Unlock Faster Java Development with Hutool: A Comprehensive Guide

Hutool is a comprehensive Java utility library that provides a wide range of ready‑to‑use tools to simplify development and avoid reinventing the wheel.

Features

tool-aop: JDK dynamic proxy wrapper for aspect support without IoC.

hutool-bloomFilter: Bloom filter implementation with various hash algorithms.

hutool-cache: Caching utilities.

hutool-core: Core utilities including Bean operations, date handling, and common helpers.

hutool-cron: Cron‑like scheduling module.

hutool-crypto: Encryption and decryption utilities.

hutool-db: JDBC wrapper based on ActiveRecord.

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

hutool-extra: Extensions for third‑party integrations such as template engines and mail.

hutool-http: Http client built on HttpUrlConnection.

hutool-log: Automatic detection of logging implementations.

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

hutool-setting: Advanced configuration file and Properties handling.

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

hutool-json: JSON utilities.

hutool-captcha: Image captcha generation.

Installation

Add the following dependency to your Maven pom.xml:

<dependency>
    <groupId>cn.hutool</groupId>
    <artifactId>hutool-all</artifactId>
    <version>4.6.3</version>
</dependency>

Simple Usage Examples

DateUtil – common date‑time operations:

// Convert between Date, long, Calendar
Date date = DateUtil.date();
date = DateUtil.date(Calendar.getInstance());
date = DateUtil.date(System.currentTimeMillis());

// Parse and format
String dateStr = "2017-03-01";
date = DateUtil.parse(dateStr);
date = DateUtil.parse(dateStr, "yyyy-MM-dd");
String format = DateUtil.format(date, "yyyy-MM-dd");

// Get components
int year = DateUtil.year(date);
int month = DateUtil.month(date);
Date beginOfDay = DateUtil.beginOfDay(date);
Date endOfDay = DateUtil.endOfDay(date);
Date newDate = DateUtil.offset(date, DateField.DAY_OF_MONTH, 2);
long betweenDay = DateUtil.between(date, newDate, DateUnit.DAY);

StrUtil – string utilities:

String str = "test";
boolean empty = StrUtil.isEmpty(str);
String noSuffix = StrUtil.removeSuffix("a.jpg", ".jpg");
String formatted = StrUtil.format("This is a placeholder: {}", "value");

NumberUtil – numeric operations:

double result = NumberUtil.add(1.234, 1.234);
BigDecimal rounded = NumberUtil.round(1.234, 2);
boolean isNum = NumberUtil.isNumber("1.234");

MapUtil – map creation and checks:

Map<Object, Object> map = MapUtil.of(new String[][]{
    {"key1", "value1"},
    {"key2", "value2"},
    {"key3", "value3"}
});
boolean empty = MapUtil.isEmpty(map);

SecureUtil – MD5 hashing:

String md5 = SecureUtil.md5("123456");

CaptchaUtil – generate image captcha:

LineCaptcha lineCaptcha = CaptchaUtil.createLineCaptcha(200, 100);
request.getSession().setAttribute("CAPTCHA_KEY", lineCaptcha.getCode());
response.setContentType("image/png");
lineCaptcha.write(response.getOutputStream());

For a full list of Hutool utilities, visit the official site: https://www.hutool.cn/