提交ProtocolPackager

skywalking-protocol/src/main/java/com/ai/cloud/skywalking/util/ProtocolPackager.java

+package com.ai.cloud.skywalking.util;
+
+import java.util.Arrays;
+
+public class ProtocolPackager {
+    public static byte[] pack(byte[] data) {
+        // 对协议格式进行修改
+        // | check sum(4 byte) |  data
+        byte[] dataPackage = new byte[data.length + 4];
+
+        packDataText(data, dataPackage);
+        packCheckSum(data, dataPackage);
+
+        return dataPackage;
+    }
+
+    private static void packCheckSum(byte[] data, byte[] dataPackage) {
+        byte[] checkSumArray = generateChecksum(data, 0);
+        System.arraycopy(checkSumArray, 0, dataPackage, 0, 4);
+    }
+
+    private static void packDataText(byte[] data, byte[] dataPackage) {
+        System.arraycopy(data, 0, dataPackage, 4, data.length);
+    }
+
+
+    public static byte[] unpack(byte[] dataPackage) {
+        if (validateCheckSum(dataPackage)) {
+            return unpackDataText(dataPackage);
+        } else {
+            return null;
+        }
+
+    }
+
+    private static byte[] unpackDataText(byte[] dataPackage) {
+        byte[] data = new byte[dataPackage.length - 4];
+        System.arraycopy(dataPackage, 4, data, 0, data.length);
+        return data;
+    }
+
+    private static boolean validateCheckSum(byte[] dataPackage){
+        byte[] checkSum = generateChecksum(dataPackage, 4);
+        byte[] originCheckSum = new byte[4];
+        System.arraycopy(dataPackage, 0, originCheckSum, 0, 4);
+        return Arrays.equals(checkSum, originCheckSum);
+    }
+
+    /**
+     * 生成校验和参数
+     *
+     * @param data
+     * @return
+     */
+    private static byte[] generateChecksum(byte[] data, int offset) {
+        int result = data[0];
+        for (int i = offset; i < data.length; i++) {
+            result ^= data[i];
+        }
+
+        return intToBytes(result);
+    }
+
+    private static byte[] intToBytes(int value) {
+        byte[] src = new byte[4];
+        src[0] = (byte) ((value >> 24) & 0xFF);
+        src[1] = (byte) ((value >> 16) & 0xFF);
+        src[2] = (byte) ((value >> 8) & 0xFF);
+        src[3] = (byte) (value & 0xFF);
+        return src;
+    }
+
+}