使用Lambda表达式.map循环遍历List集合赋值

使用Lambda表达式给对象赋值

0. 技术点

• 使用Lambda表达式.map循环遍历List集合赋值

1. 实体类

@Data
public class InfoNoticeItem implements Serializable {
    /**
     * serialVersionUID
     */
    private static final long serialVersionUID = 6411598034131994800L;
    /**
     * ids 商品内码
     */
    private String ids;
 
    /**
     * storeCode 门店编号
     */
    private String storeCode;
}

---

2. 测试类

import com.alibaba.fastjson.JSON;
 
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.stream.Collectors;
 
public class Test {
    public static void main(String[] args) {
 
        InfoNoticeItem re2 = new InfoNoticeItem();
        re2.setIds("2");
        re2.setStoreCode("高佳琪");
 
        InfoNoticeItem re4 = new InfoNoticeItem();
        re4.setIds("4");
        re4.setStoreCode("王莹莹");
 
        List<InfoNoticeItem> list = new ArrayList<>();
        Collections.addAll(list, re2, re4);
 
        ShopInfoNoticeReq shopInfoNoticeReq = new ShopInfoNoticeReq();
        shopInfoNoticeReq.setFormat(null);
        shopInfoNoticeReq.setIdList(list);
 
        // 赋值.setIdList(collect)
        // public void setIdList(List<InfoNoticeItem> idList)
        List<InfoNoticeItem> collect = shopInfoNoticeReq.getIdList().stream().map(item -> {
            InfoNoticeItem ini = new InfoNoticeItem();
            ini.setIds(item.getIds());
            ini.setStoreCode(item.getStoreCode());
            return ini;
        }).collect(Collectors.toList());
 
        try {
            Thread.sleep(2000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println(JSON.toJSON(collect));
        //TODO 输出：[{"ids":"2","storeCode":"高佳琪"},{"ids":"4","storeCode":"王莹莹"}]
    }
}

---

简单使用

  ArrayList<Student> list = new ArrayList<>();
  Collections.addAll(list, new Student(0, "张三"), new Student(10, "李四"));
 
  System.out.println(list.stream().map(value -> value.getId()).collect(Collectors.toList()));
  System.out.println(list.stream().map(Student::getId).collect(Collectors.toList()));
  //输出: [0, 10]
  //输出: [0, 10]