1 files changed, 96 insertions, 0 deletions
diff --git a/java/client/src/main/java/org/apache/qpid/nclient/util/FileMessage.java b/java/client/src/main/java/org/apache/qpid/nclient/util/FileMessage.java
new file mode 100644
index 0000000000..179c91c2e9
--- /dev/null
+++ b/java/client/src/main/java/org/apache/qpid/nclient/util/FileMessage.java
@@ -0,0 +1,96 @@
+package org.apache.qpid.nclient.util;
+
+import java.io.EOFException;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.MappedByteBuffer;
+import java.nio.channels.FileChannel;
+
+import org.apache.qpid.transport.DeliveryProperties;
+import org.apache.qpid.transport.MessageProperties;
+import org.apache.qpid.transport.Header;
+import org.apache.qpid.api.Message;
+
+/**
+ * FileMessage provides pull style semantics for
+ * larges messages backed by a disk. 
+ * Instead of loading all data into memeory it uses
+ * FileChannel to map regions of the file into memeory
+ * at a time.
+ * 
+ * The write methods are not supported. 
+ * 
+ * From the standpoint of performance it is generally 
+ * only worth mapping relatively large files into memory.
+ *    
+ * FileMessage msg = new FileMessage(in,delProps,msgProps);
+ * session.messageTransfer(dest,msg,0,0);
+ * 
+ * The messageTransfer method will read the file in chunks
+ * and stream it.
+ *
+ */
+public class FileMessage extends ReadOnlyMessage implements Message
+{
+    private FileChannel _fileChannel;
+    private int _chunkSize;
+    private long _fileSize;
+    private long _pos = 0;
+    
+    public FileMessage(FileInputStream in,int chunkSize,DeliveryProperties deliveryProperties,MessageProperties messageProperties)throws IOException
+    {
+        _messageProperties = messageProperties;
+        _deliveryProperties = deliveryProperties;
+        
+        _fileChannel = in.getChannel();
+        _chunkSize = chunkSize;
+        _fileSize = _fileChannel.size();
+        
+        if (_fileSize <= _chunkSize)
+        {
+            _chunkSize = (int)_fileSize;
+        }
+    }
+
+    public void setHeader(Header header) {
+        //To change body of implemented methods use File | Settings | File Templates.
+    }
+
+    public Header getHeader() {
+        return null;  //To change body of implemented methods use File | Settings | File Templates.
+    }
+
+    public void readData(byte[] target) throws IOException
+    {        
+        throw new UnsupportedOperationException();              
+    }
+    
+    public ByteBuffer readData() throws IOException
+    {
+        if (_pos == _fileSize)
+        {
+            throw new EOFException();
+        }
+        
+        if (_pos + _chunkSize > _fileSize)
+        {
+            _chunkSize = (int)(_fileSize - _pos);
+        }
+        MappedByteBuffer bb = _fileChannel.map(FileChannel.MapMode.READ_ONLY, _pos, _chunkSize);        
+        _pos += _chunkSize;
+        return bb;
+    }
+
+    /**
+     * This message is used by an application user to
+     * provide data to the client library using pull style
+     * semantics. Since the message is not transfered yet, it
+     * does not have a transfer id. Hence this method is not
+     * applicable to this implementation.    
+     */
+    public int getMessageTransferId()
+    {
+        throw new UnsupportedOperationException();
+    }
+}