Is Hutool Worth Using? A Deep Dive into Java’s Popular Utility Library

Is Hutool Worth Using?

The discussion about whether Hutool is worth using is hot on Zhihu; some argue its code quality is lacking, while others claim it greatly improves development efficiency because writing similar utility classes or using AI is more cumbersome.

What do you think?

Below is an answer from a senior engineer that I find practical and realistic.

For personal projects, just use it without much consideration.

For enterprise projects, consider stability and compatibility; Apache or Guava can be alternatives, but if functionality is the priority, Hutool is recommended.

Hutool Introduction

Hutool is a comprehensive Chinese Java utility library that wraps JDK methods for files, streams, encryption/decryption, encoding, regex, threading, XML, and more, providing out‑of‑the‑box functionality.

You can import the whole library with hutool-all, but it is recommended to include only the modules you actually need.

Many functions in Hutool are simple implementations (e.g., image captcha, Excel utilities) that may not satisfy complex project requirements; in such cases, consider specialized libraries like MyExcel, EasyExcel, or Imglib.

Hutool Practical Use

Adding Dependencies

Maven repository: https://mvnrepository.com/artifact/cn.hutool

<dependency>
    <groupId>cn.hutool</groupId>
    <artifactId>hutool-all</artifactId>
    <version>5.8.16</version>
</dependency>

Gradle:

implementation 'cn.hutool:hutool-all:5.8.16'

For a more elegant approach, use the hutool-bom module:

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-bom</artifactId>
            <version>${hutool.version}</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

In sub‑modules, import only the needed modules:

<dependencies>
    <dependency>
        <groupId>cn.hutool</groupId>
        <artifactId>hutool-http</artifactId>
    </dependency>
</dependencies>

Feature Demonstrations

Type Conversion

The Convert class encapsulates common Java type conversions.

long[] b = {1,2,3,4,5};
String bStr = Convert.toStr(b); // "[1, 2, 3, 4, 5]"

long a = 4535345L;
long minutes = Convert.convertTime(a, TimeUnit.MILLISECONDS, TimeUnit.MINUTES); // 75

double d = 67556.32;
String digitUppercase = Convert.digitToChinese(d); // "陆万柒仟伍佰伍拾陆元叁角贰分"

Email

Hutool wraps javax.mail to simplify email sending.

Configuration file mail.setting (placed in src/main/resources):

# SMTP host, default smtp.<sender domain>
host = smtp.yeah.net
# SMTP port, default 25
port = 25
# Sender address (must be correct)
from = [email protected]
# Username (default is the part before @)
user = hutool
# Password or SMTP authorization code
pass = q1w2e3

Send a simple email:

MailUtil.send("[email protected]", "Test", "Email sent by Hutool test", false);

Send to multiple recipients:

ArrayList<String> tos = CollUtil.newArrayList(
    "[email protected]",
    "[email protected]",
    "[email protected]",
    "[email protected]"
);
MailUtil.send(tos, "Test", "Batch email sent by Hutool", false);

Send with attachment:

MailUtil.send("[email protected]", "Test", "<h1>Email from Hutool</h1>", true, FileUtil.file("d:/aaa.xml"));

Alternatively, use a MailAccount object for custom server settings:

MailAccount account = new MailAccount();
account.setHost("smtp.yeah.net");
account.setPort("25");
account.setAuth(true);
account.setFrom("[email protected]");
account.setUser("hutool");
account.setPass("q1w2e3");
MailUtil.send(account, CollUtil.newArrayList("[email protected]"), "Test", "Email from Hutool", false);

Unique ID

Hutool provides utilities for generating UUID, ObjectId, and Snowflake IDs.

UUID

ObjectId (MongoDB)

Snowflake (Twitter)

UUID example:

String uuid = IdUtil.randomUUID(); // with hyphens
String simpleUUID = IdUtil.simpleUUID(); // without hyphens

ObjectId example:

String id = ObjectId.next(); // e.g., 5b9e306a4df4f8c54a39fb0c
String id2 = IdUtil.objectId();

Snowflake example:

long id = IdUtil.getSnowflakeNextId();
String idStr = IdUtil.getSnowflakeNextIdStr();

HTTP Request Utilities

Hutool’s HttpUtil simplifies GET and POST requests.

GET request examples:

String result1 = HttpUtil.get("https://www.baidu.com");
String result2 = HttpUtil.get("https://www.baidu.com", CharsetUtil.CHARSET_UTF_8);
HashMap<String, Object> paramMap = new HashMap<>();
paramMap.put("city", "北京");
String result3 = HttpUtil.get("https://www.baidu.com", paramMap);

POST request example:

HashMap<String, Object> paramMap = new HashMap<>();
paramMap.put("city", "北京");
String result = HttpUtil.post("https://www.baidu.com", paramMap);

File upload example:

HashMap<String, Object> paramMap = new HashMap<>();
paramMap.put("file", FileUtil.file("D:\\face.jpg"));
String result = HttpUtil.post("https://www.baidu.com", paramMap);

Cache

Hutool implements several cache strategies:

FIFO (first in first out)

LFU (least frequently used)

LRU (least recently used)

Timed

Weak

FIFO cache example:

Cache<String,String> fifoCache = CacheUtil.newFIFOCache(3);
fifoCache.put("key1", "value1", DateUnit.SECOND.getMillis()*3);
fifoCache.put("key2", "value2", DateUnit.SECOND.getMillis()*3);
fifoCache.put("key3", "value3", DateUnit.SECOND.getMillis()*3);
// Adding a fourth entry evicts the oldest (key1)
fifoCache.put("key4", "value4", DateUnit.SECOND.getMillis()*3);
String value1 = fifoCache.get("key1"); // null

Console Logging

Hutool’s Console offers a Java‑style console.log() API.

String[] a = {"java", "c++", "c"};
Console.log(a); // [java, c++, c]
Console.log("This is Console log for {}.", "test"); // This is Console log for test.

The Console object works similarly to JavaScript’s console.log() , providing a familiar syntax for developers.

Bloom Filter

BitMapBloomFilter filter = new BitMapBloomFilter(10);
filter.add("123");
filter.add("abc");
filter.add("ddd");
boolean contains = filter.contains("abc");

Encryption/Decryption

Hutool supports symmetric, asymmetric, digest, MAC algorithms, and Chinese national standards (SM2/SM3/SM4) via Bouncy Castle.

SM2 encryption/decryption example:

String text = "JavaGuide: a comprehensive guide for Java developers.";
KeyPair pair = SecureUtil.generateKeyPair("SM2");
byte[] privateKey = pair.getPrivate().getEncoded();
byte[] publicKey = pair.getPublic().getEncoded();
SM2 sm2 = SmUtil.sm2(privateKey, publicKey);
String encryptStr = sm2.encryptBcd(text, KeyType.PublicKey);
String decryptStr = StrUtil.utf8Str(sm2.decryptFromBcd(encryptStr, KeyType.PrivateKey));

SM2 signing and verification:

String sign = sm2.signHex(HexUtil.encodeHexStr(text));
boolean verify = sm2.verifyHex(HexUtil.encodeHexStr(text), sign);

Thread Pool

Hutool provides a builder‑style API for custom thread pools:

private static ExecutorService pool = ExecutorBuilder.create()
    .setCorePoolSize(10)
    .setMaxPoolSize(20)
    .setWorkQueue(new LinkedBlockingQueue<>(100))
    .setThreadFactory(ThreadFactoryBuilder.create().setNamePrefix("IM-Pool-").build())
    .build();

Hutool also offers a global thread pool; asynchronous methods run in this pool via ThreadUtil.execute and ThreadUtil.execAsync. ThreadUtil.execute: execute a task in the global pool ThreadUtil.execAsync: run a method asynchronously

Example of initializing a sensitive‑word filter asynchronously:

public static void init(final Collection<String> sensitiveWords, boolean isAsync) {
    if (isAsync) {
        ThreadUtil.execAsync(new Callable<Boolean>() {
            @Override
            public Boolean call() throws Exception {
                init(sensitiveWords);
                return true;
            }
        });
    } else {
        init(sensitiveWords);
    }
}

Related Links

Project address: https://github.com/dromara/hutool

Official site: https://hutool.cn/