Web 基础20 Filter 入门案例一 ~ 统一全站的编码 （一）

1.1 首先使用普通方法进行

1.1.1 顺便说一下案例环境

  这里我直接使用的是上次Session登录注销的案例用jsp改写的所以我这就直接放代码了不进行说明了。。。对不起

• 数据准备

package com.itbear.domain;

public class User {
    private String name;
    private String password;
    public User() {
        super();
        // TODO Auto-generated constructor stub
    }
    public User(String name, String password) {
        super();
        this.name = name;
        this.password = password;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    @Override
    public String toString() {
        return "User [name=" + name + ", password=" + password + "]";
    }
    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        result = prime * result
                + ((password == null) ? 0 : password.hashCode());
        return result;
    }
    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        User other = (User) obj;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        if (password == null) {
            if (other.password != null)
                return false;
        } else if (!password.equals(other.password))
            return false;
        return true;
    }
    
    
}

package com.itbear.domain;

import java.util.ArrayList;
import java.util.List;

public class UseDB {
    private static List users = new ArrayList();
    
    static {
        users.add(new User("itcast","123456"));
        users.add(new User("itheima","123456"));
        users.add(new User("zhangsan","123456"));
    }
    
    public static List getUsers(){
        return users;
    }
    
}

• 首页

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>







    
这里是小熊先生的个人主页
    
        
            
先完成登录
            登录
        
        
            
登录完成
            登出
        
    
    
    很重要的资源

• 登录页面

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>







    

        用户名
        密码
        
    

• 登录Servlet

package com.itbear.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import com.itbear.domain.UseDB;
import com.itbear.domain.User;

public class LoginServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
    
    public LoginServlet() {
        super();
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String name = request.getParameter("name");
        String pwd = request.getParameter("password");
        PrintWriter out = response.getWriter();
        
        User user = new User(name, pwd);
        
        List users = UseDB.getUsers();
        boolean flag = users.contains(user);
        if(flag){
            out.println("登录成功，3秒后跳转");
            response.setHeader("Refresh", "3;URL=index.jsp");
            HttpSession session = request.getSession();
            session.setAttribute("user", user);
        }else{
            
            out.println("登录失败，3秒后跳转");
            response.setHeader("Refresh", "3;URL=login.jsp");
        }
    }

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

}

• 注销Servlet

package com.itbear.domain;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 * Servlet implementation class LoginOut
 */
public class LoginOut extends HttpServlet {
    private static final long serialVersionUID = 1L;
       
    public LoginOut() {
        super();
       
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
        PrintWriter out = response.getWriter();
        
        HttpSession session = request.getSession();
        session.invalidate();
        out.println("注销完成");
        response.setHeader("Refresh", "3;URL=/mySession/index.jsp");
        
        
    }

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

}

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