search
HomeWeb Front-endJS TutorialDiscussion on Jquery's Ajax asynchronous issues

This article mainly shares with you a discussion on Jquery's Ajax asynchronous issues. It has a good reference value and I hope it will be helpful to everyone. Let’s follow the editor to have a look.

1. $.get(url, [data], [callback], [type]); can only be Asynchronous

2. $.post(url, [data], [callback], [type]); Can only be Asynchronous

#Parameter list:

# url: Represents the server-side address of the request;

                                                                             

                                                                                                                                                                                                                   

## type: Indicates the data type returned by the server (jquery will automatically type conversion according to the specified type),

Commonly used return types: text, json, html, etc.

.

$.ajax({ option1:value1,option2:value2... } )

Commonly used options are as follows:

async: whether to be asynchronous, the default is true, which means asynchronous;

data: parameters sent to the server, it is recommended to use json Format;

dataType: the data type returned by the server, commonly used text and json;

success: successfully responds to the executed function, the corresponding type is the function type;

type : Request method, POST/GET;

URL: Request server-side address.

Let’s do an example demonstration:

AjaxServle.java

package ajax;

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 AjaxServlet extends HttpServlet {

	public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		//响应请求
		//返回参数会json类型的字符串,前端jquery会自动将字符串解析为json对象
		response.getWriter().write("{\"name\":\"Tom\",\"age\":18}");
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doGet(request, response);
	}

}

TestAjax.html

<!DOCTYPE html>
<html>
  <head>
    <title>Jquery的Ajax异同步</title>
    <meta name="content-type" content="text/html; charset=UTF-8">
    <script type="text/javascript" src="jquery-1.11.3.min.js"></script>
    <script>
    
    	//Get异步响应
    	function fn1(){
	    	$.get(
	    		"/WEB/ajaxServlet", //访问的资源地址
	    		{"name":"zhangsan","age":22}, //请求服务器端的参数,可以是json格式 
	    		function(responseData) { //响应成功后执行的函数
					var str="name: "+responseData.name+"; age: "+responseData.age;
	    			document.getElementById("input1").value=str;
	    		}, 
	    		"json" //返回数据的格式
	    		)
    	}
    	
    	//Post异步响应
    	function fn2(){
    		$.post(
	    		"/WEB/ajaxServlet", //访问的资源地址
	    		{"name":"zhangsan","age":22}, //请求服务器端的参数,可以是json格式 
	    		function(responseData) { //响应成功后执行的函数
					var str="name: "+responseData.name+"; age: "+responseData.age;
	    			document.getElementById("input2").value=str;
	    		}, 
	    		"json" //返回数据的格式
	    		)
    	}
    	
    	//Ajax异步响应
    	function fn3(){
    		$.ajax(
    			{
    				url:"/WEB/ajaxServlet", 
    				async:true, // 异步
    				type:"POST", // 请求方式
					data:{"name":"lucy","age":18}, // 请求参数
					success:function(data){ // 请求成功执行函数
						document.getElementById("input3").value="Rose";
					},
					error:function(){
						alert("请求失败"); // 请求失败执行函数
					},
					dataType:"json"
    			}
    		)
    	}
    </script>
  </head>
  
  <body>
	<input type="button" value="Get异步响应" onclick="fn1()"><input type="text" id="input1">
	<br><br>
	<input type="button" value="Post异步响应" onclick="fn2()"><input type="text" id="input2">
	<br><br>
	<input type="button" value="Ajax异步响应" onclick="fn3()"><input type="text" id="input3">
  </body>
</html>
Instance effect 1: When the request is successful


Instance effect 2: Modify fn3 The url of () is "/WEB/ajaxServlet33", so that when the request fails

##

The above is the detailed content of Discussion on Jquery's Ajax asynchronous issues. For more information, please follow other related articles on the PHP Chinese website!

Statement
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
JavaScript in Action: Real-World Examples and ProjectsJavaScript in Action: Real-World Examples and ProjectsApr 19, 2025 am 12:13 AM

JavaScript's application in the real world includes front-end and back-end development. 1) Display front-end applications by building a TODO list application, involving DOM operations and event processing. 2) Build RESTfulAPI through Node.js and Express to demonstrate back-end applications.

JavaScript and the Web: Core Functionality and Use CasesJavaScript and the Web: Core Functionality and Use CasesApr 18, 2025 am 12:19 AM

The main uses of JavaScript in web development include client interaction, form verification and asynchronous communication. 1) Dynamic content update and user interaction through DOM operations; 2) Client verification is carried out before the user submits data to improve the user experience; 3) Refreshless communication with the server is achieved through AJAX technology.

Understanding the JavaScript Engine: Implementation DetailsUnderstanding the JavaScript Engine: Implementation DetailsApr 17, 2025 am 12:05 AM

Understanding how JavaScript engine works internally is important to developers because it helps write more efficient code and understand performance bottlenecks and optimization strategies. 1) The engine's workflow includes three stages: parsing, compiling and execution; 2) During the execution process, the engine will perform dynamic optimization, such as inline cache and hidden classes; 3) Best practices include avoiding global variables, optimizing loops, using const and lets, and avoiding excessive use of closures.

Python vs. JavaScript: The Learning Curve and Ease of UsePython vs. JavaScript: The Learning Curve and Ease of UseApr 16, 2025 am 12:12 AM

Python is more suitable for beginners, with a smooth learning curve and concise syntax; JavaScript is suitable for front-end development, with a steep learning curve and flexible syntax. 1. Python syntax is intuitive and suitable for data science and back-end development. 2. JavaScript is flexible and widely used in front-end and server-side programming.

Python vs. JavaScript: Community, Libraries, and ResourcesPython vs. JavaScript: Community, Libraries, and ResourcesApr 15, 2025 am 12:16 AM

Python and JavaScript have their own advantages and disadvantages in terms of community, libraries and resources. 1) The Python community is friendly and suitable for beginners, but the front-end development resources are not as rich as JavaScript. 2) Python is powerful in data science and machine learning libraries, while JavaScript is better in front-end development libraries and frameworks. 3) Both have rich learning resources, but Python is suitable for starting with official documents, while JavaScript is better with MDNWebDocs. The choice should be based on project needs and personal interests.

From C/C   to JavaScript: How It All WorksFrom C/C to JavaScript: How It All WorksApr 14, 2025 am 12:05 AM

The shift from C/C to JavaScript requires adapting to dynamic typing, garbage collection and asynchronous programming. 1) C/C is a statically typed language that requires manual memory management, while JavaScript is dynamically typed and garbage collection is automatically processed. 2) C/C needs to be compiled into machine code, while JavaScript is an interpreted language. 3) JavaScript introduces concepts such as closures, prototype chains and Promise, which enhances flexibility and asynchronous programming capabilities.

JavaScript Engines: Comparing ImplementationsJavaScript Engines: Comparing ImplementationsApr 13, 2025 am 12:05 AM

Different JavaScript engines have different effects when parsing and executing JavaScript code, because the implementation principles and optimization strategies of each engine differ. 1. Lexical analysis: convert source code into lexical unit. 2. Grammar analysis: Generate an abstract syntax tree. 3. Optimization and compilation: Generate machine code through the JIT compiler. 4. Execute: Run the machine code. V8 engine optimizes through instant compilation and hidden class, SpiderMonkey uses a type inference system, resulting in different performance performance on the same code.

Beyond the Browser: JavaScript in the Real WorldBeyond the Browser: JavaScript in the Real WorldApr 12, 2025 am 12:06 AM

JavaScript's applications in the real world include server-side programming, mobile application development and Internet of Things control: 1. Server-side programming is realized through Node.js, suitable for high concurrent request processing. 2. Mobile application development is carried out through ReactNative and supports cross-platform deployment. 3. Used for IoT device control through Johnny-Five library, suitable for hardware interaction.

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Tools

mPDF

mPDF

mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

VSCode Windows 64-bit Download

VSCode Windows 64-bit Download

A free and powerful IDE editor launched by Microsoft

EditPlus Chinese cracked version

EditPlus Chinese cracked version

Small size, syntax highlighting, does not support code prompt function

MantisBT

MantisBT

Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use