/*
* 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 com.mucommander.commons.file.archive.zip.provider;
/**
* Utility class that represents a four byte integer with conversion
* rules for the big endian byte order of ZIP files.
*
* <p>--------------------------------------------------------------------------------------------------------------<br>
* <br>
* This class is based off the <code>org.apache.tools.zip</code> package of the <i>Apache Ant</i> project. The Ant
* code has been modified under the terms of the Apache License which you can find in the bundled muCommander license
* file. It was forked at version 1.7.0 of Ant.</p>
*
* @author Apache Ant, Maxence Bernard
*/
public final class ZipLong implements Cloneable {
private long value;
/**
* Create instance from a number.
* @param value the long to store as a ZipLong
*/
public ZipLong(long value) {
this.value = value;
}
/**
* Create instance from bytes.
* @param bytes the bytes to store as a ZipLong
*/
public ZipLong (byte[] bytes) {
this(bytes, 0);
}
/**
* Create instance from the four bytes starting at offset.
* @param bytes the bytes to store as a ZipLong
* @param offset the offset to start
*/
public ZipLong (byte[] bytes, int offset) {
value = ZipLong.getValue(bytes, offset);
}
/**
* Get value as four bytes in big endian byte order.
* @return value as four bytes in big endian order
*/
public byte[] getBytes() {
return ZipLong.getBytes(value);
}
/**
* Get value as Java long.
* @return value as a long
*/
public long getValue() {
return value;
}
/**
* Converts the given int value as four bytes in big endian byte order.
* @param value the unsigned int value (stored as a long) to convert
* @return the converted value as a byte array in big endian byte order
*/
public static byte[] getBytes(long value) {
return getBytes(value, new byte[4], 0);
}
/**
* Converts the given int value as four bytes in big endian byte order. The specified byte array is used to store
* the result, starting at offset 0. The returned byte array is the same as the given one.
* @param value the unsigned int value (stored as a long) to convert
* @param result the byte array in which to store the value in big endian byte order
* @return the converted value as a byte array in big endian byte order
*/
public static byte[] getBytes(long value, byte[] result) {
return getBytes(value, result, 0);
}
/**
* Converts the given int value as four bytes in big endian byte order. The specified byte array is used to store
* the result, starting at the given offset. The returned byte array is the same as the given one.
* @param value the unsigned int value (stored as a long) to convert
* @param result the byte array in which to store the value in big endian byte order
* @param off offset at which to start writing the result in the array
* @return the converted value as a byte array in big endian byte order
*/
public static byte[] getBytes(long value, byte[] result, int off) {
result[off] = (byte) ((value & 0xFF));
result[++off] = (byte) ((value & 0xFF00) >> 8);
result[++off] = (byte) ((value & 0xFF0000) >> 16);
result[off+1] = (byte) ((value & 0xFF000000L) >> 24);
return result;
}
/**
* Helper method to get the value as a Java long from four bytes starting at given array offset
* @param bytes the array of bytes
* @param offset the offset to start
* @return the correspondanding Java long value
*/
public static long getValue(byte[] bytes, int offset) {
long value = (bytes[offset + 3] << 24) & 0xFF000000L;
value += (bytes[offset + 2] << 16) & 0xFF0000;
value += (bytes[offset + 1] << 8) & 0xFF00;
value += (bytes[offset] & 0xFF);
return value;
}
/**
* Helper method to get the value as a Java long from a four-byte array
* @param bytes the array of bytes
* @return the correspondanding Java long value
*/
public static long getValue(byte[] bytes) {
return getValue(bytes, 0);
}
/**
* Override to make two instances with same value equal.
* @param o an object to compare
* @return true if the objects are equal
*/
public boolean equals(Object o) {
if (o == null || !(o instanceof ZipLong)) {
return false;
}
return value == ((ZipLong) o).getValue();
}
/**
* Override to make two instances with same value equal.
* @return the value stored in the ZipLong
*/
public int hashCode() {
return (int) value;
}
}