jquery $.post

jquery $.post

大家好,又见面了,我是全栈君。

jQuery.post()


jQuery.post( url [, data ] [, success ] [, dataType ] )Returns:jqXHR

Description: Load data from the server using a HTTP POST request.

  • version added:1.0jQuery.post( url [, data ] [, success ] [, dataType ] )

    • url
      Type: String
      A string containing the URL to which the request is sent.
    • //解释一下:URL是必选的參数,其余參数可选。URL是request请求的路径。

    • data
      A plain object or string that is sent to the server with the request.
    • //解释一下:data是浏览器通过request请求向server发送一些參数。这个參数的类型能够是字符串类型。也但是plainObject类(感觉和Java中Object差点儿相同)。
    • success
      Type: Function( Object data,String textStatus,jqXHR jqXHR )
      A callback function that is executed if the request succeeds. Required ifdataType is provided, but can benull in that case.
    • //解释一下:success是request请求成功后触发的回调函数。

    • dataType
      Type: String
      The type of data expected from the server. Default: Intelligent Guess (xml, json, script, text, html).
    • //解释一下:dataType是从server返回的类型,能够是XML、json、script、text、HTML。

This is a shorthand Ajax function, which is equivalent to:

1
2
3
4
5
6
7
        
        
$.ajax({
type: "POST",
url: url,
data: data,
success: success,
dataType: dataType
});

The success callback function is passed the returned data, which will be an XML root element or a text string depending on the MIME type of the response. It is also passed the text status of the response.

//解释一下:上面的$.post能够用$.ajax来替代。

As of jQuery 1.5, the success callback function is also passed a“jqXHR” object (injQuery 1.4, it was passed the XMLHttpRequest object).

Most implementations will specify a success handler:

1
2
3
        
        
$.post( "ajax/test.html", function( data ) {
$( ".result" ).html( data );
});

This example fetches the requested HTML snippet and inserts it on the page.

Pages fetched with POST are never cached, so thecache andifModified options in jQuery.ajaxSetup() have no effect on these requests.

//解释一下:自从jQuery1.5后是用的jqXHR 对象,而曾经的版本号是用的XMLHttpRequest对象。通过post方法获取的数据不会缓存。

The jqXHR Object

As of jQuery 1.5, all of jQuery’s Ajax methods return a superset of theXMLHTTPRequest object. This jQuery XHR object, or “jqXHR,” returned by$.get() implements the Promise interface, giving it all the properties, methods, and behavior of a Promise (seeDeferred object for more information). ThejqXHR.done() (for success),jqXHR.fail() (for error), andjqXHR.always() (for completion, whether success or error) methods take a function argument that is called when the request terminates. For information about the arguments this function receives, see thejqXHR Object section of the $.ajax() documentation.

The Promise interface also allows jQuery’s Ajax methods, including$.get(), to chain multiple.done(), .fail(), and.always() callbacks on a single request, and even to assign these callbacks after the request may have completed. If the request is already complete, the callback is fired immediately.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
        
        
// Assign handlers immediately after making the request,
// and remember the jqxhr object for this request
var jqxhr = $.post( "example.php", function() {
alert( "success" );
})
.done(function() {
alert( "second success" );
})
.fail(function() {
alert( "error" );
})
.always(function() {
alert( "finished" );
});
// Perform other work here ...
// Set another completion function for the request above
jqxhr.always(function() {
alert( "second finished" );
});

//解释一下:向example.php发送请求假设成功就弹出success,假设发送两次都成功了。就弹出second success;假设失败,弹出error。假设完毕,弹出finished等。这里的done就是请求成功后运行的函数。fail就是请求失败后运行的函数。always就是不管请求成功还是失败都要运行的函数。

Deprecation Notice

The jqXHR.success(), jqXHR.error(), andjqXHR.complete() callback methods introduced in jQuery 1.5 aredeprecated as of jQuery 1.8. To prepare your code for their eventual removal, usejqXHR.done(),jqXHR.fail(), and jqXHR.always() instead.

//解释一下:success、error和complete方法是在jQuery1.5中出现的。如今不推荐使用,推荐用done、fail、always来取代这些函数。

Additional Notes:

  • Due to browser security restrictions, most “Ajax” requests are subject to thesame origin policy; the request can not successfully retrieve data from a different domain, subdomain, port, or protocol.
  • If a request with jQuery.post() returns an error code, it will fail silently unless the script has also called the global.ajaxError()method. Alternatively, as of jQuery 1.5, the.error() method of thejqXHR object returned by jQuery.post() is also available for error handling.
  • //解释一下:因为浏览器的安全策略,来自不同的域,子域、port和协议时,获取数据可能不成功。

Examples:

Example: Request the test.php page, but ignore the return results.

1
        
        
$.post( "test.php" );

Example: Request the test.php page and send some additional data along (while still ignoring the return results).

1
        
        
$.post( "test.php", { name: "John", time: "2pm" } );

Example: Pass arrays of data to the server (while still ignoring the return results).

1
        
        
$.post( "test.php", { 'choices[]': [ "Jon", "Susan" ] } );

Example: Send form data using ajax requests

1
        
        
$.post( "test.php", $( "#testform" ).serialize() );

Example: Alert the results from requesting test.php (HTML or XML, depending on what was returned).

1
2
3
        
        
$.post( "test.php", function( data ) {
alert( "Data Loaded: " + data );
});

Example: Alert the results from requesting test.php with an additional payload of data (HTML or XML, depending on what was returned).

1
2
3
4
        
        
$.post( "test.php", { name: "John", time: "2pm" })
.done(function( data ) {
alert( "Data Loaded: " + data );
});

Example: Post to the test.php page and get content which has been returned in json format (<?php echo json_encode(array(“name”=>”John”,”time”=>”2pm”)); ?>).

1
2
3
4
        
        
$.post( "test.php", { func: "getNameAndTime" }, function( data ) {
console.log( data.name ); // John
console.log( data.time ); // 2pm
}, "json");

//解释一下:上面是post方法的一些简单举例,涉及的东西还是上面讲到的。

Example: Post a form using ajax and put results in a div

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
            
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>jQuery.post demo</title>
<script src="//code.jquery.com/jquery-1.10.2.js"></script>
</head>
<body>
<form action="/" id="searchForm">
<input type="text" name="s" placeholder="Search...">
<input type="submit" value="Search">
</form>
<!-- the result of the search will be rendered inside this div -->
<div id="result"></div>
<script>
// Attach a submit handler to the form
$( "#searchForm" ).submit(function( event ) {
// Stop form from submitting normally
event.preventDefault();
// Get some values from elements on the page:
var $form = $( this ),
term = $form.find( "input[name='s']" ).val(),
url = $form.attr( "action" );
// Send the data using post
var posting = $.post( url, { s: term } );
// Put the results in a div
posting.done(function( data ) {
var content = $( data ).find( "#content" );
$( "#result" ).empty().append( content );
});
});
</script>
</body>
</html> //解释一下:post的一个实例,这里仅仅给出了前台页面的jQuery实现。

以下是我写的一个简单的实例(Struts+jQuery实现):

所需jar包:

jquery $.post

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_3_0.xsd" id="WebApp_ID" version="3.0"> <display-name>ajax</display-name> <welcome-file-list> <welcome-file>index.html</welcome-file> <welcome-file>index.htm</welcome-file> <welcome-file>index.jsp</welcome-file> <welcome-file>default.html</welcome-file> <welcome-file>default.htm</welcome-file> <welcome-file>default.jsp</welcome-file> </welcome-file-list> <filter> <filter-name>struts2</filter-name> <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class> </filter> <filter-mapping> <filter-name>struts2</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> </web-app>

struts.xml:

<?xml version="1.0" encoding="UTF-8" ?>  
<!DOCTYPE struts PUBLIC  
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"  
    "http://struts.apache.org/dtds/struts-2.0.dtd">  
  
<struts>  
  
    <package name="ajax" extends="json-default" namespace="/">  
        <action name="ajaxLogin" class="action.AjaxLoginAction" method="execute">  
            <result type="json">  
                <param name="root">result</param>  
            </result>  
        </action>  
    </package>  
  
</struts>  

前台页面(index.jsp):

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
	<head>
		<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
		<title>ajax</title>
		<script type="text/javascript" src="js/jquery1.11.1.js">
		</script>
		<script type="text/javascript">
			$(document).ready(function(){
				$("#btn_login").click(function(){
					$.ajax({
	                    type:"post",
	                    url:"ajaxLogin",//须要用来处理ajax请求的action
	                    dataType:"json",//设置须要返回的数据类型
	                    data:{
	                    	loginName:$("#loginName").val(),
							loginPwd:$("#loginPwd").val()
	                    },
	                    success:function(data){
	                        var d = eval("("+data+")");//将数据转换成json类型,能够把data用alert()输出出来看看究竟是什么样的结构
	                        //得到的d是一个形如{"key":"value","key1":"value1"}的数据类型,然后取值出来
	                         
	                        $("#result").html("ajax"+d.name+" "+d.pwd);
	                         
	                    },
	                    error:function(){
	                        alert("系统异常,请稍后重试!");
	                        $("#result").html("ajax error");
	                    }//这里不要加","
	                });
	            });
				$("#btn_post").click(function(){
					var params = {loginName:$("#loginName").val(),
							loginPwd:$("#loginPwd").val()};
					$.post(
	                    "ajaxLogin",//须要用来处理ajax请求的action
	                    params,
	                    function s(data){
	                        var d = eval("("+data+")");//将数据转换成json类型,能够把data用alert()输出出来看看究竟是什么样的结构
	                        //得到的d是一个形如{"key":"value","key1":"value1"}的数据类型。然后取值出来
	                         
	                        $("#result").html("ajax"+d.name+" "+d.pwd);
	                    }
	                );
	            });
			});
		</script>
	</head>
	<body>
      	<span>username:</span>  
        <input type="text" id="loginName" name="loginName">  
        <br />  
  
        <span>密码:</span>  
        <input type="password" name="loginPwd" id="loginPwd">  
        <br />  
  
        <input type="button" id="btn_login" value="Login" />  
        <input type="button" id="btn_post" value="post" />  
        <p>  
                                    这里显示ajax信息:  
            <br />  
            <span id="result"></span>  
        </p>  
</body>
</html>

Action代码:

package action;

import java.util.HashMap;
import java.util.Map;

import net.sf.json.JSONObject;

import com.opensymphony.xwork2.ActionSupport;

public class AjaxLoginAction extends ActionSupport
{
	private static final long serialVersionUID = 1L;
	
	private String result;
	private String loginName;
	private String loginPwd;
	
	public String getResult()
	{
		return result;
	}
	public void setResult(String result)
	{
		this.result = result;
	}
	public String getLoginName()
	{
		return loginName;
	}
	public void setLoginName(String loginName)
	{
		this.loginName = loginName;
	}
	public String getLoginPwd()
	{
		return loginPwd;
	}
	public void setLoginPwd(String loginPwd)
	{
		this.loginPwd = loginPwd;
	}
	
	public String execute()
	{
		Map<String, String> map = new HashMap<String, String>();
		map.put("name", this.loginName);
		map.put("pwd", this.loginPwd);
		JSONObject jo = JSONObject.fromObject(map);
		this.result = jo.toString();
		System.out.println("==============================");
		System.out.println(result);
		System.out.println("==============================");
		
		return SUCCESS;
	}
	
}

//解释一下:这里实现了post和Ajax两种方法的实现。大家能够对照一下。 如有错误,请指出!

谢谢!

版权声明:本文内容由互联网用户自发贡献,该文观点仅代表作者本人。本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容, 请联系我们举报,一经查实,本站将立刻删除。

发布者:全栈程序员-站长,转载请注明出处:https://javaforall.net/116164.html原文链接:https://javaforall.net

(0)
全栈程序员-站长的头像全栈程序员-站长


相关推荐

  • restful api接口规范和服务调用的区别_rest接口规范

    restful api接口规范和服务调用的区别_rest接口规范RESTful发展背景及简介网络应用程序,分为前端和后端两个部分。当前的发展趋势,就是前端设备层出不穷(手机、平板、桌面电脑、其他专用设备…)。因此,必须有一种统一的机制,方便不同的前端设备与后端进行通信。这导致API构架的流行,甚至出现"APIFirst"的设计思想。RESTfulAPI是目前比较成熟的一套互联网应用程序的API设计理论。REST(RepresentationalStat…

    2022年9月18日
    0
  • 手机游戏开发综述[通俗易懂]

    手机游戏开发综述[通俗易懂]一、背景介绍  现在的移动电话是小型的计算机,它的处理能力与台式机的标准处理能力相比很有限,但是足够运行一个小型的游戏。  现在的手机的一个特性就是它们还是网络计算机,能够高速发送和接收数字数据。除了语音数据以外,它们还可以发送和接收其它类型的数据。所以类似《传奇》、《千年》这样的网络游戏也可以在手机上实现。当然就处理能力和性能而言,当前阶段的支持Java的手机很接近第二代控制台游戏机、80年

    2022年6月7日
    36
  • 微信公众号网页开发和小程序开发之路哪个好_如何制作微信公众号

    微信公众号网页开发和小程序开发之路哪个好_如何制作微信公众号在微信公众号网页和小程序开发的过程中,难免会遇到一些知识外的兼容问题。在此记录我所遇到的问题,以便给需要的前端开发者查阅。

    2022年10月12日
    0
  • oracle 主键删除,联合主键的创建

    oracle 主键删除,联合主键的创建

    2021年12月9日
    49
  • Python:Python学习总结

    Python:Python学习总结背景PHP的$和->让人输入的手疼(PHP确实非常简洁和强大,适合WEB编程),Ruby的#、@、@@也好不到哪里(OO人员最该学习的一门语言)。Python应该是写起来最舒服的动态语言了,一下

    2022年7月6日
    19
  • 使用TinyXML读写xml文件

    使用TinyXML读写xml文件1、TinyXML  引用网上的原话:TinyXML是目前非常流行的一款基于DOM模型的XML解析器,简单易用且小巧玲珑,非常适合存储简单数据,配置文件,对象序列化等数据量不是很大的操作。支持对XML的读取和修改,不直接支持XPath,需要借助另一个相关的类库TinyXPath才可以支持XPath。  TinyXML源码是使用C++语言编写的,这对于C++应用来说是很好

    2022年6月3日
    40

发表回复

您的邮箱地址不会被公开。 必填项已用 * 标注

关注全栈程序员社区公众号