java实现二分查找

/**
     * 二分查找
     * @param a
     * @param n
     * @param value
     * @return
     * @date 2016-10-8
     * @author shaobn
     */
        public static int binaryFind(int[] a,int n,int value){
            int lowNum = 0;
            int highNum = n-1;
            while(lowNum<=highNum){
                int midNum = (lowNum+highNum)/2;
                if(a[midNum]==value){
                    return midNum;
                }else if (a[midNum]>value) {
                    highNum = midNum-1;
                }else if (a[midNum]<value) {
                    lowNum = midNum+1;
                }
            }
            return -1;            
        }