function check(){ var username = $("#username").val(); var password = $("#password").val(); var checkcode = $("#checkcode").val(); $.ajax({ url:"${pageContext.request.contextPath}/come/tologin", type: 'POST', // data: {username: username, password: password,checkcode:checkcode}, dataType: 'JSON', success: function(result) { if (result.success) {// 登录成功,跳转到首页 alert(result.message); window.location.href = "${pageContext.request.contextPath}/come/login"; } else { alert(result.message); window.location.href = "${pageContext.request.contextPath}/User/login.jsp"; } }, error:function (){ } })里面的result是什么,怎么导入
时间: 2024-04-01 09:37:54 浏览: 156
在这段代码中,result是从服务器返回的JSON格式的数据。当ajax请求成功时,服务器会返回一个JSON对象,其中包含了success和message属性。如果success为true,表示登录成功,此时可以通过result.message获取成功的提示信息,然后跳转到首页;如果success为false,表示登录失败,此时可以通过result.message获取失败的提示信息,然后跳转回登录页面。
在这段代码中,result是通过ajax中的success回调函数的参数来获取的。当ajax请求成功时,success回调函数会被执行,此时result参数就是从服务器返回的JSON格式的数据。在这个例子中,dataType被设置为JSON,所以jQuery会自动将从服务器返回的数据解析成JSON对象。
相关问题
function check(){ var username=$("#username").val(); var password=$("#password").val(); if(username==""||password==""){ $("#message").text("账号或密码不能为空!"); return false; } return true; }
这是一个JavaScript函数,其功能是检查用户输入的账号和密码是否为空。如果其中一个为空,则会在页面上显示一条提示信息,并返回false;否则返回true。
具体来说,函数首先通过jQuery的$()方法获取了页面上id为username和password的两个输入框的值,并分别赋给了变量username和password。然后使用if语句判断这两个变量是否为空,如果其中一个为空,则使用jQuery的text()方法将id为message的元素的文本内容设置为“账号或密码不能为空!”,并返回false;否则直接返回true。
根据以下要求写出具体代码:1、基于AJAX技术,在用户注册时,校验用户名是否在数据已存在数据库中。 1)若存在,点击登录按钮,在用户登录页面login.html,完成登录系统操作; 2)若不存在,点击注册按钮,进入注册页面 ,并在register.html页面完成注册。 设计思路: 1.视图层:register.html、login.html。 2.Servlet层: 1)LoginServlet.java //1. 获取到请求中的参数; //2. 和数据库中的内容进行比较; //3. 如果比较通过,创建会话,返回响应状态码; 2)RegisterServlet.java //1.获取请求用户名、密码等; //2.通过用户名查询对象; //3.将注册的用户信息插入数据库 3. Model层如何处理数据: 1)针对用户表的操作UserDao.Java 2)Javabean:User.java 3)jdbc数据库连接:JdbcUtil.java
以下是一个基于AJAX技术的用户注册和登录系统的代码示例:
register.html
```
<!DOCTYPE html>
<html>
<head>
<title>用户注册</title>
<script src="https://cdn.bootcdn.net/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script>
function checkUser() {
var username = $("#username").val();
$.ajax({
url: "checkUser",
type: "POST",
data: {username: username},
dataType: "json",
success: function(data) {
if (data.exist) {
alert("该用户名已存在,请直接登录!");
location.href = "login.html";
} else {
location.href = "register.html";
}
},
error: function() {
alert("服务器出错!");
}
});
}
</script>
</head>
<body>
<h1>用户注册</h1>
<form action="register" method="POST">
<label for="username">用户名:</label>
<input type="text" id="username" name="username">
<br><br>
<label for="password">密码:</label>
<input type="password" id="password" name="password">
<br><br>
<input type="button" value="检查用户名" onclick="checkUser()">
<input type="submit" value="注册">
</form>
</body>
</html>
```
login.html
```
<!DOCTYPE html>
<html>
<head>
<title>用户登录</title>
</head>
<body>
<h1>用户登录</h1>
<form action="login" method="POST">
<label for="username">用户名:</label>
<input type="text" id="username" name="username">
<br><br>
<label for="password">密码:</label>
<input type="password" id="password" name="password">
<br><br>
<input type="submit" value="登录">
</form>
</body>
</html>
```
LoginServlet.java
```
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
public class LoginServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String username = request.getParameter("username");
String password = request.getParameter("password");
UserDao userDao = new UserDao();
User user = userDao.queryByUsername(username);
if (user != null && user.getPassword().equals(password)) {
HttpSession session = request.getSession();
session.setAttribute("user", user);
response.setStatus(200);
} else {
response.sendError(401);
}
}
}
```
RegisterServlet.java
```
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class RegisterServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String username = request.getParameter("username");
String password = request.getParameter("password");
UserDao userDao = new UserDao();
User user = userDao.queryByUsername(username);
if (user != null) {
response.sendError(400);
} else {
userDao.addUser(new User(username, password));
response.setStatus(200);
}
}
}
```
UserDao.java
```
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class UserDao {
public User queryByUsername(String username) {
Connection conn = null;
PreparedStatement stmt = null;
ResultSet rs = null;
User user = null;
try {
conn = JdbcUtil.getConnection();
stmt = conn.prepareStatement("SELECT * FROM user WHERE username = ?");
stmt.setString(1, username);
rs = stmt.executeQuery();
if (rs.next()) {
user = new User(rs.getInt("id"), rs.getString("username"), rs.getString("password"));
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
JdbcUtil.close(rs, stmt, conn);
}
return user;
}
public void addUser(User user) {
Connection conn = null;
PreparedStatement stmt = null;
try {
conn = JdbcUtil.getConnection();
stmt = conn.prepareStatement("INSERT INTO user(username, password) VALUES (?, ?)");
stmt.setString(1, user.getUsername());
stmt.setString(2, user.getPassword());
stmt.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
} finally {
JdbcUtil.close(stmt, conn);
}
}
}
```
User.java
```
public class User {
private int id;
private String username;
private String password;
public User(int id, String username, String password) {
this.id = id;
this.username = username;
this.password = password;
}
public User(String username, String password) {
this.username = username;
this.password = password;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
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;
}
}
```
JdbcUtil.java
```
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class JdbcUtil {
private static String url = "jdbc:mysql://localhost:3306/dbname";
private static String user = "username";
private static String password = "password";
static {
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
public static Connection getConnection() throws SQLException {
return DriverManager.getConnection(url, user, password);
}
public static void close(ResultSet rs, PreparedStatement stmt, Connection conn) {
try {
if (rs != null) {
rs.close();
}
if (stmt != null) {
stmt.close();
}
if (conn != null) {
conn.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
public static void close(PreparedStatement stmt, Connection conn) {
try {
if (stmt != null) {
stmt.close();
}
if (conn != null) {
conn.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
```
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