the datasource, but initialize the JdbcTemplate at construction time. So here is what happens :

• jvm creates a NextShipmentDaoImpl object
• jvm initializes all fields of the object including jdbcTemplate
• spring sets the datasource field ... too late !

[It had been noted in comments by @M.Deinum, but I did not give it enough attention]

You shall never use an injected field at creation time, because at that moment it has not been injected. You should instead use an initialization method called by spring after all properties have been set :

public class NextShipmentDaoImpl implements NextShipmentDao{

    private DataSource dataSource;

    public DataSource getDataSource() {
        return dataSource;
    }

    public void setDataSource(DataSource dataSource) {
        this.dataSource = dataSource;
    }

    JdbcTemplate jdbcTemplate;

    void init(void) {
        jdbcTemplate = new JdbcTemplate(dataSource);
    }

and declare the bean that way :

<bean id="nextShipmentDao" class="com.ibrahim.dao.NextShipmentDaoImpl" 
    init-method="init">
<property name="dataSource" ref="dataSource"></property>
</bean>

Answer 3

NextShipmentDaoImpl.java looks like this

public class NextShipmentDaoImpl implements NextShipmentDao{

    private DataSource dataSource;

    JdbcTemplate jdbcTemplate;

    public NextShipmentDaoImpl(DataSource dataSource) {
        this.dataSource = dataSource;
    }

In the above lines of code I had declared JdbcTemplate inside its implementation function itself. Where it is used.

And the relevant bean I had declared is:

<bean id="nextShipmentDao" class="com.ibrahim.dao.NextShipmentDaoImpl">
<constructor-arg ref="dataSource"></constructor-arg>
</bean>

LoginController remains the same:

@Controller  
public class LoginController {  

     @Autowired
      private NextShipmentDao nextShipmentDao;

       public void setNextShipmentDao(NextShipmentDao nextShipmentDao) {
        this.nextShipmentDao = nextShipmentDao;
     }

I had shifted my spring and spring security jars from 3.2.4 to 3.2.7 Problem got solved in this manner.