diff --git a/src/main/java/com/inspect/tcpserver/tcp/MyDecoder.java b/src/main/java/com/inspect/tcpserver/tcp/MyDecoder.java
index d124db1..9636bbf 100644
--- a/src/main/java/com/inspect/tcpserver/tcp/MyDecoder.java
+++ b/src/main/java/com/inspect/tcpserver/tcp/MyDecoder.java
@@ -21,48 +21,55 @@ public class MyDecoder extends ByteToMessageDecoder {
 
     @Override
     protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
-        int length = in.readableBytes();
-        if (length < BASE_LENGTH) {
-            return;
-        }
+        try {
+            int length = in.readableBytes();
+            if (length < BASE_LENGTH) {
+                log.error("not enough readableBytes: {}", length);
+                return;
+            }
 
-        final String uuid = RandomStringUtils.randomAlphanumeric(16);
-//        ByteBuf forPrint = in.copy();
-//        log.info("###### 会话:{}, 客户:{}, 上行原始报文 ######\n {}", uuid, ctx.channel().id().asShortText(), ByteBufUtil.hexDump(forPrint));
-//        forPrint.release();
+            final String uuid = RandomStringUtils.randomAlphanumeric(16);
+//            ByteBuf forPrint = in.copy();
+//            log.info("###### 会话:{}, 客户:{}, 上行原始报文 ######\n {}", uuid, ctx.channel().id().asShortText(), ByteBufUtil.hexDump(forPrint));
+//            forPrint.release();
 
-        do {
-            byte[] start = new byte[2];
-            in.readBytes(start);
-            if (start[0]==-21 && start[1]==-112) {
-                long sendIndex = in.readLongLE();
-                long receiveIndex = in.readLongLE();
-                byte sourceFlag = in.readByte();
-                int xmlLength = in.readIntLE();
-                length = in.readableBytes();
-                if (length >= xmlLength + 2) {
-                    byte[] payload = new byte[xmlLength];
-                    in.readBytes(payload);
-                    in.skipBytes(2);
+            do {
+                byte[] start = new byte[2];
+                in.readBytes(start);
+                if (start[0] == -21 && start[1] == -112) {
+                    long sendIndex = in.readLongLE();
+                    long receiveIndex = in.readLongLE();
+                    byte sourceFlag = in.readByte();
+                    int xmlLength = in.readIntLE();
+                    length = in.readableBytes();
+                    if (length >= xmlLength + 2) {
+                        byte[] payload = new byte[xmlLength];
+                        in.readBytes(payload);
+                        in.skipBytes(2);
 
-                    BinaryModel binaryModel = new BinaryModel();
-                    binaryModel.receiveIndex = receiveIndex;
-                    binaryModel.sendIndex = sendIndex;
-                    binaryModel.sourceFlag = sourceFlag;
-                    binaryModel.dataLength = xmlLength;
-                    binaryModel.dataBuf = Unpooled.copiedBuffer(payload);
-                    binaryModel.uuid = uuid;
-                    out.add(binaryModel);
-                    break;
+                        BinaryModel binaryModel = new BinaryModel();
+                        binaryModel.receiveIndex = receiveIndex;
+                        binaryModel.sendIndex = sendIndex;
+                        binaryModel.sourceFlag = sourceFlag;
+                        binaryModel.dataLength = xmlLength;
+                        binaryModel.dataBuf = Unpooled.copiedBuffer(payload);
+                        binaryModel.uuid = uuid;
+                        out.add(binaryModel);
+                        break;
+                    } else {
+                        in.readerIndex(in.readerIndex() - 23);
+                        log.error("wrong xml length: {}, total length: {}", xmlLength, length);
+                    }
                 } else {
-                    in.readerIndex(in.readerIndex() - 23);
+                    in.readerIndex(in.readerIndex() - 2);
+                    log.error("wrong start flag: [{},{}]", start[0], start[1]);
                 }
-            } else {
-                in.readerIndex(in.readerIndex() - 2);
-            }
 
-            in.readByte();
-            length = in.readableBytes();
-        } while(length >= BASE_LENGTH);
+                in.readByte();
+                length = in.readableBytes();
+            } while (length >= BASE_LENGTH);
+        } catch (Exception e) {
+            log.error("error" , e);
+        }
     }
 }