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    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  import java.io.InputStream;
    24
    25  import org.apache.mina.core.buffer.IoBuffer;
    26  import org.apache.mina.core.filterchain.IoFilter;
    27
    28  /**
    29   * Filter implementation which makes it possible to write {@link InputStream}
    30   * objects directly using {@link IoSession#write(Object)}. When an
    31   * {@link InputStream} is written to a session this filter will read the bytes
    32   * from the stream into {@link IoBuffer} objects and write those buffers
    33   * to the next filter. When end of stream has been reached this filter will
    34   * call {@link IoFilter.NextFilter#messageSent(IoSession,WriteRequest)} using the original
    35   * {@link InputStream} written to the session and notifies
    36   * {@link org.apache.mina.core.future.WriteFuture} on the
    37   * original {@link org.apache.mina.core.write.WriteRequest}.
    38   * <p/>
    39   * This filter will ignore written messages which aren't {@link InputStream}
    40   * instances. Such messages will be passed to the next filter directly.
    41   * </p>
    42   * <p/>
    43   * NOTE: this filter does not close the stream after all data from stream
    44   * has been written. The {@link org.apache.mina.core.service.IoHandler} should take
    45   * care of that in its
    46   * {@link org.apache.mina.core.service.IoHandler#messageSent(IoSession,Object)}
    47   * callback.
    48   * </p>
    49   *
    50   * @author <a href="http://mina.apache.org">Apache MINA Project</a>
    51   * @org.apache.xbean.XBean
    52   */
    53  public class StreamWriteFilter extends AbstractStreamWriteFilter<InputStream> {
    54
    55      @Override
    56      protected IoBuffer getNextBuffer(InputStream is) throws IOException {
    57          byte[] bytes = new byte[getWriteBufferSize()];
    58
    59          int off = 0;
    60          int n = 0;
    61          while (off < bytes.length && (n = is.read(bytes, off, bytes.length - off)) != -1) {
    62              off += n;
    63          }
    64
    65          if (n == -1 && off == 0) {
    66              return null;
    67          }
    68
    69          IoBuffer buffer = IoBuffer.wrap(bytes, 0, off);
    70
    71          return buffer;
    72      }
    73
    74      @Override
    75      protected Class<InputStream> getMessageClass() {
    76          return InputStream.class;
    77      }
    78
    79  }