/*
* 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.
*/
/*
* Copyright (C) 2008 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.
*/
package java.lang.reflect;
/**
* This class provides static methods to create and access arrays dynamically.
*/
public final class Array {
/**
* Prevent this class from being instantiated.
*/
private Array(){
//do nothing
}
/**
* Returns the element of the array at the specified index. This reproduces
* the effect of {@code array[index]}. If the array component is a primitive
* type, the result is automatically boxed.
*
* @param array
* the array
* @param index
* the index
*
* @return the requested element, possibly boxed
*
* @throws NullPointerException
* if the array is null
* @throws IllegalArgumentException
* if {@code array} is not an array
* @throws ArrayIndexOutOfBoundsException
* if {@code index < 0 || index >= array.length}
*/
public static Object get(Object array, int index)
throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
if (array instanceof Object[])
return ((Object[]) array)[index];
if (array instanceof boolean[])
return ((boolean[]) array)[index] ? Boolean.TRUE : Boolean.FALSE;
if (array instanceof byte[])
return Byte.valueOf(((byte[]) array)[index]);
if (array instanceof char[])
return Character.valueOf(((char[]) array)[index]);
if (array instanceof short[])
return Short.valueOf(((short[]) array)[index]);
if (array instanceof int[])
return Integer.valueOf(((int[]) array)[index]);
if (array instanceof long[])
return Long.valueOf(((long[]) array)[index]);
if (array instanceof float[])
return new Float(((float[]) array)[index]);
if (array instanceof double[])
return new Double(((double[]) array)[index]);
if (array == null)
throw new NullPointerException();
throw new IllegalArgumentException("Not an array");
}
/**
* Returns the element of the array at the specified index, converted to a
* {@code boolean}, if possible. This reproduces the effect of {@code
* array[index]}
*
* @param array
* the array
* @param index
* the index
*
* @return the requested element
*
* @throws NullPointerException
* if the {@code array} is {@code null}
* @throws IllegalArgumentException
* if {@code array} is not an array or the element at the
* index position can not be converted to the return type
* @throws ArrayIndexOutOfBoundsException
* if {@code index < 0 || index >= array.length}
*/
public static boolean getBoolean(Object array, int index)
throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
if (array instanceof boolean[]) {
return ((boolean[]) array)[index];
} else if (array == null) {
throw new NullPointerException();
} else if (array.getClass().isArray()) {
throw new IllegalArgumentException("Wrong array type");
} else {
throw new IllegalArgumentException("Not an array");
}
}
/**
* Returns the element of the array at the specified index, converted to a
* {@code byte}, if possible. This reproduces the effect of {@code
* array[index]}
*
* @param array
* the array
* @param index
* the index
*
* @return the requested element
*
* @throws NullPointerException
* if the {@code array} is {@code null}
* @throws IllegalArgumentException
* if {@code array} is not an array or the element at the
* index position can not be converted to the return type
* @throws ArrayIndexOutOfBoundsException
* if {@code index < 0 || index >= array.length}
*/
public static byte getByte(Object array, int index)
throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
if (array instanceof byte[]) {
return ((byte[]) array)[index];
} else {
return getBoolean(array, index) ? (byte)1 : (byte)0;
}
}
/**
* Returns the element of the array at the specified index, converted to a
* {@code char}, if possible. This reproduces the effect of {@code
* array[index]}
*
* @param array
* the array
* @param index
* the index
*
* @return the requested element
*
* @throws NullPointerException
* if the {@code array} is {@code null}
* @throws IllegalArgumentException
* if {@code array} is not an array or the element at the
* index position can not be converted to the return type
* @throws ArrayIndexOutOfBoundsException
* if {@code index < 0 || index >= array.length}
*/
public static char getChar(Object array, int index)
throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
if (array instanceof char[]) {
return ((char[]) array)[index];
} else if (array == null) {
throw new NullPointerException();
} else if (array.getClass().isArray()) {
throw new IllegalArgumentException("Wrong array type");
} else {
throw new IllegalArgumentException("Not an array");
}
}
/**
* Returns the element of the array at the specified index, converted to a
* {@code double}, if possible. This reproduces the effect of {@code
* array[index]}
*
* @param array
* the array
* @param index
* the index
*
* @return the requested element
*
* @throws NullPointerException
* if the {@code array} is {@code null}
* @throws IllegalArgumentException
* if {@code array} is not an array or the element at the
* index position can not be converted to the return type
* @throws ArrayIndexOutOfBoundsException
* if {@code index < 0 || index >= array.length}
*/
public static double getDouble(Object array, int index)
throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
if (array instanceof double[]) {
return ((double[]) array)[index];
} else {
return getFloat(array, index);
}
}
/**
* Returns the element of the array at the specified index, converted to a
* {@code float}, if possible. This reproduces the effect of {@code
* array[index]}
*
* @param array
* the array
* @param index
* the index
*
* @return the requested element
*
* @throws NullPointerException
* if the {@code array} is {@code null}
* @throws IllegalArgumentException
* if {@code array} is not an array or the element at the
* index position can not be converted to the return type
* @throws ArrayIndexOutOfBoundsException
* if {@code index < 0 || index >= array.length}
*/
public static float getFloat(Object array, int index)
throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
if (array instanceof float[]) {
return ((float[]) array)[index];
} else {
return getLong(array, index);
}
}
/**
* Returns the element of the array at the specified index, converted to an
* {@code int}, if possible. This reproduces the effect of {@code
* array[index]}
*
* @param array
* the array
* @param index
* the index
*
* @return the requested element
*
* @throws NullPointerException
* if the {@code array} is {@code null}
* @throws IllegalArgumentException
* if {@code array} is not an array or the element at the
* index position can not be converted to the return type
* @throws ArrayIndexOutOfBoundsException
* if {@code index < 0 || index >= array.length}
*/
public static int getInt(Object array, int index)
throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
if (array instanceof int[]) {
return ((int[]) array)[index];
} else {
return getShort(array, index);
}
}
/**
* Returns the length of the array. This reproduces the effect of {@code
* array.length}
*
* @param array
* the array
*
* @return the length of the array
*
* @throws NullPointerException
* if the {@code array} is {@code null}
* @throws IllegalArgumentException
* if {@code array} is not an array
*/
public static int getLength(Object array) {
if (array instanceof Object[])
return ((Object[]) array).length;
if (array instanceof boolean[])
return ((boolean[]) array).length;
if (array instanceof byte[])
return ((byte[]) array).length;
if (array instanceof char[])
return ((char[]) array).length;
if (array instanceof short[])
return ((short[]) array).length;
if (array instanceof int[])
return ((int[]) array).length;
if (array instanceof long[])
return ((long[]) array).length;
if (array instanceof float[])
return ((float[]) array).length;
if (array instanceof double[])
return ((double[]) array).length;
if (array == null)
throw new NullPointerException();
throw new IllegalArgumentException("Not an array");
}
/**
* Returns the element of the array at the specified index, converted to a
* {@code long}, if possible. This reproduces the effect of {@code
* array[index]}
*
* @param array
* the array
* @param index
* the index
*
* @return the requested element
*
* @throws NullPointerException
* if the {@code array} is {@code null}
* @throws IllegalArgumentException
* if {@code array} is not an array or the element at the
* index position can not be converted to the return type
* @throws ArrayIndexOutOfBoundsException
* if {@code index < 0 || index >= array.length}
*/
public static long getLong(Object array, int index)
throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
if (array instanceof long[]) {
return ((long[]) array)[index];
} else {
return getInt(array, index);
}
}
/**
* Returns the element of the array at the specified index, converted to a
* {@code short}, if possible. This reproduces the effect of {@code
* array[index]}
*
* @param array
* the array
* @param index
* the index
*
* @return the requested element
*
* @throws NullPointerException
* if the {@code array} is {@code null}
* @throws IllegalArgumentException
* if {@code array} is not an array or the element at the
* index position can not be converted to the return type
* @throws ArrayIndexOutOfBoundsException
* if {@code index < 0 || index >= array.length}
*/
public static short getShort(Object array, int index)
throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
if (array instanceof short[])
return ((short[]) array)[index];
return getByte(array, index);
}
/**
* Returns a new multidimensional array of the specified component type and
* dimensions. This reproduces the effect of {@code new
* componentType[d0][d1]...[dn]} for a dimensions array of { d0, d1, ... ,
* dn }.
*
* @param componentType
* the component type of the new array
* @param dimensions
* the dimensions of the new array
*
* @return the new array
*
* @throws NullPointerException
* if the component type is {@code null}
* @throws NegativeArraySizeException
* if any of the dimensions are negative
* @throws IllegalArgumentException
* if the array of dimensions is of size zero, or exceeds the
* limit of the number of dimension for an array (currently 255)
*/
public static Object newInstance(Class<?> componentType, int... dimensions)
throws NegativeArraySizeException, IllegalArgumentException {
if (dimensions.length <= 0 || dimensions.length > 255)
throw new IllegalArgumentException("Bad number of dimensions");
if (componentType == void.class)
throw new IllegalArgumentException();
if (componentType == null)
throw new NullPointerException();
return createMultiArray(componentType, dimensions);
}
/*
* Create a multi-dimensional array of objects with the specified type.
*/
native private static Object createMultiArray(Class<?> componentType,
int[] dimensions) throws NegativeArraySizeException;
/**
* Returns a new array of the specified component type and length. This
* reproduces the effect of {@code new componentType[size]}.
*
* @param componentType
* the component type of the new array
* @param size
* the length of the new array
*
* @return the new array
*
* @throws NullPointerException
* if the component type is null
* @throws NegativeArraySizeException
* if {@code size < 0}
*/
public static Object newInstance(Class<?> componentType, int size)
throws NegativeArraySizeException {
if (!componentType.isPrimitive()) {
return createObjectArray(componentType, size);
}
if (componentType == boolean.class) {
return new boolean[size];
}
if (componentType == byte.class) {
return new byte[size];
}
if (componentType == char.class) {
return new char[size];
}
if (componentType == short.class) {
return new short[size];
}
if (componentType == int.class) {
return new int[size];
}
if (componentType == long.class) {
return new long[size];
}
if (componentType == float.class) {
return new float[size];
}
if (componentType == double.class) {
return new double[size];
}
if (componentType == void.class) {
throw new IllegalArgumentException();
}
throw new AssertionError();
}
/*
* Create a one-dimensional array of objects with the specified type.
*/
native private static Object createObjectArray(Class<?> componentType,
int length) throws NegativeArraySizeException;
/**
* Sets the element of the array at the specified index to the value. This
* reproduces the effect of {@code array[index] = value}. If the array
* component is a primitive type, the value is automatically unboxed.
*
* @param array
* the array
* @param index
* the index
* @param value
* the new value
*
* @throws NullPointerException
* if the {@code array} is {@code null}
* @throws IllegalArgumentException
* if {@code array} is not an array or the value cannot be
* converted to the array type by a widening conversion
* @throws ArrayIndexOutOfBoundsException
* if {@code index < 0 || index >= array.length}
*/
public static void set(Object array, int index, Object value)
throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
if (!array.getClass().isArray()) {
throw new IllegalArgumentException("Not an array type");
}
if (array instanceof Object[]) {
if (value != null &&
!array.getClass().getComponentType().isInstance(value)) {
// incompatible object type for this array
throw new IllegalArgumentException("Wrong array type");
}
((Object[]) array)[index] = value;
} else {
if (value == null) {
throw new IllegalArgumentException("Primitive array can't take null values.");
}
if (value instanceof Boolean)
setBoolean(array, index, ((Boolean) value).booleanValue());
else if (value instanceof Byte)
setByte(array, index, ((Byte) value).byteValue());
else if (value instanceof Character)
setChar(array, index, ((Character) value).charValue());
else if (value instanceof Short)
setShort(array, index, ((Short) value).shortValue());
else if (value instanceof Integer)
setInt(array, index, ((Integer) value).intValue());
else if (value instanceof Long)
setLong(array, index, ((Long) value).longValue());
else if (value instanceof Float)
setFloat(array, index, ((Float) value).floatValue());
else if (value instanceof Double)
setDouble(array, index, ((Double) value).doubleValue());
}
}
/**
* Sets the element of the array at the specified index to the {@code
* boolean} value. This reproduces the effect of {@code array[index] =
* value}.
*
* @param array
* the array
* @param index
* the index
* @param value
* the new value
*
* @throws NullPointerException
* if the {@code array} is {@code null}
* @throws IllegalArgumentException
* if the {@code array} is not an array or the value cannot be
* converted to the array type by a widening conversion
* @throws ArrayIndexOutOfBoundsException
* if {@code index < 0 || index >= array.length}
*/
public static void setBoolean(Object array, int index, boolean value) {
if (array instanceof boolean[]) {
((boolean[]) array)[index] = value;
} else {
setByte(array, index, value ? (byte)1 : (byte)0);
}
}
/**
* Sets the element of the array at the specified index to the {@code byte}
* value. This reproduces the effect of {@code array[index] = value}.
*
* @param array
* the array
* @param index
* the index
* @param value
* the new value
*
* @throws NullPointerException
* if the {@code array} is {@code null}
* @throws IllegalArgumentException
* if the {@code array} is not an array or the value cannot be
* converted to the array type by a widening conversion
* @throws ArrayIndexOutOfBoundsException
* if {@code index < 0 || index >= array.length}
*/
public static void setByte(Object array, int index, byte value)
throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
if (array instanceof byte[]) {
((byte[]) array)[index] = value;
} else {
setShort(array, index, value);
}
}
/**
* Set the element of the array at the specified index to the {@code char}
* value. This reproduces the effect of {@code array[index] = value}.
*
* @param array
* the array
* @param index
* the index
* @param value
* the new value
*
* @throws NullPointerException
* if the {@code array} is {@code null}
* @throws IllegalArgumentException
* if the {@code array} is not an array or the value cannot be
* converted to the array type by a widening conversion
* @throws ArrayIndexOutOfBoundsException
* if {@code index < 0 || index >= array.length}
*/
public static void setChar(Object array, int index, char value)
throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
if (array instanceof char[]) {
((char[]) array)[index] = value;
} else if (array == null) {
throw new NullPointerException();
} else if (!array.getClass().isArray()) {
throw new IllegalArgumentException("Not an array");
} else {
throw new IllegalArgumentException("Wrong array type");
}
}
/**
* Set the element of the array at the specified index to the {@code double}
* value. This reproduces the effect of {@code array[index] = value}.
*
* @param array
* the array
* @param index
* the index
* @param value
* the new value
*
* @throws NullPointerException
* if the {@code array} is {@code null}
* @throws IllegalArgumentException
* if the {@code array} is not an array or the value cannot be
* converted to the array type by a widening conversion
* @throws ArrayIndexOutOfBoundsException
* if {@code index < 0 || index >= array.length}
*/
public static void setDouble(Object array, int index, double value)
throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
if (array instanceof double[]) {
((double[]) array)[index] = value;
} else if (array == null) {
throw new NullPointerException();
} else if (!array.getClass().isArray()) {
throw new IllegalArgumentException("Not an array");
} else {
throw new IllegalArgumentException("Wrong array type");
}
}
/**
* Set the element of the array at the specified index to the {@code float}
* value. This reproduces the effect of {@code array[index] = value}.
*
* @param array
* the array
* @param index
* the index
* @param value
* the new value
*
* @throws NullPointerException
* if the {@code array} is {@code null}
* @throws IllegalArgumentException
* if the {@code array} is not an array or the value cannot be
* converted to the array type by a widening conversion
* @throws ArrayIndexOutOfBoundsException
* if {@code index < 0 || index >= array.length}
*/
public static void setFloat(Object array, int index, float value)
throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
if (array instanceof float[]) {
((float[]) array)[index] = value;
} else {
setDouble(array, index, value);
}
}
/**
* Set the element of the array at the specified index to the {@code int}
* value. This reproduces the effect of {@code array[index] = value}.
*
* @param array
* the array
* @param index
* the index
* @param value
* the new value
*
* @throws NullPointerException
* if the {@code array} is {@code null}
* @throws IllegalArgumentException
* if the {@code array} is not an array or the value cannot be
* converted to the array type by a widening conversion
* @throws ArrayIndexOutOfBoundsException
* if {@code index < 0 || index >= array.length}
*/
public static void setInt(Object array, int index, int value)
throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
if (array instanceof int[]) {
((int[]) array)[index] = value;
} else {
setLong(array, index, value);
}
}
/**
* Set the element of the array at the specified index to the {@code long}
* value. This reproduces the effect of {@code array[index] = value}.
*
* @param array
* the array
* @param index
* the index
* @param value
* the new value
*
* @throws NullPointerException
* if the {@code array} is {@code null}
* @throws IllegalArgumentException
* if the {@code array} is not an array or the value cannot be
* converted to the array type by a widening conversion
* @throws ArrayIndexOutOfBoundsException
* if {@code index < 0 || index >= array.length}
*/
public static void setLong(Object array, int index, long value)
throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
if (array instanceof long[]) {
((long[]) array)[index] = value;
} else {
setFloat(array, index, value);
}
}
/**
* Set the element of the array at the specified index to the {@code short}
* value. This reproduces the effect of {@code array[index] = value}.
*
* @param array
* the array
* @param index
* the index
* @param value
* the new value
*
* @throws NullPointerException
* if the {@code array} is {@code null}
* @throws IllegalArgumentException
* if the {@code array} is not an array or the value cannot be
* converted to the array type by a widening conversion
* @throws ArrayIndexOutOfBoundsException
* if {@code index < 0 || index >= array.length}
*/
public static void setShort(Object array, int index, short value)
throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
if (array instanceof short[]) {
((short[]) array)[index] = value;
} else {
setInt(array, index, value);
}
}
}