src/main/java/org/apache/commons/io/EndianUtils.java - commons-io - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF 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 org.apache.commons.io;

 import static org.apache.commons.io.IOUtils.EOF;

 import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;

 /**
  * Helps with reading and writing primitive numeric types ({@code short},
  * {@code int}, {@code long}, {@code float}, and {@code double}) that are
  * encoded in little endian using two's complement or unsigned representations.
  * <p>
  * Different computer architectures have different conventions for
  * byte ordering. In "Little Endian" architectures (e.g. X86),
  * the low-order byte is stored in memory at the lowest address, and
  * subsequent bytes at higher addresses. In "Big Endian" architectures
  * (e.g. Motorola 680X0), the situation is reversed.
  * Most methods and classes throughout Java &mdash; e.g. {@code DataInputStream} and
  * {@code Double.longBitsToDouble()} &mdash; assume data is laid out
  * in big endian order with the most significant byte first.
  * The methods in this class read and write data in little endian order,
  * generally by reversing the bytes and then using the
  * regular Java methods to convert the swapped bytes to a primitive type.
  * </p>
  * <p>
  * Provenance: Excalibur
  * </p>
  *
  * @see org.apache.commons.io.input.SwappedDataInputStream
  */
 public class EndianUtils {

     /**
      * Reads the next byte from the input stream.
      * @param input  the stream
      * @return the byte
      * @throws IOException if the end of file is reached
      */
     private static int read(final InputStream input) throws IOException {
         final int value = input.read();
         if (EOF == value) {
             throw new EOFException("Unexpected EOF reached");
         }
         return value;
     }

     /**
      * Reads a little endian {@code double} value from a byte array at a given offset.
      *
      * @param data source byte array
      * @param offset starting offset in the byte array
      * @return the value read
      * @throws IllegalArgumentException if the part of the byte array starting at offset does not have at least 8 bytes
      */
     public static double readSwappedDouble(final byte[] data, final int offset) {
         return Double.longBitsToDouble(readSwappedLong(data, offset));
     }

     /**
      * Reads a little endian {@code double} value from an InputStream.
      *
      * @param input source InputStream
      * @return the value just read
      * @throws IOException in case of an I/O problem
      */
     public static double readSwappedDouble(final InputStream input) throws IOException {
         return Double.longBitsToDouble(readSwappedLong(input));
     }

     /**
      * Reads a little endian {@code float} value from a byte array at a given offset.
      *
      * @param data source byte array
      * @param offset starting offset in the byte array
      * @return the value read
      * @throws IllegalArgumentException if the part of the byte array starting at offset does not have at least 4 bytes
      */
     public static float readSwappedFloat(final byte[] data, final int offset) {
         return Float.intBitsToFloat(readSwappedInteger(data, offset));
     }

     /**
      * Reads a little endian {@code float} value from an InputStream.
      *
      * @param input source InputStream
      * @return the value just read
      * @throws IOException in case of an I/O problem
      */
     public static float readSwappedFloat(final InputStream input) throws IOException {
         return Float.intBitsToFloat(readSwappedInteger(input));
     }

     /**
      * Reads a little endian {@code int} value from a byte array at a given offset.
      *
      * @param data source byte array
      * @param offset starting offset in the byte array
      * @return the value read
      * @throws IllegalArgumentException if the part of the byte array starting at offset does not have at least 4 bytes
      */
     public static int readSwappedInteger(final byte[] data, final int offset) {
         validateByteArrayOffset(data, offset, Integer.SIZE / Byte.SIZE);
         return ((data[offset + 0] & 0xff) << 0) +
             ((data[offset + 1] & 0xff) << 8) +
             ((data[offset + 2] & 0xff) << 16) +
             ((data[offset + 3] & 0xff) << 24);
     }

     /**
      * Reads a little endian {@code int} value from an InputStream.
      *
      * @param input source InputStream
      * @return the value just read
      * @throws IOException in case of an I/O problem
      */
     public static int readSwappedInteger(final InputStream input) throws IOException {
         final int value1 = read(input);
         final int value2 = read(input);
         final int value3 = read(input);
         final int value4 = read(input);
         return ((value1 & 0xff) << 0) + ((value2 & 0xff) << 8) + ((value3 & 0xff) << 16) + ((value4 & 0xff) << 24);
     }

     /**
      * Reads a little endian {@code long} value from a byte array at a given offset.
      *
      * @param data source byte array
      * @param offset starting offset in the byte array
      * @return the value read
      * @throws IllegalArgumentException if the part of the byte array starting at offset does not have at least 8 bytes
      */
     public static long readSwappedLong(final byte[] data, final int offset) {
         validateByteArrayOffset(data, offset, Long.SIZE / Byte.SIZE);
         final long low = readSwappedInteger(data, offset);
         final long high = readSwappedInteger(data, offset + 4);
         return (high << 32) + (0xffffffffL & low);
     }

     /**
      * Reads a little endian {@code long} value from an InputStream.
      *
      * @param input source InputStream
      * @return the value just read
      * @throws IOException in case of an I/O problem
      */
     public static long readSwappedLong(final InputStream input) throws IOException {
         final byte[] bytes = new byte[8];
         for (int i = 0; i < 8; i++) {
             bytes[i] = (byte) read(input);
         }
         return readSwappedLong(bytes, 0);
     }

     /**
      * Reads a little endian {@code short} value from a byte array at a given offset.
      *
      * @param data source byte array
      * @param offset starting offset in the byte array
      * @return the value read
      * @throws IllegalArgumentException if the part of the byte array starting at offset does not have at least 2 bytes
      */
     public static short readSwappedShort(final byte[] data, final int offset) {
         validateByteArrayOffset(data, offset, Short.SIZE / Byte.SIZE);
         return (short) (((data[offset + 0] & 0xff) << 0) + ((data[offset + 1] & 0xff) << 8));
     }

     /**
      * Reads a little endian {@code short} value from an InputStream.
      *
      * @param input source InputStream
      * @return the value just read
      * @throws IOException in case of an I/O problem
      */
     public static short readSwappedShort(final InputStream input) throws IOException {
         return (short) (((read(input) & 0xff) << 0) + ((read(input) & 0xff) << 8));
     }

     /**
      * Reads a little endian unsigned integer (32-bit) value from a byte array at a given
      * offset.
      *
      * @param data source byte array
      * @param offset starting offset in the byte array
      * @return the value read
      * @throws IllegalArgumentException if the part of the byte array starting at offset does not have at least 4 bytes
     */
     public static long readSwappedUnsignedInteger(final byte[] data, final int offset) {
         validateByteArrayOffset(data, offset, Integer.SIZE / Byte.SIZE);
         final long low = ((data[offset + 0] & 0xff) << 0) +
                      ((data[offset + 1] & 0xff) << 8) +
                      ((data[offset + 2] & 0xff) << 16);
         final long high = data[offset + 3] & 0xff;
         return (high << 24) + (0xffffffffL & low);
     }

     /**
      * Reads a little endian unsigned integer (32-bit) from an InputStream.
      *
      * @param input source InputStream
      * @return the value just read
      * @throws IOException in case of an I/O problem
      */
     public static long readSwappedUnsignedInteger(final InputStream input) throws IOException {
         final int value1 = read(input);
         final int value2 = read(input);
         final int value3 = read(input);
         final int value4 = read(input);
         final long low = ((value1 & 0xff) << 0) + ((value2 & 0xff) << 8) + ((value3 & 0xff) << 16);
         final long high = value4 & 0xff;
         return (high << 24) + (0xffffffffL & low);
     }

     /**
      * Reads an unsigned short (16-bit) value from a byte array in little endian order at a given
      * offset.
      *
      * @param data source byte array
      * @param offset starting offset in the byte array
      * @return the value read
      * @throws IllegalArgumentException if the part of the byte array starting at offset does not have at least 2 bytes
      */
     public static int readSwappedUnsignedShort(final byte[] data, final int offset) {
         validateByteArrayOffset(data, offset, Short.SIZE / Byte.SIZE);
         return ((data[offset + 0] & 0xff) << 0) + ((data[offset + 1] & 0xff) << 8);
     }

     /**
      * Reads an unsigned short (16-bit) from an InputStream in little endian order.
      *
      * @param input source InputStream
      * @return the value just read
      * @throws IOException in case of an I/O problem
      */
     public static int readSwappedUnsignedShort(final InputStream input) throws IOException {
         final int value1 = read(input);
         final int value2 = read(input);

         return ((value1 & 0xff) << 0) + ((value2 & 0xff) << 8);
     }

     /**
      * Converts a {@code double} value from big endian to little endian
      * and vice versa. That is, it converts the {@code double} to bytes,
      * reverses the bytes, and then reinterprets those bytes as a new {@code double}.
      * This can be useful if you have a number that was read from the
      * underlying source in the wrong endianness.
      *
      * @param value value to convert
      * @return the converted value
      */
     public static double swapDouble(final double value) {
         return Double.longBitsToDouble(swapLong(Double.doubleToLongBits(value)));
     }

     /**
      * Converts a {@code float} value from big endian to little endian and vice versa.
      *
      * @param value value to convert
      * @return the converted value
      */
     public static float swapFloat(final float value) {
         return Float.intBitsToFloat(swapInteger(Float.floatToIntBits(value)));
     }

     /**
      * Converts an {@code int} value from big endian to little endian and vice versa.
      *
      * @param value value to convert
      * @return the converted value
      */
     public static int swapInteger(final int value) {
         return
             ((value >> 0 & 0xff) << 24) +
             ((value >> 8 & 0xff) << 16) +
             ((value >> 16 & 0xff) << 8) +
             ((value >> 24 & 0xff) << 0);
     }

     /**
      * Converts a {@code long} value from big endian to little endian and vice versa.
      *
      * @param value value to convert
      * @return the converted value
      */
     public static long swapLong(final long value) {
         return
             ((value >> 0 & 0xff) << 56) +
             ((value >> 8 & 0xff) << 48) +
             ((value >> 16 & 0xff) << 40) +
             ((value >> 24 & 0xff) << 32) +
             ((value >> 32 & 0xff) << 24) +
             ((value >> 40 & 0xff) << 16) +
             ((value >> 48 & 0xff) << 8) +
             ((value >> 56 & 0xff) << 0);
     }

     /**
      * Converts a {@code short} value from big endian to little endian and vice versa.
      *
      * @param value value to convert
      * @return the converted value
      */
     public static short swapShort(final short value) {
         return (short) (((value >> 0 & 0xff) << 8) +
             ((value >> 8 & 0xff) << 0));
     }

     /**
      * Validates if the provided byte array has enough data.
      *
      * @param data the input byte array
      * @param offset the input offset
      * @param byteNeeded the needed number of bytes
      * @throws IllegalArgumentException if the byte array does not have enough data
      */
     private static void validateByteArrayOffset(final byte[] data, final int offset, final int byteNeeded) {
         if (data.length < offset + byteNeeded) {
             throw new IllegalArgumentException("Data only has " + data.length + "bytes, needed " + (offset + byteNeeded) + "bytes.");
         }
     }

     /**
      * Writes the 8 bytes of a {@code double} to a byte array at a given offset in little endian order.
      *
      * @param data target byte array
      * @param offset starting offset in the byte array
      * @param value value to write
      * @throws IllegalArgumentException if the part of the byte array starting at offset does not have at least 8 bytes
      */
     public static void writeSwappedDouble(final byte[] data, final int offset, final double value) {
         writeSwappedLong(data, offset, Double.doubleToLongBits(value));
     }

     /**
      * Writes the 8 bytes of a {@code double} to an output stream in little endian order.
      *
      * @param output target OutputStream
      * @param value value to write
      * @throws IOException in case of an I/O problem
      */
     public static void writeSwappedDouble(final OutputStream output, final double value) throws IOException {
         writeSwappedLong(output, Double.doubleToLongBits(value));
     }

     /**
      * Writes the 4 bytes of a {@code float} to a byte array at a given offset in little endian order.
      *
      * @param data target byte array
      * @param offset starting offset in the byte array
      * @param value value to write
      * @throws IllegalArgumentException if the part of the byte array starting at offset does not have at least 4 bytes
      */
     public static void writeSwappedFloat(final byte[] data, final int offset, final float value) {
         writeSwappedInteger(data, offset, Float.floatToIntBits(value));
     }

     /**
      * Writes the 4 bytes of a {@code float} to an output stream in little endian order.
      *
      * @param output target OutputStream
      * @param value value to write
      * @throws IOException in case of an I/O problem
     */
     public static void writeSwappedFloat(final OutputStream output, final float value) throws IOException {
         writeSwappedInteger(output, Float.floatToIntBits(value));
     }

     /**
      * Writes the 4 bytes of an {@code int} to a byte array at a given offset in little endian order.
      *
      * @param data target byte array
      * @param offset starting offset in the byte array
      * @param value value to write
      * @throws IllegalArgumentException if the part of the byte array starting at offset does not have at least 4 bytes
      */
     public static void writeSwappedInteger(final byte[] data, final int offset, final int value) {
         validateByteArrayOffset(data, offset, Integer.SIZE / Byte.SIZE);
         data[offset + 0] = (byte) (value >> 0 & 0xff);
         data[offset + 1] = (byte) (value >> 8 & 0xff);
         data[offset + 2] = (byte) (value >> 16 & 0xff);
         data[offset + 3] = (byte) (value >> 24 & 0xff);
     }

     /**
      * Writes the 4 bytes of an {@code int} to an output stream in little endian order.
      *
      * @param output target OutputStream
      * @param value value to write
      * @throws IOException in case of an I/O problem
      */
     public static void writeSwappedInteger(final OutputStream output, final int value) throws IOException {
         output.write((byte) (value >> 0 & 0xff));
         output.write((byte) (value >> 8 & 0xff));
         output.write((byte) (value >> 16 & 0xff));
         output.write((byte) (value >> 24 & 0xff));
     }

     /**
      * Writes the 8 bytes of a {@code long} to a byte array at a given offset in little endian order.
      *
      * @param data target byte array
      * @param offset starting offset in the byte array
      * @param value value to write
      * @throws IllegalArgumentException if the part of the byte array starting at offset does not have at least 8 bytes
      */
     public static void writeSwappedLong(final byte[] data, final int offset, final long value) {
         validateByteArrayOffset(data, offset, Long.SIZE / Byte.SIZE);
         data[offset + 0] = (byte) (value >> 0 & 0xff);
         data[offset + 1] = (byte) (value >> 8 & 0xff);
         data[offset + 2] = (byte) (value >> 16 & 0xff);
         data[offset + 3] = (byte) (value >> 24 & 0xff);
         data[offset + 4] = (byte) (value >> 32 & 0xff);
         data[offset + 5] = (byte) (value >> 40 & 0xff);
         data[offset + 6] = (byte) (value >> 48 & 0xff);
         data[offset + 7] = (byte) (value >> 56 & 0xff);
     }

     /**
      * Writes the 8 bytes of a {@code long} to an output stream in little endian order.
      *
      * @param output target OutputStream
      * @param value value to write
      * @throws IOException in case of an I/O problem
      */
     public static void writeSwappedLong(final OutputStream output, final long value) throws IOException {
         output.write((byte) (value >> 0 & 0xff));
         output.write((byte) (value >> 8 & 0xff));
         output.write((byte) (value >> 16 & 0xff));
         output.write((byte) (value >> 24 & 0xff));
         output.write((byte) (value >> 32 & 0xff));
         output.write((byte) (value >> 40 & 0xff));
         output.write((byte) (value >> 48 & 0xff));
         output.write((byte) (value >> 56 & 0xff));
     }

     /**
      * Writes the 2 bytes of a {@code short} to a byte array at a given offset in little endian order.
      *
      * @param data target byte array
      * @param offset starting offset in the byte array
      * @param value value to write
      * @throws IllegalArgumentException if the part of the byte array starting at offset does not have at least 2 bytes
      */
     public static void writeSwappedShort(final byte[] data, final int offset, final short value) {
         validateByteArrayOffset(data, offset, Short.SIZE / Byte.SIZE);
         data[offset + 0] = (byte) (value >> 0 & 0xff);
         data[offset + 1] = (byte) (value >> 8 & 0xff);
     }

     /**
      * Writes the 2 bytes of a {@code short} to an output stream using little endian encoding.
      *
      * @param output target OutputStream
      * @param value value to write
      * @throws IOException in case of an I/O problem
      */
     public static void writeSwappedShort(final OutputStream output, final short value) throws IOException {
         output.write((byte) (value >> 0 & 0xff));
         output.write((byte) (value >> 8 & 0xff));
     }

     /**
      * Instances should NOT be constructed in standard programming.
      *
      * @deprecated TODO Make private in 3.0.
      */
     @Deprecated
     public EndianUtils() {
         // empty
     }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF 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 org.apache.commons.io;

	import static org.apache.commons.io.IOUtils.EOF;

	import java.io.EOFException;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.OutputStream;

	/**
	* Helps with reading and writing primitive numeric types ({@code short},
	* {@code int}, {@code long}, {@code float}, and {@code double}) that are
	* encoded in little endian using two's complement or unsigned representations.
	* <p>
	* Different computer architectures have different conventions for
	* byte ordering. In "Little Endian" architectures (e.g. X86),
	* the low-order byte is stored in memory at the lowest address, and
	* subsequent bytes at higher addresses. In "Big Endian" architectures
	* (e.g. Motorola 680X0), the situation is reversed.
	* Most methods and classes throughout Java — e.g. {@code DataInputStream} and
	* {@code Double.longBitsToDouble()} — assume data is laid out
	* in big endian order with the most significant byte first.
	* The methods in this class read and write data in little endian order,
	* generally by reversing the bytes and then using the
	* regular Java methods to convert the swapped bytes to a primitive type.
	* </p>
	* <p>
	* Provenance: Excalibur
	* </p>
	*
	* @see org.apache.commons.io.input.SwappedDataInputStream
	*/
	public class EndianUtils {

	/**
	* Reads the next byte from the input stream.
	* @param input the stream
	* @return the byte
	* @throws IOException if the end of file is reached
	*/
	private static int read(final InputStream input) throws IOException {
	final int value = input.read();
	if (EOF == value) {
	throw new EOFException("Unexpected EOF reached");
	}
	return value;
	}

	/**
	* Reads a little endian {@code double} value from a byte array at a given offset.
	*
	* @param data source byte array
	* @param offset starting offset in the byte array
	* @return the value read
	* @throws IllegalArgumentException if the part of the byte array starting at offset does not have at least 8 bytes
	*/
	public static double readSwappedDouble(final byte[] data, final int offset) {
	return Double.longBitsToDouble(readSwappedLong(data, offset));
	}

	/**
	* Reads a little endian {@code double} value from an InputStream.
	*
	* @param input source InputStream
	* @return the value just read
	* @throws IOException in case of an I/O problem
	*/
	public static double readSwappedDouble(final InputStream input) throws IOException {
	return Double.longBitsToDouble(readSwappedLong(input));
	}

	/**
	* Reads a little endian {@code float} value from a byte array at a given offset.
	*
	* @param data source byte array
	* @param offset starting offset in the byte array
	* @return the value read
	* @throws IllegalArgumentException if the part of the byte array starting at offset does not have at least 4 bytes
	*/
	public static float readSwappedFloat(final byte[] data, final int offset) {
	return Float.intBitsToFloat(readSwappedInteger(data, offset));
	}

	/**
	* Reads a little endian {@code float} value from an InputStream.
	*
	* @param input source InputStream
	* @return the value just read
	* @throws IOException in case of an I/O problem
	*/
	public static float readSwappedFloat(final InputStream input) throws IOException {
	return Float.intBitsToFloat(readSwappedInteger(input));
	}

	/**
	* Reads a little endian {@code int} value from a byte array at a given offset.
	*
	* @param data source byte array
	* @param offset starting offset in the byte array
	* @return the value read
	* @throws IllegalArgumentException if the part of the byte array starting at offset does not have at least 4 bytes
	*/
	public static int readSwappedInteger(final byte[] data, final int offset) {
	validateByteArrayOffset(data, offset, Integer.SIZE / Byte.SIZE);
	return ((data[offset + 0] & 0xff) << 0) +
	((data[offset + 1] & 0xff) << 8) +
	((data[offset + 2] & 0xff) << 16) +
	((data[offset + 3] & 0xff) << 24);
	}

	/**
	* Reads a little endian {@code int} value from an InputStream.
	*
	* @param input source InputStream
	* @return the value just read
	* @throws IOException in case of an I/O problem
	*/
	public static int readSwappedInteger(final InputStream input) throws IOException {
	final int value1 = read(input);
	final int value2 = read(input);
	final int value3 = read(input);
	final int value4 = read(input);
	return ((value1 & 0xff) << 0) + ((value2 & 0xff) << 8) + ((value3 & 0xff) << 16) + ((value4 & 0xff) << 24);
	}

	/**
	* Reads a little endian {@code long} value from a byte array at a given offset.
	*
	* @param data source byte array
	* @param offset starting offset in the byte array
	* @return the value read
	* @throws IllegalArgumentException if the part of the byte array starting at offset does not have at least 8 bytes
	*/
	public static long readSwappedLong(final byte[] data, final int offset) {
	validateByteArrayOffset(data, offset, Long.SIZE / Byte.SIZE);
	final long low = readSwappedInteger(data, offset);
	final long high = readSwappedInteger(data, offset + 4);
	return (high << 32) + (0xffffffffL & low);
	}

	/**
	* Reads a little endian {@code long} value from an InputStream.
	*
	* @param input source InputStream
	* @return the value just read
	* @throws IOException in case of an I/O problem
	*/
	public static long readSwappedLong(final InputStream input) throws IOException {
	final byte[] bytes = new byte[8];
	for (int i = 0; i < 8; i++) {
	bytes[i] = (byte) read(input);
	}
	return readSwappedLong(bytes, 0);
	}

	/**
	* Reads a little endian {@code short} value from a byte array at a given offset.
	*
	* @param data source byte array
	* @param offset starting offset in the byte array
	* @return the value read
	* @throws IllegalArgumentException if the part of the byte array starting at offset does not have at least 2 bytes
	*/
	public static short readSwappedShort(final byte[] data, final int offset) {
	validateByteArrayOffset(data, offset, Short.SIZE / Byte.SIZE);
	return (short) (((data[offset + 0] & 0xff) << 0) + ((data[offset + 1] & 0xff) << 8));
	}

	/**
	* Reads a little endian {@code short} value from an InputStream.
	*
	* @param input source InputStream
	* @return the value just read
	* @throws IOException in case of an I/O problem
	*/
	public static short readSwappedShort(final InputStream input) throws IOException {
	return (short) (((read(input) & 0xff) << 0) + ((read(input) & 0xff) << 8));
	}

	/**
	* Reads a little endian unsigned integer (32-bit) value from a byte array at a given
	* offset.
	*
	* @param data source byte array
	* @param offset starting offset in the byte array
	* @return the value read
	* @throws IllegalArgumentException if the part of the byte array starting at offset does not have at least 4 bytes
	*/
	public static long readSwappedUnsignedInteger(final byte[] data, final int offset) {
	validateByteArrayOffset(data, offset, Integer.SIZE / Byte.SIZE);
	final long low = ((data[offset + 0] & 0xff) << 0) +
	((data[offset + 1] & 0xff) << 8) +
	((data[offset + 2] & 0xff) << 16);
	final long high = data[offset + 3] & 0xff;
	return (high << 24) + (0xffffffffL & low);
	}

	/**
	* Reads a little endian unsigned integer (32-bit) from an InputStream.
	*
	* @param input source InputStream
	* @return the value just read
	* @throws IOException in case of an I/O problem
	*/
	public static long readSwappedUnsignedInteger(final InputStream input) throws IOException {
	final int value1 = read(input);
	final int value2 = read(input);
	final int value3 = read(input);
	final int value4 = read(input);
	final long low = ((value1 & 0xff) << 0) + ((value2 & 0xff) << 8) + ((value3 & 0xff) << 16);
	final long high = value4 & 0xff;
	return (high << 24) + (0xffffffffL & low);
	}

	/**
	* Reads an unsigned short (16-bit) value from a byte array in little endian order at a given
	* offset.
	*
	* @param data source byte array
	* @param offset starting offset in the byte array
	* @return the value read
	* @throws IllegalArgumentException if the part of the byte array starting at offset does not have at least 2 bytes
	*/
	public static int readSwappedUnsignedShort(final byte[] data, final int offset) {
	validateByteArrayOffset(data, offset, Short.SIZE / Byte.SIZE);
	return ((data[offset + 0] & 0xff) << 0) + ((data[offset + 1] & 0xff) << 8);
	}

	/**
	* Reads an unsigned short (16-bit) from an InputStream in little endian order.
	*
	* @param input source InputStream
	* @return the value just read
	* @throws IOException in case of an I/O problem
	*/
	public static int readSwappedUnsignedShort(final InputStream input) throws IOException {
	final int value1 = read(input);
	final int value2 = read(input);

	return ((value1 & 0xff) << 0) + ((value2 & 0xff) << 8);
	}

	/**
	* Converts a {@code double} value from big endian to little endian
	* and vice versa. That is, it converts the {@code double} to bytes,
	* reverses the bytes, and then reinterprets those bytes as a new {@code double}.
	* This can be useful if you have a number that was read from the
	* underlying source in the wrong endianness.
	*
	* @param value value to convert
	* @return the converted value
	*/
	public static double swapDouble(final double value) {
	return Double.longBitsToDouble(swapLong(Double.doubleToLongBits(value)));
	}

	/**
	* Converts a {@code float} value from big endian to little endian and vice versa.
	*
	* @param value value to convert
	* @return the converted value
	*/
	public static float swapFloat(final float value) {
	return Float.intBitsToFloat(swapInteger(Float.floatToIntBits(value)));
	}

	/**
	* Converts an {@code int} value from big endian to little endian and vice versa.
	*
	* @param value value to convert
	* @return the converted value
	*/
	public static int swapInteger(final int value) {
	return
	((value >> 0 & 0xff) << 24) +
	((value >> 8 & 0xff) << 16) +
	((value >> 16 & 0xff) << 8) +
	((value >> 24 & 0xff) << 0);
	}

	/**
	* Converts a {@code long} value from big endian to little endian and vice versa.
	*
	* @param value value to convert
	* @return the converted value
	*/
	public static long swapLong(final long value) {
	return
	((value >> 0 & 0xff) << 56) +
	((value >> 8 & 0xff) << 48) +
	((value >> 16 & 0xff) << 40) +
	((value >> 24 & 0xff) << 32) +
	((value >> 32 & 0xff) << 24) +
	((value >> 40 & 0xff) << 16) +
	((value >> 48 & 0xff) << 8) +
	((value >> 56 & 0xff) << 0);
	}

	/**
	* Converts a {@code short} value from big endian to little endian and vice versa.
	*
	* @param value value to convert
	* @return the converted value
	*/
	public static short swapShort(final short value) {
	return (short) (((value >> 0 & 0xff) << 8) +
	((value >> 8 & 0xff) << 0));
	}

	/**
	* Validates if the provided byte array has enough data.
	*
	* @param data the input byte array
	* @param offset the input offset
	* @param byteNeeded the needed number of bytes
	* @throws IllegalArgumentException if the byte array does not have enough data
	*/
	private static void validateByteArrayOffset(final byte[] data, final int offset, final int byteNeeded) {
	if (data.length < offset + byteNeeded) {
	throw new IllegalArgumentException("Data only has " + data.length + "bytes, needed " + (offset + byteNeeded) + "bytes.");
	}
	}

	/**
	* Writes the 8 bytes of a {@code double} to a byte array at a given offset in little endian order.
	*
	* @param data target byte array
	* @param offset starting offset in the byte array
	* @param value value to write
	* @throws IllegalArgumentException if the part of the byte array starting at offset does not have at least 8 bytes
	*/
	public static void writeSwappedDouble(final byte[] data, final int offset, final double value) {
	writeSwappedLong(data, offset, Double.doubleToLongBits(value));
	}

	/**
	* Writes the 8 bytes of a {@code double} to an output stream in little endian order.
	*
	* @param output target OutputStream
	* @param value value to write
	* @throws IOException in case of an I/O problem
	*/
	public static void writeSwappedDouble(final OutputStream output, final double value) throws IOException {
	writeSwappedLong(output, Double.doubleToLongBits(value));
	}

	/**
	* Writes the 4 bytes of a {@code float} to a byte array at a given offset in little endian order.
	*
	* @param data target byte array
	* @param offset starting offset in the byte array
	* @param value value to write
	* @throws IllegalArgumentException if the part of the byte array starting at offset does not have at least 4 bytes
	*/
	public static void writeSwappedFloat(final byte[] data, final int offset, final float value) {
	writeSwappedInteger(data, offset, Float.floatToIntBits(value));
	}

	/**
	* Writes the 4 bytes of a {@code float} to an output stream in little endian order.
	*
	* @param output target OutputStream
	* @param value value to write
	* @throws IOException in case of an I/O problem
	*/
	public static void writeSwappedFloat(final OutputStream output, final float value) throws IOException {
	writeSwappedInteger(output, Float.floatToIntBits(value));
	}

	/**
	* Writes the 4 bytes of an {@code int} to a byte array at a given offset in little endian order.
	*
	* @param data target byte array
	* @param offset starting offset in the byte array
	* @param value value to write
	* @throws IllegalArgumentException if the part of the byte array starting at offset does not have at least 4 bytes
	*/
	public static void writeSwappedInteger(final byte[] data, final int offset, final int value) {
	validateByteArrayOffset(data, offset, Integer.SIZE / Byte.SIZE);
	data[offset + 0] = (byte) (value >> 0 & 0xff);
	data[offset + 1] = (byte) (value >> 8 & 0xff);
	data[offset + 2] = (byte) (value >> 16 & 0xff);
	data[offset + 3] = (byte) (value >> 24 & 0xff);
	}

	/**
	* Writes the 4 bytes of an {@code int} to an output stream in little endian order.
	*
	* @param output target OutputStream
	* @param value value to write
	* @throws IOException in case of an I/O problem
	*/
	public static void writeSwappedInteger(final OutputStream output, final int value) throws IOException {
	output.write((byte) (value >> 0 & 0xff));
	output.write((byte) (value >> 8 & 0xff));
	output.write((byte) (value >> 16 & 0xff));
	output.write((byte) (value >> 24 & 0xff));
	}

	/**
	* Writes the 8 bytes of a {@code long} to a byte array at a given offset in little endian order.
	*
	* @param data target byte array
	* @param offset starting offset in the byte array
	* @param value value to write
	* @throws IllegalArgumentException if the part of the byte array starting at offset does not have at least 8 bytes
	*/
	public static void writeSwappedLong(final byte[] data, final int offset, final long value) {
	validateByteArrayOffset(data, offset, Long.SIZE / Byte.SIZE);
	data[offset + 0] = (byte) (value >> 0 & 0xff);
	data[offset + 1] = (byte) (value >> 8 & 0xff);
	data[offset + 2] = (byte) (value >> 16 & 0xff);
	data[offset + 3] = (byte) (value >> 24 & 0xff);
	data[offset + 4] = (byte) (value >> 32 & 0xff);
	data[offset + 5] = (byte) (value >> 40 & 0xff);
	data[offset + 6] = (byte) (value >> 48 & 0xff);
	data[offset + 7] = (byte) (value >> 56 & 0xff);
	}

	/**
	* Writes the 8 bytes of a {@code long} to an output stream in little endian order.
	*
	* @param output target OutputStream
	* @param value value to write
	* @throws IOException in case of an I/O problem
	*/
	public static void writeSwappedLong(final OutputStream output, final long value) throws IOException {
	output.write((byte) (value >> 0 & 0xff));
	output.write((byte) (value >> 8 & 0xff));
	output.write((byte) (value >> 16 & 0xff));
	output.write((byte) (value >> 24 & 0xff));
	output.write((byte) (value >> 32 & 0xff));
	output.write((byte) (value >> 40 & 0xff));
	output.write((byte) (value >> 48 & 0xff));
	output.write((byte) (value >> 56 & 0xff));
	}

	/**
	* Writes the 2 bytes of a {@code short} to a byte array at a given offset in little endian order.
	*
	* @param data target byte array
	* @param offset starting offset in the byte array
	* @param value value to write
	* @throws IllegalArgumentException if the part of the byte array starting at offset does not have at least 2 bytes
	*/
	public static void writeSwappedShort(final byte[] data, final int offset, final short value) {
	validateByteArrayOffset(data, offset, Short.SIZE / Byte.SIZE);
	data[offset + 0] = (byte) (value >> 0 & 0xff);
	data[offset + 1] = (byte) (value >> 8 & 0xff);
	}

	/**
	* Writes the 2 bytes of a {@code short} to an output stream using little endian encoding.
	*
	* @param output target OutputStream
	* @param value value to write
	* @throws IOException in case of an I/O problem
	*/
	public static void writeSwappedShort(final OutputStream output, final short value) throws IOException {
	output.write((byte) (value >> 0 & 0xff));
	output.write((byte) (value >> 8 & 0xff));
	}

	/**
	* Instances should NOT be constructed in standard programming.
	*
	* @deprecated TODO Make private in 3.0.
	*/
	@Deprecated
	public EndianUtils() {
	// empty
	}
	}