前后端与数据库的交互II
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@page import="java.util.List"%>
<%@page import="longin1.User"%>
<%@page import="longin1.MyJDBCUtil"%>
<%
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 'user.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>
<table>
<caption>用户列表</caption>
<tr><th>qq</th><th>用户名</th><th>密码</th></tr>
<%
List<User> list= MyJDBCUtil.findAllUser();
for (int i = 0; i < list.size(); i++) {
User user = list.get(i);
%>
<tr><td><%=user.getQq() %></td><td><%=user.getUserName() %></td><td><%= user.getPassWord()%></td></tr>
<% }
%>
</table>
</body>
</html>
package longin1;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import com.mysql.jdbc.Connection;
import com.mysql.jdbc.PreparedStatement;
public class MyJDBCUtil {
public static List<User> findAllUser() {
List<User> list = new ArrayList<User>();
try {
Class.forName("com.mysql.jdbc.Driver");
Connection con = (Connection) DriverManager.getConnection(
"jdbc:mysql://localhost:3306/qqzone", "root", "123456");
PreparedStatement ps = (PreparedStatement) con
.prepareStatement("select * from user");
ResultSet res = ps.executeQuery();
while (res.next()) {
User user = new User();
// String username=res.getString("username");
// String password=res.getString("password");
// int qq=res.getInt("qq");
user.setUserName(res.getString("username"));
user.setPassWord(res.getString("password"));
user.setQq(res.getInt("qq"));
list.add(user);
}
con.close();
ps.close();
} catch (Exception e) {
// TODO: handle exception
}
return list;
}
public static User findUserByPas(String userName, String passWord) {
User user = new User();
String sql = "select * from user where username=? and password=?";
try {
Class.forName("com.mysql.jdbc.Driver");
Connection con = (Connection) DriverManager.getConnection(
"jdbc:mysql://localhost:3306/qqzone", "root", "123456");
PreparedStatement preparedStatement = (PreparedStatement) con
.prepareStatement(sql);
preparedStatement.setString(1, userName);
preparedStatement.setString(2, passWord);
ResultSet res = preparedStatement.executeQuery();
while (res.next()) {
user.setUserName(res.getString("username"));
user.setPassWord(res.getString("password"));
user.setQq(res.getInt("qq"));
}
preparedStatement.close();
con.close();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return user;
}
public static void main(String[] args) {
User u = findUserByPas("admin", "123");
System.out.println(u);
}
}
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@page import="java.util.List"%>
<%@page import="longin1.User"%>
<%@page import="longin1.MyJDBCUtil"%>
<%
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 'user.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>
<table>
<caption>用户列表</caption>
<tr><th>qq</th><th>用户名</th><th>密码</th></tr>
<%
List<User> list= MyJDBCUtil.findAllUser();
for (int i = 0; i < list.size(); i++) {
User user = list.get(i);
%>
<tr><td><%=user.getQq() %></td><td><%=user.getUserName() %></td><td><%= user.getPassWord()%></td></tr>
<% }
%>
</table>
</body>
</html>