目标
将对象List中的某个字段放到新的List中
转载自：list stream:将对象List中的某个字段放到新的List中
实现
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| public class Test {
public static void main(String[] args) {
List<TAdslot> userList = new ArrayList<>();
TAdslot adslot1 = new TAdslot();
adslot1.setName("One");
adslot1.setNameList(Lists.newArrayList("A","B","C"));
TAdslot adslot2 = new TAdslot();
adslot2.setName("Zero");
adslot2.setNameList(Lists.newArrayList("D","E","F"));
TAdslot adslot3 = new TAdslot();
adslot3.setName("Two");
adslot3.setNameList(Lists.newArrayList("H","I","J"));
TAdslot adslot4 = new TAdslot();
adslot4.setName("Four");
userList.add(adslot1);
userList.add(adslot2);
userList.add(adslot3);
userList.add(adslot4);
List<String> stringList = userList.stream().map(TAdslot::getName).collect(Collectors.toList());
System.out.println(stringList);
List<String> userListStr = userList.stream().map(TAdslot::getNameList).filter(Objects::nonNull).flatMap(List::stream).collect(Collectors.toList());
System.out.println(userListStr);
}
}
@Data
class TAdslot {
public String name;
public List<String> nameList;
}
|
输出结果：
[One, Zero, Two, Four]
[A, B, C, D, E, F, H, I, J]