Question

List<Accumulation> accumulations = repository.getAccumulation();

public class Accumulation implements Serializable {
    private static final long serialVersionUID = 1L;

    private String mobileNo;
    private String address;
    private int count;

    --
    getter
    setter
}

如何从abobe列表中获取总计数是使用java的最简单方法。

目前我正在使用一些基本和常用代码，如下所示：

int totalCount = 0;

for (Accumulation cccumulation : accumulations) {
    totalCount += cccumulation.getCount();
}

Answer 1

我不知道这是一种更好的编程方式，但我可以通过这个获得它

class Entity extends ArrayList<Entity>{

    public static int totalCount;
    public static int totalListCount;

    private String mobileNo;
    private String address;
    private int count;
    public String getMobileNo() {
        return mobileNo;
    }
    public void setMobileNo(String mobileNo) {
        this.mobileNo = mobileNo;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    public int getCount() {
        return count;
    }
    public void setCount(int count) {
        this.count = count;
        totalCount += count;
    }
    public Entity(String mobileNo, String address, int count) {
        super();
        this.mobileNo = mobileNo;
        this.address = address;
        this.count = count;
        totalCount += count;
    }
    public Entity() {
        super();
    }
    public boolean add(Entity entity) {

        totalListCount += entity.getCount();
        return super.add(entity);       
    }
}

public class CountEntityInList {

    public static void main(String[] args) {

        Entity e1 = new Entity("9999999999", "aaa", 10);
        Entity e2 = new Entity("9999999999", "aaa", 10);
        Entity e3 = new Entity("9999999999", "aaa", 10);
        Entity e4 = new Entity("9999999999", "aaa", 10);
        Entity e5 = new Entity("9999999999", "aaa", 10);
        List<Entity> list = new Entity();
        list.add(e1);
        list.add(e2);
        list.add(e3);
        list.add(e4);
        list.add(e5);
        System.out.println(Entity.totalCount);

        Entity e6 = new Entity();
        e6.setCount(20);
        Entity e7 = new Entity();
        e7.setCount(20);
        Entity e8 = new Entity();
        e8.setCount(20);
        Entity e9 = new Entity();
        e9.setCount(20);
        Entity e10 = new Entity();
        e10.setCount(20);
        System.out.println(Entity.totalCount);

        System.out.println(Entity.totalListCount);
    }
}

从列表中计算数据的优化方法

1 个答案: