java8的List对象去重

List中的对象必须实现下面两个方法

public static void main(String[] args) {
    	List<QuestionModel> list = new ArrayList<QuestionModel>();
    	QuestionModel questionModel1 = new QuestionModel();
    	questionModel1.setQuestion("111");
    	questionModel1.setAnswer("111");
    	QuestionModel questionModel2 = new QuestionModel();
    	questionModel2.setQuestion("333");
    	questionModel2.setAnswer("333");
    	QuestionModel questionModel3 = new QuestionModel();
    	questionModel3.setQuestion("333");
    	questionModel3.setAnswer("333");
    	list.add(questionModel1);
    	list.add(questionModel2);
    	list.add(questionModel3);
    	//集合去重
    	List<QuestionModel> list2 = list.stream().distinct().collect(Collectors.toList());
    	for (int i = 0; i < list2.size(); i++) {
    		System.out.println("第"+(i+1)+"个"+list2.get(i).getQuestion()+ "----------" + list2.get(i).getAnswer());
		}
	}

删除之后的结果：