效果展示

项目结构

源码
java
AjaxServlet.java
package servlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.URLDecoder;
public class AjaxServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
this.doPost(req, resp);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOException {
// 设置请求的编码
req.setCharacterEncoding("utf-8");
// 设置响应的编码
resp.setContentType("text/html;charset=utf-8");
// 获取用户名并进行解码
String username = URLDecoder.decode(req.getParameter("username"), "utf-8");
// 获取密码并进行解码
String password = URLDecoder.decode(req.getParameter("password"), "utf-8");
// 输出
String str = username + "的密码是 " + password;
// 控制台输出
System.out.println(str);
// 前台响应输出
PrintWriter out = resp.getWriter();
out.print(str);
out.close();
}
}
web
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
version="2.5">
<!--欢迎页面-->
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<!--AjaxServlet-->
<servlet>
<servlet-name>AjaxServlet</servlet-name>
<servlet-class>servlet.AjaxServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>AjaxServlet</servlet-name>
<url-pattern>/ajaxServlet</url-pattern>
</servlet-mapping>
</web-app>
index.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>ajax</title>
<script type="text/javascript" src="js/jquery.min.js"></script>
</head>
<body>
<form ction="">
用户名: <input name="username" type="text" id="username"/><br>
密码: <input name="password" type="password" id="password"/><br>
<input type="button" value="提交" onclick="ajaxSubmit();">
</form>
<script type="text/javascript" charset="UTF-8">
function ajaxSubmit() {
var username = $("#username").val();
var password = $("#password").val();
// 将数据以JSON的方式传到后端
var jsonData = {"username": username, "password": password};
// "ajaxServlet"指的是后端处理Servlet,jsonData指的是传过去的JSON数据,function(data)指的是返回的数据
$.post("ajaxServlet", {"username": username, "password": password}, function (data) {
// data为返回的数据
alert(data);
});
}
</script>
</body>
</html>