org.apache.tools.zip.ZipShort Maven / Gradle / Ivy
/*
* 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.tools.zip;
import static org.apache.tools.zip.ZipConstants.BYTE_MASK;
/**
* Utility class that represents a two byte integer with conversion
* rules for the big endian byte order of ZIP files.
*
*/
public final class ZipShort implements Cloneable {
private static final int BYTE_1_MASK = 0xFF00;
private static final int BYTE_1_SHIFT = 8;
private final int value;
/**
* Create instance from a number.
* @param value the int to store as a ZipShort
* @since 1.1
*/
public ZipShort (int value) {
this.value = value;
}
/**
* Create instance from bytes.
* @param bytes the bytes to store as a ZipShort
* @since 1.1
*/
public ZipShort (byte[] bytes) {
this(bytes, 0);
}
/**
* Create instance from the two bytes starting at offset.
* @param bytes the bytes to store as a ZipShort
* @param offset the offset to start
* @since 1.1
*/
public ZipShort (byte[] bytes, int offset) {
value = ZipShort.getValue(bytes, offset);
}
/**
* Get value as two bytes in big endian byte order.
* @return the value as a a two byte array in big endian byte order
* @since 1.1
*/
public byte[] getBytes() {
byte[] result = new byte[2];
putShort(value, result, 0);
return result;
}
/**
* put the value as two bytes in big endian byte order.
* @param value the Java int to convert to bytes
* @param buf the output buffer
* @param offset
* The offset within the output buffer of the first byte to be written.
* must be non-negative and no larger than buf.length-2
*/
public static void putShort(int value, byte[] buf, int offset) {
buf[offset] = (byte) (value & BYTE_MASK);
buf[offset+1] = (byte) ((value & BYTE_1_MASK) >> BYTE_1_SHIFT);
}
/**
* Get value as Java int.
* @return value as a Java int
* @since 1.1
*/
public int getValue() {
return value;
}
/**
* Get value as two bytes in big endian byte order.
* @param value the Java int to convert to bytes
* @return the converted int as a byte array in big endian byte order
*/
public static byte[] getBytes(int value) {
byte[] result = new byte[2];
result[0] = (byte) (value & BYTE_MASK);
result[1] = (byte) ((value & BYTE_1_MASK) >> BYTE_1_SHIFT);
return result;
}
/**
* Helper method to get the value as a java int from two bytes starting at given array offset
* @param bytes the array of bytes
* @param offset the offset to start
* @return the corresponding java int value
*/
public static int getValue(byte[] bytes, int offset) {
int value = (bytes[offset + 1] << BYTE_1_SHIFT) & BYTE_1_MASK;
value += (bytes[offset] & BYTE_MASK);
return value;
}
/**
* Helper method to get the value as a java int from a two-byte array
* @param bytes the array of bytes
* @return the corresponding java int value
*/
public static int 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
* @since 1.1
*/
@Override
public boolean equals(Object o) {
if (o == null || !(o instanceof ZipShort)) {
return false;
}
return value == ((ZipShort) o).getValue();
}
/**
* Override to make two instances with same value equal.
* @return the value stored in the ZipShort
* @since 1.1
*/
@Override
public int hashCode() {
return value;
}
@Override
public Object clone() {
try {
return super.clone();
} catch (CloneNotSupportedException cnfe) {
// impossible
throw new RuntimeException(cnfe);
}
}
@Override
public String toString() {
return "ZipShort value: " + value;
}
}