# Hutool: The Java Utility Library That Ships All Its Modules Separately

> Hutool is a MulanPSL-2.0 Java utility library split into roughly twenty modules, from hutool-core to hutool-ai. Its main design tension is between the convenience of hutool-all and the dependency weight of pulling everything at once.

**chinabugotech/hutool** — 🍬A set of tools that keep Java sweet.

- Repository: https://github.com/chinabugotech/hutool
- Website: https://hutool.cn
- Stars: 30,269 · Forks: 7,568
- Language: Java
- License: MulanPSL-2.0
- Published: 2026-09-10 · Updated: 2026-09-10 · Language: en
- Canonical page: https://hysenlabs.com/projects/chinabugotech-hutool

## What Hutool replaces, and who ends up using it

Hutool is a Java utility library. The README describes it as "a set of tools that keep Java sweet" and lists the ground it covers: strings, numbers, collections, encoding, dates, files, IO, encryption, JDBC, JSON and an HTTP client. That list is the point. A Java project that needs to parse a date, read a file into a string, compute a digest and POST some JSON would otherwise pull in several small dependencies or write the same private helper classes again.

The intended user is a Java developer on JDK 8 or newer who wants those helpers behind one consistent API. The project also positions itself as a learning resource. Its stated philosophy is that it is both a toolset and a knowledge base, that most utility classes are collected rather than invented, and that readers may copy and modify the code without marking attribution, with a request to report bugs back. That is an unusual stance for a library and it shapes how you should treat the source: as reference material you are invited to lift from, not only as a binary dependency.

Hutool is not a framework. It does not own your application lifecycle, inject anything, or require a container. You call static methods. That keeps adoption cheap, and it also means Hutool cannot help you structure an application.

## Module layout: hutool-all versus picking individual artifacts

The repository is a multi-module Maven build. Top-level directories map to artifacts: hutool-core, hutool-json, hutool-http, hutool-crypto, hutool-db, hutool-cron, hutool-cache, hutool-captcha, hutool-poi, hutool-socket, hutool-jwt, hutool-ai and others, plus hutool-all and a hutool-bom directory for dependency management.

The README states that each module can be imported on its own, or all of them through hutool-all. This is the decision that matters most at adoption time. hutool-all is the path of least resistance and the one most examples assume, but it drags every module into your classpath, including ones that wrap third-party libraries such as POI. If your build already has a strict dependency policy, or you care about jar size, importing hutool-core and hutool-json alone is the leaner route, and the README explicitly supports it.

The module boundaries are also a rough map of what is inside each artifact, which helps when you are deciding. hutool-http is described as an HttpUrlConnection-based client wrapper, not an abstraction over several HTTP engines. hutool-log is a facade that detects the logging implementation on the classpath. hutool-db is a JDBC wrapper built on ActiveRecord ideas. Each of those is a deliberate choice to stay thin.

## Installing Hutool with Maven or Gradle

The README gives Maven and Gradle coordinates for the current release, 5.8.47. For Maven, add the dependency to the dependencies block of pom.xml. Note the groupId is cn.hutool, not the GitHub organization name.

```xml
<dependency>
    <groupId>cn.hutool</groupId>
    <artifactId>hutool-all</artifactId>
    <version>5.8.47</version>
</dependency>
```

For Gradle, the same artifact is a single implementation line.

```
implementation 'cn.hutool:hutool-all:5.8.47'
```

If you would rather not build from Maven Central, the README also links a direct jar download at repo1.maven.org under cn/hutool/hutool-all/5.8.47/. For source builds, it points to the Gitee project page, where you download the v5-master or v5-dev branch and run the install script from the project directory.

```sh
./hutool.sh install
```

After that, the README says the artifacts are available for Maven to resolve. Two version constraints are stated plainly: Hutool 5.x supports JDK 8 and above, and JDK 7 projects should stay on Hutool 4.x, which the README notes is no longer updated. A first real use is simply calling a static utility, for example a date or string helper from hutool-core, once the dependency resolves and your IDE can see the classes.

## Where Hutool stops being the right dependency

The most concrete limitation is stated by the project itself: Android is not tested, and the README says it cannot guarantee that all utility classes or methods work there. If you ship an Android app, treat Hutool as unverified rather than supported, and test any helper you adopt.

The second limitation is the hutool-all default. It is convenient, but it means a project that only wanted string and date helpers now has a POI wrapper and a socket module on its classpath. That is a real cost in dependency review and in upgrade surface, and it is the reason the per-module artifacts exist.

The third is scope. Hutool's HTTP client is built on HttpUrlConnection, so it is not a drop-in replacement for a client with connection pooling, HTTP/2 and interceptors as first-class features. Its cache module is described as a simple cache implementation, which is a different product from a distributed cache. Its cron module is a scheduler inside your JVM, not a cluster-aware job system. Hutool is at its best as a bag of helpers; when you need operational guarantees, you want a library whose whole purpose is that guarantee.

The fourth is licensing and provenance. The project is explicit that most utility classes are collected from elsewhere and that copying without attribution is acceptable to it. That is generous, but it means you should not assume every method has been independently reviewed for your threat model, particularly in the crypto module. Hutool is a convenience layer, and convenience layers are where subtle security defaults hide.

## Hutool compared with Apache Commons and Guava

The obvious alternatives are Apache Commons and Guava, and the difference is breadth rather than quality. Commons is a family of narrow libraries, each with its own artifact and its own release cycle: commons-lang3 for strings and reflection helpers, commons-io for streams and files, commons-codec for encoding. Guava is a single library with a strong collections core plus utilities and its own opinions about immutable data. Both are long-established, and both are widely reviewed.

Hutool's approach is to consolidate. One project, one version number, roughly twenty modules, and a Chinese-first documentation set with an English README. If you want date handling, file IO, a JSON implementation, a JDBC wrapper and an HTTP client from one coordinate and one upgrade cadence, Hutool does that and the others do not. If you want each concern owned by a specialist library with a narrow API, Commons and Guava fit that model better.

There is also a documentation difference worth weighing. Hutool's primary docs are in Chinese, with an English README-EN.md and a reference API site. If your team cannot read Chinese, you will be relying on the English README, the Javadoc and the source, and the project states that its comments are written to be readable by source learners. That is a genuine mitigation, but it is not the same as complete English prose documentation.

## Maintenance, releases and what the licence asks of you

The repository is not archived, and the last push was on 2026-09-08. Recent releases listed are 5.8.47 on 2026-07-09, v5.8.46 on 2026-05-25 and v5.8.44 on 2026-03-12. That is a steady 5.8.x line rather than a major-version churn, which is what you want from a utility library: patch and minor releases you can take without rewriting call sites.

The branch model matters for contributors and for anyone building from source. The README states that v5-master is the release branch whose contents match the jar published to Maven Central, and that it accepts no pull requests or modifications. v5-dev is the development branch, defaults to the next version as a SNAPSHOT, and is where changes and pull requests go. If you fork and patch, patch against v5-dev, and expect to rebase when the next release lands.

On licensing, Hutool uses MulanPSL-2.0, a Chinese open source licence. The README badge links to the licence text at license.coscl.org.cn. This is a permissive-style licence, but it is not Apache-2.0 or MIT, and its text is not as familiar to many legal reviewers. If your organization runs a licence allowlist, MulanPSL-2.0 needs to be checked against it before you ship, and the project's own statement that you may copy and modify code without attribution is a project norm, not a substitute for reading the licence. Nothing here is legal advice; read the licence text and route it through whoever approves dependencies.

## Conclusion

Hutool fits teams that want JDK 8 compatible helpers for strings, dates, IO, crypto, JSON and HTTP without assembling several small libraries, and it suits codebases that value Chinese comments in dependency source. It is the wrong choice if you need a tested Android target, if you want a single-purpose library with a narrow API surface, or if you object to copying code without attribution being an explicit project stance. Before adopting, verify which modules your project actually needs so you do not ship hutool-all by default, and check the last push date and release cadence against your own upgrade window.

## FAQ

### What is Hutool?

Hutool is a Java utility library covering strings, numbers, collections, encoding, dates, files, IO, encryption, JDBC, JSON and HTTP. It is organized into modules such as hutool-core, hutool-json and hutool-http, which can be imported individually or all at once through hutool-all.

### How do I install Hutool with Maven?

Add cn.hutool:hutool-all with version 5.8.47 to the dependencies block of pom.xml, or use the Gradle line implementation 'cn.hutool:hutool-all:5.8.47'. The README also links a direct jar download from Maven Central.

### Which JDK versions does Hutool support?

The README states that Hutool 5.x supports JDK 8 and above. Projects on JDK 7 are directed to Hutool 4.x, which the README notes is no longer updated.

### Does Hutool work on Android?

The README says Hutool has not been tested on Android and cannot guarantee that all utility classes or methods are usable there. Treat Android support as unverified.

## Sources

- [chinabugotech/hutool on GitHub](https://github.com/chinabugotech/hutool)
- [License: MulanPSL-2.0](https://github.com/chinabugotech/hutool/blob/v5-master/LICENSE)
- [Project website](https://hutool.cn)
- [README](https://github.com/chinabugotech/hutool/blob/v5-master/README.md)
- [Releases](https://github.com/chinabugotech/hutool/releases)

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Hysen Labs editorial analysis, written from the project's own repository and release notes. Cite the canonical page: https://hysenlabs.com/projects/chinabugotech-hutool