View Javadoc

    1   /*
    2    * Copyright 2012 The Netty Project
    3    *
    4    * The Netty Project licenses this file to you under the Apache License,
    5    * version 2.0 (the "License"); you may not use this file except in compliance
    6    * with the License. You may obtain a copy of the License at:
    7    *
    8    *   http://www.apache.org/licenses/LICENSE-2.0
    9    *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
    12   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
    13   * License for the specific language governing permissions and limitations
    14   * under the License.
    15   */
    16  package org.jboss.netty.buffer;
    17
    18  import java.io.DataOutput;
    19  import java.io.DataOutputStream;
    20  import java.io.IOException;
    21  import java.io.OutputStream;
    22
    23  /**
    24   * An {@link OutputStream} which writes data to a {@link ChannelBuffer}.
    25   * <p>
    26   * A write operation against this stream will occur at the {@code writerIndex}
    27   * of its underlying buffer and the {@code writerIndex} will increase during
    28   * the write operation.
    29   * <p>
    30   * This stream implements {@link DataOutput} for your convenience.
    31   * The endianness of the stream is not always big endian but depends on
    32   * the endianness of the underlying buffer.
    33   *
    34   * @see ChannelBufferInputStream
    35   * @apiviz.uses org.jboss.netty.buffer.ChannelBuffer
    36   */
    37  public class ChannelBufferOutputStream extends OutputStream implements DataOutput {
    38
    39      private final ChannelBuffer buffer;
    40      private final int startIndex;
    41      private final DataOutputStream utf8out = new DataOutputStream(this);
    42
    43      /**
    44       * Creates a new stream which writes data to the specified {@code buffer}.
    45       */
    46      public ChannelBufferOutputStream(ChannelBuffer buffer) {
    47          if (buffer == null) {
    48              throw new NullPointerException("buffer");
    49          }
    50          this.buffer = buffer;
    51          startIndex = buffer.writerIndex();
    52      }
    53
    54      /**
    55       * Returns the number of written bytes by this stream so far.
    56       */
    57      public int writtenBytes() {
    58          return buffer.writerIndex() - startIndex;
    59      }
    60
    61      @Override
    62      public void write(byte[] b, int off, int len) throws IOException {
    63          if (len == 0) {
    64              return;
    65          }
    66
    67          buffer.writeBytes(b, off, len);
    68      }
    69
    70      @Override
    71      public void write(byte[] b) throws IOException {
    72          buffer.writeBytes(b);
    73      }
    74
    75      @Override
    76      public void write(int b) throws IOException {
    77          buffer.writeByte((byte) b);
    78      }
    79
    80      public void writeBoolean(boolean v) throws IOException {
    81          write(v? (byte) 1 : (byte) 0);
    82      }
    83
    84      public void writeByte(int v) throws IOException {
    85          write(v);
    86      }
    87
    88      public void writeBytes(String s) throws IOException {
    89          int len = s.length();
    90          for (int i = 0; i < len; i ++) {
    91              write((byte) s.charAt(i));
    92          }
    93      }
    94
    95      public void writeChar(int v) throws IOException {
    96          writeShort((short) v);
    97      }
    98
    99      public void writeChars(String s) throws IOException {
    100         int len = s.length();
    101         for (int i = 0 ; i < len ; i ++) {
    102             writeChar(s.charAt(i));
    103         }
    104     }
    105
    106     public void writeDouble(double v) throws IOException {
    107         writeLong(Double.doubleToLongBits(v));
    108     }
    109
    110     public void writeFloat(float v) throws IOException {
    111         writeInt(Float.floatToIntBits(v));
    112     }
    113
    114     public void writeInt(int v) throws IOException {
    115         buffer.writeInt(v);
    116     }
    117
    118     public void writeLong(long v) throws IOException {
    119         buffer.writeLong(v);
    120     }
    121
    122     public void writeShort(int v) throws IOException {
    123         buffer.writeShort((short) v);
    124     }
    125
    126     public void writeUTF(String s) throws IOException {
    127         utf8out.writeUTF(s);
    128     }
    129
    130     /**
    131      * Returns the buffer where this stream is writing data.
    132      */
    133     public ChannelBuffer buffer() {
    134         return buffer;
    135     }
    136 }