xref: /libcore/ojluni/src/main/java/java/lang/reflect/Array.java

/*
 * Copyright (C) 2014 The Android Open Source Project
 * Copyright (c) 1996, 2006, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package java.lang.reflect;

/**
 * The {@code Array} class provides static methods to dynamically create and
 * access Java arrays.
 *
 * <p>{@code Array} permits widening conversions to occur during a get or set
 * operation, but throws an {@code IllegalArgumentException} if a narrowing
 * conversion would occur.
 *
 * @author Nakul Saraiya
 */
public final
class Array {

    /**
     * Constructor.  Class Array is not instantiable.
     */
    private Array() {}

    /**
     * Creates a new array with the specified component type and
     * length.
     * Invoking this method is equivalent to creating an array
     * as follows:
     * <blockquote>
     * <pre>
     * int[] x = {length};
     * Array.newInstance(componentType, x);
     * </pre>
     * </blockquote>
     *
     * @param componentType the {@code Class} object representing the
     * component type of the new array
     * @param length the length of the new array
     * @return the new array
     * @exception NullPointerException if the specified
     * {@code componentType} parameter is null
     * @exception IllegalArgumentException if componentType is {@link Void#TYPE}
     * @exception NegativeArraySizeException if the specified {@code length}
     * is negative
     */
    public static Object newInstance(Class<?> componentType, int length)
        throws NegativeArraySizeException {
        return newArray(componentType, length);
    }

    /**
     * Creates a new array
     * with the specified component type and dimensions.
     * If {@code componentType}
     * represents a non-array class or interface, the new array
     * has {@code dimensions.length} dimensions and
     * {@code componentType} as its component type. If
     * {@code componentType} represents an array class, the
     * number of dimensions of the new array is equal to the sum
     * of {@code dimensions.length} and the number of
     * dimensions of {@code componentType}. In this case, the
     * component type of the new array is the component type of
     * {@code componentType}.
     *
     * <p>The number of dimensions of the new array must not
     * exceed the number of array dimensions supported by the
     * implementation (typically 255).
     *
     * @param componentType the {@code Class} object representing the component
     * type of the new array
     * @param dimensions an array of {@code int} representing the dimensions of
     * the new array
     * @return the new array
     * @exception NullPointerException if the specified
     * {@code componentType} argument is null
     * @exception IllegalArgumentException if the specified {@code dimensions}
     * argument is a zero-dimensional array, or if the number of
     * requested dimensions exceeds the limit on the number of array dimensions
     * supported by the implementation (typically 255), or if componentType
     * is {@link Void#TYPE}.
     * @exception NegativeArraySizeException if any of the components in
     * the specified {@code dimensions} argument is negative.
     */
    public static Object newInstance(Class<?> componentType, int... dimensions)
        throws IllegalArgumentException, NegativeArraySizeException {
        if (dimensions.length <= 0 || dimensions.length > 255) {
            throw new IllegalArgumentException("Bad number of dimensions: " + dimensions.length);
        }
        if (componentType == void.class) {
            throw new IllegalArgumentException("Can't allocate an array of void");
        }
        if (componentType == null) {
            throw new NullPointerException("componentType == null");
        }
        return createMultiArray(componentType, dimensions);
    }

    /**
     * Returns the length of the specified array object, as an {@code int}.
     *
     * @param array the array
     * @return the length of the array
     * @exception IllegalArgumentException if the object argument is not
     * an array
     */
    public static int getLength(Object array) {
        if (array instanceof Object[]) {
            return ((Object[]) array).length;
        } else if (array instanceof boolean[]) {
            return ((boolean[]) array).length;
        } else if (array instanceof byte[]) {
            return ((byte[]) array).length;
        } else if (array instanceof char[]) {
            return ((char[]) array).length;
        } else if (array instanceof double[]) {
            return ((double[]) array).length;
        } else if (array instanceof float[]) {
            return ((float[]) array).length;
        } else if (array instanceof int[]) {
            return ((int[]) array).length;
        } else if (array instanceof long[]) {
            return ((long[]) array).length;
        } else if (array instanceof short[]) {
            return ((short[]) array).length;
        }
        throw badArray(array);
      }

    /**
     * Returns the value of the indexed component in the specified
     * array object.  The value is automatically wrapped in an object
     * if it has a primitive type.
     *
     * @param array the array
     * @param index the index
     * @return the (possibly wrapped) value of the indexed component in
     * the specified array
     * @exception NullPointerException If the specified object is null
     * @exception IllegalArgumentException If the specified object is not
     * an array
     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
     * argument is negative, or if it is greater than or equal to the
     * length of the specified array
     */
    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("array == null");
        }
        throw notAnArray(array);
    }

    /**
     * Returns the value of the indexed component in the specified
     * array object, as a {@code boolean}.
     *
     * @param array the array
     * @param index the index
     * @return the value of the indexed component in the specified array
     * @exception NullPointerException If the specified object is null
     * @exception IllegalArgumentException If the specified object is not
     * an array, or if the indexed element cannot be converted to the
     * return type by an identity or widening conversion
     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
     * argument is negative, or if it is greater than or equal to the
     * length of the specified array
     * @see Array#get
     */
    public static boolean getBoolean(Object array, int index) throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
        if (array instanceof boolean[]) {
            return ((boolean[]) array)[index];
        }
        throw badArray(array);
    }

    /**
     * Returns the value of the indexed component in the specified
     * array object, as a {@code byte}.
     *
     * @param array the array
     * @param index the index
     * @return the value of the indexed component in the specified array
     * @exception NullPointerException If the specified object is null
     * @exception IllegalArgumentException If the specified object is not
     * an array, or if the indexed element cannot be converted to the
     * return type by an identity or widening conversion
     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
     * argument is negative, or if it is greater than or equal to the
     * length of the specified array
     * @see Array#get
     */
    public static byte getByte(Object array, int index) throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
        if (array instanceof byte[]) {
            return ((byte[]) array)[index];
        }
        throw badArray(array);
    }

    /**
     * Returns the value of the indexed component in the specified
     * array object, as a {@code char}.
     *
     * @param array the array
     * @param index the index
     * @return the value of the indexed component in the specified array
     * @exception NullPointerException If the specified object is null
     * @exception IllegalArgumentException If the specified object is not
     * an array, or if the indexed element cannot be converted to the
     * return type by an identity or widening conversion
     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
     * argument is negative, or if it is greater than or equal to the
     * length of the specified array
     * @see Array#get
     */
    public static char getChar(Object array, int index) throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
        if (array instanceof char[]) {
            return ((char[]) array)[index];
        }
        throw badArray(array);
    }

    /**
     * Returns the value of the indexed component in the specified
     * array object, as a {@code short}.
     *
     * @param array the array
     * @param index the index
     * @return the value of the indexed component in the specified array
     * @exception NullPointerException If the specified object is null
     * @exception IllegalArgumentException If the specified object is not
     * an array, or if the indexed element cannot be converted to the
     * return type by an identity or widening conversion
     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
     * argument is negative, or if it is greater than or equal to the
     * length of the specified array
     * @see Array#get
     */
    public static short getShort(Object array, int index) throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
        if (array instanceof short[]) {
            return ((short[]) array)[index];
        } else if (array instanceof byte[]) {
            return ((byte[]) array)[index];
        }
        throw badArray(array);
    }

    /**
     * Returns the value of the indexed component in the specified
     * array object, as an {@code int}.
     *
     * @param array the array
     * @param index the index
     * @return the value of the indexed component in the specified array
     * @exception NullPointerException If the specified object is null
     * @exception IllegalArgumentException If the specified object is not
     * an array, or if the indexed element cannot be converted to the
     * return type by an identity or widening conversion
     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
     * argument is negative, or if it is greater than or equal to the
     * length of the specified array
     * @see Array#get
     */
    public static int getInt(Object array, int index) throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
        if (array instanceof int[]) {
            return ((int[]) array)[index];
        } else if (array instanceof byte[]) {
            return ((byte[]) array)[index];
        } else if (array instanceof char[]) {
            return ((char[]) array)[index];
        } else if (array instanceof short[]) {
            return ((short[]) array)[index];
        }
        throw badArray(array);
    }

    /**
     * Returns the value of the indexed component in the specified
     * array object, as a {@code long}.
     *
     * @param array the array
     * @param index the index
     * @return the value of the indexed component in the specified array
     * @exception NullPointerException If the specified object is null
     * @exception IllegalArgumentException If the specified object is not
     * an array, or if the indexed element cannot be converted to the
     * return type by an identity or widening conversion
     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
     * argument is negative, or if it is greater than or equal to the
     * length of the specified array
     * @see Array#get
     */
    public static long getLong(Object array, int index) throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
        if (array instanceof long[]) {
            return ((long[]) array)[index];
        } else if (array instanceof byte[]) {
            return ((byte[]) array)[index];
        } else if (array instanceof char[]) {
            return ((char[]) array)[index];
        } else if (array instanceof int[]) {
            return ((int[]) array)[index];
        } else if (array instanceof short[]) {
            return ((short[]) array)[index];
        }
        throw badArray(array);
    }

    /**
     * Returns the value of the indexed component in the specified
     * array object, as a {@code float}.
     *
     * @param array the array
     * @param index the index
     * @return the value of the indexed component in the specified array
     * @exception NullPointerException If the specified object is null
     * @exception IllegalArgumentException If the specified object is not
     * an array, or if the indexed element cannot be converted to the
     * return type by an identity or widening conversion
     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
     * argument is negative, or if it is greater than or equal to the
     * length of the specified array
     * @see Array#get
     */
    public static float getFloat(Object array, int index) throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
        if (array instanceof float[]) {
            return ((float[]) array)[index];
        } else if (array instanceof byte[]) {
            return ((byte[]) array)[index];
        } else if (array instanceof char[]) {
            return ((char[]) array)[index];
        } else if (array instanceof int[]) {
            return ((int[]) array)[index];
        } else if (array instanceof long[]) {
            return ((long[]) array)[index];
        } else if (array instanceof short[]) {
            return ((short[]) array)[index];
        }
        throw badArray(array);
    }

    /**
     * Returns the value of the indexed component in the specified
     * array object, as a {@code double}.
     *
     * @param array the array
     * @param index the index
     * @return the value of the indexed component in the specified array
     * @exception NullPointerException If the specified object is null
     * @exception IllegalArgumentException If the specified object is not
     * an array, or if the indexed element cannot be converted to the
     * return type by an identity or widening conversion
     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
     * argument is negative, or if it is greater than or equal to the
     * length of the specified array
     * @see Array#get
     */
    public static double getDouble(Object array, int index) throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
        if (array instanceof double[]) {
            return ((double[]) array)[index];
        } else if (array instanceof byte[]) {
            return ((byte[]) array)[index];
        } else if (array instanceof char[]) {
            return ((char[]) array)[index];
        } else if (array instanceof float[]) {
            return ((float[]) array)[index];
        } else if (array instanceof int[]) {
            return ((int[]) array)[index];
        } else if (array instanceof long[]) {
            return ((long[]) array)[index];
        } else if (array instanceof short[]) {
            return ((short[]) array)[index];
        }
        throw badArray(array);
    }

    /**
     * Sets the value of the indexed component of the specified array
     * object to the specified new value.  The new value is first
     * automatically unwrapped if the array has a primitive component
     * type.
     * @param array the array
     * @param index the index into the array
     * @param value the new value of the indexed component
     * @exception NullPointerException If the specified object argument
     * is null
     * @exception IllegalArgumentException If the specified object argument
     * is not an array, or if the array component type is primitive and
     * an unwrapping conversion fails
     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
     * argument is negative, or if it is greater than or equal to
     * the length of the specified array
     */
    public static void set(Object array, int index, Object value) throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
        if (!array.getClass().isArray()) {
            throw notAnArray(array);
        }

        if (array instanceof Object[]) {
            if (value != null && !array.getClass().getComponentType().isInstance(value)) {
                throw incompatibleType(array);
            }
            ((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 value of the indexed component of the specified array
     * object to the specified {@code boolean} value.
     * @param array the array
     * @param index the index into the array
     * @param value the new value of the indexed component
     * @exception NullPointerException If the specified object argument
     * is null
     * @exception IllegalArgumentException If the specified object argument
     * is not an array, or if the specified value cannot be converted
     * to the underlying array's component type by an identity or a
     * primitive widening conversion
     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
     * argument is negative, or if it is greater than or equal to
     * the length of the specified array
     * @see Array#set
     */
    // Android changed param name s/z/value
    public static void setBoolean(Object array, int index, boolean value) {
        if (array instanceof boolean[]) {
            ((boolean[]) array)[index] = value;
        } else {
            throw badArray(array);
        }
    }

    /**
     * Sets the value of the indexed component of the specified array
     * object to the specified {@code byte} value.
     * @param array the array
     * @param index the index into the array
     * @param value the new value of the indexed component
     * @exception NullPointerException If the specified object argument
     * is null
     * @exception IllegalArgumentException If the specified object argument
     * is not an array, or if the specified value cannot be converted
     * to the underlying array's component type by an identity or a
     * primitive widening conversion
     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
     * argument is negative, or if it is greater than or equal to
     * the length of the specified array
     * @see Array#set
     */
    // Android changed param name s/b/value
    public static void setByte(Object array, int index, byte value) throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
        if (array instanceof byte[]) {
            ((byte[]) array)[index] = value;
        } else if (array instanceof double[]) {
            ((double[]) array)[index] = value;
        } else if (array instanceof float[]) {
            ((float[]) array)[index] = value;
        } else if (array instanceof int[]) {
            ((int[]) array)[index] = value;
        } else if (array instanceof long[]) {
            ((long[]) array)[index] = value;
        } else if (array instanceof short[]) {
            ((short[]) array)[index] = value;
        } else {
            throw badArray(array);
        }
    }

    /**
     * Sets the value of the indexed component of the specified array
     * object to the specified {@code char} value.
     * @param array the array
     * @param index the index into the array
     * @param value the new value of the indexed component
     * @exception NullPointerException If the specified object argument
     * is null
     * @exception IllegalArgumentException If the specified object argument
     * is not an array, or if the specified value cannot be converted
     * to the underlying array's component type by an identity or a
     * primitive widening conversion
     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
     * argument is negative, or if it is greater than or equal to
     * the length of the specified array
     * @see Array#set
     */
    // Android changed param name s/c/value
    public static void setChar(Object array, int index, char value) throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
        if (array instanceof char[]) {
            ((char[]) array)[index] = value;
        } else if (array instanceof double[]) {
            ((double[]) array)[index] = value;
        } else if (array instanceof float[]) {
            ((float[]) array)[index] = value;
        } else if (array instanceof int[]) {
            ((int[]) array)[index] = value;
        } else if (array instanceof long[]) {
            ((long[]) array)[index] = value;
        } else {
            throw badArray(array);
        }
    }

    /**
     * Sets the value of the indexed component of the specified array
     * object to the specified {@code short} value.
     * @param array the array
     * @param index the index into the array
     * @param value the new value of the indexed component
     * @exception NullPointerException If the specified object argument
     * is null
     * @exception IllegalArgumentException If the specified object argument
     * is not an array, or if the specified value cannot be converted
     * to the underlying array's component type by an identity or a
     * primitive widening conversion
     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
     * argument is negative, or if it is greater than or equal to
     * the length of the specified array
     * @see Array#set
     */
    // Android changed param name s/s/value
    public static void setShort(Object array, int index, short value) throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
        if (array instanceof short[]) {
            ((short[]) array)[index] = value;
        } else if (array instanceof double[]) {
            ((double[]) array)[index] = value;
        } else if (array instanceof float[]) {
            ((float[]) array)[index] = value;
        } else if (array instanceof int[]) {
            ((int[]) array)[index] = value;
        } else if (array instanceof long[]) {
            ((long[]) array)[index] = value;
        } else {
            throw badArray(array);
        }
    }

    /**
     * Sets the value of the indexed component of the specified array
     * object to the specified {@code int} value.
     * @param array the array
     * @param index the index into the array
     * @param value the new value of the indexed component
     * @exception NullPointerException If the specified object argument
     * is null
     * @exception IllegalArgumentException If the specified object argument
     * is not an array, or if the specified value cannot be converted
     * to the underlying array's component type by an identity or a
     * primitive widening conversion
     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
     * argument is negative, or if it is greater than or equal to
     * the length of the specified array
     * @see Array#set
     */
    // Android changed param name s/i/value
    public static void setInt(Object array, int index, int value) throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
        if (array instanceof int[]) {
            ((int[]) array)[index] = value;
        } else if (array instanceof double[]) {
            ((double[]) array)[index] = value;
        } else if (array instanceof float[]) {
            ((float[]) array)[index] = value;
        } else if (array instanceof long[]) {
            ((long[]) array)[index] = value;
        } else {
            throw badArray(array);
        }
    }

    /**
     * Sets the value of the indexed component of the specified array
     * object to the specified {@code long} value.
     * @param array the array
     * @param index the index into the array
     * @param value the new value of the indexed component
     * @exception NullPointerException If the specified object argument
     * is null
     * @exception IllegalArgumentException If the specified object argument
     * is not an array, or if the specified value cannot be converted
     * to the underlying array's component type by an identity or a
     * primitive widening conversion
     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
     * argument is negative, or if it is greater than or equal to
     * the length of the specified array
     * @see Array#set
     */
    // Android changed param name s/l/value
    public static void setLong(Object array, int index, long value) throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
        if (array instanceof long[]) {
            ((long[]) array)[index] = value;
        } else if (array instanceof double[]) {
            ((double[]) array)[index] = value;
        } else if (array instanceof float[]) {
            ((float[]) array)[index] = value;
        } else {
            throw badArray(array);
        }
    }

    /**
     * Sets the value of the indexed component of the specified array
     * object to the specified {@code float} value.
     * @param array the array
     * @param index the index into the array
     * @param value the new value of the indexed component
     * @exception NullPointerException If the specified object argument
     * is null
     * @exception IllegalArgumentException If the specified object argument
     * is not an array, or if the specified value cannot be converted
     * to the underlying array's component type by an identity or a
     * primitive widening conversion
     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
     * argument is negative, or if it is greater than or equal to
     * the length of the specified array
     * @see Array#set
     */
    // Android changed param name s/f/value
    public static void setFloat(Object array, int index, float value) throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
        if (array instanceof float[]) {
            ((float[]) array)[index] = value;
        } else if (array instanceof double[]) {
            ((double[]) array)[index] = value;
        } else {
            throw badArray(array);
        }
    }

    /**
     * Sets the value of the indexed component of the specified array
     * object to the specified {@code double} value.
     * @param array the array
     * @param index the index into the array
     * @param value the new value of the indexed component
     * @exception NullPointerException If the specified object argument
     * is null
     * @exception IllegalArgumentException If the specified object argument
     * is not an array, or if the specified value cannot be converted
     * to the underlying array's component type by an identity or a
     * primitive widening conversion
     * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
     * argument is negative, or if it is greater than or equal to
     * the length of the specified array
     * @see Array#set
     */
    // Android changed param name s/d/value
    public static void setDouble(Object array, int index, double value) throws IllegalArgumentException, ArrayIndexOutOfBoundsException {
        if (array instanceof double[]) {
            ((double[]) array)[index] = value;
        } else {
            throw badArray(array);
        }
    }

    /*
     * Create a multi-dimensional array of objects with the specified type.
     */
    private static native Object createMultiArray(Class<?> componentType, int[] dimensions) throws NegativeArraySizeException;

    /**
     * Returns a new array of the specified component type and length.
     * Equivalent to {@code new componentType[size]}.
     *
     * @throws NullPointerException
     *             if the component type is null
     * @throws NegativeArraySizeException
     *             if {@code size < 0}
     */
    private static Object newArray(Class<?> componentType, int size) throws NegativeArraySizeException {
        if (!componentType.isPrimitive()) {
            return createObjectArray(componentType, size);
        } else if (componentType == char.class) {
            return new char[size];
        } else if (componentType == int.class) {
            return new int[size];
        } else if (componentType == byte.class) {
            return new byte[size];
        } else if (componentType == boolean.class) {
            return new boolean[size];
        } else if (componentType == short.class) {
            return new short[size];
        } else if (componentType == long.class) {
            return new long[size];
        } else if (componentType == float.class) {
            return new float[size];
        } else if (componentType == double.class) {
            return new double[size];
        } else if (componentType == void.class) {
            throw new IllegalArgumentException("Can't allocate an array of void");
        }
        throw new AssertionError();
    }

    /*
     * Create a one-dimensional array of objects with the specified type.
     */
    private static native Object createObjectArray(Class<?> componentType, int length) throws NegativeArraySizeException;

    private static IllegalArgumentException notAnArray(Object o) {
        throw new IllegalArgumentException("Not an array: " + o.getClass());
    }

    private static IllegalArgumentException incompatibleType(Object o) {
        throw new IllegalArgumentException("Array has incompatible type: " + o.getClass());
    }

    private static RuntimeException badArray(Object array) {
        if (array == null) {
            throw new NullPointerException("array == null");
        } else if (!array.getClass().isArray()) {
            throw notAnArray(array);
        } else {
            throw incompatibleType(array);
        }
    }
}