lambda表達式替換list中某個實體類的某個屬性值

1. 實體類

// 測試用的Bean
public class Bean {

    private int v1;
    private int v2;

    public Bean(int v1, int v2) {
        super();
        this.v1 = v1;
        this.v2 = v2;
    }

    public int getV1() {
        return v1;
    }

    public void setV1(int v1) {
        this.v1 = v1;
    }

    public int getV2() {
        return v2;
    }

    public void setV2(int v2) {
        this.v2 = v2;
    }

    @Override
    public String toString() {
        return "Bean [v1=" + v1 + ", v2=" + v2 + "]";
    }
}

2. 測試方法

Bean bean1 = new Bean(1, 2);
        Bean bean2 = new Bean(3, 4);
        List<Bean> list = new ArrayList<>();
        list.add(bean1);
        list.add(bean2);
        System.out.println("list1 : " + list);

        list.stream().filter(bean -> {
            bean.setV1(233);
            return true;
        }).collect(Collectors.toList());
        System.out.println("list2 : " + list);
    }

3. 測試結果

list里面所有實體類的v1屬性都被修改了