java - spring中bean的destroy方法什么时候被调用？

Question

这是用于存储有关特定用户的详细信息的 bean 类。它有两个方法，名为 init 和 destroy。 bean初始化和销毁​​时需要调用。

package org.springframework.HelloWorld.beans;

public class User {
    private int userId;
    private String userName;
    private String address;
    private String mobileNumber;

    public User() {
        super();
    }

    public User(int userId, String userName, String address, String mobileNumber) {
        super();
        this.userId = userId;
        this.userName = userName;
        this.address = address;
        this.mobileNumber = mobileNumber;
    }

    public int getUserId() {
        return userId;
    }

    public void setUserId(int userId) {
        this.userId = userId;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String getMobileNumber() {
        return mobileNumber;
    }

    public void setMobileNumber(String mobileNumber) {
        this.mobileNumber = mobileNumber;
    }

    @Override
    public String toString() {
        return "User [userId=" + userId + ", userName=" + userName
                + ", address=" + address + ", mobileNumber=" + mobileNumber
                + "]";
    }

    public void init(){
        System.out.println("Initialized");
    }

    public void destroy(){
        System.out.println("Destroyed");
    }
}

这是我用过的主要方法。这里我从 Beans.xml 文件中获取 User 对象。

public static void main(String[] args) {
        @SuppressWarnings("resource")
        ApplicationContext ctx = new ClassPathXmlApplicationContext("Beans.xml");
        User user = (User) ctx.getBean("user");
        System.out.println(user);
        user.setUserName("Gnanadurai Asudoss");
        user.setAddress("Chxxxxx");
        System.out.println(user);
        user = (User) ctx.getBean("user");
        System.out.println(user);
        user=null;
    }

下面是 Beans.xml 文件，这里我提到了 bean、init 方法和 destroy 方法。

<bean id="user" class="org.springframework.HelloWorld.beans.User" init-method="init" destroy-method="destroy">
		<property name="userId" value="1"></property>
		<property name="userName" value="Gnanadurai"></property>
		<property name="address" value="Saxxxx"></property>
		<property name="mobileNumber" value="xxxxxxxx49"></property>
	</bean>

这是我得到的输出。这里你可以看到Initialized方法被调用，而Destroy方法没有被调用。

Initialized
User [userId=1, userName=Gnanadurai, address=Saxxx, mobileNumber=xxxxxxxx49]
User [userId=1, userName=Gnanadurai Asudoss, address=Chxxxx, mobileNumber=xxxxxxxx49]
User [userId=17505, userName=Gnanadurai Asudoss, address=Chxxxx, mobileNumber=xxxxxxxx49]

所以我不知道什么时候会调用 destroy 方法..你能告诉我什么时候会调用它吗？举个例子。

谢谢...

Answer 1

根据这篇文章，您需要关闭您的applicationContext，在此操作之后，您的销毁将被调用。 Related SO question

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

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