net.anotheria.util.ArrayUtils Maven / Gradle / Ivy
package net.anotheria.util;
import java.lang.reflect.Array;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
/**
* An util for handling of arrays.
*
* @author denis
* @version $Id: $Id
*/
public class ArrayUtils {
/**
* Merges two arrays in a third array.
*
* @param firstArray an array of T objects.
* @param secondArray a T object.
* @return an array of T objects.
*/
public static T[] mergeArrays(T[] firstArray, T... secondArray) {
T[] ret = Arrays.copyOf(firstArray, firstArray.length + secondArray.length);
System.arraycopy(secondArray, firstArray.length - firstArray.length, ret, firstArray.length, ret.length - firstArray.length);
return ret;
}
/**
* mergeArrays.
*
* @param firstArray an array of int.
* @param secondArray a int.
* @return an array of int.
*/
public static int[] mergeArrays(int[] firstArray, int... secondArray) {
return toIntArray(mergeArrays(toIntegerArray(firstArray), toIntegerArray(secondArray)));
}
/**
* addToArray.
*
* @param array an array of T objects.
* @param element a T object.
* @param a T object.
* @return an array of T objects.
*/
public static T[] addToArray(T[] array, T element){
T[] ret = Arrays.copyOf(array, array.length + 1);
ret[array.length] = element;
return ret;
}
/**
* addToArray.
*
* @param array an array of int.
* @param element a int.
* @return an array of int.
*/
public static int[] addToArray(int[] array, int element){
int[] ret = Arrays.copyOf(array, array.length + 1);
ret[array.length] = element;
return ret;
}
/**
* subArray.
*
* @param src an array of T objects.
* @param from a int.
* @param to a int.
* @param a T object.
* @return an array of T objects.
*/
public static T[] subArray(T[] src, int from, int to){
return Arrays.copyOfRange(src, from, to);
}
/**
* subArray.
*
* @param src an array of int.
* @param from a int.
* @param to a int.
* @return an array of int.
*/
public static int[] subArray(int[] src, int from, int to){
return Arrays.copyOfRange(src, from, to);
}
/**
* Returns the List that contains elements from array.
* NOTE: vararg of parameterized types (here @param array) for primitive arrays doesn't work properly.
* This utility have to be accomplished with asList methods for each primitive arrays!!!
*
* @param array a T object.
* @param a T object.
* @return a {@link java.lang.Iterable} object.
*/
public static Iterable asList(T... array){
return Arrays.asList(array);
}
/**
* asList.
*
* @param array an array of int.
* @return a {@link java.lang.Iterable} object.
*/
public static Iterable asList(int[] array){
List ret = new ArrayList<>(array.length);
for(int a:array)
ret.add(a);
return ret;
}
/**
* asList.
*
* @param array an array of long.
* @return a {@link java.lang.Iterable} object.
*/
public static Iterable asList(long[] array){
List ret = new ArrayList<>(array.length);
for(long a:array)
ret.add(a);
return ret;
}
/**
* asList.
*
* @param array an array of float.
* @return a {@link java.lang.Iterable} object.
*/
public static Iterable asList(float[] array){
List ret = new ArrayList<>(array.length);
for(float a:array)
ret.add(a);
return ret;
}
/**
* asArray.
*
* @param integerList a {@link java.util.List} object.
* @return an array of int.
*/
public static int[] asArray(List integerList){
int[] ret = new int[integerList.size()];
for(int i = 0; i < integerList.size(); i++)
ret[i] = integerList.get(i);
return ret;
}
/**
* toIntArray.
*
* @param integerArray a {@link java.lang.Integer} object.
* @return an array of int.
*/
public static int[] toIntArray(Integer... integerArray){
int[] ret = new int[integerArray.length];
for(int i = 0; i < integerArray.length; i++)
ret[i] = integerArray[i];
return ret;
}
/**
* toIntegerArray.
*
* @param intArray a int.
* @return an array of {@link java.lang.Integer} objects.
*/
public static Integer[] toIntegerArray(int... intArray){
Integer[] ret = new Integer[intArray.length];
for(int i = 0; i < intArray.length; i++)
ret[i] = intArray[i];
return ret;
}
/**
* parseStringListAsInt.
*
* @param stringList a {@link java.util.List} object.
* @return an array of int.
*/
public static int[] parseStringListAsInt(List stringList){
int[] ret = new int[stringList.size()];
for(int i = 0; i < stringList.size(); i++)
ret[i] = Integer.parseInt(stringList.get(i));
return ret;
}
/**
* parseStringArray.
*
* @param stringArray a {@link java.lang.String} object.
* @return an array of int.
*/
public static int[] parseStringArray(String... stringArray){
int[] ret = new int[stringArray.length];
for(int i = 0; i < stringArray.length; i++)
ret[i] = Integer.parseInt(stringArray[i]);
return ret;
}
/**
* Converts an Objects list to the list of Strings by calling toString method of each Object from incoming list.
*
* @deprecated Use StringUtils.toStringList() instead.
* @param list incoming list of Objects
* @return list where each incoming object converted to string.
*/
@Deprecated
public static List toStringList(Collection list){
List ret = new ArrayList<>(list.size());
for(Object el: list)
ret.add(el.toString());
return ret;
}
/**
* toStringList.
*
* @param array a int.
* @return a {@link java.util.List} object.
*/
public static List toStringList(int... array){
List ret = new ArrayList<>(array.length);
for(int el: array)
ret.add(String.valueOf(el));
return ret;
}
/**
* toStringList.
*
* @param array a T object.
* @param a T object.
* @return a {@link java.util.List} object.
*/
public static List toStringList(T... array){
List ret = new ArrayList<>(array.length);
for(T el: array)
ret.add(String.valueOf(el));
return ret;
}
/**
* toString.
*
* @param array a int.
* @param a T object.
* @return a {@link java.lang.String} object.
*/
public static String toString(int... array){
return toString(toIntegerArray(array));
}
/**
* toString.
*
* @param array a T object.
* @param a T object.
* @return a {@link java.lang.String} object.
*/
public static String toString(T... array){
if(array.length == 0)
return "[]";
String ret = "[";
ret += array[0];
for(int i = 1; i < array.length; i++)
ret += "," + array[i];
ret += "]";
return ret;
}
/**
* contains.
*
* @param array an array of int.
* @param element a int.
* @return a boolean.
*/
public static boolean contains(int[] array, int element){
for(int i:array)
if(i == element)
return true;
return false;
}
/**
* contains.
*
* @param array an array of T objects.
* @param element a T object.
* @param a T object.
* @return a boolean.
*/
public static boolean contains(T[] array, T element){
for(T a:array)
if(a.equals(element))
return true;
return false;
}
/**
* Finds all elements that the array1 and the array2 have in common.
* The array1 and the array2 must be sorted ascent.
*
* @return the array of elements that the array1 and the array2 have in common
* @param array1 an array of int.
* @param array2 a int.
*/
public static int[] intersection(int[] array1, int... array2){
if(array1.length == 0 || array2.length == 0)
return new int[0];
if(!isSorted(array1) || !isSorted(array2))
throw new RuntimeException("Arrays must be sorted: array1 " + toString(array1) + ", array2 " + toString(array2));
int position1 = 0;
int position2 = 0;
int[] buff = new int[Math.min(array1.length, array2.length)];
int positionBuff = 0;
while(position1 < array1.length && position2 < array2.length){
int a1 = array1[position1];
int a2 = array2[position2];
if(a1 == a2) {
buff[positionBuff] = a1;
position1++;
position2++;
positionBuff++;
} else if(a1 > a2) {
position2++;
} else {
position1++;
}
}
int[] ret = new int[positionBuff];
System.arraycopy(buff, 0, ret, 0, positionBuff);
return ret;
}
/**
* isSorted.
*
* @param desc a boolean.
* @param array a int.
* @return a boolean.
*/
public static boolean isSorted(boolean desc, int... array){
for(int i = 0; i < array.length - 1; i++)
if((array[i+1] - array[i]) * (desc? -1: 1) < 0)
return false;
return true;
}
/**
* isSorted.
*
* @param array a int.
* @return a boolean.
*/
public static boolean isSorted(int... array){
return isSorted(false, array);
}
/**
* createInstance.
*
* @param a an array of T objects.
* @param size a int.
* @param a T object.
* @return an array of T objects.
*/
public static T[] createInstance(T[] a, int size){
return (T[]) Array.newInstance(a.getClass().getComponentType(), size);
}
}
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