Struts2 + MySql 数据库实现登录

 一、搭建Struts2环境

1.所需Jar包：（需要添加MySql数据库驱动）

         commons-fileupload-1.2.1.jar
         commons-logging-1.0.4.jar
         freemarker-2.3.13.jar
         mysql-connector-java-5.1.6-bin.jar
         ognl-2.6.11.jar
         struts2-core-2.1.6.jar
         xwork-2.1.2.jar
2.配置web.xml

<?xml version="1.0" encoding="gbk"?>
<web-app version="2.5" 
 xmlns="http://java.sun.com/xml/ns/javaee" 
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
 http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
  <welcome-file-list>
    <welcome-file>login.jsp</welcome-file>
  </welcome-file-list>
  <!--编码 -->
  <filter>  
  <filter-name>encodingFilter</filter-name>  
  <filter-class>com.login.filter.EncodingFilter</filter-class>  
 </filter>  
  <filter-mapping>  
  <filter-name>encodingFilter</filter-name>  
  <url-pattern>/*</url-pattern>  
 </filter-mapping>
<!--Struts2拦截器配置-->

     <filter>
        <filter-name>struts2</filter-name>
        <filter-class>
 org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter
 </filter-class>
    </filter>
    <filter-mapping>
        <filter-name>struts2</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

</web-app>

3.Struts.xml配置

 <?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
 <include file="struts-default.xml" />
 <constant name="struts.locale" value="zh_CN"/>
 <constant name="struts.i18n.encoding" value="GBK"/>
 
    <package name="lee" namespace="/" extends="struts-default">
        <action name="login" class="com.loginAction.LoginAction">
            <result name="success">/success.jsp</result>
            <result name="login">/error.jsp</result>
        </action>
    </package>
</struts>

4.创建数据库login，然后在数据库login中创建一个user表，该表有两个字段username和password，字段类型为varchar类型。然后再输入两条记录
 
二、编写Java代码

1.建立一个com.login.filter包，在包下新建一个Java类
package com.login.filter;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
public class EncodingFilter implements Filter {
 public void destroy() {
  // TODO Auto-generated method stub
 }
 public void doFilter(ServletRequest arg0, ServletResponse arg1,
   FilterChain arg2) throws IOException, ServletException {
  // TODO Auto-generated method stub
  arg0.setCharacterEncoding("GBK");
  arg2.doFilter(arg0, arg1);
 }
 public void init(FilterConfig arg0) throws ServletException {
  // TODO Auto-generated method stub
 }
}
2.创建一个com.loginAction包，在该包下新建一个Java类
package com.loginAction;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Statement;
import com.opensymphony.xwork2.ActionSupport;
public class LoginAction extends ActionSupport {
 private String username;
 private String password;
 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 execute(){
  boolean flag=Login(username,password);
  if(flag)
   return SUCCESS;
  else
   return LOGIN;
 }
 
  /*验证登录是否成功*/
 public boolean Login(String username,String password){
  boolean flag=false;
  Connection conn = null;
  ResultSet rs = null;
  Statement stmt = null;
     String DBDriver = "com.mysql.jdbc.Driver";
  try{
   Class.forName(DBDriver);
   conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/login", "root", "root");  
   stmt=conn.createStatement();
   System.out.println("测试连接！");
   System.out.println(username);
   rs = stmt.executeQuery("select * from user where username ='" + username +"' and password = '"+ password+"'");
   if(rs.next()){
    System.out.println("登录成功！");
    flag=true; 
   }
  }catch(Exception e){
   System.out.print("连接错误！");
   e.printStackTrace();
  }
  return flag;
 } 
  
}
 

三、编写页面代码

需要3个页面login.jsp、success.jsp和error.jsp

1.login.jsp页面代码：
<%@ page language="java" import="java.util.*" pageEncoding="gbk"%>

<html>  
  <body>
    <center><h2>
    <form action="login" method="post">
  用户名:<input name="username"/><br/>
  密&nbsp&nbsp码:<input name="password"/><br/>
  <input value="登录" type="submit"><input type="reset" value="取消"/>
 </form>
  </body>
</html> 
2.success.jsp页面代码:
<%@ page language="java" import="java.util.*" pageEncoding="gbk"%>

<html>

  <body>
    <center><h1>登录成功！</h1></center> <br>
  </body>
</html> 
3.error.jsp页面代码：
<%@ page language="java" import="java.util.*" pageEncoding="gbk"%>

<html>

  <body>
    <center><h1>登录失败！</h1> <br>
    <a href="login.jsp">返回登录页面<a/>
  </body>
</html> 
 


四、运行结果

运行项目，实现登录功能。