Description
Convert an array of primitives to a byte[] using native endian order.
License
Apache License
Parameter
| Parameter | Description |
|---|
| array | array of primitives |
Exception
| Parameter | Description |
|---|
| IllegalArgumentException | if array was not an array of primitives |
Return
array converted into byte array using native endian order
Declaration
public static <T> byte[] toByteArray(T array)
Method Source Code
//package com.java2s;
/*// w w w. ja v a 2 s . com
* Copyright (C) 2014 The Android Open Source Project
*
* 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.
*/
import android.util.Log;
import java.lang.reflect.Array;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.util.Arrays;
public class Main {
private static final String TAG = "ByteArrayHelpers";
private static boolean VERBOSE = false;
/**
* Convert an array of byte primitives to a {@code byte[]} using native endian order.
*
* <p>This function is a pass-through; it's here only to provide overloads for
* every single type of primitive arrays.
*
* @param array array of primitives
* @return array
*/
public static byte[] toByteArray(byte[] array) {
return array;
}
/**
* Convert an array of shorts to a {@code byte[]} using native endian order.
*
* @param array array of shorts
* @return array converted into byte array using native endian order
*/
public static byte[] toByteArray(short[] array) {
return toByteArray(array, Short.SIZE);
}
/**
* Convert an array of chars to a {@code byte[]} using native endian order.
*
* @param array array of chars
* @return array converted into byte array using native endian order
*/
public static byte[] toByteArray(char[] array) {
return toByteArray(array, Character.SIZE);
}
/**
* Convert an array of ints to a {@code byte[]} using native endian order.
*
* @param array array of ints
* @return array converted into byte array using native endian order
*/
public static byte[] toByteArray(int[] array) {
return toByteArray(array, Integer.SIZE);
}
/**
* Convert an array of longs to a {@code byte[]} using native endian order.
*
* @param array array of longs
* @return array converted into byte array using native endian order
*/
public static byte[] toByteArray(long[] array) {
return toByteArray(array, Long.SIZE);
}
/**
* Convert an array of floats to a {@code byte[]} using native endian order.
*
* @param array array of floats
* @return array converted into byte array using native endian order
*/
public static byte[] toByteArray(float[] array) {
return toByteArray(array, Float.SIZE);
}
/**
* Convert an array of doubles to a {@code byte[]} using native endian order.
*
* @param array array of doubles
* @return array converted into byte array using native endian order
*/
public static byte[] toByteArray(double[] array) {
return toByteArray(array, Double.SIZE);
}
/**
* Convert an array of primitives to a {@code byte[]} using native endian order.
*
* <p>Arguments other than arrays are not supported. The array component must be primitive,
* the wrapper class is not allowed (e.g. {@code int[]} is ok, but {@code Integer[]} is not.</p>
*
* @param array array of primitives
* @return array converted into byte array using native endian order
*
* @throws IllegalArgumentException if {@code array} was not an array of primitives
*/
public static <T> byte[] toByteArray(T array) {
@SuppressWarnings("unchecked")
Class<T> klass = (Class<T>) array.getClass();
if (!klass.isArray()) {
throw new IllegalArgumentException(
"array class must be an array");
}
Class<?> componentClass = klass.getComponentType();
if (!componentClass.isPrimitive()) {
throw new IllegalArgumentException(
"array's component must be a primitive");
}
int sizeInBits;
if (klass == int.class) {
sizeInBits = Integer.SIZE;
} else if (klass == float.class) {
sizeInBits = Float.SIZE;
} else if (klass == double.class) {
sizeInBits = Double.SIZE;
} else if (klass == short.class) {
sizeInBits = Short.SIZE;
} else if (klass == char.class) {
sizeInBits = Character.SIZE;
} else if (klass == long.class) {
sizeInBits = Long.SIZE;
} else if (klass == byte.class) {
sizeInBits = Byte.SIZE;
} else {
throw new AssertionError();
}
return toByteArray(array, sizeInBits);
}
/**
* Convert a variadic list of {@code Number}s into a byte array using native endian order.
*
* <p>Each {@link Number} must be an instance of a primitive wrapper class
* (e.g. {@link Integer} is OK, since it wraps {@code int}, but {@code BigInteger} is not.</p>
*
* @param numbers variadic list of numeric values
* @return array converted into byte array using native endian order
*
* @throws IllegalArgumentException
* if {@code numbers} contained a class that wasn't a primitive wrapper
*/
public static byte[] toByteArray(Number... numbers) {
if (numbers.length == 0) {
throw new IllegalArgumentException("too few numbers");
}
if (VERBOSE)
Log.v(TAG, "toByteArray - input: " + Arrays.toString(numbers));
// Have a large enough capacity to fit in every number as a double
ByteBuffer byteBuffer = ByteBuffer.allocate(
numbers.length * (Double.SIZE / Byte.SIZE)).order(
ByteOrder.nativeOrder());
for (int i = 0; i < numbers.length; ++i) {
Number value = numbers[i];
Class<? extends Number> klass = value.getClass();
if (VERBOSE)
Log.v(TAG, "toByteArray - number " + i + ", class " + klass);
if (klass == Integer.class) {
byteBuffer.putInt((Integer) value);
} else if (klass == Float.class) {
byteBuffer.putFloat((Float) value);
} else if (klass == Double.class) {
byteBuffer.putDouble((Double) value);
} else if (klass == Short.class) {
byteBuffer.putShort((Short) value);
} else if (klass == Long.class) {
byteBuffer.putLong((Long) value);
} else if (klass == Byte.class) {
byteBuffer.put((Byte) value);
} else {
throw new IllegalArgumentException(
"number class invalid; must be wrapper around primitive class");
}
}
if (VERBOSE)
Log.v(TAG, "toByteArray - end of loop");
// Each number written is at least 1 byte, so the position should be at least length
if (numbers.length != 0 && byteBuffer.position() < numbers.length) {
throw new AssertionError(String.format(
"Had %d numbers, but byte buffer position was only %d",
numbers.length, byteBuffer.position()));
}
byteBuffer.flip();
byte[] bytes = new byte[byteBuffer.limit()];
byteBuffer.get(bytes);
if (VERBOSE)
Log.v(TAG, "toByteArray - output: " + Arrays.toString(bytes));
return bytes;
}
private static <T> byte[] toByteArray(T array, int sizeOfTBits) {
@SuppressWarnings("unchecked")
Class<T> klass = (Class<T>) array.getClass();
if (!klass.isArray()) {
throw new IllegalArgumentException(
"array class must be an array");
}
int sizeOfT = sizeOfTBits / Byte.SIZE;
int byteLength = Array.getLength(array) * sizeOfT;
if (klass == byte[].class) {
// Always return a copy
return Arrays.copyOf((byte[]) array, byteLength);
}
ByteBuffer byteBuffer = ByteBuffer.allocate(byteLength).order(
ByteOrder.nativeOrder());
if (klass == int[].class) {
byteBuffer.asIntBuffer().put((int[]) array);
} else if (klass == float[].class) {
byteBuffer.asFloatBuffer().put((float[]) array);
} else if (klass == double[].class) {
byteBuffer.asDoubleBuffer().put((double[]) array);
} else if (klass == short[].class) {
byteBuffer.asShortBuffer().put((short[]) array);
} else if (klass == char[].class) {
byteBuffer.asCharBuffer().put((char[]) array);
} else if (klass == long[].class) {
byteBuffer.asLongBuffer().put((long[]) array);
} else {
throw new IllegalArgumentException(
"array class invalid; must be a primitive array");
}
return byteBuffer.array();
}
}
Related
- toByteArray(Bundle bundle)
- toByteArray(ContentValues contentValues)
- toByteArray(Number... numbers)
- toByteArray(Serializable serializable)
- toByteArray(Spanned spanned)
- toByteArray(T array, int sizeOfTBits)
- toByteArray(byte[] array)
- toByteArray(char[] array)
- toByteArray(double[] array)