嵌套POJO列表的流到另一个POJO列表

import java.util.List;
import java.util.stream.Collectors;

public class NestedPOJOExample {
    public static void main(String[] args) {
        List<OuterPOJO> outerList = getOuterPOJOList();

        List<InnerPOJO> innerList = outerList.stream()
                .flatMap(outer -> outer.getInnerList().stream())
                .map(inner -> new InnerPOJO(inner.getPropertyA(), inner.getPropertyB()))
                .collect(Collectors.toList());

        System.out.println(innerList);
    }

    private static List<OuterPOJO> getOuterPOJOList() {
        // 假设获取包含嵌套POJO的外部列表的方法
        // 返回一个包含多个OuterPOJO对象的列表
    }

    private static class OuterPOJO {
        private List<InnerPOJO> innerList;

        public List<InnerPOJO> getInnerList() {
            return innerList;
        }

        public void setInnerList(List<InnerPOJO> innerList) {
            this.innerList = innerList;
        }
    }

    private static class InnerPOJO {
        private String propertyA;
        private String propertyB;

        public InnerPOJO(String propertyA, String propertyB) {
            this.propertyA = propertyA;
            this.propertyB = propertyB;
        }

        public String getPropertyA() {
            return propertyA;
        }

        public void setPropertyA(String propertyA) {
            this.propertyA = propertyA;
        }

        public String getPropertyB() {
            return propertyB;
        }

        public void setPropertyB(String propertyB) {
            this.propertyB = propertyB;
        }
    }
}