Main.java Source code

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Here is the source code for Main.java

Source

//package com.java2s;
//License from project: Apache License 

public class Main {
    /**
     * get next element of the target element, after the first one that match the target element front to back
     * <ul>
     * <li>if array is empty, return defaultValue</li>
     * <li>if target element is not exist in array, return defaultValue</li>
     * <li>if target element exist in array and not the last one in array, return the next element</li>
     * <li>if target element exist in array and the last one in array, return the first one in array if isCircle is
     * true, else return defaultValue</li>
     * </ul>
     *
     * @param <V>
     * @param sourceArray
     * @param value        value of target element
     * @param defaultValue default return value
     * @param isCircle     whether is circle
     * @return
     */
    public static <V> V getNext(V[] sourceArray, V value, V defaultValue, boolean isCircle) {
        if (isEmpty(sourceArray)) {
            return defaultValue;
        }

        int currentPosition = -1;
        for (int i = 0; i < sourceArray.length; i++) {
            if (isEquals(value, sourceArray[i])) {
                currentPosition = i;
                break;
            }
        }
        if (currentPosition == -1) {
            return defaultValue;
        }

        if (currentPosition == sourceArray.length - 1) {
            return isCircle ? sourceArray[0] : defaultValue;
        }
        return sourceArray[currentPosition + 1];
    }

    /**
     * @see {@link ArrayUtils#getNext(Object[], Object, Object, boolean)} defaultValue is null
     */
    public static <V> V getNext(V[] sourceArray, V value, boolean isCircle) {
        return getNext(sourceArray, value, null, isCircle);
    }

    /**
     * @see {@link ArrayUtils#getNext(Object[], Object, Object, boolean)} Object is Long
     */
    public static long getNext(long[] sourceArray, long value, long defaultValue, boolean isCircle) {
        if (sourceArray.length == 0) {
            throw new IllegalArgumentException("The length of source array must be greater than 0.");
        }

        Long[] array = transformLongArray(sourceArray);
        return getNext(array, value, defaultValue, isCircle);
    }

    /**
     * @see {@link ArrayUtils#getNext(Object[], Object, Object, boolean)} Object is Integer
     */
    public static int getNext(int[] sourceArray, int value, int defaultValue, boolean isCircle) {
        if (sourceArray.length == 0) {
            throw new IllegalArgumentException("The length of source array must be greater than 0.");
        }

        Integer[] array = transformIntArray(sourceArray);
        return getNext(array, value, defaultValue, isCircle);
    }

    /**
     * is null or its length is 0
     *
     * @param <V>
     * @param sourceArray
     * @return
     */
    public static <V> boolean isEmpty(V[] sourceArray) {
        return (sourceArray == null || sourceArray.length == 0);
    }

    /**
     * compare two object
     *
     * @param actual
     * @param expected
     * @return <ul>
     * <li>if both are null, return true</li>
     * <li>return actual.{@link Object#equals(Object)}</li>
     * </ul>
     */
    public static boolean isEquals(Object actual, Object expected) {
        return actual == expected || (actual == null ? expected == null : actual.equals(expected));
    }

    /**
     * convert long array to Long array
     *
     * @param source
     * @return
     */
    public static Long[] transformLongArray(long[] source) {
        Long[] destin = new Long[source.length];
        for (int i = 0; i < source.length; i++) {
            destin[i] = source[i];
        }
        return destin;
    }

    /**
     * convert Long array to long array
     *
     * @param source
     * @return
     */
    public static long[] transformLongArray(Long[] source) {
        long[] destin = new long[source.length];
        for (int i = 0; i < source.length; i++) {
            destin[i] = source[i];
        }
        return destin;
    }

    /**
     * convert int array to Integer array
     *
     * @param source
     * @return
     */
    public static Integer[] transformIntArray(int[] source) {
        Integer[] destin = new Integer[source.length];
        for (int i = 0; i < source.length; i++) {
            destin[i] = source[i];
        }
        return destin;
    }

    /**
     * convert Integer array to int array
     *
     * @param source
     * @return
     */
    public static int[] transformIntArray(Integer[] source) {
        int[] destin = new int[source.length];
        for (int i = 0; i < source.length; i++) {
            destin[i] = source[i];
        }
        return destin;
    }
}