/*
* 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.input;
import java.io.DataInput;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import org.apache.commons.io.EndianUtils;
/**
* DataInput for systems relying on little endian data formats. When read,
* values will be changed from little endian to big endian formats for internal
* usage.
* <p>
* <b>Origin of code: </b>Avalon Excalibur (IO)
*
* @version CVS $Revision: 1302050 $
*/
public class SwappedDataInputStream extends ProxyInputStream implements
DataInput {
/**
* Constructs a SwappedDataInputStream.
*
* @param input InputStream to read from
*/
public SwappedDataInputStream(InputStream input) {
super(input);
}
/**
* Return <code>{@link #readByte()} != 0</code>
*
* @return false if the byte read is zero, otherwise true
* @throws IOException if an I/O error occurs
* @throws EOFException if an end of file is reached unexpectedly
*/
public boolean readBoolean() throws IOException, EOFException {
return 0 != readByte();
}
/**
* Invokes the delegate's <code>read()</code> method.
*
* @return the byte read or -1 if the end of stream
* @throws IOException if an I/O error occurs
* @throws EOFException if an end of file is reached unexpectedly
*/
public byte readByte() throws IOException, EOFException {
return (byte) in.read();
}
/**
* Reads a character delegating to {@link #readShort()}.
*
* @return the byte read or -1 if the end of stream
* @throws IOException if an I/O error occurs
* @throws EOFException if an end of file is reached unexpectedly
*/
public char readChar() throws IOException, EOFException {
return (char) readShort();
}
/**
* Delegates to {@link EndianUtils#readSwappedDouble(InputStream)}.
*
* @return the read long
* @throws IOException if an I/O error occurs
* @throws EOFException if an end of file is reached unexpectedly
*/
public double readDouble() throws IOException, EOFException {
return EndianUtils.readSwappedDouble(in);
}
/**
* Delegates to {@link EndianUtils#readSwappedFloat(InputStream)}.
*
* @return the read long
* @throws IOException if an I/O error occurs
* @throws EOFException if an end of file is reached unexpectedly
*/
public float readFloat() throws IOException, EOFException {
return EndianUtils.readSwappedFloat(in);
}
/**
* Invokes the delegate's <code>read(byte[] data, int, int)</code> method.
*
* @param data the buffer to read the bytes into
* @throws EOFException if an end of file is reached unexpectedly
* @throws IOException if an I/O error occurs
*/
public void readFully(byte[] data) throws IOException, EOFException {
readFully(data, 0, data.length);
}
/**
* Invokes the delegate's <code>read(byte[] data, int, int)</code> method.
*
* @param data the buffer to read the bytes into
* @param offset The start offset
* @param length The number of bytes to read
* @throws EOFException if an end of file is reached unexpectedly
* @throws IOException if an I/O error occurs
*/
public void readFully(byte[] data, int offset, int length)
throws IOException, EOFException {
int remaining = length;
while (remaining > 0) {
int location = offset + length - remaining;
int count = read(data, location, remaining);
if (-1 == count) {
throw new EOFException();
}
remaining -= count;
}
}
/**
* Delegates to {@link EndianUtils#readSwappedInteger(InputStream)}.
*
* @return the read long
* @throws EOFException if an end of file is reached unexpectedly
* @throws IOException if an I/O error occurs
*/
public int readInt() throws IOException, EOFException {
return EndianUtils.readSwappedInteger(in);
}
/**
* Not currently supported - throws {@link UnsupportedOperationException}.
*
* @return the line read
* @throws EOFException if an end of file is reached unexpectedly
* @throws IOException if an I/O error occurs
*/
public String readLine() throws IOException, EOFException {
throw new UnsupportedOperationException(
"Operation not supported: readLine()");
}
/**
* Delegates to {@link EndianUtils#readSwappedLong(InputStream)}.
*
* @return the read long
* @throws EOFException if an end of file is reached unexpectedly
* @throws IOException if an I/O error occurs
*/
public long readLong() throws IOException, EOFException {
return EndianUtils.readSwappedLong(in);
}
/**
* Delegates to {@link EndianUtils#readSwappedShort(InputStream)}.
*
* @return the read long
* @throws EOFException if an end of file is reached unexpectedly
* @throws IOException if an I/O error occurs
*/
public short readShort() throws IOException, EOFException {
return EndianUtils.readSwappedShort(in);
}
/**
* Invokes the delegate's <code>read()</code> method.
*
* @return the byte read or -1 if the end of stream
* @throws EOFException if an end of file is reached unexpectedly
* @throws IOException if an I/O error occurs
*/
public int readUnsignedByte() throws IOException, EOFException {
return in.read();
}
/**
* Delegates to {@link EndianUtils#readSwappedUnsignedShort(InputStream)}.
*
* @return the read long
* @throws EOFException if an end of file is reached unexpectedly
* @throws IOException if an I/O error occurs
*/
public int readUnsignedShort() throws IOException, EOFException {
return EndianUtils.readSwappedUnsignedShort(in);
}
/**
* Not currently supported - throws {@link UnsupportedOperationException}.
*
* @return UTF String read
* @throws EOFException if an end of file is reached unexpectedly
* @throws IOException if an I/O error occurs
*/
public String readUTF() throws IOException, EOFException {
throw new UnsupportedOperationException(
"Operation not supported: readUTF()");
}
/**
* Invokes the delegate's <code>skip(int)</code> method.
*
* @param count the number of bytes to skip
* @return the number of bytes to skipped or -1 if the end of stream
* @throws EOFException if an end of file is reached unexpectedly
* @throws IOException if an I/O error occurs
*/
public int skipBytes(int count) throws IOException, EOFException {
return (int) in.skip(count);
}
}