Why Hutool Is the Must‑Have Java Utility Library for Faster Coding

What is Hutool?

Hutool is a comprehensive Java utility library that wraps common JDK functionality—such as file operations, streams, encryption/decryption, encoding, regular expressions, threading, and XML processing—into convenient utility classes.

Key modules

hutool-aop : JDK dynamic‑proxy wrapper that provides AOP support without requiring an IoC container.

hutool-bloomFilter : Bloom‑filter implementation with multiple hash algorithms.

hutool-cache : Simple caching utilities.

hutool-core : Core helpers (Bean manipulation, date handling, type conversion, etc.).

hutool-cron : Lightweight cron‑style scheduler that works without external frameworks.

hutool-crypto : Encryption and decryption utilities (MD5, SHA, AES, etc.).

hutool-db : JDBC wrapper based on ActiveRecord concepts.

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

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

hutool-http : HttpClient wrapper built on HttpURLConnection.

hutool-log : Automatic detection of the underlying logging implementation.

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

hutool-setting : Advanced configuration file and Properties handling.

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

hutool-json : JSON parsing and generation helpers.

hutool-captcha : Image‑captcha generation.

Typical usage examples

SecureUtil – MD5 hashing

Generate an MD5 digest for a password or any string: String md5 = SecureUtil.md5(password); Typical login code:

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

HtmlUtil – HTML sanitization

Encode user‑generated text to prevent XSS or SQL injection:

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

Additional useful methods: HtmlUtil.restoreEscaped – restore escaped HTML characters. HtmlUtil.cleanHtmlTag – remove all HTML tags. HtmlUtil.removeHtmlTag – remove a specific tag and its content. HtmlUtil.unwrapHtmlTag – strip a tag but keep inner text. HtmlUtil.removeHtmlAttr – delete attributes from a tag. HtmlUtil.removeAllHtmlAttr – delete all attributes from a tag. HtmlUtil.filter – filter HTML to block XSS payloads.

CronUtil – lightweight scheduling

Define cron expressions directly in code or a properties file. Example expressions that run daily at 01:00:

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 * * ?

Start the scheduler (e.g., in a Spring ContextRefreshedEvent listener):

@Override
public void onApplicationEvent(ContextRefreshedEvent event) {
    // other initialization code …
    CronUtil.start();
    log.info("Scheduled tasks started successfully!");
}

Installation

For Maven projects, add the following dependency to pom.xml:

<dependency>
    <groupId>cn.hutool</groupId>
    <artifactId>hutool-all</artifactId>
    <version>5.3.10</version>
</dependency>

For Gradle projects, use:

compile 'cn.hutool:hutool-all:5.3.10'

Project links

https://github.com/looly/hutool/

https://hutool.cn/