jsp语言代码示例（jsp程序设计代码）
更新：2022-11-14 19:00
本文目录一览：
需要一个可以运行的JSP简单代码？
<%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%>
<%
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 'index.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>
This is my JSP page. <br>
</body>
</html>
用文字语言描述下列JSP代码意思
我给你写上注释吧 （1）
// 注册驱动
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver").newInstance();
// 根据url获得数据库连接
Connection con = DriverManager.getConnection("jdbc:odbc:internet"," ", " ");
// 用连接创建Statement对象
Statement stmt = con.createStatement();
// 获取表单content内容,或者url传来的content参数内容
String content = request.getParameter("content");
// 将content转码为GBK编码
content = new String(content.getBytes("ISO-8859-1"), "GBK");
// 创建日期格式化对象
java.text.DateFormat df = new java.text.SimpleDateFormat("yyyy-MM-dd HH:mm");
// 获得当前电脑时间
java.util.Date date = new java.util.Date();
// 将日期格式化为字符串,格式为:yyyy-MM-dd HH:mm
String datestr = df.format(date);
// 将datestr转码为GBK编码
datestr = new String(datestr.getBytes("ISO-8859-1"), "GBK");
String msg = "您在留言成功。";
// 创建查询sql语句
String sql2 = "select count(*) from liuyan_temp";
// 查询liuyan_temp表中所有数据的条数
ResultSet rs = stmt.executeQuery(sql2);
int i = 0;
// 遍历结果集
while (rs.next())
i = rs.getInt(1); // 获得liuyan_temp表记录条数
i = i + 1;
（2）
try {
// 注册驱动
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
} catch (ClassNotFoundException e) { // 捕获类未找到异常
out.print(e); // 在jsp页面打印异常信息
}
try {
// 创建url信息
String url = "jdbc:odbc:internet";
// 获得数据库连接
conn = DriverManager.getConnection(url, " ", " ");
// 根据sql语句创建PrepareStatement
ps = conn.prepareStatement("select * from shipin");
// 执行查询,返回结果集
result = ps.executeQuery();
// 遍历结果集
while (result.next()) {
// ...
}
}
（3）
try {
// 注册驱动
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
} catch(ClassNotFoundException cnfe) { // 捕获类未找到异常
out.println(cnfe); // 打印异常
}
try {
String url = "jdbc:odbc:internet";
// 创建数据库连接
conn = DriverManager.getConnection(url,"","");
// 根据sql语句创建PrepareStatement
psSelect = conn.prepareStatement("select * from userInformation where userID=?");
// 为sql语句中第一个问号设置值
psSelect.setString(1,userID);
// 执行查询,返回结果集
result = psSelect.executeQuery();
// 判断,如果结果集中有查询结果
if(result.next()) {
%>
<tr>
<!-- 输出结果集当前行第一个字段的值 -->
<td><%=result.getString(1) %></td>
<!-- 输出结果集当前行第二个字段的值 -->
<td><%=result.getString(2) %></td>
</tr>
<%
} else {
// 打印JavaScript信息
out.println("<script>alert('查询错误，请重新输入！')");
// 浏览器的页面url指向manageUser.jsp页面(javascript方法)
out.println("window.navigate('manageUser.jsp')</script>");
}
%>
jsp登陆界面源代码
1. login.jsp文件
<%@ page language="java" contentType="text/html; charset=GB18030"
pageEncoding="GB18030"%>
<%@ page import="java.util.*" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>登录页面</title>
</head>
<body>
<form name="loginForm" method="post" action="judgeUser.jsp">
<table>
<tr>
<td>用户名:<input type="text" name="userName" id="userName"/></td>
</tr>
<tr>
<td>密码:<input type="password" name="password" id="password"/></td>
</tr>
<tr>
<td><input type="submit" value="登录" style="background-color:pink" />
<input type="reset" value="重置" style="background-color:red"/></td>
</tr>
</table>
</form>
</body>
</html>
2. judge.jsp文件
<%@ page language="java" contentType="text/html; charset=GB18030"
pageEncoding="GB18030"%>
<%@ page import="java.util.*" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>身份验证</title>
</head>
<body>
<%
request.setCharacterEncoding("GB18030");
String name = request.getParameter("userName");
String password = request.getParameter("password");
if(name.equals("abc") && password.equals("123")) {
%>
<jsp:forward page="afterLogin.jsp">
<jsp:param name="userName" value="<%=name%>"/>
</jsp:forward>
<%
} else {
%>
<jsp:forward page="login.jsp"/>
<%
}
%>
</body>
</html>
3. afterLogin.jsp文件
<%@ page language="java" contentType="text/html; charset=GB18030"
pageEncoding="GB18030"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>登录成功</title>
</head>
<body>
<%
request.setCharacterEncoding("GB18030");
String name = request.getParameter("userName");
out.println("欢迎你:" + name);
%>
</body>
</html>
扩展资料：
java web登录界面源代码：
1. Data_uil.java文件
import java.sql.*;
public class Data_uil {
public Connection getConnection() {
try {
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
} catch(ClassNotFoundException e) {
e.printStackTrace();
}
String user="***";
String password="***";
String url="jdbc:sqlserver://127.0.0.1:1433;DatabaseName=***";
Connection con = null;
try {
con = DriverManager.getConnection(url, user, password);
} catch(SQLException e) {
e.printStackTrace();
}
return con;
}
public String selectPassword(String username) {
Connection connection = getConnection();
String sql = "select * from login where username=?";
PreparedStatement preparedStatement = null;
ResultSet result = null;
String password = null;
try {
preparedStatement = connection.prepareStatement(sql);
preparedStatement.setString(1, username);
result = preparedStatement.executeQuery();
if(result.next())
password = result.getString("password");
} catch(SQLException e) {
e.printStackTrace();
} finally {
close(preparedStatement);
close(result);
close(connection);
}
System.out.println("找到的数据库密码为：" + password);
return password;
}
public void close(Connection con) {
try {
if(con != null) {
con.close();
}
} catch(SQLException e) {
e.printStackTrace();
}
}
public void close(PreparedStatement preparedStatement) {
try {
if(preparedStatement != null) {
preparedStatement.close();
}
} catch(SQLException e) {
e.printStackTrace();
}
}
public void close(ResultSet resultSet) {
try {
if(resultSet != null) {
resultSet.close();
}
} catch(SQLException e) {
e.printStackTrace();
}
}
}
2. login_check.jsp文件
<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>验证用户密码</title>
</head>
<body>
<jsp:useBean id="util" class="util.Data_uil" scope="page" />
<%
String username = (String)request.getParameter("username");
String password = (String)request.getParameter("password");
if(username == null || "".equals(username)) {
out.print("<script language='javaScript'> alert('用户名不能为空'); </script>");
response.setHeader("refresh", "0;url=user_login.jsp");
} else {
System.out.println("输入的用户名:" + username);
String passwordInDataBase = util.selectPassword(username);
System.out.println("密码：" + passwordInDataBase);
if(passwordInDataBase == null || "".equals(passwordInDataBase)) {
out.print("<script language='javaScript'> alert('用户名不存在'); </script>");
response.setHeader("refresh", "0;url=user_login.jsp");
} else if(passwordInDataBase.equals(password)) {
out.print("<script language='javaScript'> alert('登录成功'); </script>");
response.setHeader("refresh", "0;url=loginSucces.jsp");
} else {
out.print("<script language='javaScript'> alert('密码错误'); </script>");
response.setHeader("refresh", "0;url=user_login.jsp");
}
}
%>
</body>
</html>
3. loginSucces.jsp文件
<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<hr size="10" width="26%" align="left" color="green">
<font size="6" color="red">登录成功</font>
<hr size="10" width="26%" align="left" color="green">
</body>
</html>
4. user_login.jsp文件
<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>登录界面</title>
</head>
<body background="C:\Users\win8\workspace\Login\image\9dcbdc339e72a5663b5c289fb5573c13_10.jpg">
<center>
<br><br><br><br><br><br>
<h1 style="color:yellow">Login</h1>
<br>
<form name="loginForm" action="login_check.jsp" method="post">
<table Border="0">
<tr>
<td>账号</td>
<td><input type="text" name="username"/></td>
</tr>
<tr>
<td>密码</td>
<td><input type="password" name="password"></td>
</tr>
</table>
<br>
<input type="submit" value="登录" style="color:#BC8F8F"/>
</form>
</center>
</body>
</html>
求大神写一下jsp的简单的注册界面代码。
1. 需要一个jsp页面：
<!-- login.jsp核心代码 -->
<form action="${pageContext.request.contextPath}/servlet/UserServlet" method="post">
<input type="text" name="loginname" />
<input type="password" name="password"/>
<input type="submit" value="登录"/>
</form>
2. 需要一个servlet来验证登录信息
// UserServlet 核心代码
class UserServlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
process(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
process(request, response);
}
private void process(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
PrintWriter pw = response.getWriter();
request.setCharacterEncoding("UTF-8");
response.setContentType("text/html");
String loginname = request.getParameter("loginname");
String password = request.getParameter("password");
// 创建一个service来处理业务逻辑（包括查询数据库操作）
UserService service = new UserService();
boolean bool = service.validateUser(loginname, password);
if(!bool) {
pw.println("用户名或密码错误");
} else {
pw.println("登录成功");
}
}
}
3. 需要一个service处理业务逻辑（包括查询数据库操作）
// UserService 核心代码
public class UserService {
/**
* 查询数据库验证用户是否存在，返回boolean
*/
public boolean validateUser(String loginname, String password) {
boolean bool = false;
Connection conn = null;
PreparedStatement ps = null;
// 这里以mysql为例
try {
Class.forName("com.mysql.jdbc.Driver").newInstance();
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "");
String sql = "select login_name,pass_word from t_user where login_name=? and pass_word=?";
ps = conn.prepareStatement(sql);
ps.setString(0, loginname);
ps.setString(1, password);
ResultSet rs = ps.executeQuery();
if(rs.next()) {
bool = true;
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if(conn != null) {
conn.close();
conn = null;
}
if(ps != null) {
ps.close();
ps = null;
}
} catch (SQLException e) {
e.printStackTrace();
}
}
return bool;
}
}
