org.esa.beam.util
Class ArrayUtils

java.lang.Object
  org.esa.beam.util.ArrayUtils

public class ArrayUtils
extends Object

A utility class providing a set of static functions frequently used when working with basic Java arrays.

All functions have been implemented with extreme caution in order to provide a maximum performance.

Version:

$Revision$ $Date$

Author:

Norman Fomferra

Constructor Summary

ArrayUtils()

Method Summary

static int[]	addArrays(int[] firstArray, int[] secondArray) Gives a new int array who contains both, all ints form all the given arrays.
static int[]	addToArray(int[] array, int value) Gives a new int array who contains both, all ints form the given array and the given new value.
static int[]	createIntArray(int min, int max) Creates an int array which containes all values between the given min and the given max.
static boolean	equalArrays(double[] array1, double[] array2, double eps) Indicates whether the given arrays arrays are "equal to" each other.
static boolean	equalArrays(float[] array1, float[] array2, float eps) Indicates whether the given arrays arrays are "equal to" each other.
static boolean	equalArrays(Object[] array1, Object[] array2) Indicates whether the given objects arrays are "equal to" each other.
static int	getElementIndex(Object element, Object[] array) Returns the index of the specified object within the given object array.
static boolean	isMemberOf(Object element, Object[] array) Checks if the given object is member of the specified array.
static double[]	recycleOrCreateArray(double[] array, int length) Recycles or creates a new double array of the given length.
static float[]	recycleOrCreateArray(float[] array, int length) Recycles or creates a new float array of the given length.
static int[]	recycleOrCreateArray(int[] array, int length) Recycles or creates a new int array of the given length.
static void	swapArray(byte[] array) Swaps the content of the given array of bytes.
static void	swapArray(char[] array) Swaps the content of the given array of chars.
static void	swapArray(double[] array) Swaps the content of the given array of doubles.
static void	swapArray(float[] array) Swaps the content of the given array of floats.
static void	swapArray(int[] array) Swaps the content of the given array of ints.
static void	swapArray(long[] array) Swaps the content of the given array of longs.
static void	swapArray(Object array) Swaps the content of the given array.
static void	swapArray(Object[] array) Swaps the content of the given array of Objects.
static void	swapArray(short[] array) Swaps the content of the given array of shorts.

Methods inherited from class java.lang.Object

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

Constructor Detail

ArrayUtils

public ArrayUtils()

Method Detail

equalArrays

public static boolean equalArrays(float[] array1,
                                  float[] array2,
                                  float eps)

Indicates whether the given arrays arrays are "equal to" each other.

Parameters:

array1 - the first array, can be null

array2 - the second array, can also be null

eps - the maximum allowed absolute difference between the elements in both arrays

Returns:

true if each element in the first object array equals each element in the second, in fact in the same order; false otherwise.

equalArrays

public static boolean equalArrays(double[] array1,
                                  double[] array2,
                                  double eps)

Indicates whether the given arrays arrays are "equal to" each other.

Parameters:

array1 - the first array, can be null

array2 - the second array, can also be null

eps - the maximum allowed absolute difference between the elements in both arrays

Returns:

true if each element in the first object array equals each element in the second, in fact in the same order; false otherwise.

equalArrays

public static boolean equalArrays(Object[] array1,
                                  Object[] array2)

Indicates whether the given objects arrays are "equal to" each other.

This method should be used in place of the Object.equals if one ore both arguments can be null and if an element-by-element comparision shall be performed, since this is what this method does: for each element pair the ObjectUtils.equalObjects method is called.

Parameters:

array1 - the first object array, can be null

array2 - the second object array, can also be null

Returns:

true if each element in the first object array equals each element in the second, in fact in the same order; false otherwise.

getElementIndex

public static int getElementIndex(Object element,
                                  Object[] array)

Returns the index of the specified object within the given object array.

The method calls the ObjectUtils.equalObjects with the specified element on each of the array's elements. If both are equal, the index is immediately returned.

Parameters:

element - the element to be searched

array - the array in which to search the element, must not be null

Returns:

the array index in the range 0 to array.length - 1 if the element was found, -1 otherwise

isMemberOf

public static boolean isMemberOf(Object element,
                                 Object[] array)

Checks if the given object is member of the specified array.

The method simply returns getElementIndex(element, array) >= 0.

Parameters:

element - the element to be searched

array - the array in which to search the element, must not be null

Returns:

true if the given object is member of the specified array

swapArray

public static void swapArray(byte[] array)

Swaps the content of the given array of bytes.

Parameters:

array - the array of bytes

Throws:

IllegalArgumentException - if the given array is null

swapArray

public static void swapArray(char[] array)

Swaps the content of the given array of chars.

Parameters:

array - the array of chars

Throws:

IllegalArgumentException - if the given array is null

swapArray

public static void swapArray(short[] array)

Swaps the content of the given array of shorts.

Parameters:

array - the array of shorts

Throws:

IllegalArgumentException - if the given array is null

swapArray

public static void swapArray(int[] array)

Swaps the content of the given array of ints.

Parameters:

array - the array of ints

Throws:

IllegalArgumentException - if the given array is null

swapArray

public static void swapArray(long[] array)

Swaps the content of the given array of longs.

Parameters:

array - the array of longs

Throws:

IllegalArgumentException - if the given array is null

swapArray

public static void swapArray(float[] array)

Swaps the content of the given array of floats.

Parameters:

array - the array of floats

Throws:

IllegalArgumentException - if the given array is null

swapArray

public static void swapArray(double[] array)

Swaps the content of the given array of doubles.

Parameters:

array - the array of doubles

Throws:

IllegalArgumentException - if the given array is null

swapArray

public static void swapArray(Object[] array)

Swaps the content of the given array of Objects.

Parameters:

array - the array of Objects

Throws:

IllegalArgumentException - if the given array is null

swapArray

public static void swapArray(Object array)

Swaps the content of the given array.

Parameters:

array - the array, must be an instance of a native array type such as float[]

Throws:

IllegalArgumentException - if the given array is null or does not have a native array type

recycleOrCreateArray

public static int[] recycleOrCreateArray(int[] array,
                                         int length)

Recycles or creates a new int array of the given length.

Parameters:

array - an array which can possibly be recycled

length - the requested array length

Returns:

if the given array is not null and has exactly the requested length the given array is returned, otherwise a new array is created

recycleOrCreateArray

public static float[] recycleOrCreateArray(float[] array,
                                           int length)

Recycles or creates a new float array of the given length.

Parameters:

array - an array which can possibly be recycled

length - the requested array length

Returns:

if the given array is not null and has exactly the requested length the given array is returned, otherwise a new array is created

recycleOrCreateArray

public static double[] recycleOrCreateArray(double[] array,
                                            int length)

Recycles or creates a new double array of the given length.

Parameters:

array - an array which can possibly be recycled

length - the requested array length

Returns:

if the given array is not null and has exactly the requested length the given array is returned, otherwise a new array is created

addToArray

public static int[] addToArray(int[] array,
                               int value)
                        throws IllegalArgumentException

Gives a new int array who contains both, all ints form the given array and the given new value. The given value was added to the end of array

Returns:

new int[] with all ints and the new value

Throws:

IllegalArgumentException - if the given array is null

addArrays

public static int[] addArrays(int[] firstArray,
                              int[] secondArray)
                       throws IllegalArgumentException

Gives a new int array who contains both, all ints form all the given arrays. The given second array was added to the end of th first array.

Returns:

new int[] with all ints of both arrays

Throws:

IllegalArgumentException - if any of the given arrays are null

createIntArray

public static int[] createIntArray(int min,
                                   int max)

Creates an int array which containes all values between the given min and the given max. If min and max are equal an int[] which only contains one value was returned.

Parameters:

min - the given minimum

max - the given maximum

Returns:

an int array which containes all values between the given min and the given max.