对LIST对象多个字段进行排序

灰太狼 2023-02-13 14:45 22阅读 0赞

jdk1.8之前的做法

参考: http://blog.csdn.net/enable1234\_\_\_/article/details/53224740

jdk1.8新特性的做法：

参考: http://blog.csdn.net/aitangyong/article/details/54880228

Student.java

public class Student {
    	private Long id;
    	private String name;
    	private String age;
    	private Date birthday;
     
    	public Student() {
    	}
     
    	public Student(Long id, String name, String age) {
    		this.id = id;
    		this.name = name;
    		this.age = age;
    	}
     
    	public Student(String name, String age) {
    		this.name = name;
    		this.age = age;
    	}
     
    	public Student(String name, String age, Date birthday) {
    		this.name = name;
    		this.age = age;
    		this.birthday = birthday;
    	}
     
    	public Long getId() {
    		return id;
    	}
     
    	public void setId(Long id) {
    		this.id = id;
    	}
     
    	public String getName() {
    		return name;
    	}
     
    	public void setName(String name) {
    		this.name = name;
    	}
     
    	public String getAge() {
    		return age;
    	}
     
    	public void setAge(String age) {
    		this.age = age;
    	}
     
    	public Date getBirthday() {
    		return birthday;
    	}
     
    	public String getBirthdayStr() {
    		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
    		return sdf.format(birthday);
    	}
     
    	public void setBirthday(Date birthday) {
    		this.birthday = birthday;
    	}
     
    	@Override
    	public String toString() {
    		return "Student [name=" + name + ", age=" + age + ", birthday=" + getBirthdayStr() + "]";
    	}
    }

Listtest.java

public class ListTest {
    	@Test
    	public void test() {
    		List<Student> stuList = new ArrayList<Student>();
    		SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd");
    		stuList.add(new Student("wang", "18", sdf.parse("2007/04/01")));
    		stuList.add(new Student("li", "19", sdf.parse("2007/05/01")));
    		stuList.add(new Student("liu", "20", sdf.parse("2006/04/01")));
    		stuList.add(new Student("xi", "15", sdf.parse("2007/04/01")));
    		stuList.add(new Student("li", "17", sdf.parse("2007/05/01")));
    		stuList.add(new Student("wang", "19", sdf.parse("2007/06/01")));
     
    		// age升序
    		Comparator<Student> byIdASC = Comparator.comparing(Student::getAge);
     
    		// named不分区大小写降序
    		Comparator<Student> byNameDESC = Comparator.comparing(Student::getName, String.CASE_INSENSITIVE_ORDER)
    				.reversed();
     
    		// birthday 降序
    		Comparator<Student> byBirthdayDESC = Comparator.comparing(Student::getBirthday).reversed();
     
    		// 联合排序
    		Comparator<Student> finalComparator = byIdASC.thenComparing(byNameDESC).thenComparing(byBirthdayDESC);
     
    		List<Student> result = stuList.stream().sorted(finalComparator).collect(Collectors.toList());
    		print(result);
    		// 输出结果:
    		// Student [name=xi, age=15, birthday=2007-04-01]
    		// Student [name=li, age=17, birthday=2007-05-01]
    		// Student [name=wang, age=18, birthday=2007-04-01]
    		// Student [name=wang, age=19, birthday=2007-06-01]
    		// Student [name=li, age=19, birthday=2007-05-01]
    		// Student [name=liu, age=20, birthday=2006-04-01]
     
    	}
    }