array.java

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/*
 * @(#)Array.java	1.3 96/11/23
 * 
 * Copyright (c) 1995, 1996 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * This software is the confidential and proprietary information of Sun
 * Microsystems, Inc. ("Confidential Information").  You shall not
 * disclose such Confidential Information and shall use it only in
 * accordance with the terms of the license agreement you entered into
 * with Sun.
 * 
 * SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF THE
 * SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
 * PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR ANY DAMAGES
 * SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING
 * THIS SOFTWARE OR ITS DERIVATIVES.
 * 
 * CopyrightVersion 1.1_beta
 * 
 */

package java.lang.reflect;

/**
 * The Array class provides static methods to dynamically create and
 * access Java arrays.
 *
 * <p>Array permits widening conversions to occur during a get or set
 * operation, but throws an 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.

     * The effect is that of the equivalent array creation expression:
     * <pre>
     *    new componentType[length]
     * </pre>
     *
     * @param componentType the 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
     * componentType parameter is null
     * @exception NegativeArraySizeException if the specified 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.
     *
     * <p>The effect is that of the equivalent array creation expression:
     * <pre>
     *    new componentType[dimensions[0]][dimensions[1]]...
     * </pre>
     *
     * @param componentType the Class object representing the component
     * type of the new array
     * @param dimensions an array of ints representing the dimensions of
     * the new array
     * @return the new array
     * @exception NullPointerException if the specified 
     * componentType argument is null
     * @exception IllegalArgumentException if the specified 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).
     * @exception NegativeArraySizeException if any of the components in
     * the specified dimension argument is negative.
     */
    public static Object newInstance(Class componentType, int[] dimensions)
	throws IllegalArgumentException, NegativeArraySizeException {
	return multiNewArray(componentType, dimensions);
    }

    /**
     * Returns the length of the specified array object, as an int.
     *
     * @param array the array
     * @return the length of the array
     * @exception IllegalArgumentException if the object argument is not
     * an array
     */
    public static native int getLength(Object array)
	throws IllegalArgumentException;

    /**
     * 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 index
     * argument is negative, or if it is greater than or equal to the
     * length of the specified array
     */
    public static native Object get(Object array, int index)
 	throws IllegalArgumentException, ArrayIndexOutOfBoundsException;

    /**
     * Returns the value of the indexed component in the specified
     * array object, as a 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 index
     * argument is negative, or if it is greater than or equal to the
     * length of the specified array
     * @see Array#get
     */
    public static native boolean getBoolean(Object array, int index)
	throws IllegalArgumentException, ArrayIndexOutOfBoundsException;

    /**
     * Returns the value of the indexed component in the specified
     * array object, as a 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 index
     * argument is negative, or if it is greater than or equal to the
     * length of the specified array
     * @see Array#get
     */
    public static native byte getByte(Object array, int index)
	throws IllegalArgumentException, ArrayIndexOutOfBoundsException;

    /**
     * Returns the value of the indexed component in the specified
     * array object, as a 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 index
     * argument is negative, or if it is greater than or equal to the
     * length of the specified array
     * @see Array#get
     */
    public static native char getChar(Object array, int index)
	throws IllegalArgumentException, ArrayIndexOutOfBoundsException;

    /**
     * Returns the value of the indexed component in the specified
     * array object, as a 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 index
     * argument is negative, or if it is greater than or equal to the
     * length of the specified array
     * @see Array#get
     */
    public static native short getShort(Object array, int index)
	throws IllegalArgumentException, ArrayIndexOutOfBoundsException;

    /**
     * Returns the value of the indexed component in the specified
     * array object, as an 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 index
     * argument is negative, or if it is greater than or equal to the
     * length of the specified array
     * @see Array#get
     */
    public static native int getInt(Object array, int index)
	throws IllegalArgumentException, ArrayIndexOutOfBoundsException;

    /**
     * Returns the value of the indexed component in the specified
     * array object, as a 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 index
     * argument is negative, or if it is greater than or equal to the
     * length of the specified array
     * @see Array#get
     */
    public static native long getLong(Object array, int index)
	throws IllegalArgumentException, ArrayIndexOutOfBoundsException;