绑定解绑钝化活化监听器

1 知识点

2 绑定与解绑代码演示

1 person类

package www.test.domian;

import javax.servlet.http.HttpSessionBindingEvent;
import javax.servlet.http.HttpSessionBindingListener;

public class Person implements HttpSessionBindingListener{

    private String id;
    private String name;
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    
    
    @Override
    //绑定的方法
    public void valueBound(HttpSessionBindingEvent event) {
        System.out.println("person被绑定了");
    }
    @Override
    //解绑方法
    public void valueUnbound(HttpSessionBindingEvent event) {
        System.out.println("person被解绑了");
    }
  
}

2 TestPersonBindingServlet

package www.test.domian;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class TestPersonBindingServlet extends HttpServlet {

    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        
        HttpSession session = request.getSession();
        
        //将person对象绑到session中
        Person p = new Person();
        p.setId("100");
        p.setName("zhangsanfeng");
                
        session.setAttribute("person", p);
        
        
        //将person对象从session中解绑
        session.removeAttribute("person");
        
        
        
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }
}

3 钝化与活化监听器

4 钝化与活化代码演示

1 自定义Customer 类

必须要实现：implements HttpSessionActivationListener,Serializable这两个接口

package www.test.domian;

import java.io.Serializable;

import javax.servlet.http.HttpSessionActivationListener;
import javax.servlet.http.HttpSessionEvent;

public class Customer implements HttpSessionActivationListener,Serializable{

    private String id;
    private String name;
    
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    
    
    @Override
    //钝化
    public void sessionWillPassivate(HttpSessionEvent se) {
        System.out.println("customer被钝化了");
    }
    @Override
    //活化
    public void sessionDidActivate(HttpSessionEvent se) {
        System.out.println("customer被活化了");
    }
    
    
}

2 TestCustomerActiveServlet  测试钝化

package www.test.domian;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class TestCustomerActiveServlet extends HttpServlet {

    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        
        HttpSession session = request.getSession();
    
        //将customer放到session中
        Customer customer =new Customer();
        customer.setId("200");
        customer.setName("lucy");
        session.setAttribute("customer", customer);
        System.out.println("customer被放到session域中了");
        
        
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }
}

3 TestCustomerActiveServlet2 测试活化

package www.test.domian;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class TestCustomerActiveServlet2 extends HttpServlet {

    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        
        //从session域中获得customer
        HttpSession session = request.getSession();
        Customer customer = (Customer) session.getAttribute("customer");
        
        System.out.println(customer.getName());
        
    }
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }
}

4 配置文件

<?xml version="1.0" encoding="UTF-8"?>
<Context>
    <!-- maxIdleSwap:session中的对象多长时间不使用就钝化 -->
    <!-- directory:钝化后的对象的文件写到磁盘的哪个目录下 配置钝化的对象文件在 work/catalina/localhost/钝化文件 -->
    <Manager className="org.apache.catalina.session.PersistentManager" maxIdleSwap="1">
        <Store className="org.apache.catalina.session.FileStore" directory="webtest23" />
    </Manager>
</Context>