JSP 中 如何使用 Attribute监听 我写的怎么没反应

来源：百度知道 编辑：UC知道 时间：2024/06/19 18:12:19
package chat;

import javax.servlet.*;
import javax.servlet.http.*;
import java.util.*;

public class Chat implements HttpSessionAttributeListener {
private String a="123";

public void attributeAdded(HttpSessionBindingEvent se) {
if("account".equals(se.getName())){
a="attributeAdded";
}
}

public void attributeRemoved(HttpSessionBindingEvent se) {
if("account".equals(se.getName())){
a="attributeRemoved";
}
}

public void attributeReplaced(HttpSessionBindingEvent se){
if("account".equals(se.getName())){
a="attributeReplaced";
}
}

public String getmessage(){
return a;
}

}

<%
session.setAttribute("account","qwe");
String getmessage=chat.getmessage();
out.println(getmessage);
%>

你所写的Attribute监听是不是在用的时候要去用方法去掉用他啊

package book.form;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.*;

public class MainForm extends JFrame{
private Container con;
private JButton addBook,addSort,queryBook;

public MainForm(){
super("主窗口");
con=this.getContentPane();
con.setLayout(new FlowLayout());

Myaction ma=new Myaction();

addBook=new JButton("添加图书");
addSort=new JButton("添加分类");
queryBook=new JButton("查询图书");
addBook.addActionListener(ma);
addSort.addActionListener(ma);
queryBook.addActionListener(ma);

con.add(addBook);
con.add(addSort);
con.add(queryBook);

this.pack();
Toolkit tool=Toolkit.getDefaultToolkit();
this.setLocation(tool.getScreenResolution()*3,