与session中的绑定的对象相关的监听器（对象感知监听器）

淡淡的烟草味﹌ 2022-04-08 11:48 185阅读 0赞

当用户很多的时候，怎么对服务器进行优化？

这里介绍session的钝化与活化！

钝化状态：是将session内存中的对象持久化（序列化）到磁盘

活化状态：就是将磁盘上的对象再次恢复到session内存中

Customer实体类

实现 HttpSessionActivationListener,Serializable

关于实现Serializable接口 ：当对象被序列化到磁盘中的时候需要实现此接口

package domain;
    
    import java.io.Serializable;
    
    import javax.servlet.http.HttpSessionActivationListener;
    import javax.servlet.http.HttpSessionEvent;
    
    public class Customer implements HttpSessionActivationListener,Serializable{
    
    	private int id;
    	private String username;
    	private String password;
    	private String realname;
    	private String birthday;
    	private String email;
    	public int getId() {
    		return id;
    	}
    	public void setId(int id) {
    		this.id = id;
    	}
    	public String getUsername() {
    		return username;
    	}
    	public void setUsername(String username) {
    		this.username = username;
    	}
    	public String getPassword() {
    		return password;
    	}
    	public void setPassword(String password) {
    		this.password = password;
    	}
    	public String getRealname() {
    		return realname;
    	}
    	public void setRealname(String realname) {
    		this.realname = realname;
    	}
    	public String getBirthday() {
    		return birthday;
    	}
    	public void setBirthday(String birthday) {
    		this.birthday = birthday;
    	}
    	public String getEmail() {
    		return email;
    	}
    	public void setEmail(String email) {
    		this.email = email;
    	}
    	@Override
    	public String toString() {
    		return "Customer [id=" + id + ", username=" + username + ", password=" + password + ", realname=" + realname
    				+ ", birthday=" + birthday + ", email=" + email + "]";
    	}
    	@Override
    	public void sessionDidActivate(HttpSessionEvent arg0) {
    		System.out.println("活化。。。。");
    	}
    	@Override
    	public void sessionWillPassivate(HttpSessionEvent arg0) {
    		System.out.println("钝化....");
    	}
    	
    	
    	
    }

servlet ：Active1

HttpSession session = request.getSession();
    Customer c =(Customer) session.getAttribute("customer");
    System.out.println(c.toString());

servlet ：Active2

HttpSession session = request.getSession();
    Customer customer = new Customer();
    customer.setBirthday("2018-02-26");
    customer.setEmail("jack@jack.com");
    customer.setPassword("123");
    customer.setRealname("jack");
    customer.setUsername("jack123");
    session.setAttribute("customer", customer);
    System.out.println("set OK");

context.xml

![20181213175955507.png][]

<?xml version="1.0" encoding="UTF-8"?>
    <Context>
    	
    	
    	<Manager className="org.apache.catalina.session.PersistentManager" maxIdleSwap="1">
    		<Store className="org.apache.catalina.session.FileStore" directory="jack" />
    	</Manager>
    </Context>

1.启动tomcat   访问Avtive1  然后关闭tomcat

![20181213180522701.png][]

![20181213180534670.png][]  
查看此文件夹，发现 设置的jack文件夹

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNTY2Nzcy_size_16_color_FFFFFF_t_70][]

![2018121318061661.png][]

此时开启tomcat   访问Active2

![20181213180705351.png][]

[20181213175955507.png]: /images/20220405/2b532a7a34d948608069033a6e1546dc.png
[20181213180522701.png]: /images/20220405/ef912380918a46019c2bc0bdbb1983de.png
[20181213180534670.png]: /images/20220405/c14773def87343bbb20f4c9e97131c95.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNTY2Nzcy_size_16_color_FFFFFF_t_70]: /images/20220405/95b785dddb434a9fa604fa29c715adf7.png
[2018121318061661.png]: /images/20220405/326d87653caf4ec2a4b2e6e9a4b1e515.png
[20181213180705351.png]: /images/20220405/2003fc51fb554f14a75e20b62ac1a917.png