Hutool: 39 ~repack~

Understanding Hutool 5.8.39: The Java Utility Library That Keeps Code Sweet

For Java developers, boilerplate code is a constant enemy. Whether it's handling date formats, managing file I/O, or making HTTP requests, the standard JDK often requires several lines of code for tasks that feel like they should take one. This is where Hutool steps in.

As of its recent stable release, Hutool 5.8.39 (released June 2025) continues to serve as a comprehensive "Swiss Army Knife" for Java development. By encapsulating complex logic into simple static methods, it reduces the cost of learning APIs and makes Java feel as elegant as a functional language. What’s New in Hutool 5.8.39?

The 5.8.39 update introduces several modern features and performance optimizations designed to keep pace with evolving developer needs. 1. Enhanced AI Integration

Perhaps the most notable addition in this version is the expansion of the 【ai】 module.

SSE Streaming Support: Added a callback parameter for Server-Sent Events (SSE) streaming returns, allowing for real-time data flow in AI applications.

New Model Support: Added text-to-image interfaces for Doubao and Grok, and video generation support for Doubao.

Platform Launch: The introduction of the HutoolAI platform provides a unified gateway for accessing various AI capabilities directly within your Java projects. 2. Core Utility Improvements

The core library received several practical updates focused on data privacy and reliability:

Passport Desensitization: The DesensitizedUtil now includes a method specifically for desensitizing passport numbers, aiding in GDPR and data privacy compliance.

Collection Assertions: New methods in the Assert class allow for cleaner code when asserting that a given collection is empty.

Performance: Optimizations to XXXToMapCopier provide faster bean-to-map conversions. 3. Database and Network Enhancements

Global FetchSize: Developers can now set a global FetchSize in the db module, providing better control over memory usage during large database queries.

Flexible HTTP Requests: HttpConfig now includes setIgnoreContentLength, allowing the client to ignore the content-length header when reading responses—useful for certain non-standard API behaviors. Why Use Hutool?

Hutool is designed to replace the messy util packages found in most projects. It is organized into modular components, so you only need to import what you use. hutool-core hutool 39

The foundation; includes tool classes for strings, dates, collections, and reflection. hutool-http

A simple HTTP client that simplifies requests and file uploads. hutool-crypto

Easy-to-use encryption and decryption for various algorithms. hutool-db

A JDBC wrapper that uses the ActiveRecord pattern to simplify SQL operations. hutool-json A lightweight JSON parser and generator. Getting Started with 5.8.39

To use the full suite of tools in your project, add the following dependency to your pom.xml from Maven Central:

cn.hutool hutool-all 5.8.39 Use code with caution. For Gradle users: implementation 'cn.hutool:hutool-all:5.8.39' Use code with caution.

By upgrading to Hutool 5.8.39, you gain access to a more robust, AI-ready toolkit that minimizes bugs by using pre-tested, high-quality community-driven code. Central Repository: cn/hutool/hutool-system/5.8.39

Central Repository: cn/hutool/hutool-system/5.8. 39. cn/hutool/hutool-system/5.8.39. ../ hutool-system-5.8.39-javadoc.jar 2025-06- hutool/README-EN.md at v5-master - GitHub

D. `HttpUtil` (HTTP Client)

A lightweight HTTP client wrapper (doesn't require Apache HttpClient dependencies).

import cn.hutool.http.HttpUtil;
import cn.hutool.json.JSONUtil;
// 1. Simple GET Request
String response = HttpUtil.get("https://api.github.com/users/hutool");
// 2. Simple POST Request
String postResult = HttpUtil.post("https://httpbin.org/post", "param1=value1");
// 3. Download File
long size = HttpUtil.downloadFile("https://example.com/file.zip", FileUtil.file("dest.zip"));

A Note on Versioning

Hutool 3.9 is not the latest version (as of subsequent releases, 5.x is current). However, 3.9 remains in use on legacy JDK 8 projects that value API stability over new features. For new projects, consider Hutool 5.x; for maintenance of existing systems, 3.9 is a battle-tested choice.

Part 3: Real-World Example (Using 10 of the 39 Methods)

Let’s combine multiple methods from the “Hutool 39” set to build a user import script:

public class UserImporter {
    public static void main(String[] args) {
        // #10, #11: Create and read a file
        FileUtil.touch("users.csv");
        String csvContent = FileUtil.readUtf8String("users.csv");
    // #32: Parse CSV
    CsvReader reader = CsvUtil.getReader();
    List<CsvRow> rows = reader.read(StrUtil.getReader(csvContent));
// #6, #7: Collection handling
    List<User> users = CollUtil.newArrayList();
    for (CsvRow row : rows) 
        if (CollUtil.isEmpty(row)) continue;
// #1: Safe conversion
        String name = Convert.toStr(row.get(0), "Anonymous");
        String birthStr = row.get(1);
// #19, #22: Date parsing and age calculation
        DateTime birth = DateUtil.parse(birthStr);
        int age = DateUtil.ageOfNow(birth);
// #36: Unique ID
        String userId = IdUtil.fastSimpleUUID();
User u = new User(userId, name, age);
        users.add(u);
// #30: Bean copy to DTO
    List<UserDTO> dtos = CollUtil.newArrayList();
    for (User u : users) 
        UserDTO dto = new UserDTO();
        BeanUtil.copyProperties(u, dto);
        dtos.add(dto);
// #18: Notification via embedded server (simulated)
    HttpUtil.post("http://localhost:8080/api/import", BeanUtil.beanToMap(dtos));
System.out.println(StrUtil.format("Imported {} users", users.size()));
}

}

This 20-line script replaces nearly 150 lines of traditional Java with BufferedReader, SimpleDateFormat, try-catch-finally, and manual JSON serialization. Understanding Hutool 5

Why Not Just Use Java 8+ Features?

Java 8 added Files.readAllLines, HttpClient (in 11), and java.time.
True – but:

HttpClient didn’t exist until Java 11
Files methods throw checked exceptions everywhere
java.time is great but verbose for simple “add 1 day to Date”
Hutool 3.9 works from Java 8 upwards

Hutool gives you one import, one method call, zero checked exceptions (usually).

A. `StrUtil` (String Tool)

Replaces Apache Commons Lang StringUtils.

import cn.hutool.core.util.StrUtil;
// 1. Null-safe checks
boolean isEmpty = StrUtil.isEmpty(str); 
boolean isBlank = StrUtil.isBlank(str); // Checks for null, empty, or whitespace only
// 2. Formatting (Uses {} placeholder, similar to SLF4J)
String template = "Hello, {}! Welcome to {}.";
String result = StrUtil.format(template, "User", "Hutool Guide");
// Output: "Hello, User! Welcome to Hutool Guide."
// 3. Substring
String sub = StrUtil.sub("Hutool Guide", 2, 5); // "tool"

8. Useful Cheat Sheet

| Task | Hutool Method | | :--- | :--- | | Check Empty String | StrUtil.isEmpty(str) / StrUtil.isBlank(str) | | Format String | StrUtil.format("Hi {}", name) | | Get Current Date | DateUtil.date() | | Read File | FileUtil.readUtf8String(file) | | HTTP Get | HttpUtil.get(url) | | JSON Parse | JSONUtil.parseObj(str) | | MD5 Hash | DigestUtil.md5Hex(str) | | Random ID | IdUtil.simpleUUID() |

This guide covers the essentials for the modern Hutool library. You can explore the official documentation (available in Chinese and English) for more advanced features like Excel processing (hutool-poi) and Database operations (hutool-db).

is a maintenance release of the popular Java utility library, published on June 20, 2025

. It focuses on expanding AI integration, improving core performance, and adding practical utility methods. 🤖 AI & SSE Enhancements SSE Support parameter to Server-Sent Events (SSE) streaming functions. Timeout Config : New configuration options for stream timeouts. New Interfaces : Added "Text-to-Image" (文生图) support for Video Generation : Added model support for Doubao video generation. HutoolAI Platform

: Introduction of a dedicated platform module for AI operations. 🛠️ Core & Utility Updates Desensitization DesensitizedUtil now includes a method for passport number Performance : Optimized the XXXToMapCopier for faster object-to-map conversions. Assertions

methods to verify if a collection is empty, including new unit tests. : Introduced RecyclableBatchThreadPoolExecutor for handling recyclable batch tasks. 🌐 HTTP & Database HTTP Config setIgnoreContentLength parameter to optionally ignore response length headers. now supports global settings to optimize large query performance. ⚠️ Security & Compatibility Vulnerability Checks : As of this release, tools like CVE Details

monitor this version for potential security issues; always check the latest security advisories before deployment. JDK Support : Version 5.x requires Maven Central : Available under the group ID hutool-all Full library bundle hutool-core Basic tools (Array, String, Date, etc.) hutool-http Client-side HTTP requests JDBC wrapper & SQL execution If you're using an older version, would you like a migration guide dependency snippet cn.hutool:hutool-extra 5.8.39 vulnerabilities | Snyk

Hutool 3.9: A Comprehensive PHP Framework for Efficient Development

Hutool 3.9 is the latest version of the widely-used PHP development framework, Hutool. This framework has been a favorite among PHP developers for its simplicity, flexibility, and extensive feature set. With Hutool 3.9, developers can build robust, scalable, and maintainable applications with ease.

Key Features of Hutool 3.9

Modular Design: Hutool 3.9 follows a modular design approach, allowing developers to easily organize and structure their code. This makes it simple to maintain and extend the framework.
Improved Performance: The latest version of Hutool boasts improved performance, with optimized database operations and caching mechanisms.
Enhanced Security: Hutool 3.9 includes a range of security features, such as input validation, CSRF protection, and secure password hashing.
Expanded Database Support: The framework supports a wide range of databases, including MySQL, PostgreSQL, MongoDB, and more.
Robust API Support: Hutool 3.9 provides a comprehensive set of APIs for building RESTful APIs and web services.

What's New in Hutool 3.9?

Support for PHP 8: Hutool 3.9 is compatible with PHP 8, ensuring that developers can take advantage of the latest PHP features.
Improved Routing: The framework's routing system has been enhanced, making it easier to define and manage routes.
Enhanced Debugging Tools: Hutool 3.9 includes improved debugging tools, making it easier for developers to identify and fix issues.

Benefits of Using Hutool 3.9

Faster Development: Hutool 3.9's extensive feature set and modular design enable developers to build applications quickly and efficiently.
Improved Maintainability: The framework's structure and organization make it easy to maintain and extend applications.
Scalability: Hutool 3.9 is designed to handle large volumes of traffic and can scale to meet the needs of growing applications.

In conclusion, Hutool 3.9 is a powerful and feature-rich PHP framework that is well-suited for building a wide range of applications. Its modular design, improved performance, and enhanced security features make it an excellent choice for developers. Whether you're building a small web application or a large-scale enterprise system, Hutool 3.9 is definitely worth considering.

"Hutool 39" most likely refers to Hutool version 5.8.39, a recent stable release of the popular Chinese open-source Java tool library. Hutool is designed to simplify Java development by providing a comprehensive set of static utility methods, often referred to as the "Swiss Army Knife" for Java. Overview of Hutool 5.8.39

Released on June 23, 2025, version 5.8.39 is part of the mature 5.x branch. This version is widely used in enterprise applications to replace repetitive "util" classes, allowing developers to focus on business logic.

Goal: To make Java "sweet" by providing functional-style elegance and reducing the learning curve for complex APIs.

Compatibility: Supports JDK 8 and above. For legacy projects using JDK 7, developers are advised to use the older Hutool 4.x branch. Key Modules & Capabilities

Hutool is modular, meaning you can import the entire library (hutool-all) or specific components based on your needs: hutool-core Core utilities for collections, strings, beans, and dates. hutool-http A lightweight HTTP client for making web requests. hutool-crypto

Simplified encapsulation for symmetric, asymmetric, and digest algorithms. hutool-json Tools for JSON parsing and creation. hutool-extra

Third-party wrappers for things like mail, templates, and QR codes. Recent Security Context

While version 5.8.39 is a stable release, it has been noted in security databases like Snyk and CVE Details to monitor for potential vulnerabilities. Common issues addressed in recent versions of libraries like Hutool often include:

Insecure Expression Evaluation: Risks associated with expression engines (like QLExpress) that could lead to remote code execution.

Dependency Management: Ensuring that third-party integrations (e.g., Jackson or Netty) are updated to avoid inherited security flaws. hutool-all » 5.8.39 - Maven Repository

23-Jun-2025 — Hutool All » 5.8. 39. Hutool是一个小而全的Java工具类库，通过静态方法封装，降低相关API的学习成本，提高工作效率，使Java拥有函数式语言般的优雅，让Java语言也可以“甜甜的”。 Maven Repository hutool/README-EN.md at v5-master - GitHub

If you meant version 3.9 specifically (not 4.x or 5.x), this post highlights the features that made that release line so popular. A Note on Versioning Hutool 3