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/*
* Copyright (c) CQSE GmbH
*
* 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 org.conqat.lib.commons.collections;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.Arrays;
import java.util.Objects;
import org.conqat.lib.commons.string.StringUtils;
import org.conqat.lib.commons.test.IndexValueClass;
/**
* A wrapper class around a byte array that supports a clean implementation of {@link #hashCode()}
* and {@link #equals(Object)}, so byte arrays can be used, e.g., in a {@link java.util.HashMap}.
*
* The class is immutable.
*
* @implNote Custom (de)serialization is provided to make this efficient to use in storage or RMI
* scenarios.
*/
@IndexValueClass(containedInBackup = true)
public class ByteArrayWrapper implements Serializable, Comparable {
/** Version used for serialization. */
private static final long serialVersionUID = 1;
/** The wrapped array. */
protected byte[] array;
/** Constructor. */
public ByteArrayWrapper(byte[] array) {
this.array = array.clone();
}
/** Returns a copy of the internal byte representation. */
public byte[] getBytes() {
return array.clone();
}
/** Returns the length of this array in bytes. */
public int getLength() {
return array.length;
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (!(o instanceof ByteArrayWrapper)) {
return false;
}
ByteArrayWrapper that = (ByteArrayWrapper) o;
if (!that.canEqual(this)) {
return false;
}
return Objects.deepEquals(array, that.array);
}
/**
* @return Whether {@code other} can be equal to this object.
* @apiNote This is called during {@link #equals(Object)} on the other object, to make sure
* that the equality is symmetric.
* @see How to Write an Equality
* Method in Java
*/
protected boolean canEqual(Object other) {
return other instanceof ByteArrayWrapper;
}
@Override
public int hashCode() {
return Arrays.hashCode(array);
}
@Override
public String toString() {
return StringUtils.encodeAsHex(array);
}
@Override
public int compareTo(ByteArrayWrapper other) {
int lengthDelta = array.length - other.array.length;
if (lengthDelta != 0) {
return lengthDelta;
}
for (int i = 0; i < array.length; ++i) {
int delta = array[i] - other.array[i];
if (delta != 0) {
return delta;
}
}
return 0;
}
/** Custom serialization. */
private void writeObject(ObjectOutputStream out) throws IOException {
out.writeInt(array.length);
out.write(array);
}
/** Custom deserialization. */
private void readObject(ObjectInputStream in) throws IOException {
int size = in.readInt();
array = new byte[size];
int pos = 0;
while (pos < size) {
pos += in.read(array, pos, size - pos);
}
}
}