How to verify whether the image verification code is correct in JAVA
Nov 23, 2019 pm 02:47 PMKnowledge supplement:
toString()
method is used to return a Number object value represented by a string.
equalsIgnoreCase()
The method is used to compare a string with the specified object, regardless of case.
Verification method:
First, you need to obtain the verification code object entered by the user, and then determine whether the verification code is empty. If it is not empty, use the "toString()" method Obtain the "Number" object value represented by the verification code, and finally compare the verification code object value with the specified object to determine whether it is correct.
Sample code:
/** * Author: SamGroves * * Description: 獲得前端輸入驗(yàn)證碼的驗(yàn)證 * * Date: 2017/8/26 */@Controller@RequestMapping("/api")public class VerifyController extends BaseController{ /** * @param checkCode 前端用戶輸入返回的驗(yàn)證碼 * 參數(shù)若需要,自行添加 */ @RequestMapping(value = "/verify") @ResponseBody public String checkcode(HttpServletRequest request, HttpSession session, String checkCode) throws Exception { // 獲得驗(yàn)證碼對(duì)象 Object cko = session.getAttribute("simpleCaptcha"); if (cko == null) { request.setAttribute("errorMsg", "請(qǐng)輸入驗(yàn)證碼!"); return "請(qǐng)輸入驗(yàn)證碼!"; } String captcha = cko.toString(); // 判斷驗(yàn)證碼輸入是否正確 if (StringUtils.isEmpty(checkCode) || captcha == null || !(checkCode.equalsIgnoreCase(captcha))) { request.setAttribute("errorMsg", "驗(yàn)證碼錯(cuò)誤!"); return "驗(yàn)證碼錯(cuò)誤,請(qǐng)重新輸入!"; // 驗(yàn)證碼有效時(shí)長(zhǎng)為1分鐘 Date now = new Date(); Long codeTime = Long.valueOf(session.getAttribute("codeTime") + ""); } else if ((now.getTime() - codeTime) / 1000 / 60 > 1) { request.setAttribute("errorMsg", "驗(yàn)證碼已失效,請(qǐng)重新輸入!"); return "驗(yàn)證碼已失效,請(qǐng)重新輸入!"; } else { // 在這里可以處理自己需要的事務(wù),比如驗(yàn)證登陸等 return "驗(yàn)證通過(guò)!"; } }}
Recommended tutorial: Getting started with java development
The above is the detailed content of How to verify whether the image verification code is correct in JAVA. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undress AI Tool
Undress images for free

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics

The key to writing good comments is to explain "why" rather than just "what was done" to improve the readability of the code. 1. Comments should explain logical reasons, such as considerations behind value selection or processing; 2. Use paragraph annotations for complex logic to summarize the overall idea of functions or algorithms; 3. Regularly maintain comments to ensure consistency with the code, avoid misleading, and delete outdated content if necessary; 4. Synchronously check comments when reviewing the code, and record public logic through documents to reduce the burden of code comments.

The key to writing PHP comments is to clarify the purpose and specifications. Comments should explain "why" rather than "what was done", avoiding redundancy or too simplicity. 1. Use a unified format, such as docblock (/*/) for class and method descriptions to improve readability and tool compatibility; 2. Emphasize the reasons behind the logic, such as why JS jumps need to be output manually; 3. Add an overview description before complex code, describe the process in steps, and help understand the overall idea; 4. Use TODO and FIXME rationally to mark to-do items and problems to facilitate subsequent tracking and collaboration. Good annotations can reduce communication costs and improve code maintenance efficiency.

Comments cannot be careless because they want to explain the reasons for the existence of the code rather than the functions, such as compatibility with old interfaces or third-party restrictions, otherwise people who read the code can only rely on guessing. The areas that must be commented include complex conditional judgments, special error handling logic, and temporary bypass restrictions. A more practical way to write comments is to select single-line comments or block comments based on the scene. Use document block comments to explain parameters and return values at the beginning of functions, classes, and files, and keep comments updated. For complex logic, you can add a line to the previous one to summarize the overall intention. At the same time, do not use comments to seal code, but use version control tools.

The first step is to select the integrated environment package XAMPP or MAMP to build a local server; the second step is to select the appropriate PHP version according to the project needs and configure multiple version switching; the third step is to select VSCode or PhpStorm as the editor and debug with Xdebug; in addition, you need to install Composer, PHP_CodeSniffer, PHPUnit and other tools to assist in development.

The key to writing PHP comments is clear, useful and concise. 1. Comments should explain the intention behind the code rather than just describing the code itself, such as explaining the logical purpose of complex conditional judgments; 2. Add comments to key scenarios such as magic values, old code compatibility, API interfaces, etc. to improve readability; 3. Avoid duplicate code content, keep it concise and specific, and use standard formats such as PHPDoc; 4. Comments should be updated synchronously with the code to ensure accuracy. Good comments should be thought from the perspective of others, reduce the cost of understanding, and become a code understanding navigation device.

There are three common ways to use PHP comments: single-line comments are suitable for briefly explaining code logic, such as // or # for the explanation of the current line; multi-line comments /*...*/ are suitable for detailed description of the functions or classes; document comments DocBlock start with /** to provide prompt information for the IDE. When using it, you should avoid nonsense, keep updating synchronously, and do not use comments to block codes for a long time.

PHP comparison operators need to pay attention to type conversion issues. 1. Use == to compare values only, and type conversion will be performed, such as 1=="1" is true; 2. Use === to require the same value as the type, such as 1==="1" is false; 3. Size comparison can be used on values and strings, such as "apple"

PHP comments are parts of the code that are used to interpret logic, tag tasks, or temporarily block code and are not executed by the server. Its core functions include: 1. Improve the readability of the code, which facilitates quick understanding of others and future self; 2. Supports two formats: single-line comments (// or #) and multi-line comments (//); 3. Common uses cover function descriptions, complex logic explanations, TODO markings and disable code during debugging; 4. Effective comments should avoid duplicate code, explain the reasons rather than operations, keep it concise and add version records where necessary, thereby significantly improving code maintenance efficiency.
