删除更多的无用代码，提高代码清晰度

skywalking-api/src/main/java/com/ai/cloud/skywalking/buffer/BufferGroup.java

@@ -47,7 +47,6 @@ public class BufferGroup {
     class ConsumerWorker extends Thread {
         private int start = 0;
         private int end = BUFFER_MAX_SIZE;
-        private StringBuilder builder = new StringBuilder();
 
         private ConsumerWorker(int start, int end) {
             this.start = start;

skywalking-api/src/main/java/com/ai/cloud/skywalking/sender/DataSenderFactory.java

@@ -62,7 +62,6 @@ public class DataSenderFactory {
             }
             avaiableSize = (int) Math.ceil(socketAddresses.size() * ((1.0 * CONNECT_PERCENT / 100) % 100));
             // 初始化DataSender
-            Iterator<SocketAddress> it = socketAddresses.iterator();
             List<SocketAddress> usedSocketAddress = new ArrayList<SocketAddress>();
 
             for (SocketAddress socketAddress : socketAddresses) {

skywalking-server/src/main/java/com/ai/cloud/skywalking/reciever/util/ByteArrayUtil.java

@@ -1,18 +0,0 @@
-package com.ai.cloud.skywalking.reciever.util;
-
-public class ByteArrayUtil {
-
-    private ByteArrayUtil() {
-    }
-
-    public static int byteArrayToInt(byte[] b, int offset) {
-        int value = 0;
-        for (int i = 0; i < 4; i++) {
-            int shift = (4 - 1 - i) * 8;
-            value += (b[i + offset] & 0x000000FF) << shift;
-        }
-        return value;
-    }
-
-
-}