diff --git a/mybatis-flex-core/src/main/java/com/mybatisflex/core/keygen/KeyGeneratorFactory.java b/mybatis-flex-core/src/main/java/com/mybatisflex/core/keygen/KeyGeneratorFactory.java
index 895f3822..fd0d480b 100644
--- a/mybatis-flex-core/src/main/java/com/mybatisflex/core/keygen/KeyGeneratorFactory.java
+++ b/mybatis-flex-core/src/main/java/com/mybatisflex/core/keygen/KeyGeneratorFactory.java
@@ -19,6 +19,7 @@ import com.mybatisflex.core.exception.FlexExceptions;
import com.mybatisflex.core.exception.locale.LocalizedFormats;
import com.mybatisflex.core.keygen.impl.FlexIDKeyGenerator;
import com.mybatisflex.core.keygen.impl.SnowFlakeIDKeyGenerator;
+import com.mybatisflex.core.keygen.impl.ULIDKeyGenerator;
import com.mybatisflex.core.keygen.impl.UUIDKeyGenerator;
import com.mybatisflex.core.util.StringUtil;
@@ -39,6 +40,8 @@ public class KeyGeneratorFactory {
register(KeyGenerators.uuid, new UUIDKeyGenerator());
register(KeyGenerators.flexId, new FlexIDKeyGenerator());
register(KeyGenerators.snowFlakeId, new SnowFlakeIDKeyGenerator());
+ register(KeyGenerators.ulid, new ULIDKeyGenerator());
+
}
@@ -49,7 +52,7 @@ public class KeyGeneratorFactory {
* @return 主键生成器
*/
public static IKeyGenerator getKeyGenerator(String name) {
- if (StringUtil.isBlank(name)){
+ if (StringUtil.isBlank(name)) {
throw FlexExceptions.wrap(LocalizedFormats.KEY_GENERATOR_BLANK);
}
return KEY_GENERATOR_MAP.get(name.trim());
diff --git a/mybatis-flex-core/src/main/java/com/mybatisflex/core/keygen/KeyGenerators.java b/mybatis-flex-core/src/main/java/com/mybatisflex/core/keygen/KeyGenerators.java
index 90eee69b..062bc6eb 100644
--- a/mybatis-flex-core/src/main/java/com/mybatisflex/core/keygen/KeyGenerators.java
+++ b/mybatis-flex-core/src/main/java/com/mybatisflex/core/keygen/KeyGenerators.java
@@ -38,4 +38,9 @@ public class KeyGenerators {
*/
public static final String snowFlakeId = "snowFlakeId";
+ /**
+ * ulid 主键生成器
+ * {@link com.mybatisflex.core.keygen.impl.ULIDKeyGenerator}
+ */
+ public static final String ulid = "ulid";
}
diff --git a/mybatis-flex-core/src/main/java/com/mybatisflex/core/keygen/impl/ULIDKeyGenerator.java b/mybatis-flex-core/src/main/java/com/mybatisflex/core/keygen/impl/ULIDKeyGenerator.java
new file mode 100644
index 00000000..2bbb511c
--- /dev/null
+++ b/mybatis-flex-core/src/main/java/com/mybatisflex/core/keygen/impl/ULIDKeyGenerator.java
@@ -0,0 +1,120 @@
+/*
+ * Copyright (c) 2022-2025, Mybatis-Flex (fuhai999@gmail.com).
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.mybatisflex.core.keygen.impl;
+
+import com.mybatisflex.core.keygen.IKeyGenerator;
+
+import java.util.concurrent.ThreadLocalRandom;
+
+/**
+ * ULID: 对比UUID的优势在于可排序性和性能。
+ *
+ * 特点：
+ * 1、保证 id 生成的顺序为时间顺序，越往后生成的 ID 值越大；
+ * 2、可以按照生成的时间进行排序，而不需要全局协调；
+ * 3、生成速度快；
+ *
+ *
参考：Sequence
+ */
+public class ULIDKeyGenerator implements IKeyGenerator {
+
+ private static final char[] ENCODING_CHARS = {
+ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
+ 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K',
+ 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'V', 'W', 'X',
+ 'Y', 'Z'
+ };
+
+ private static final long TIMESTAMP_OVERFLOW_MASK = 0xFFFF_0000_0000_0000L;
+
+ private static final ThreadLocal THREAD_LOCAL_BUILDER =
+ ThreadLocal.withInitial(() -> new StringBuilder(26));
+
+ private long lastTimestamp = 0;
+
+ private long lastRandom = 0;
+
+ @Override
+ public Object generate(Object entity, String keyColumn) {
+ return nextId();
+ }
+
+ /**
+ * 生成一个 ULID
+ *
+ * @return ULID
+ */
+ public String nextId() {
+ return generateULID(System.currentTimeMillis()).toLowerCase();
+ }
+
+ /**
+ * 生成一个严格单调的 ULID
+ *
+ * @return ULID
+ */
+ public synchronized String nextMonotonicId() {
+ long timestamp = System.currentTimeMillis();
+ if (timestamp > lastTimestamp) {
+ lastTimestamp = timestamp;
+ lastRandom = ThreadLocalRandom.current().nextLong();
+ } else {
+ lastRandom++;
+ if (lastRandom == 0) {
+ timestamp = waitNextMillis(lastTimestamp);
+ lastTimestamp = timestamp;
+ lastRandom = ThreadLocalRandom.current().nextLong();
+ }
+ }
+ return generateULID(lastTimestamp, lastRandom).toLowerCase();
+ }
+
+ private String generateULID(long timestamp) {
+ return generateULID(timestamp, ThreadLocalRandom.current().nextLong());
+ }
+
+ private String generateULID(long timestamp, long random) {
+ checkTimestamp(timestamp);
+ StringBuilder builder = THREAD_LOCAL_BUILDER.get();
+ builder.setLength(0);
+
+ appendCrockford(builder, timestamp, 10);
+ appendCrockford(builder, random, 16);
+
+ return builder.toString();
+ }
+
+ private long waitNextMillis(long lastTimestamp) {
+ long timestamp = System.currentTimeMillis();
+ while (timestamp <= lastTimestamp) {
+ timestamp = System.currentTimeMillis();
+ }
+ return timestamp;
+ }
+
+ private static void appendCrockford(StringBuilder builder, long value, int count) {
+ for (int i = (count - 1) * 5; i >= 0; i -= 5) {
+ int index = (int) ((value >>> i) & 0x1F);
+ builder.append(ENCODING_CHARS[index]);
+ }
+ }
+
+ private static void checkTimestamp(long timestamp) {
+ if ((timestamp & TIMESTAMP_OVERFLOW_MASK) != 0) {
+ throw new IllegalArgumentException("ULID does not support timestamps after +10889-08-02T05:31:50.655Z!");
+ }
+ }
+}
diff --git a/mybatis-flex-core/src/main/java/com/mybatisflex/core/row/RowKey.java b/mybatis-flex-core/src/main/java/com/mybatisflex/core/row/RowKey.java
index ecac3c0d..9bc90c2e 100644
--- a/mybatis-flex-core/src/main/java/com/mybatisflex/core/row/RowKey.java
+++ b/mybatis-flex-core/src/main/java/com/mybatisflex/core/row/RowKey.java
@@ -46,6 +46,11 @@ public class RowKey implements Serializable {
*/
public static final RowKey SNOW_FLAKE_ID = RowKey.of("id", KeyType.Generator, KeyGenerators.snowFlakeId, true);
+ /**
+ * ulid
+ */
+ public static final RowKey ULID = RowKey.of("id", KeyType.Generator, KeyGenerators.ulid, true);
+
public static RowKey of(String keyColumn) {
SqlUtil.keepColumnSafely(keyColumn);
diff --git a/mybatis-flex-core/src/test/java/com/mybatisflex/coretest/IdGenTest.java b/mybatis-flex-core/src/test/java/com/mybatisflex/coretest/IdGenTest.java
index 256ccebd..4af39608 100644
--- a/mybatis-flex-core/src/test/java/com/mybatisflex/coretest/IdGenTest.java
+++ b/mybatis-flex-core/src/test/java/com/mybatisflex/coretest/IdGenTest.java
@@ -22,6 +22,7 @@ import com.mybatisflex.core.keygen.KeyGenerators;
import org.junit.Assert;
import org.junit.Test;
+import java.util.Arrays;
import java.util.stream.LongStream;
/**
@@ -54,4 +55,15 @@ public class IdGenTest {
Assert.assertEquals(size, LongStream.of(ids).distinct().count());
}
+ @Test
+ public void ULID() {
+ int size = 100_0000;
+ String[] ids = new String[size];
+ IKeyGenerator keyGenerator = KeyGeneratorFactory.getKeyGenerator(KeyGenerators.ulid);
+ for (int i = 0; i < size; i++) {
+ ids[i] = (String) keyGenerator.generate(null, null);
+ }
+ long distinctCount = Arrays.stream(ids).distinct().count();
+ Assert.assertEquals(size, distinctCount);
+ }
}