public final class Array extends Object
Array
class provides static methods to dynamically create and access Java arrays. Array
permits widening conversions to occur during a get or set operation, but throws an IllegalArgumentException
if a narrowing conversion would occur.
Modifier and Type | Method | Description |
---|---|---|
static Object |
get |
Returns the value of the indexed component in the specified array object. |
static boolean |
getBoolean |
Returns the value of the indexed component in the specified array object, as a boolean . |
static byte |
getByte |
Returns the value of the indexed component in the specified array object, as a byte . |
static char |
getChar |
Returns the value of the indexed component in the specified array object, as a char . |
static double |
getDouble |
Returns the value of the indexed component in the specified array object, as a double . |
static float |
getFloat |
Returns the value of the indexed component in the specified array object, as a float . |
static int |
getInt |
Returns the value of the indexed component in the specified array object, as an int . |
static int |
getLength |
Returns the length of the specified array object, as an int . |
static long |
getLong |
Returns the value of the indexed component in the specified array object, as a long . |
static short |
getShort |
Returns the value of the indexed component in the specified array object, as a short . |
static Object |
newInstance |
Creates a new array with the specified component type and length. |
static Object |
newInstance |
Creates a new array with the specified component type and dimensions. |
static void |
set |
Sets the value of the indexed component of the specified array object to the specified new value. |
static void |
setBoolean |
Sets the value of the indexed component of the specified array object to the specified boolean value. |
static void |
setByte |
Sets the value of the indexed component of the specified array object to the specified byte value. |
static void |
setChar |
Sets the value of the indexed component of the specified array object to the specified char value. |
static void |
setDouble |
Sets the value of the indexed component of the specified array object to the specified double value. |
static void |
setFloat |
Sets the value of the indexed component of the specified array object to the specified float value. |
static void |
setInt |
Sets the value of the indexed component of the specified array object to the specified int value. |
static void |
setLong |
Sets the value of the indexed component of the specified array object to the specified long value. |
static void |
setShort |
Sets the value of the indexed component of the specified array object to the specified short value. |
public static Object newInstance(Class<?> componentType, int length) throws NegativeArraySizeException
int[] x = {length}; Array.newInstance(componentType, x);
The number of dimensions of the new array must not exceed 255.
componentType
- the Class
object representing the component type of the new arraylength
- the length of the new arrayNullPointerException
- if the specified componentType
parameter is nullIllegalArgumentException
- if componentType is Void.TYPE
or if the number of dimensions of the requested array instance exceed 255.NegativeArraySizeException
- if the specified length
is negativepublic static Object newInstance(Class<?> componentType, int... dimensions) throws IllegalArgumentException, NegativeArraySizeException
componentType
represents a non-array class or interface, the new array has dimensions.length
dimensions and componentType
as its component type. If componentType
represents an array class, the number of dimensions of the new array is equal to the sum of dimensions.length
and the number of dimensions of componentType
. In this case, the component type of the new array is the component type of componentType
. The number of dimensions of the new array must not exceed 255.
componentType
- the Class
object representing the component type of the new arraydimensions
- an array of int
representing the dimensions of the new arrayNullPointerException
- if the specified componentType
argument is nullIllegalArgumentException
- if the specified dimensions
argument is a zero-dimensional array, if componentType is Void.TYPE
, or if the number of dimensions of the requested array instance exceed 255.NegativeArraySizeException
- if any of the components in the specified dimensions
argument is negative.public static int getLength(Object array) throws IllegalArgumentException
int
.array
- the arrayIllegalArgumentException
- if the object argument is not an arraypublic static Object get(Object array, int index) throws IllegalArgumentException, ArrayIndexOutOfBoundsException
array
- the arrayindex
- the indexNullPointerException
- If the specified object is nullIllegalArgumentException
- If the specified object is not an arrayArrayIndexOutOfBoundsException
- If the specified index
argument is negative, or if it is greater than or equal to the length of the specified arraypublic static boolean getBoolean(Object array, int index) throws IllegalArgumentException, ArrayIndexOutOfBoundsException
boolean
.array
- the arrayindex
- the indexNullPointerException
- If the specified object is nullIllegalArgumentException
- 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 conversionArrayIndexOutOfBoundsException
- If the specified index
argument is negative, or if it is greater than or equal to the length of the specified arraypublic static byte getByte(Object array, int index) throws IllegalArgumentException, ArrayIndexOutOfBoundsException
byte
.array
- the arrayindex
- the indexNullPointerException
- If the specified object is nullIllegalArgumentException
- 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 conversionArrayIndexOutOfBoundsException
- If the specified index
argument is negative, or if it is greater than or equal to the length of the specified arraypublic static char getChar(Object array, int index) throws IllegalArgumentException, ArrayIndexOutOfBoundsException
char
.array
- the arrayindex
- the indexNullPointerException
- If the specified object is nullIllegalArgumentException
- 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 conversionArrayIndexOutOfBoundsException
- If the specified index
argument is negative, or if it is greater than or equal to the length of the specified arraypublic static short getShort(Object array, int index) throws IllegalArgumentException, ArrayIndexOutOfBoundsException
short
.array
- the arrayindex
- the indexNullPointerException
- If the specified object is nullIllegalArgumentException
- 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 conversionArrayIndexOutOfBoundsException
- If the specified index
argument is negative, or if it is greater than or equal to the length of the specified arraypublic static int getInt(Object array, int index) throws IllegalArgumentException, ArrayIndexOutOfBoundsException
int
.array
- the arrayindex
- the indexNullPointerException
- If the specified object is nullIllegalArgumentException
- 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 conversionArrayIndexOutOfBoundsException
- If the specified index
argument is negative, or if it is greater than or equal to the length of the specified arraypublic static long getLong(Object array, int index) throws IllegalArgumentException, ArrayIndexOutOfBoundsException
long
.array
- the arrayindex
- the indexNullPointerException
- If the specified object is nullIllegalArgumentException
- 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 conversionArrayIndexOutOfBoundsException
- If the specified index
argument is negative, or if it is greater than or equal to the length of the specified arraypublic static float getFloat(Object array, int index) throws IllegalArgumentException, ArrayIndexOutOfBoundsException
float
.array
- the arrayindex
- the indexNullPointerException
- If the specified object is nullIllegalArgumentException
- 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 conversionArrayIndexOutOfBoundsException
- If the specified index
argument is negative, or if it is greater than or equal to the length of the specified arraypublic static double getDouble(Object array, int index) throws IllegalArgumentException, ArrayIndexOutOfBoundsException
double
.array
- the arrayindex
- the indexNullPointerException
- If the specified object is nullIllegalArgumentException
- 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 conversionArrayIndexOutOfBoundsException
- If the specified index
argument is negative, or if it is greater than or equal to the length of the specified arraypublic static void set(Object array, int index, Object value) throws IllegalArgumentException, ArrayIndexOutOfBoundsException
array
- the arrayindex
- the index into the arrayvalue
- the new value of the indexed componentNullPointerException
- If the specified object argument is nullIllegalArgumentException
- If the specified object argument is not an array, or if the array component type is primitive and an unwrapping conversion failsArrayIndexOutOfBoundsException
- If the specified index
argument is negative, or if it is greater than or equal to the length of the specified arraypublic static void setBoolean(Object array, int index, boolean z) throws IllegalArgumentException, ArrayIndexOutOfBoundsException
boolean
value.array
- the arrayindex
- the index into the arrayz
- the new value of the indexed componentNullPointerException
- If the specified object argument is nullIllegalArgumentException
- 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 conversionArrayIndexOutOfBoundsException
- If the specified index
argument is negative, or if it is greater than or equal to the length of the specified arraypublic static void setByte(Object array, int index, byte b) throws IllegalArgumentException, ArrayIndexOutOfBoundsException
byte
value.array
- the arrayindex
- the index into the arrayb
- the new value of the indexed componentNullPointerException
- If the specified object argument is nullIllegalArgumentException
- 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 conversionArrayIndexOutOfBoundsException
- If the specified index
argument is negative, or if it is greater than or equal to the length of the specified arraypublic static void setChar(Object array, int index, char c) throws IllegalArgumentException, ArrayIndexOutOfBoundsException
char
value.array
- the arrayindex
- the index into the arrayc
- the new value of the indexed componentNullPointerException
- If the specified object argument is nullIllegalArgumentException
- 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 conversionArrayIndexOutOfBoundsException
- If the specified index
argument is negative, or if it is greater than or equal to the length of the specified arraypublic static void setShort(Object array, int index, short s) throws IllegalArgumentException, ArrayIndexOutOfBoundsException
short
value.array
- the arrayindex
- the index into the arrays
- the new value of the indexed componentNullPointerException
- If the specified object argument is nullIllegalArgumentException
- 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 conversionArrayIndexOutOfBoundsException
- If the specified index
argument is negative, or if it is greater than or equal to the length of the specified arraypublic static void setInt(Object array, int index, int i) throws IllegalArgumentException, ArrayIndexOutOfBoundsException
int
value.array
- the arrayindex
- the index into the arrayi
- the new value of the indexed componentNullPointerException
- If the specified object argument is nullIllegalArgumentException
- 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 conversionArrayIndexOutOfBoundsException
- If the specified index
argument is negative, or if it is greater than or equal to the length of the specified arraypublic static void setLong(Object array, int index, long l) throws IllegalArgumentException, ArrayIndexOutOfBoundsException
long
value.array
- the arrayindex
- the index into the arrayl
- the new value of the indexed componentNullPointerException
- If the specified object argument is nullIllegalArgumentException
- 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 conversionArrayIndexOutOfBoundsException
- If the specified index
argument is negative, or if it is greater than or equal to the length of the specified arraypublic static void setFloat(Object array, int index, float f) throws IllegalArgumentException, ArrayIndexOutOfBoundsException
float
value.array
- the arrayindex
- the index into the arrayf
- the new value of the indexed componentNullPointerException
- If the specified object argument is nullIllegalArgumentException
- 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 conversionArrayIndexOutOfBoundsException
- If the specified index
argument is negative, or if it is greater than or equal to the length of the specified arraypublic static void setDouble(Object array, int index, double d) throws IllegalArgumentException, ArrayIndexOutOfBoundsException
double
value.array
- the arrayindex
- the index into the arrayd
- the new value of the indexed componentNullPointerException
- If the specified object argument is nullIllegalArgumentException
- 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 conversionArrayIndexOutOfBoundsException
- If the specified index
argument is negative, or if it is greater than or equal to the length of the specified array
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