myword

for (int k = 0; k < eachTypeCount[j]; k++){//题型中的题目个数
                        //选择不重复的题目
                    	int index = rand.nextInt(oneTypeProblem.size() - k);
                    	Problem pro = new Problem();
                    	BeanUtils.copyProperties(pro,oneTypeProblem.get(index));
                        paper.ProblemList.add(pro);
                        Problem temp = new Problem();
                        BeanUtils.copyProperties(temp,oneTypeProblem.get(oneTypeProblem.size() - 1 - k));
                        BeanUtils.copyProperties(oneTypeProblem.get(oneTypeProblem.size() - 1 - k),oneTypeProblem.get(index));//后面赋值给前面
                        BeanUtils.copyProperties(oneTypeProblem.get(index),temp);
                    }