Merge pull request #1494 from FULaBUla/v5-dev

Fix (hutool-core): 修复拆分byte数组时最后一组长度不足 len 时依旧按照 len 分配空间导致读取过多额外数据的问题

hutool-core/src/main/java/cn/hutool/core/util/PrimitiveArrayUtil.java

@@ -520,26 +520,26 @@ public class PrimitiveArrayUtil {
 	// ---------------------------------------------------------------------- split
 
 	/**
-	 * 拆分byte数组为几个等份（最后一份可能小于len）
+	 * 拆分byte数组为几个等份（最后一份按照剩余长度分配空间）
 	 *
 	 * @param array 数组
 	 * @param len   每个小节的长度
 	 * @return 拆分后的数组
 	 */
 	public static byte[][] split(byte[] array, int len) {
-		int x = array.length / len;
+		int amount = array.length / len;
-		int y = array.length % len;
+		int remainder = array.length % len;
-		int z = 0;
+		if (remainder != 0) {
-		if (y != 0) {
+			++amount;
-			z = 1;
 		}
-		byte[][] arrays = new byte[x + z][];
+		byte[][] arrays = new byte[amount][];
 		byte[] arr;
-		for (int i = 0; i < x + z; i++) {
+		for (int i = 0; i < amount; i++) {
-			arr = new byte[len];
+			if (i == amount - 1 && remainder != 0) {
-			if (i == x + z - 1 && y != 0) {
+				arr = new byte[remainder];
-				System.arraycopy(array, i * len, arr, 0, y);
+				System.arraycopy(array, i * len, arr, 0, remainder);
 			} else {
+				arr = new byte[len];
 				System.arraycopy(array, i * len, arr, 0, len);
 			}
 			arrays[i] = arr;

hutool-core/src/test/java/cn/hutool/core/util/ArrayUtilTest.java

@@ -424,4 +424,12 @@ public class ArrayUtilTest {
 			Assert.assertTrue(o instanceof Integer);
 		}
 	}
+
+	@Test
+	public void splitTest() {
+		byte[] array = new byte[1024];
+		byte[][] arrayAfterSplit = ArrayUtil.split(array, 500);
+		Assert.assertEquals(3, arrayAfterSplit.length);
+		Assert.assertEquals(24, arrayAfterSplit[2].length);
+	}
 }