Java二分法

贴段代码,有少许注释:
package ibees;
import java.util.Arrays;
public class BinarySearch {

/**
* @param args
*/
public static void main(String[] args) {
double[] src = new double[]{1.3,9.9,10.89,12.89,89.0};
System.out.println(new BinarySearch().binarySearch(src, 89.0));
}

/**
* 二分法查找
* */
public int binarySearch(double[] src, double des){
Arrays.sort(src);
int beginIndex = 0;
int endIndex = src.length-1;
int middle = (endIndex+beginIndex)/2;

while(src[middle] != des && beginIndex != endIndex){

//最后两项
if(beginIndex+1 == endIndex){
if(src[beginIndex] == des){
return beginIndex;
}else if(src[endIndex] == des){
return endIndex;
}else{
return -1;
}

}

//判断中间的数与给定数之间的关系
if(des > src[middle]){
beginIndex = middle+1;
}else if(des < src[middle]){
endIndex = middle-1;
}else{
return middle;
}

middle = (endIndex + beginIndex)/2;

}
return middle;
}
}

想想返回的数组索引是不对的。