diff --git a/other/java/client/src/main/java/seaweedfs/client/SeaweedOutputStream.java b/other/java/client/src/main/java/seaweedfs/client/SeaweedOutputStream.java
index d5c3399ed..68c281992 100644
--- a/other/java/client/src/main/java/seaweedfs/client/SeaweedOutputStream.java
+++ b/other/java/client/src/main/java/seaweedfs/client/SeaweedOutputStream.java
@@ -33,6 +33,7 @@ public class SeaweedOutputStream extends OutputStream {
     private ByteBuffer buffer;
     private long outputIndex;
     private String replication = "";
+    private String collection = "";
 
     public SeaweedOutputStream(FilerClient filerClient, final String fullpath) {
         this(filerClient, fullpath, "");
@@ -53,7 +54,6 @@ public class SeaweedOutputStream extends OutputStream {
         this.lastFlushOffset = 0;
         this.bufferSize = bufferSize;
         this.buffer = ByteBufferPool.request(bufferSize);
-        this.outputIndex = 0;
         this.writeOperations = new ConcurrentLinkedDeque<>();
 
         this.maxConcurrentRequestCount = Runtime.getRuntime().availableProcessors();
@@ -83,6 +83,13 @@ public class SeaweedOutputStream extends OutputStream {
 
     }
 
+    public void setReplication(String replication) {
+        this.replication = replication;
+    }
+    public void setCollection(String collection) {
+        this.collection = collection;
+    }
+
     public static String getParentDirectory(String path) {
         int protoIndex = path.indexOf("://");
         if (protoIndex >= 0) {
@@ -144,13 +151,11 @@ public class SeaweedOutputStream extends OutputStream {
 
             if (numberOfBytesToWrite < writableBytes) {
                 buffer.put(data, currentOffset, numberOfBytesToWrite);
-                outputIndex += numberOfBytesToWrite;
                 break;
             }
 
             // System.out.println(path + "     [" + (outputIndex + currentOffset) + "," + ((outputIndex + currentOffset) + writableBytes) + ") " + buffer.capacity());
             buffer.put(data, currentOffset, writableBytes);
-            outputIndex += writableBytes;
             currentOffset += writableBytes;
             writeCurrentBufferToService();
             numberOfBytesToWrite = numberOfBytesToWrite - writableBytes;
@@ -194,7 +199,6 @@ public class SeaweedOutputStream extends OutputStream {
             lastError = new IOException("Stream is closed!");
             ByteBufferPool.release(buffer);
             buffer = null;
-            outputIndex = 0;
             closed = true;
             writeOperations.clear();
             if (!threadExecutor.isShutdown()) {
@@ -225,7 +229,7 @@ public class SeaweedOutputStream extends OutputStream {
         }
         final Future<Void> job = completionService.submit(() -> {
             // System.out.println(path + " is going to save [" + (writePosition) + "," + ((writePosition) + bytesLength) + ")");
-            SeaweedWrite.writeData(entry, replication, filerClient, writePosition, bufferToWrite.array(), bufferToWrite.position(), bufferToWrite.limit(), path);
+            SeaweedWrite.writeData(entry, replication, collection, filerClient, writePosition, bufferToWrite.array(), bufferToWrite.position(), bufferToWrite.limit(), path);
             // System.out.println(path + " saved [" + (writePosition) + "," + ((writePosition) + bytesLength) + ")");
             ByteBufferPool.release(bufferToWrite);
             return null;
diff --git a/other/java/client/src/main/java/seaweedfs/client/SeaweedWrite.java b/other/java/client/src/main/java/seaweedfs/client/SeaweedWrite.java
index f477303c9..88c7cefbe 100644
--- a/other/java/client/src/main/java/seaweedfs/client/SeaweedWrite.java
+++ b/other/java/client/src/main/java/seaweedfs/client/SeaweedWrite.java
@@ -26,6 +26,7 @@ public class SeaweedWrite {
 
     public static void writeData(FilerProto.Entry.Builder entry,
                                  final String replication,
+                                 String collection,
                                  final FilerClient filerClient,
                                  final long offset,
                                  final byte[] bytes,
@@ -36,7 +37,7 @@ public class SeaweedWrite {
         for (long waitTime = 1000L; waitTime < 10 * 1000; waitTime += waitTime / 2) {
             try {
                 FilerProto.FileChunk.Builder chunkBuilder = writeChunk(
-                        replication, filerClient, offset, bytes, bytesOffset, bytesLength, path);
+                        replication, collection, filerClient, offset, bytes, bytesOffset, bytesLength, path);
                 lastException = null;
                 synchronized (entry) {
                     entry.addChunks(chunkBuilder);
@@ -59,6 +60,7 @@ public class SeaweedWrite {
     }
 
     public static FilerProto.FileChunk.Builder writeChunk(final String replication,
+                                                          final String collection,
                                                           final FilerClient filerClient,
                                                           final long offset,
                                                           final byte[] bytes,
@@ -67,7 +69,7 @@ public class SeaweedWrite {
                                                           final String path) throws IOException {
         FilerProto.AssignVolumeResponse response = filerClient.getBlockingStub().assignVolume(
                 FilerProto.AssignVolumeRequest.newBuilder()
-                        .setCollection(filerClient.getCollection())
+                        .setCollection(Strings.isNullOrEmpty(collection) ? filerClient.getCollection() : collection)
                         .setReplication(Strings.isNullOrEmpty(replication) ? filerClient.getReplication() : replication)
                         .setDataCenter("")
                         .setTtlSec(0)