when is a spring beans destroy-method called?

问题

I have put a sysout statement in the "destroy-method" for a bean. When i run a sample code, the sysout is not getting output. Does that mean the destroy-method is not getting called ?

The Test Class:

  package spring.test;

  import org.springframework.context.ApplicationContext;
  import org.springframework.context.support.ClassPathXmlApplicationContext;

  public class InitTest {
    public static void main(String[] args) {
        ApplicationContext ctx = new ClassPathXmlApplicationContext("InitTestContext.xml");
        InitTestBean bean = (InitTestBean)ctx.getBean("InitTestBean");
        bean.display();
    }
  }

The Bean

  package spring.test;

  public class InitTestBean {
    private String prop1;
    private String prop2;

    public InitTestBean(String prop1, String prop2) {
        System.out.println("Instantiating InitTestBean");
        this.prop1 = prop1;
        this.prop2 = prop2;
    }

    public void setProp1(String prop1) {
        System.out.println("In setProp1");
        this.prop1 = prop1;
    }

    public void setProp2(String prop2) {
        System.out.println("In setProp2");
        this.prop2 = prop2;
    }

    public String getProp1() {
        return prop1;
    }

    public String getProp2() {
        return prop2;
    }

    public void display() {
        System.out.println("Prop1 is " + prop1);
        System.out.println("Prop2 is " + prop2);
    }

    public void initialize(){
        System.out.println("In initialize");
        this.prop1 = "init-prop1";
        this.prop2 = "init-prop2";
    }

    public void teardown() {
        System.out.println("In teardown");
        this.prop1 = null;
        this.prop2 = null;
    }
  }

The Config file:

<?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:aop="http://www.springframework.org/schema/aop"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

    <bean id="InitTestBean" class="spring.test.InitTestBean" init-method="initialize" destroy-method="teardown">
        <constructor-arg value="Prop1" />
        <constructor-arg value="Prop2" />
        <property name="prop1" value="setProp1"/>
        <property name="prop2" value="setProp2"/>
    </bean>

</beans>

回答1:

Your example doesn't work because you're not shutting down the appcontext, you're just letting the program terminate.

Call close() on the context, and you'll see the bean destroy-methods being called.

回答2:

It may be too late for the OP, but if someone is still looking for it...

The close method is in AbstractApplicationContext and not ApplicationContext, also another way is to use ctx.registerShutdownHook() instead of ctx.close() for obvious reasons that while running Junits you might want to close the context but not while in production environment so let Spring decide on when to close it.

回答3:

//Getting application context
ApplicationContext context = new ClassPathXmlApplicationContext(beansXML); 

//cleaning context
((ClassPathXmlApplicationContext) context).close(); 

回答4:

The "destroy-method" is only called if and only if the bean is a singleton instance

See the log output of the IOC container

INFO: Destroying singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@1a0ce4c: defining beans [book1]; root of factory hierarchy

回答5:

hi you need to change ApplicationContext to AbstractApplicationContext and then register to a ShutDownhook which will destroy your bean and also implement the DisposableBean interface eg:

  package spring.test;

  import org.springframework.context.ApplicationContext;
  import org.springframework.context.support.ClassPathXmlApplicationContext;
  import org.springframework.context.support.AbstractApplicationContext;
  public class InitTest {
    public static void main(String[] args) {
       AbstractApplicationContext ctx = new ClassPathXmlApplicationContext("InitTestContext.xml");
  ctx.registerShutdownHook();
        InitTestBean bean = (InitTestBean)ctx.getBean("InitTestBean");
        bean.display();
    }
  }

and now implemnt the DisposableBean interface

package spring.test;
import org.springframework.beans.factory.DisposableBean;
  public class InitTestBean implements DisposableBean{
    private String prop1;
    private String prop2;
    public InitTestBean(String prop1, String prop2) {
        System.out.println("Instantiating InitTestBean");
        this.prop1 = prop1;
        this.prop2 = prop2;
    }
    public void setProp1(String prop1) {
        System.out.println("In setProp1");
        this.prop1 = prop1;
    }
    public void setProp2(String prop2) {
        System.out.println("In setProp2");
        this.prop2 = prop2;
    }
    public String getProp1() {
        return prop1;
    }
    public String getProp2() {
        return prop2;
    }
    public void display() {
        System.out.println("Prop1 is " + prop1);
        System.out.println("Prop2 is " + prop2);
    }
    public void initialize(){
        System.out.println("In initialize");
        this.prop1 = "init-prop1";
        this.prop2 = "init-prop2";
    }
    public void teardown() {
        System.out.println("In teardown");
        this.prop1 = null;
        this.prop2 = null;
    }
    @Override
    public void destroy() throws Exception {

        System.out.println(" the bean has been destroyed");
    }
  }

回答6:

factory.destroySingletons(); after your bean.display() as destroy-method is valued in the bean definition. The default scope with which bean is created is singleton hence, invoking the factory.destroySingletons() will call the method mentioned in the destroy-method.

来源：https://stackoverflow.com/questions/4460384/when-is-a-spring-beans-destroy-method-called