diff --git a/HISTORY b/HISTORY
index a62ec4a..aff4406 100644
--- a/HISTORY
+++ b/HISTORY
@@ -1,6 +1,7 @@
 
 Version 1.38  2025-11-27
   * bugfixed: loadStorageServersFromTracker correctly with rw option
+  * throw IOException with msg "connection broken" when in.read() < 0
 
 Version 1.37  2025-11-06
   * query file info support two combined flags:
diff --git a/pom.xml b/pom.xml
index cb8f62b..e291567 100644
--- a/pom.xml
+++ b/pom.xml
@@ -4,7 +4,7 @@
 
   <groupId>org.csource</groupId>
   <artifactId>fastdfs-client-java</artifactId>
-  <version>1.37-SNAPSHOT</version>
+  <version>1.38-SNAPSHOT</version>
   <name>fastdfs-client-java</name>
   <description>fastdfs client for java</description>
   <packaging>jar</packaging>
diff --git a/src/main/java/org/csource/fastdfs/ProtoCommon.java b/src/main/java/org/csource/fastdfs/ProtoCommon.java
index 0b06c5e..273d7fb 100644
--- a/src/main/java/org/csource/fastdfs/ProtoCommon.java
+++ b/src/main/java/org/csource/fastdfs/ProtoCommon.java
@@ -180,9 +180,13 @@ public class ProtoCommon {
     long pkg_len;
 
     header = new byte[FDFS_PROTO_PKG_LEN_SIZE + 2];
-
-    if ((bytes = in.read(header)) != header.length) {
-      throw new IOException("recv package size " + bytes + " != " + header.length);
+    bytes = in.read(header);
+    if (bytes != header.length) {
+        if (bytes < 0) {
+            throw new IOException("connection broken");
+        } else {
+            throw new IOException("recv package size " + bytes + " != " + header.length);
+        }
     }
 
     if (header[PROTO_HEADER_CMD_INDEX] != expect_cmd) {
@@ -222,7 +226,7 @@ public class ProtoCommon {
     byte[] body = new byte[(int) header.body_len];
     int totalBytes = 0;
     int remainBytes = (int) header.body_len;
-    int bytes;
+    int bytes = 0;
 
     while (totalBytes < header.body_len) {
       if ((bytes = in.read(body, totalBytes, remainBytes)) < 0) {
@@ -234,7 +238,12 @@ public class ProtoCommon {
     }
 
     if (totalBytes != header.body_len) {
-      throw new IOException("recv package size " + totalBytes + " != " + header.body_len);
+        if (totalBytes == 0) {
+            throw new IOException("connection broken");
+        } else {
+            throw new IOException("connection broken, recv length: " + totalBytes
+                    + ", expect length: " + header.body_len);
+        }
     }
 
     return new RecvPackageInfo((byte) 0, body);
diff --git a/src/main/java/org/csource/fastdfs/TrackerClient.java b/src/main/java/org/csource/fastdfs/TrackerClient.java
index 565ee56..83d5ad7 100644
--- a/src/main/java/org/csource/fastdfs/TrackerClient.java
+++ b/src/main/java/org/csource/fastdfs/TrackerClient.java
@@ -85,13 +85,13 @@ public class TrackerClient {
             connection = trackerServer.getConnection();
         } catch (IOException e) {
             if (failOver) {
-                System.err.println("trackerServer get connection error, emsg:" + e.getMessage());
+                System.err.println("trackerServer get connection error, " + e.getMessage());
             } else {
                 throw e;
             }
         } catch (MyException e) {
             if (failOver) {
-                System.err.println("trackerServer get connection error, emsg:" + e.getMessage());
+                System.err.println("trackerServer get connection error, " + e.getMessage());
             } else {
                 throw e;
             }
diff --git a/src/main/java/org/csource/fastdfs/pool/ConnectionFactory.java b/src/main/java/org/csource/fastdfs/pool/ConnectionFactory.java
index 0a6b663..9e49dee 100644
--- a/src/main/java/org/csource/fastdfs/pool/ConnectionFactory.java
+++ b/src/main/java/org/csource/fastdfs/pool/ConnectionFactory.java
@@ -23,7 +23,7 @@ public class ConnectionFactory {
             sock.connect(socketAddress, ClientGlobal.g_connect_timeout);
             return new Connection(sock, socketAddress);
         } catch (Exception e) {
-            throw new MyException("connect to server " + socketAddress.getAddress().getHostAddress() + ":" + socketAddress.getPort() + " fail, emsg:" + e.getMessage());
+            throw new MyException("connect to server " + socketAddress.getAddress().getHostAddress() + ":" + socketAddress.getPort() + " fail, emsg: " + e.getMessage());
         }
     }
 }
diff --git a/src/main/java/org/csource/fastdfs/pool/ConnectionManager.java b/src/main/java/org/csource/fastdfs/pool/ConnectionManager.java
index fa76798..4f39352 100644
--- a/src/main/java/org/csource/fastdfs/pool/ConnectionManager.java
+++ b/src/main/java/org/csource/fastdfs/pool/ConnectionManager.java
@@ -62,7 +62,7 @@ public class ConnectionManager {
                         try {
                             isActive = connection.activeTest();
                         } catch (IOException e) {
-                            System.err.println("send to server[" + inetSocketAddress.getAddress().getHostAddress() + ":" + inetSocketAddress.getPort() + "] active test error ,emsg:" + e.getMessage());
+                            System.err.println("send to server[" + inetSocketAddress.getAddress().getHostAddress() + ":" + inetSocketAddress.getPort() + "] active test error, emsg: " + e.getMessage());
                             isActive = false;
                         }
                         if (!isActive) {
@@ -84,7 +84,7 @@ public class ConnectionManager {
                         throw new MyException("connect to server " + inetSocketAddress.getAddress().getHostAddress() + ":" + inetSocketAddress.getPort() + " fail, wait_time > " + ClientGlobal.g_connection_pool_max_wait_time_in_ms + "ms");
                     } catch (InterruptedException e) {
                         e.printStackTrace();
-                        throw new MyException("connect to server " + inetSocketAddress.getAddress().getHostAddress() + ":" + inetSocketAddress.getPort() + " fail, emsg:" + e.getMessage());
+                        throw new MyException("connect to server " + inetSocketAddress.getAddress().getHostAddress() + ":" + inetSocketAddress.getPort() + " fail, emsg: " + e.getMessage());
                     }
                 }
                 return connection;
@@ -117,7 +117,7 @@ public class ConnectionManager {
                 connection.closeDirectly();
             }
         } catch (IOException e) {
-            System.err.println("close socket[" + inetSocketAddress.getAddress().getHostAddress() + ":" + inetSocketAddress.getPort() + "] error ,emsg:" + e.getMessage());
+            System.err.println("close socket[" + inetSocketAddress.getAddress().getHostAddress() + ":" + inetSocketAddress.getPort() + "] error, emsg: " + e.getMessage());
             e.printStackTrace();
         }
     }