java.lang.reflect
Class Array

java.lang.Object
  java.lang.reflect.Array

public final class Array
extends Object

Array provides methods to create instances of array and to access the elements of arrays of different types.

Since:

1.2

Constructor Summary

Array()

Method Summary

static Object	get(Object array, int index) get returns the element of a given array at given index.
static boolean	getBoolean(Object array, int index) getBoolean returns the contents of a boolean array.
static byte	getByte(Object array, int index) getByte returns the contents of a byte array.
static char	getChar(Object array, int index) getChar returns the contents of a char array.
static double	getDouble(Object array, int index) getDouble returns the contents of a double array.
static float	getFloat(Object array, int index) getFloat returns the contents of a float array.
static int	getInt(Object array, int index) getInt returns the contents of a int array.
static int	getLength(Object array) getLength returns the length of the given array instance.
static long	getLong(Object array, int index) getLong returns the contents of a long array.
static short	getShort(Object array, int index) getShort returns the contents of a short array.
static Object	newInstance(Class<?> componentType, int length) Create a new instance of an array with given component type and length.
static Object	newInstance(Class<?> componentType, int[] dimensions) newInstance
static void	set(Object a, int i, Object v) set sets an array element to a a given value.
static void	setBoolean(Object array, int index, boolean z) setBoolean sets an array element to a a given value.
static void	setByte(Object array, int index, byte b) setByte sets an array element to a a given value.
static void	setChar(Object array, int index, char c) setChar sets an array element to a a given value.
static void	setDouble(Object array, int index, double d) setDouble sets an array element to a a given value.
static void	setFloat(Object array, int index, float f) setFloat sets an array element to a a given value.
static void	setInt(Object array, int index, int i) setInt sets an array element to a a given value.
static void	setLong(Object array, int index, long l) setLong sets an array element to a a given value.
static void	setShort(Object array, int index, short s) setShort sets an array element to a a given value.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Array

public Array()

Method Detail

newInstance

public static Object newInstance(Class<?> componentType,
                                 int length)
                          throws NegativeArraySizeException,
                                 IllegalArgumentException,
                                 NullPointerException

Create a new instance of an array with given component type and length.

Parameters:

componentType - the element type for the array. May be either a normal class, an array or a primitive type such as Boolean.TYPE, Byte.TYPE, etc.

length - the number of elements for the new array.

Returns:

a new array instance with result.getClass()getComponentType()==compontentType and getLength(result) == length.

Throws:

NegativeArraySizeException - if length < 0

NullPointerException - if compontentType == null

IllegalArgumentException - if componentType == Void.TYPE

newInstance

public static Object newInstance(Class<?> componentType,
                                 int[] dimensions)
                          throws IllegalArgumentException,
                                 NegativeArraySizeException

newInstance

Parameters:

componentType -

dimensions -

Returns:

the new array

Throws:

IllegalArgumentException

NegativeArraySizeException

getLength

public static int getLength(Object array)
                     throws IllegalArgumentException

getLength returns the length of the given array instance.

Parameters:

array - instance of an array

Returns:

the length of the array

Throws:

IllegalArgumentException - if argument is not an array.

NullPointerException - if array is null.

get

public static Object get(Object array,
                         int index)
                  throws IllegalArgumentException,
                         ArrayIndexOutOfBoundsException

get returns the element of a given array at given index. If the array is a primitive array (such as int[]), the result is boxed into a corresponding instance (such java.lang.Integer).

Parameters:

array - an array

index - an index in array

Returns:

the element array[index]

Throws:

IllegalArgumentException - if array is not an array

ArrayIndexOutOfBoundsException - if index is negative or larger than or equal to getLength(array).

NullPointerException - if array is null.

getBoolean

public static boolean getBoolean(Object array,
                                 int index)
                          throws IllegalArgumentException,
                                 ArrayIndexOutOfBoundsException

getBoolean returns the contents of a boolean array.

Parameters:

array - an array of boolean elements.

index - an index in array

Returns:

the boolean value array[index].

Throws:

IllegalArgumentException - if the array is not of the required type

NullPointerException - if array is null

ArrayIndexOutOfBoundsException - if index is negative or larger than or equal to getLength(array).

getByte

public static byte getByte(Object array,
                           int index)
                    throws IllegalArgumentException,
                           ArrayIndexOutOfBoundsException

getByte returns the contents of a byte array.

Parameters:

array - an array of boolean elements.

index - an index in array

Returns:

the byte value array[index].

Throws:

IllegalArgumentException - if the array is not of the required type

NullPointerException - if array is null

ArrayIndexOutOfBoundsException - if index is negative or larger than or equal to getLength(array).

getChar

public static char getChar(Object array,
                           int index)
                    throws IllegalArgumentException,
                           ArrayIndexOutOfBoundsException

getChar returns the contents of a char array.

Parameters:

array - an array of char elements.

index - an index in array

Returns:

the char value array[index].

Throws:

IllegalArgumentException - if the array is not of the required type

NullPointerException - if array is null

ArrayIndexOutOfBoundsException - if index is negative or larger than or equal to getLength(array).

getShort

public static short getShort(Object array,
                             int index)
                      throws IllegalArgumentException,
                             ArrayIndexOutOfBoundsException

getShort returns the contents of a short array.

Parameters:

array - an array of short elements.

index - an index in array

Returns:

the short value array[index].

Throws:

IllegalArgumentException - if the array is not of the required type

NullPointerException - if array is null

ArrayIndexOutOfBoundsException - if index is negative or larger than or equal to getLength(array).

getInt

public static int getInt(Object array,
                         int index)
                  throws IllegalArgumentException,
                         ArrayIndexOutOfBoundsException

getInt returns the contents of a int array.

Parameters:

array - an array of int elements.

index - an index in array

Returns:

the int value array[index].

Throws:

IllegalArgumentException - if the array is not of the required type

NullPointerException - if array is null

ArrayIndexOutOfBoundsException - if index is negative or larger than or equal to getLength(array).

getLong

public static long getLong(Object array,
                           int index)
                    throws IllegalArgumentException,
                           ArrayIndexOutOfBoundsException

getLong returns the contents of a long array.

Parameters:

array - an array of long elements.

index - an index in array

Returns:

the long value array[index].

Throws:

IllegalArgumentException - if the array is not of the required type

NullPointerException - if array is null

ArrayIndexOutOfBoundsException - if index is negative or larger than or equal to getLength(array).

getFloat

public static float getFloat(Object array,
                             int index)
                      throws IllegalArgumentException,
                             ArrayIndexOutOfBoundsException

getFloat returns the contents of a float array.

Parameters:

array - an array of float elements.

index - an index in array

Returns:

the float value array[index].

Throws:

IllegalArgumentException - if the array is not of the required type

NullPointerException - if array is null

ArrayIndexOutOfBoundsException - if index is negative or larger than or equal to getLength(array).

getDouble

public static double getDouble(Object array,
                               int index)
                        throws IllegalArgumentException,
                               ArrayIndexOutOfBoundsException

getDouble returns the contents of a double array.

Parameters:

array - an array of double elements.

index - an index in array

Returns:

the double value array[index].

Throws:

IllegalArgumentException - if the array is not of the required type

NullPointerException - if array is null

ArrayIndexOutOfBoundsException - if index is negative or larger than or equal to getLength(array).

set

public static void set(Object a,
                       int i,
                       Object v)
                throws IllegalArgumentException,
                       ArrayIndexOutOfBoundsException

set sets an array element to a a given value. The array may be an array of objects or of primitive types. In case of an array of primitive types, the value is unboxed and converted if possible.

Parameters:

a - an array

i - the index to be set

v - the value to be stored at the index

Throws:

IllegalArgumentException - if array is not an array or value could not be unboxed or converted to the array element type.

NullPointerException - if array is null

ArrayIndexOutOfBoundsException - if index is negative or larger than or equal to getLength(array).

setBoolean

public static void setBoolean(Object array,
                              int index,
                              boolean z)
                       throws IllegalArgumentException,
                              ArrayIndexOutOfBoundsException

setBoolean sets an array element to a a given value.

Parameters:

array - an array

index - the index to be set

z - the value to be stored at the index

Throws:

IllegalArgumentException - if array is not an array or z could not be converted to the array element type.

NullPointerException - if array is null

ArrayIndexOutOfBoundsException - if index is negative or larger than or equal to getLength(array).

setByte

public static void setByte(Object array,
                           int index,
                           byte b)
                    throws IllegalArgumentException,
                           ArrayIndexOutOfBoundsException

setByte sets an array element to a a given value.

Parameters:

array - an array

index - the index to be set

b - the value to be stored at the index

Throws:

IllegalArgumentException - if array is not an array or b could not be converted to the array element type.

NullPointerException - if array is null

ArrayIndexOutOfBoundsException - if index is negative or larger than or equal to getLength(array).

setChar

public static void setChar(Object array,
                           int index,
                           char c)
                    throws IllegalArgumentException,
                           ArrayIndexOutOfBoundsException

setChar sets an array element to a a given value.

Parameters:

array - an array

index - the index to be set

c - the value to be stored at the index

Throws:

IllegalArgumentException - if array is not an array or c could not be converted to the array element type.

NullPointerException - if array is null

ArrayIndexOutOfBoundsException - if index is negative or larger than or equal to getLength(array).

setShort

public static void setShort(Object array,
                            int index,
                            short s)
                     throws IllegalArgumentException,
                            ArrayIndexOutOfBoundsException

setShort sets an array element to a a given value.

Parameters:

array - an array

index - the index to be set

s - the value to be stored at the index

Throws:

IllegalArgumentException - if array is not an array or s could not be converted to the array element type.

NullPointerException - if array is null

ArrayIndexOutOfBoundsException - if index is negative or larger than or equal to getLength(array).

setInt

public static void setInt(Object array,
                          int index,
                          int i)
                   throws IllegalArgumentException,
                          ArrayIndexOutOfBoundsException

setInt sets an array element to a a given value.

Parameters:

array - an array

index - the index to be set

i - the value to be stored at the index

Throws:

IllegalArgumentException - if array is not an array or i could not be converted to the array element type.

NullPointerException - if array is null

ArrayIndexOutOfBoundsException - if index is negative or larger than or equal to getLength(array).

setLong

public static void setLong(Object array,
                           int index,
                           long l)
                    throws IllegalArgumentException,
                           ArrayIndexOutOfBoundsException

setLong sets an array element to a a given value.

Parameters:

array - an array

index - the index to be set

l - the value to be stored at the index

Throws:

IllegalArgumentException - if array is not an array or l could not be converted to the array element type.

NullPointerException - if array is null

ArrayIndexOutOfBoundsException - if index is negative or larger than or equal to getLength(array).

setFloat

public static void setFloat(Object array,
                            int index,
                            float f)
                     throws IllegalArgumentException,
                            ArrayIndexOutOfBoundsException

setFloat sets an array element to a a given value.

Parameters:

array - an array

index - the index to be set

f - the value to be stored at the index

Throws:

IllegalArgumentException - if array is not an array or f could not be converted to the array element type.

NullPointerException - if array is null

ArrayIndexOutOfBoundsException - if index is negative or larger than or equal to getLength(array).

setDouble

public static void setDouble(Object array,
                             int index,
                             double d)
                      throws IllegalArgumentException,
                             ArrayIndexOutOfBoundsException

setDouble sets an array element to a a given value.

Parameters:

array - an array

index - the index to be set

d - the value to be stored at the index

Throws:

IllegalArgumentException - if array is not an array or d could not be converted to the array element type.

NullPointerException - if array is null

ArrayIndexOutOfBoundsException - if index is negative or larger than or equal to getLength(array).