View Javadoc

    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.util;
    21
    22  import java.io.OutputStream;
    23  import java.nio.ByteBuffer;
    24
    25  /**
    26   * {@link OutputStream} wrapper for {@link ByteBuffer}
    27   *
    28   * <p>
    29   * <i>Currently this class is only used and available in MINA's codec module</i>
    30   * </p>
    31   *
    32   * @author <a href="http://mina.apache.org">Apache MINA Project</a>
    33   *
    34   */
    35  public class ByteBufferOutputStream extends OutputStream {
    36      private ByteBuffer buffer;
    37
    38      private boolean elastic = false;
    39
    40      public ByteBufferOutputStream() {
    41          this(1024);
    42      }
    43
    44      private ByteBufferOutputStream(ByteBuffer buffer) {
    45          this.buffer = buffer;
    46      }
    47
    48      public ByteBufferOutputStream(int initialSize) {
    49          this(ByteBuffer.allocate(initialSize));
    50      }
    51
    52      public ByteBuffer getByteBuffer() {
    53          ByteBuffer out = buffer.asReadOnlyBuffer();
    54          out.limit(out.position());
    55          out.position(0);
    56
    57          return out;
    58      }
    59
    60      public boolean isElastic() {
    61          return elastic;
    62      }
    63
    64      private void needSpace(int len) {
    65          if (elastic && buffer.capacity() - buffer.position() < len) {
    66              ByteBuffer newBuffer = ByteBuffer.allocate(Math.max(buffer.capacity() * 2, buffer.position() + len));
    67              buffer.limit(buffer.position());
    68              newBuffer.put(buffer);
    69              buffer = newBuffer;
    70          }
    71      }
    72
    73      public void setElastic(boolean elastic) {
    74          this.elastic = elastic;
    75      }
    76
    77      @Override
    78      public void write(byte[] b, int off, int len) {
    79          needSpace(len);
    80          buffer.put(b, off, len);
    81      }
    82
    83      @Override
    84      public void write(int b) {
    85          needSpace(1);
    86          buffer.put((byte) b);
    87      }
    88  }