1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, 13 * software distributed under the License is distributed on an 14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 15 * KIND, either express or implied. See the License for the 16 * specific language governing permissions and limitations 17 * under the License. 18 * 19 */ 20 package org.apache.mina.filter.stream; 21 22 import java.io.IOException; 23 24 import org.apache.mina.core.buffer.IoBuffer; 25 import org.apache.mina.core.file.FileRegion; 26 import org.apache.mina.core.filterchain.IoFilter; 27 import org.apache.mina.core.session.IoSession; 28 import org.apache.mina.core.write.WriteRequest; 29 30 /** 31 * Filter implementation that converts a {@link FileRegion} to {@link IoBuffer} 32 * objects and writes those buffers to the next filter. When end of the 33 * {@code FileRegion} has been reached this filter will call 34 * {@link IoFilter.NextFilter#messageSent(IoSession,WriteRequest)} using the 35 * original {@link FileRegion} written to the session and notifies 36 * {@link org.apache.mina.core.future.WriteFuture} on the original 37 * {@link org.apache.mina.core.write.WriteRequest}. 38 * <p>Normall {@code FileRegion} objects should be handled by the 39 * {@link org.apache.mina.core.service.IoProcessor} but this is not always possible 40 * if a filter is being used that needs to modify the contents of the file 41 * before sending over the network (i.e. the 42 * {@link org.apache.mina.filter.ssl.SslFilter} or a data compression filter.) 43 * </p> 44 * <p> This filter will ignore written messages which aren't {@link FileRegion} 45 * instances. Such messages will be passed to the next filter directly. 46 * </p> 47 * <p><b>NOTE:</b> this filter does not close the file channel in 48 * {@link FileRegion#getFileChannel()} after the data from the file has been 49 * written. The {@code FileChannel} should be closed in either 50 * {@link org.apache.mina.core.service.IoHandler#messageSent(IoSession,Object)} 51 * or in an {@link org.apache.mina.core.future.IoFutureListener} associated with the 52 * {@code WriteFuture}. 53 * </p> 54 * 55 * @author The Apache MINA Project (dev@mina.apache.org) 56 * @version $Rev$, $Date$ 57 */ 58 public class FileRegionWriteFilter extends 59 AbstractStreamWriteFilter<FileRegion> { 60 61 @Override 62 protected Class<FileRegion> getMessageClass() { 63 return FileRegion.class; 64 } 65 66 @Override 67 protected IoBuffer getNextBuffer(FileRegion fileRegion) throws IOException { 68 // If there are no more bytes to read, return null 69 if (fileRegion.getRemainingBytes() <= 0) { 70 return null; 71 } 72 73 // Allocate the buffer for reading from the file 74 final int bufferSize = (int) Math.min(getWriteBufferSize(), fileRegion.getRemainingBytes()); 75 IoBuffer buffer = IoBuffer.allocate(bufferSize); 76 77 // Read from the file 78 int bytesRead = fileRegion.getFileChannel().read(buffer.buf(), 79 fileRegion.getPosition()); 80 fileRegion.update(bytesRead); 81 82 // return the buffer 83 buffer.flip(); 84 return buffer; 85 } 86 87 }