java 提取出List 的某一屬性組成list (java 8及以上版本 )

使用java 8 及以上版本

提取list bean中某一屬性組成list

 

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

/**
 * @ClassName: ListBeanTest
 * @Desc: 使用java 8 提取出list中bean的某一屬性組成list
 * @author: hatebugs
 * @date: 2021年12月11日 下午1:51:16
 */
public class ListBeanTest {

    public static void main(String[] args) {
        List<Student> stuList = new ArrayList<Student>();
        Student st1 = new Student("101", "AAAA");
        Student st2 = new Student("102", "BBBB");
        Student st3 = new Student("103", "CCCC");
        Student st4 = new Student("102", "DDDD");
        stuList.add(st1);
        stuList.add(st2);
        stuList.add(st3);
        stuList.add(st4);
        // 1.提取出list對象中的一個屬性
        List<String> stIdList1 = stuList.stream().map(Student::getId).collect(Collectors.toList());
        stIdList1.forEach(s -> System.out.print(s + " "));
        System.out.println();
        System.out.println("----------");

        // 2.提取出list對象中的一個屬性並去重
        List<String> stIdList2 = stuList.stream().map(Student::getId).distinct().collect(Collectors.toList());
        stIdList2.forEach(s -> System.out.print(s + " "));
    }

}
/**
 * 輸出結果：
 * 
 * 101 102 103 102 ---------- 101 102 103
 * 
 **/

public class Student {
    
    private String id;
    private String lastname;
    

    public Student(String id, String lastname) {
        super();
        this.id = id;
        this.lastname = lastname;
    }
    
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getLastname() {
        return lastname;
    }
    public void setLastname(String lastname) {
        this.lastname = lastname;
    }
}

 

 

參考自： https://blog.csdn.net/nightliar/article/details/78657949