Java tutorial
/* * Copyright 2012 The Netty Project * * The Netty Project licenses this file to you under the Apache License, * version 2.0 (the "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. */ package io.netty.buffer; import io.netty.util.CharsetUtil; import io.netty.util.internal.ObjectUtil; import java.io.DataOutput; import java.io.DataOutputStream; import java.io.IOException; import java.io.OutputStream; /** * An {@link OutputStream} which writes data to a {@link ByteBuf}. * <p> * A write operation against this stream will occur at the {@code writerIndex} * of its underlying buffer and the {@code writerIndex} will increase during * the write operation. * <p> * This stream implements {@link DataOutput} for your convenience. * The endianness of the stream is not always big endian but depends on * the endianness of the underlying buffer. * * @see ByteBufInputStream */ public class ByteBufOutputStream extends OutputStream implements DataOutput { private final ByteBuf buffer; private final int startIndex; private final DataOutputStream utf8out = new DataOutputStream(this); /** * Creates a new stream which writes data to the specified {@code buffer}. */ public ByteBufOutputStream(ByteBuf buffer) { this.buffer = ObjectUtil.checkNotNull(buffer, "buffer"); startIndex = buffer.writerIndex(); } /** * Returns the number of written bytes by this stream so far. */ public int writtenBytes() { return buffer.writerIndex() - startIndex; } @Override public void write(byte[] b, int off, int len) throws IOException { if (len == 0) { return; } buffer.writeBytes(b, off, len); } @Override public void write(byte[] b) throws IOException { buffer.writeBytes(b); } @Override public void write(int b) throws IOException { buffer.writeByte(b); } @Override public void writeBoolean(boolean v) throws IOException { buffer.writeBoolean(v); } @Override public void writeByte(int v) throws IOException { buffer.writeByte(v); } @Override public void writeBytes(String s) throws IOException { buffer.writeCharSequence(s, CharsetUtil.US_ASCII); } @Override public void writeChar(int v) throws IOException { buffer.writeChar(v); } @Override public void writeChars(String s) throws IOException { int len = s.length(); for (int i = 0; i < len; i++) { buffer.writeChar(s.charAt(i)); } } @Override public void writeDouble(double v) throws IOException { buffer.writeDouble(v); } @Override public void writeFloat(float v) throws IOException { buffer.writeFloat(v); } @Override public void writeInt(int v) throws IOException { buffer.writeInt(v); } @Override public void writeLong(long v) throws IOException { buffer.writeLong(v); } @Override public void writeShort(int v) throws IOException { buffer.writeShort((short) v); } @Override public void writeUTF(String s) throws IOException { utf8out.writeUTF(s); } /** * Returns the buffer where this stream is writing data. */ public ByteBuf buffer() { return buffer; } }