java web中表单 与MySQL的连接 以及中文乱码的解决
<span style="font-family:SimHei;font-size:48px;">注意：所有页面编码 如pageEncoding或charset 与数据库 都保持一致 一般为utf-8，如果乱码再将连接数据库的JSP内加入</span>
<span style="font-family:SimHei;font-size:48px;">request.setCharacterEncoding("utf-8");便可解决乱码问题</span>
登陆代码
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'login.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<h1>登录操作</h1>
<hr/>
<form action="login_check.jsp" type="post">
<table border="1">
<tr>
<td colspan="2">用户登录</td>
</tr>
<tr>
<td>登录ID：</td>
<td><input type="text" name="id"></td>
</tr>
<tr>
<td>登录密码：</td>
<td><input type="password" name="password"></td>
</tr>
<tr>
<td colspan="2">
<input type="submit" value="登录">
<input type="reset" value="重置">"
</td>
</tr>
</table>
</form>
</html>
登录检查代码
</pre><pre name="code" class="plain"><pre name="code" class="plain"><%@ page language="java" import="java.util.*,java.sql.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'login_check.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<%!
//定义数据库驱动程序
public static final String DBDRIVER="com.mysql.jdbc.Driver";
public static final String DBURL="jdbc:mysql://localhost:3306/mldn";
public static final String DBUSER="root";
public static final String DBPASS="123456";
%>
<%
Connection conn=null; //声明数据库连接对象\
PreparedStatement pstmt=null; //声明数据库操作
ResultSet rs=null; //声明数据库结果集
boolean flag=false; //定义标志位
String name=null; //接收用户的真实姓名
%>
<%
request.setCharacterEncoding("utf-8"); //防止乱码
try{
Class.forName(DBDRIVER); //加载驱动程序
conn=DriverManager.getConnection(DBURL,DBUSER,DBPASS); //取得数据库连接
//编写要使用的SQL语句，验证用户id和密码，如果正确，则取出真实姓名
String sql="SELECT name FROM user WHERE userid=? AND password=?";
pstmt=conn.prepareStatement(sql); //实例化数据库操作对象
pstmt.setString(1,request.getParameter("id")); //设置查询所需要的内容
pstmt.setString(2,request.getParameter("password")); //设置查询所需要的内容
rs=pstmt.executeQuery(); //执行查询
if(rs.next()){ //如果可以查询得到，则表示合法用户
name=rs.getString(1); //取出真实姓名
flag=true;
}
}catch(Exception e){
System.out.println(e);
}finally{
try{
rs.close();//关闭查询对象
pstmt.close();//关闭操作对象
conn.close();//关闭数据库连接
}catch(Exception e){
}
}
%>
<%
if(flag) { //登陆成功，跳转到成功页
%>
<jsp:forward page="login_success.jsp">
<jsp:param name="uanme" value="<%=name %>"/>
</jsp:forward>
<%
}else{ //登录失败，跳转到失败页
%>
<jsp:forward page="login_failurel.html"/> <!-- 执行跳转操作 -->
<%
}
%>
</body>
</html>
登录成功界面代码
<pre name="code" class="plain"><%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'login_success.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<h1>登录操作</h1>
<h2>登录成功</h2>
<h2>欢迎<font color="red">
<%=request.getParameter("uanme") %> 光临！
</font></h2>
</body>
</html>
</pre><pre name="code" class="plain">
登录失败代码
</pre><pre name="code" class="plain"><pre name="code" class="plain"><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>login_failurel.html</title>
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="this is my page">
<meta http-equiv="content-type" content="text/html; charset=utf-8">
<!--<link rel="stylesheet" type="text/css" href="./styles.css">-->
</head>
<body>
<h1>登录操作</h1>
<h2>登录失败，请重新<a href="login.jsp">登录</a>！</h2>
</body>
</html>
</pre><pre name="code" class="plain">
</pre><pre name="code" class="plain">