From 9de865b67bcf510ff2285a1bbe693deb98101c1b Mon Sep 17 00:00:00 2001
From: huanghaiquan <huanghaiquan@jd.com>
Date: Fri, 29 Jan 2021 09:12:22 +0800
Subject: [PATCH] added new methods for BytesUtils and BinarySerializeUtils;

---
 .../src/main/java/utils/io/BytesUtils.java    | 70 +++++++++++++++----
 .../binary/BinarySerializeUtils.java          |  8 +++
 2 files changed, 63 insertions(+), 15 deletions(-)

diff --git a/utils-common/src/main/java/utils/io/BytesUtils.java b/utils-common/src/main/java/utils/io/BytesUtils.java
index a2161ed..0dd06e4 100644
--- a/utils-common/src/main/java/utils/io/BytesUtils.java
+++ b/utils-common/src/main/java/utils/io/BytesUtils.java
@@ -7,6 +7,8 @@ import java.io.ObjectOutputStream;
 import java.io.OutputStream;
 import java.io.UnsupportedEncodingException;
 
+import org.bouncycastle.util.Arrays;
+
 import utils.ByteSequence;
 import utils.Bytes;
 import utils.IllegalDataException;
@@ -37,11 +39,11 @@ public class BytesUtils {
 	 * 比较指定的两个字节数组是否一致；
 	 * <p>
 	 * 
-	 * 此方法不处理两者其中之一为 null 的情形，因为无法定义相等性，所以将引发 {@link NullPointerException} 异常；
+	 * 注：要比较的两个数组的长度都为 0 时总是返回 true;
 	 * 
-	 * @param bytes1 bytes1
-	 * @param bytes2 bytes2
-	 * @return boolean
+	 * @param bytes1 要比较的数组1；
+	 * @param bytes2 要比较的数组2；
+	 * @return boolean 
 	 */
 	public static boolean equals(byte[] bytes1, byte[] bytes2) {
 		if (bytes1 == bytes2) {
@@ -61,6 +63,40 @@ public class BytesUtils {
 		return true;
 	}
 
+	/**
+	 * 验证两个数组中，从指定偏移开始的相同长度的数据是否相等；<p>
+	 * 
+	 * 注：<br>
+	 * 要比较的两个数组中任意一个的有效长度不满足指定的长度时，返回 false；
+	 * 
+	 * @param bytes1  要比较的数组1；
+	 * @param offset1 数组1的起始偏移量；
+	 * @param bytes2  要比较的数组2；
+	 * @param offset2 数组2的起始偏移量；
+	 * @param length  要比较的数据的长度； 在有效的偏移量前提下，当指定长度为 0 时，总是返回 true;
+	 * @return
+	 */
+	public static boolean equals(byte[] bytes1, int offset1, byte[] bytes2, int offset2, int length) {
+		if (bytes1 == bytes2) {
+			return true;
+		}
+		if (bytes1 == null || bytes2 == null) {
+			return false;
+		}
+		
+		//验证两个数组的有效长度；
+		if (bytes1.length >= (offset1 + length) && bytes2.length >= (offset2 + length)) {
+			for (int i = 0; i < length; i++) {
+				if (bytes1[offset1 + i] != bytes2[offset2 + i]) {
+					return false;
+				}
+			}
+			return true;
+		}
+		
+		return false;
+	}
+
 	public static byte[] toBytes(BytesWriter bytesWriter) {
 		try {
 			ByteArrayOutputStream out = new ByteArrayOutputStream();
@@ -209,7 +245,6 @@ public class BytesUtils {
 		bytes[offset + 3] = (byte) (value & 0x00FF);
 		return 4;
 	}
-	
 
 	/**
 	 * 将 int 值转为4字节的二进制数组；
@@ -228,6 +263,7 @@ public class BytesUtils {
 		bytes[offset + 3] = (byte) ((value >>> 24) & 0x00FF);
 		return 4;
 	}
+
 	/**
 	 * 将 int 值转为4字节的二进制数组；
 	 * <p>
@@ -279,6 +315,11 @@ public class BytesUtils {
 		bytes[offset] = (byte) ((value >>> 8) & 0x00FF);
 		bytes[offset + 1] = (byte) (value & 0x00FF);
 	}
+	
+	public static void toBytes_BigEndian(short value, byte[] bytes, int offset) {
+		bytes[offset] = (byte) ((value >>> 8) & 0x00FF);
+		bytes[offset + 1] = (byte) (value & 0x00FF);
+	}
 
 	public static void toBytes(char value, byte[] bytes, int offset) {
 		bytes[offset] = (byte) ((value >>> 8) & 0x00FF);
@@ -326,7 +367,7 @@ public class BytesUtils {
 	}
 
 	public static byte[] toBytes(String str, String charset) {
-		if(null == str) {
+		if (null == str) {
 			return null;
 		}
 		try {
@@ -704,38 +745,38 @@ public class BytesUtils {
 
 		return bytesAll;
 	}
-	
+
 	public static byte[] concat(Bytes... bytesList) {
 		int size = 0;
 		for (Bytes bs : bytesList) {
 			size += bs.size();
 		}
-		
+
 		byte[] bytesAll = new byte[size];
 		size = 0;
 		for (Bytes bs : bytesList) {
 			bs.copyTo(bytesAll, size, bs.size());
 			size += bs.size();
 		}
-		
+
 		return bytesAll;
 	}
-	
+
 	public static byte[] concat(ByteSequence... bytesList) {
 		int size = 0;
 		for (ByteSequence bs : bytesList) {
 			size += bs.size();
 		}
-		
+
 		byte[] bytesAll = new byte[size];
 		size = 0;
 		for (ByteSequence bs : bytesList) {
 			size += bs.copyTo(bytesAll, size, bs.size());
 		}
-		
+
 		return bytesAll;
 	}
-	
+
 	public static char[] concat(char[]... bytesList) {
 		int size = 0;
 		for (char[] bs : bytesList) {
@@ -747,11 +788,10 @@ public class BytesUtils {
 			System.arraycopy(bs, 0, bytesAll, size, bs.length);
 			size += bs.length;
 		}
-		
+
 		return bytesAll;
 	}
 
-
 	public static long toLong(ByteArray byteArray) {
 		return toLong(byteArray.bytes());
 	}
diff --git a/utils-serialize/src/main/java/utils/serialize/binary/BinarySerializeUtils.java b/utils-serialize/src/main/java/utils/serialize/binary/BinarySerializeUtils.java
index d59d9c0..deba355 100644
--- a/utils-serialize/src/main/java/utils/serialize/binary/BinarySerializeUtils.java
+++ b/utils-serialize/src/main/java/utils/serialize/binary/BinarySerializeUtils.java
@@ -41,6 +41,14 @@ public class BinarySerializeUtils {
 		ByteArrayInputStream in = new ByteArrayInputStream(bytes);
 		return deserialize(in);
 	}
+	
+	public static <T> T deserialize(byte[] bytes, int offset, int length) {
+		if (bytes == null || bytes.length == 0) {
+			return null;
+		}
+		ByteArrayInputStream in = new ByteArrayInputStream(bytes, offset, length);
+		return deserialize(in);
+	}
 
 	@SuppressWarnings("unchecked")
 	public static <T> T deserialize(InputStream in) {
-- 
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