double[] intervalPoint = {0, 0.2, 0.1, 0.3, 0.2, 0.3};      
int intervalNum = intervalPoint.length/2;   
Interval1D[] intervals = new Interval1D[intervalNum];

for(int i=0; i<intervals.length; i++){
    intervals[i] = new Interval1D(intervalPoint[2*i], intervalPoint[2*i+1]);
}

for(int i=0; i<intervals.length; i++){
    for(int j=i+1; j<intervals.length; j++){
        if(isIntersection(intervals[0], intervals[j]))
        System.out.println("(" + intervals[i] + ", " + intervals[j] + ")");
    }
}

/**
* 判斷區(qū)間a,b是否有交集
* @param a
* @param b
* @return
*/
public static boolean isIntersection(Interval1D a, Interval1D b){
    if(a.contains(b.min()) || a.contains(b.max()))return true;
    if(b.contains(a.min()) || b.contains(a.max()))return true;
    return false;
}