Hutool 3.9 | 2025 |

Hutool 3.9 — Key changes, upgrade notes, and quick migration guide

In the landscape of Java enterprise development, boilerplate code and repetitive utility implementation remain significant hurdles to rapid application development. While Apache Commons and Google Guava provide robust solutions, they often introduce complex dependency trees or steep learning curves for simple tasks. This paper introduces Hutool 3.9, a comprehensive, lightweight utility library designed to encapsulate common Java operations into a coherent, developer-friendly API. We analyze the architectural improvements introduced in version 3.9, specifically focusing on the stabilization of the HttpUtil client, enhanced encryption utilities, and the modular design philosophy. Comparative analysis suggests that Hutool 3.9 significantly reduces code verbosity and improves maintenance efficiency in standard web applications. Hutool 3.9

import cn.hutool.core.util.StrUtil;
public class StringExample 
    public static void main(String[] args) 
        String text = "   Hello, World!   ";
String trimmedText = StrUtil.trim(text);
        System.out.println("Trimmed text: " + trimmedText);
String[] splitText = StrUtil.split(text, ",");
        System.out.println("Split text: " + splitText);

Upgrading is painless. If you are using Maven or Gradle: Hutool 3

Maven:

<dependency>
    <groupId>cn.hutool</groupId>
    <artifactId>hutool-all</artifactId>
    <version>3.9.0</version>
</dependency>

Gradle:

implementation 'cn.hutool:hutool-all:3.9.0'

Note: There are no breaking changes in the public API between 3.8 and 3.9. You can drop in the new JAR and recompile. The only “gotcha” is that some deprecated methods (mostly from 3.1) were finally removed—check your logs for warnings. Changed return types or method signatures: check compile