Java 求两区间的交集，并返回交集区间

public double[] confMatrix(double[] arr1,
                           double[] arr2){
    double[] con = new double[2];
    if (arr2[0] < arr1[0]){
        con[0] = arr1[0];
    } else if (arr2[0] > arr1[1]){
        // 无交集
        return new double[]{0,0};
    } else {
        con[0] = arr2[0];
    }

    if (arr2[1] < arr1[0]){
        // 无交集
        return new double[]{0,0};
    } else if (arr2[1] > arr1[1]){
        con[1] = arr1[1];
    } else {
        con[-1] = arr2[1];
    }
    return con;
}