What should I do if the jquery $.post method does not execute?-JS Tutorial-php.cn

Home

Web Front-end

JS Tutorial

What should I do if the jquery $.post method does not execute?

coldplay.xixi

Nov 25, 2020 pm 03:54 PM

jquery

The solution to the problem that the jquery $.post method is not executed: Set the returned data to json data, and the code is [out.print(JSONObject.fromObject(result));].

What should I do if the jquery $.post method does not execute?

The operating environment of this tutorial: windows7 system, jquery3.2.1 version. This method is suitable for all brands of computers.

Solution to the problem that the jquery $.post method does not execute:

About the problem that JQuery’s post callback function does not execute

The front-end post callback function is No execution, after setting the breakpoint debug or directly skip the execution

Error demonstration:

Background code

@RequestMapping(value = "login")
public void CheckUserAccount(@RequestParam("account")String account, HttpServletResponse response) throws IOException{
JSONObject json_account = JSONObject.fromObject(account);
int username = (Integer)json_account.get("username");
String password = json_account.getString("password");
logger.info("username = " + username + " password = " + password);
int status;
status = checkUserAccountService.IsCorrect(username, password);
Map<String, Object> result = new HashMap<String, Object>();
Map<String, String> info_json = new HashMap<String, String>();
if(status == 1){
info_json.put("status", "success");
}else if(status == 0){
info_json.put("status", "errorpassword");
}else{
info_json.put("status", "noexitaccount");
}
result.put("info", info_json);
JSONObject json_object = JSONObject.fromObject(result);
response.setContentType("text/json; charset=utf-8");
response.setHeader("Cache-Control", "no-cache");
PrintWriter out = response.getWriter();
out.print(result);
out.flush();
out.close();
logger.info("验证结果是" + ((Map<String, String>)(result.get("info"))).get("status"));

The key sentence is:

response.setContentType("text/json; charset=utf-8");

The data returned here is set to json data, but out.print(result);The output here is A Map, so the front end cannot recognize any data. As a result, the callback function is skipped and not executed (because the callback function only executes json data)

Correct demonstration:

Change to: out .print(JSONObject.fromObject(result));

is fine.

Related free learning recommendations: javascript (video)

The above is the detailed content of What should I do if the jquery $.post method does not execute?. 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 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 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 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 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 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 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 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.

Building a Multi-Tenant SaaS Application with Next.js (Backend Integration)Apr 11, 2025 am 08:23 AM

I built a functional multi-tenant SaaS application (an EdTech app) with your everyday tech tool and you can do the same. First, what’s a multi-tenant SaaS application? Multi-tenant SaaS applications let you serve multiple customers from a sing

See all articles