Introduction to Hutool: A Comprehensive Java Utility Library

Hutool is an open‑source Java utility library that provides a wide range of helper classes for common tasks such as file I/O, encryption, regular expressions, threading, XML handling, and more.

Features

hutool-aop: JDK dynamic proxy wrapper offering AOP support without an IoC container.

hutool-bloomFilter: Bloom filter implementation with various hash algorithms.

hutool-cache: Caching utilities.

hutool-core: Core utilities including Bean operations, date handling, and general helpers.

hutool-cron: Cron‑style scheduling without external frameworks.

hutool-crypto: Encryption and decryption utilities.

hutool-db: JDBC wrapper based on ActiveRecord concepts.

hutool-dfa: Multi‑keyword search based on DFA model.

hutool-extra: Extensions for third‑party integrations (template engines, mail, etc.).

hutool-http: HttpClient wrapper built on HttpUrlConnection.

hutool-log: Automatic detection of logging implementations.

hutool-script: Script execution utilities (e.g., JavaScript).

hutool-setting: Advanced configuration file handling.

hutool-system: System parameter utilities (JVM info, etc.).

hutool-json: JSON processing utilities.

hutool-captcha: Image captcha generation.

Simple Tests

SecureUtil (Encryption/Decryption)

Used for MD5 hashing of passwords during login and password change operations.

user = userService.userLoginByName(loginName, SecureUtil.md5(loginPwd));

HtmlUtil (HTML Processing)

HtmlUtil.encode converts characters to safe HTML entities, preventing XSS and SQL injection.

comment.setCommentAuthor(HtmlUtil.encode(comment.getCommentAuthor()));

Additional HtmlUtil methods include restoreEscaped, cleanHtmlTag, removeHtmlTag, unwrapHtmlTag, removeHtmlAttr, removeAllHtmlAttr, and filter for XSS protection.

CronUtil (Scheduling)

CronUtil enables cron‑style tasks without external dependencies; a simple configuration file under resources activates tasks such as daily backups.

cc.ryanc.halo.web.controller.admin.BackupController.backupResources = 0 0 1 * * ?
cc.ryanc.halo.web.controller.admin.BackupController.backupDatabase = 0 0 1 * * ?
cc.ryanc.halo.web.controller.admin.BackupController.backupPosts = 0 0 1 * * ?
@Override
public void onApplicationEvent(ContextRefreshedEvent event){
    this.loadActiveTheme();
    this.loadOptions();
    this.loadFiles();
    this.loadThemes();
    // Start scheduled tasks
    CronUtil.start();
    log.info("定时任务启动成功！");
}

For full documentation, visit http://hutool.mydoc.io/?t=255673 . The official website is http://www.hutool.cn/ .

Overall, Hutool offers a rich set of utilities that can greatly simplify Java development, making it a valuable addition to any backend project.