From f2ef68a9ae945a4daaec1fbbc4edf295b5a2a8e8 Mon Sep 17 00:00:00 2001
From: weidong <weidong@im-droid.com>
Date: Tue, 28 Oct 2025 10:06:15 +0800
Subject: [PATCH] =?UTF-8?q?1=E3=80=81=E4=BF=AE=E6=94=B9d331=E8=A7=A3?=
 =?UTF-8?q?=E6=9E=90=E8=A7=92=E5=BA=A6=E7=9A=84bug?=
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---
 .../sideslope/message/D331RtcmMessage.java    | 21 ++++++++++---------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/sec-beidou-rtcm/src/main/java/com/imdroid/sideslope/message/D331RtcmMessage.java b/sec-beidou-rtcm/src/main/java/com/imdroid/sideslope/message/D331RtcmMessage.java
index a0d80e7d..63b72a48 100644
--- a/sec-beidou-rtcm/src/main/java/com/imdroid/sideslope/message/D331RtcmMessage.java
+++ b/sec-beidou-rtcm/src/main/java/com/imdroid/sideslope/message/D331RtcmMessage.java
@@ -20,21 +20,22 @@ public class D331RtcmMessage extends BaseMessage {
     @Override
     public void decodeBody(ByteBuf src) {
         // get操作不会移动指针，这样可以确保整个全转发出去
+        int pos = 0;
         this.packetNum = 1;
         this.len = src.readableBytes();//this.len & 0x7FF;//有可能两个d331粘包
-        this.header = src.getUnsignedShort(0); // flag
-        int onePacketLen = src.getUnsignedShort(2); // length:11 bits
+        this.header = src.getUnsignedShort(pos); pos+=2;// flag
+        int onePacketLen = src.getUnsignedShort(pos); pos+=2;// length:11 bits
         this.seq = onePacketLen >> 11;
         onePacketLen = onePacketLen&0x7FF;
-        this.id = String.valueOf(src.getUnsignedInt(4)); //id
-        int pos = onePacketLen + 4;
-        while(pos < this.len){
-            if(src.getUnsignedShort(pos) == 0xd331){
-                onePacketLen = src.getUnsignedShort(pos+2)&0x7FF;
-                pos = pos+4+onePacketLen;
-                packetNum ++;
+        this.id = String.valueOf(src.getUnsignedInt(pos)); pos+=4;//id
+        if(onePacketLen + 4<this.len) {
+            while (pos < this.len) {
+                if (src.getUnsignedShort(pos) == 0xd331) {
+                    onePacketLen = src.getUnsignedShort(pos + 2) & 0x7FF;
+                    pos = pos + 4 + onePacketLen;
+                    packetNum++;
+                } else pos++;
             }
-            else pos++;
         }
         /*if (src.readableBytes() - 4 < this.len) {
             String msg = String.format("id[%s],长度字段值[%s]效益包的消息体长度[%s]", id, this.len, src.readableBytes() - 4);