Ajax simple practical case
This time I will bring you a simple practical case of Ajax. What are the precautions of Ajax in actual combat? The following is a practical case, let's take a look.
I will implement a simple Ajax page user verification case without refreshing:
The effect is as follows:
The main process of implementation:
Receive and verify the form data in the foreground in the checkUser method in the UsersAction class. According to different situations, return a status code code to the jsp page, and then accept the background transmission through the $.post method in ajax1.jsp. The status code
makes different responses.
The specific code is as follows:
1. Entity class
package com.bean;
import java.io.Serializable;
public class Users implements Serializable {
private String uname;
private String passwd;
public String getUname() {
return uname;
}
public void setUname(String uname) {
this.uname = uname;
}
public String getPasswd() {
return passwd;
}
public void setPasswd(String passwd) {
this.passwd = passwd;
}
public Users(String uname, String passwd) {
super();
this.uname = uname;
this.passwd = passwd;
}
public Users() {
super();
}
}2. Action class
package com.action;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts2.ServletActionContext;
import org.apache.struts2.convention.annotation.Action;
import com.bean.Users;
public class UsersAction {
private Users us;
public Users getUs() {
return us;
}
public void setUs(Users us) {
this.us = us;
}
@Action(value="checkUser")
public String checkUser() {
System.out.println("aaaaaaaaa");
HttpServletResponse response = ServletActionContext.getResponse();
response.setCharacterEncoding("utf-8");
try {
PrintWriter out = response.getWriter();
int code = 0;
if (us == null) {
out.print(0);
return null;
} else {
if (us.getUname() == null || us.getUname().trim().equals("")) {
code = 1;
out.print(code);
return null;
} else {
if (us.getPasswd() == null
|| us.getPasswd().trim().equals("")) {
code = 2;
out.print(code);
return null;
} else {
code = 200;
out.print(code);
}
}
}
out.flush();
out.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
}3.ajax1.jsp
<%@ 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%>" rel="external nofollow" >
<title>Ajax练习</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" rel="external nofollow" >
-->
<script type="text/javascript" src="js/jquery-1.9.1.js"></script>
<script>
$(function() {
$("#btok").click(function() {
//获取数据
var uname = $("#uname").val();
var passwd = $("#passwd").val();
//将数据组织为json格式
var json = {"us.uname":uname,"us.passwd":passwd};
//进行异步请求
$.post("checkUser.action",json,function(msg){
if(msg == '0') {
alert("用户名和密码错误！");
return;
}
if(msg == '1') {
$("#uerror").html("用户名错误！");
return;
} else {
$("#uerror").html("*");
}
if(msg == '2') {
$("#perror").html("密码错误！");
return;
} else {
$("#perror").html("*");
}
if(msg == '200') {
alert("登陆成功！");
return;
}
});
});
});
</script>
</head>
<body>
<form name="form1" method="post" action="">
<table width="450" border="1" align="center" cellpadding="1" cellspacing="0">
<tr>
<td colspan="2" align="center" valign="middle" bgcolor="#FFFFCC">用户注册</td>
</tr>
<tr>
<td width="88">账号:</td>
<td width="352"><label for="uname"></label>
<input type="text" name="uname" id="uname">
<span id="uerror" style="color:#F06;">*</span></td>
</tr>
<tr>
<td>密码:</td>
<td><label for="passwd"></label>
<input type="password" name="passwd" id="passwd">
<span id="perror" style="color:#F06;">*</span></td>
</tr>
<tr align="center" valign="middle" bgcolor="#FFFFCC">
<td colspan="2"><input type="button" name="button" id="btok" value="确定">
<input type="reset" name="button2" id="button2" value="重置"></td>
</tr>
</table>
</form>
<br>
</body>
</html>I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the PHP Chinese website!
Recommended reading:
How to use Ajax to dynamically load data
How to use Ajax to implement the progress bar of uploading files Codular
The above is the detailed content of Ajax simple practical case. For more information, please follow other related articles on the PHP Chinese website!
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