cn.gnux.core.utils.ArrayUtil Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of utils Show documentation
提供丰富的Java工具方法
The newest version!
package cn.gnux.core.utils;

/**
 * 数组工具类
 * 
 * 继承自{@link org.apache.commons.lang3.ArrayUtils}
 * {@link ArrayUtils#getLast(Object[], Object, Object, boolean)}
 * 得到array中某个元素（从前到后第一次匹配）的前一个元素
 * {@link ArrayUtils#getNext(Object[], Object, Object, boolean)}
 * 得到array中某个元素（从前到后第一次匹配）的后一个元素
 * 
 * 
 * @author kelvin
 *
 */
public class ArrayUtil extends org.apache.commons.lang3.ArrayUtils {

	/**
	 * 得到array中某个元素（从前到后第一次匹配）的前一个元素
	 * 
	 * 若数组为空，返回defaultValue
	 * 若数组中未找到value，返回defaultValue
	 * 若找到了value并且不为第一个元素，返回该元素的前一个元素
	 * 若找到了value并且为第一个元素，isCircle为true时，返回数组最后一个元素；isCircle为false时，
	 * 返回defaultValue
	 * 
	 * 
	 * @param 
	 * @param sourceArray
	 *            源array
	 * @param value
	 *            待查找值，若value为null同样适用，会查找第一个为null的值
	 * @param defaultValue
	 *            默认返回值
	 * @param isCircle
	 *            是否是圆
	 * @return V
	 */
	public static  V getLast(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 (ObjectUtil.isEquals(value, sourceArray[i])) {
				currentPosition = i;
				break;
			}
		}

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

	public static  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 (ObjectUtil.isEquals(value, sourceArray)) {
				currentPosition = i;
				break;
			}
		}
		if (currentPosition == -1) {
			return defaultValue;
		}

		if (currentPosition == sourceArray.length - 1) {
			return isCircle ? sourceArray[0] : defaultValue;
		}
		return sourceArray[currentPosition + 1];
	}
	
    /**
     * 参考{@link ArrayUtils#getLast(Object[], Object, Object, boolean)} defaultValue为null
     */
    public static  V getLast(V[] sourceArray, V value, boolean isCircle) {
        return getLast(sourceArray, value, null, isCircle);
    }

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

    /**
     * 参考{@link ArrayUtils#getLast(Object[], Object, Object, boolean)} Object为Long
     */
    public static long getLast(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 = ObjectUtil.transformLongArray(sourceArray);
        return getLast(array, value, defaultValue, isCircle);

    }

    /**
     * 参考{@link ArrayUtils#getNext(Object[], Object, Object, boolean)} Object为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 = ObjectUtil.transformLongArray(sourceArray);
        return getNext(array, value, defaultValue, isCircle);
    }

    /**
     * 参考{@link ArrayUtils#getLast(Object[], Object, Object, boolean)} Object为Integer
     */
    public static int getLast(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 = ObjectUtil.transformIntArray(sourceArray);
        return getLast(array, value, defaultValue, isCircle);

    }

    /**
     * 参考{@link ArrayUtils#getNext(Object[], Object, Object, boolean)} Object为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 = ObjectUtil.transformIntArray(sourceArray);
        return getNext(array, value, defaultValue, isCircle);
    }
}