/*
 * Copyright (C) 2007 The Guava Authors
 *
 * Licensed 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 com.google.common.io;

import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.base.Preconditions;
import com.google.common.primitives.Longs;
import java.io.DataOutput;
import java.io.DataOutputStream;
import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;

An implementation of DataOutput that uses little-endian byte ordering for writing char, short, int, float, double, and long values.

Note: This class intentionally violates the specification of its supertype DataOutput, which explicitly requires big-endian byte order.

Author:Chris Nokleberg, Keith Bottner
Since:8.0
/** * An implementation of {@link DataOutput} that uses little-endian byte ordering for writing {@code * char}, {@code short}, {@code int}, {@code float}, {@code double}, and {@code long} values. * * <p><b>Note:</b> This class intentionally violates the specification of its supertype {@code * DataOutput}, which explicitly requires big-endian byte order. * * @author Chris Nokleberg * @author Keith Bottner * @since 8.0 */
@Beta @GwtIncompatible public final class LittleEndianDataOutputStream extends FilterOutputStream implements DataOutput {
Creates a LittleEndianDataOutputStream that wraps the given stream.
Params:
  • out – the stream to delegate to
/** * Creates a {@code LittleEndianDataOutputStream} that wraps the given stream. * * @param out the stream to delegate to */
public LittleEndianDataOutputStream(OutputStream out) { super(new DataOutputStream(Preconditions.checkNotNull(out))); } @Override public void write(byte[] b, int off, int len) throws IOException { // Override slow FilterOutputStream impl out.write(b, off, len); } @Override public void writeBoolean(boolean v) throws IOException { ((DataOutputStream) out).writeBoolean(v); } @Override public void writeByte(int v) throws IOException { ((DataOutputStream) out).writeByte(v); }
Deprecated:The semantics of writeBytes(String s) are considered dangerous. Please use writeUTF(String s), writeChars(String s) or another write method instead.
/** * @deprecated The semantics of {@code writeBytes(String s)} are considered dangerous. Please use * {@link #writeUTF(String s)}, {@link #writeChars(String s)} or another write method instead. */
@Deprecated @Override public void writeBytes(String s) throws IOException { ((DataOutputStream) out).writeBytes(s); }
Writes a char as specified by DataOutputStream.writeChar(int), except using little-endian byte order.
Throws:
/** * Writes a char as specified by {@link DataOutputStream#writeChar(int)}, except using * little-endian byte order. * * @throws IOException if an I/O error occurs */
@Override public void writeChar(int v) throws IOException { writeShort(v); }
Writes a String as specified by DataOutputStream.writeChars(String), except each character is written using little-endian byte order.
Throws:
/** * Writes a {@code String} as specified by {@link DataOutputStream#writeChars(String)}, except * each character is written using little-endian byte order. * * @throws IOException if an I/O error occurs */
@Override public void writeChars(String s) throws IOException { for (int i = 0; i < s.length(); i++) { writeChar(s.charAt(i)); } }
Writes a double as specified by DataOutputStream.writeDouble(double), except using little-endian byte order.
Throws:
/** * Writes a {@code double} as specified by {@link DataOutputStream#writeDouble(double)}, except * using little-endian byte order. * * @throws IOException if an I/O error occurs */
@Override public void writeDouble(double v) throws IOException { writeLong(Double.doubleToLongBits(v)); }
Writes a float as specified by DataOutputStream.writeFloat(float), except using little-endian byte order.
Throws:
/** * Writes a {@code float} as specified by {@link DataOutputStream#writeFloat(float)}, except using * little-endian byte order. * * @throws IOException if an I/O error occurs */
@Override public void writeFloat(float v) throws IOException { writeInt(Float.floatToIntBits(v)); }
Writes an int as specified by DataOutputStream.writeInt(int), except using little-endian byte order.
Throws:
/** * Writes an {@code int} as specified by {@link DataOutputStream#writeInt(int)}, except using * little-endian byte order. * * @throws IOException if an I/O error occurs */
@Override public void writeInt(int v) throws IOException { out.write(0xFF & v); out.write(0xFF & (v >> 8)); out.write(0xFF & (v >> 16)); out.write(0xFF & (v >> 24)); }
Writes a long as specified by DataOutputStream.writeLong(long), except using little-endian byte order.
Throws:
/** * Writes a {@code long} as specified by {@link DataOutputStream#writeLong(long)}, except using * little-endian byte order. * * @throws IOException if an I/O error occurs */
@Override public void writeLong(long v) throws IOException { byte[] bytes = Longs.toByteArray(Long.reverseBytes(v)); write(bytes, 0, bytes.length); }
Writes a short as specified by DataOutputStream.writeShort(int), except using little-endian byte order.
Throws:
/** * Writes a {@code short} as specified by {@link DataOutputStream#writeShort(int)}, except using * little-endian byte order. * * @throws IOException if an I/O error occurs */
@Override public void writeShort(int v) throws IOException { out.write(0xFF & v); out.write(0xFF & (v >> 8)); } @Override public void writeUTF(String str) throws IOException { ((DataOutputStream) out).writeUTF(str); } // Overriding close() because FilterOutputStream's close() method pre-JDK8 has bad behavior: // it silently ignores any exception thrown by flush(). Instead, just close the delegate stream. // It should flush itself if necessary. @Override public void close() throws IOException { out.close(); } }