: Concise methods for filtering and transforming lists and sets.
Most modules (excluding the extra package) follow a "no-dependency" principle, meaning you can drop them into projects without bloating your classpath with third-party libraries.
If you are looking to migrate from 3.x to the latest 5.x version, or need specific examples of how to replace boilerplate code, let me know! Hutool 3.9
Simplistic HTTP client replacing Apache HttpClient / HttpURLConnection Data serialization
When you do not want to pull in heavy third-party HTTP clients, HttpUtil offers a fluent, built-in alternative. : Concise methods for filtering and transforming lists
: Wrapping complex native Java APIs into easy-to-use static methods.
Before the java.time package was popularized, Java's Date and Calendar APIs were notoriously difficult to work with. Hutool provides seamless date formatting, parsing (automatically guessing date formats), and delta calculations (e.g., finding the number of days between two dates). 4. File and Stream Operations ( FileUtil ) Core Utilities ( hutool-core )
A common question is how Hutool 3.9 compares against native language upgrades and rival toolkits.
: Includes safe methods to copy, move, delete, and read files. It abstracts away the stream lifecycle entirely.
// 5. HTTP Requests: Simple GET request String url = "https://www.example.com"; String result = HttpUtil.get(url); System.out.println("HTTP GET response length: " + result.length());
Hutool is not a monolithic giant; it is a carefully organized ecosystem of highly specialized modules. In version 3.9, these modules are structured to cover almost every standard API bottleneck in Java SE. 1. Core Utilities ( hutool-core )