Class UlidGenerator

java.lang.Object
cloud.opencode.base.id.ulid.UlidGenerator
All Implemented Interfaces:
IdGenerator<String>
public final class UlidGenerator extends Object implements IdGenerator<String>
ULID Generator - Universally Unique Lexicographically Sortable Identifier ULID生成器 - 通用唯一字典序可排序标识符

Generates Universally Unique Lexicographically Sortable Identifiers. ULID is a 128-bit identifier encoded as 26 characters using Crockford's Base32.

生成通用唯一字典序可排序标识符。ULID是128位标识符， 使用Crockford的Base32编码为26个字符。

ULID Structure | ULID结构:

 01AN4Z07BY      79KA1307SR9X4MV3
|----------|    |----------------|
 Timestamp          Randomness
  48bits             80bits

Features | 主要功能:

  • Lexicographically sortable - 字典序可排序
  • Case insensitive - 大小写不敏感
  • URL safe - URL安全
  • Monotonic within same millisecond (configurable) - 同毫秒内单调递增（可配置）
  • Non-monotonic mode via UlidConfig - 通过UlidConfig配置非单调模式

Usage Examples | 使用示例:

// Monotonic (default)
UlidGenerator gen = UlidGenerator.create();
String ulid = gen.generate();
// -> "01ARZ3NDEKTSV4RRFFQ69G5FAV"

// Non-monotonic
UlidGenerator gen2 = UlidGenerator.create(UlidConfig.nonMonotonic());
String ulid2 = gen2.generate();

// Validate
boolean valid = UlidGenerator.isValid(ulid);

// Compare
int cmp = UlidGenerator.compare(ulid1, ulid2);

Security | 安全性:

  • Thread-safe: Yes (synchronized) - 线程安全: 是（同步）
  • Entropy: SecureRandom - 熵源: SecureRandom
Since:
JDK 25, opencode-base-id V1.0.0
Author:
Leon Soo www.LeonSoo.com
See Also:

  • Method Details

    • create

      public static UlidGenerator create()
      Creates a default monotonic ULID generator (singleton) 创建默认单调ULID生成器（单例）
      Returns:
      monotonic generator | 单调生成器

    • create

      public static UlidGenerator create(UlidConfig config)
      Creates a ULID generator with explicit configuration 使用显式配置创建ULID生成器

      Examples | 示例:

      UlidGenerator.create(UlidConfig.defaultConfig())    // monotonic singleton
UlidGenerator.create(UlidConfig.nonMonotonic())     // new non-monotonic instance
      Parameters:
      config - the ULID configuration | ULID配置
      Returns:
      generator | 生成器

    • isMonotonic

      public boolean isMonotonic()
      Returns whether this generator uses monotonic mode 返回此生成器是否使用单调模式
      Returns:
      true if monotonic | 如果是单调模式返回true

    • generate

      public String generate()
      Description copied from interface: IdGenerator
      Generates the next ID 生成下一个ID
      Specified by:
      generate in interface IdGenerator<String>
      Returns:
      generated ID | 生成的ID

    • generate

      public String generate(long timestamp)
      Generates a ULID with specific timestamp 使用指定时间戳生成ULID
      Parameters:
      timestamp - the timestamp in milliseconds | 时间戳（毫秒）
      Returns:
      ULID string (26 characters) | ULID字符串（26字符）

    • generateBytes

      public byte[] generateBytes()
      Generates ULID as byte array 生成ULID字节数组
      Returns:
      16-byte array | 16字节数组

    • isValid

      public static boolean isValid(String ulid)
      Validates a ULID string 验证ULID字符串
      Parameters:
      ulid - the ULID string | ULID字符串
      Returns:
      true if valid | 如果有效返回true

    • parse

      public static UlidParser.ParsedUlid parse(String ulid)
      Parses a ULID string 解析ULID字符串
      Parameters:
      ulid - the ULID string | ULID字符串
      Returns:
      parsed result | 解析结果

    • compare

      public static int compare(String ulid1, String ulid2)
      Compares two ULID strings 比较两个ULID字符串
      Parameters:
      ulid1 - first ULID | 第一个ULID
      ulid2 - second ULID | 第二个ULID
      Returns:
      comparison result | 比较结果
      Throws:
      NullPointerException - if either argument is null

    • getType

      public String getType()
      Description copied from interface: IdGenerator
      Gets the generator type name 获取生成器类型名称
      Specified by:
      getType in interface IdGenerator<String>
      Returns:
      type name | 类型名称