Homework is given to students together, and multiple entities are sorted by their attributes (just after learning object-oriented, the interface written is not used, just for students to learn how to use it):

/**
 * @comment:Student Information
 * @author Fourier series
 * @date 2018 October 22, 2001, 2:18:14 p.m.
 */
public class Student {

	private String name;
	private int age;
	private int height;
	private int mathScore;
	private int engScore;
	private String schName;
	
	
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	public int getHeight() {
		return height;
	}
	public void setHeight(int height) {
		this.height = height;
	}
	public int getMathScore() {
		return mathScore;
	}
	public void setMathScore(int mathScore) {
		this.mathScore = mathScore;
	}
	public int getEngScore() {
		return engScore;
	}
	public void setEngScore(int engScore) {
		this.engScore = engScore;
	}
	public String getSchName() {
		return schName;
	}
	public void setSchName(String schName) {
		this.schName = schName;
	}
	
	
	
	
	@Override
	public String toString() {
		return "Full name: "+this.name+"  ,Age: "+this.age+"  ,Height:"+this.height+"  ,School:"+this.schName+
				"  ,Mathematics Achievements:"+this.mathScore+"  ,English Achievements:"+this.engScore;
	}
}

/**
 * @comment:Sorting Method Interface
 * @author Fourier series
 * @date 2018 October 22, 2001, 3:46:53 p.m.
 */
public interface StuSortInt {
	
	
	/**
	 * @comment:Sorting of Student Information
	 * @author:Fourier series
	 * @date:2018 22 October 2000, 2:40:11 p.m.
	 * @param list
	 */
	public void compareStudent(List<Student> list);
	
	
	/**
	 * @comment:Multiple Sorting of Student Information
	 * @author:Fourier series
	 * @date:2018 October 22, 2001, 3:28:19 p.m.
	 * @param list
	 */
	public void compareStudentInfo(List<Student> list);
}

/**
 *@comment:Implementation class of interface
 *@author Fourier series
 *@date 2018 October 22, 2001, 3:28:41 p.m.
 */
public class StuSortImpl implements StuSortInt{

	/**
	 * @comment:Students'information is sorted by age
	 * @author Fourier series
	 * @date 2018 October 22, 2001, 3:26:43 p.m.
	 */
	@Override
	public void compareStudent(List<Student> list) {
		Comparator<Student> comparator = new Comparator<Student>(){
			@Override
			public int compare(Student st1, Student st2) {
				return st2.getAge()-st1.getAge();
			}
		};
		
		Collections.sort(list, comparator);
		for (Student student : list) {
			System.out.println(student.toString());
		}
	}

	
	
	
	
	
	/**
	 * @comment:Multiple Sorting of Student Information
	 * @author Fourier series
	 * @date 2018 October 22, 2001, 3:28:50 p.m.
	 */
	@Override
	public void compareStudentInfo(List<Student> list) {
		Comparator<Student> comparator = new Comparator<Student>(){
			@Override
			public int compare(Student st1, Student st2) { // Rewrite compare method
				if(st2.getAge()!=st1.getAge()){ // According to age standard
					return st2.getAge()-st1.getAge();
				}else if(!st2.getName().equals(st1.getName())){ // The same age, according to the name standard
					return st2.getName().compareTo(st1.getName());
				}else{
					return st2.getMathScore()-st1.getMathScore(); // According to Mathematics Achievement Standard
				}
			}
		};
		// Call Collection's sort method for sorting
		Collections.sort(list, comparator);
		
		// ergodic
		for (Student student : list) {
			System.out.println(student.toString());
		}
	}
}

/**
 * @comment:Student Information Management
 * @author Fourier series
 * @date 2018 October 22, 2001, 2:19:10 p.m.
 */
public class StudentController {

	public static void main(String[] args) {
		/**
		 * Student Information Making Data
		 */
		Student stu = new Student();
		Student stu1 = new Student();
		Student stu2 = new Student();
		Student stu3 = new Student();
		
		
		stu.setName("Ye Liang Chen");
		stu.setAge(22);
		stu.setSchName("Lan Xiang");
		stu.setHeight(171);
		stu.setMathScore(85);
		stu.setEngScore(88);
		
		
		stu1.setName("Zhao Tian Tian");
		stu1.setAge(23);
		stu1.setSchName("Green Xiang");
		stu1.setHeight(176);
		stu1.setMathScore(99);
		stu1.setEngScore(77);
		
		
		stu2.setName("Ye Liang Chen");
		stu2.setAge(28);
		stu2.setSchName("Hung Xiang");
		stu2.setHeight(180);
		stu2.setMathScore(99);
		stu2.setEngScore(99);
		
		
		stu3.setName("Uncle of Science");
		stu3.setAge(23);
		stu3.setSchName("Luo Xiang");
		stu3.setHeight(198);
		stu3.setMathScore(23);
		stu3.setEngScore(32);
		
		
		List<Student> list = new ArrayList<>();
		list.add(stu);
		list.add(stu1);
		list.add(stu2);
		list.add(stu3);
		
		
		StuSortImpl stuSortImpl = new StuSortImpl();
		//1. Sort by age
		stuSortImpl.compareStudent(list);
		System.out.println("Sort by multiple criteria:");
		//2. Multiple standards
		stuSortImpl.compareStudentInfo(list);
	}

}

Result:

Name: Ye Liangchen, Age: 28, Height: 180, School: Hongxiang, Mathematics Achievement: 99, English Achievement: 99
Name: Zhao Ritian, age: 23, height: 176, school: Lvxiang, math score: 99, English score: 77
Name: Uncle Ke, age: 23, height: 198, school: Luoxiang, math score: 23, English score: 32
Name: Ye Liangchen, Age: 22, Height: 171, School: Lanxiang, Mathematics Achievement: 85, English Achievement: 88
Sort by multiple criteria:
Name: Ye Liangchen, Age: 28, Height: 180, School: Hongxiang, Mathematics Achievement: 99, English Achievement: 99
Name: Zhao Ritian, age: 23, height: 176, school: Lvxiang, math score: 99, English score: 77
Name: Uncle Ke, age: 23, height: 198, school: Luoxiang, math score: 23, English score: 32
Name: Ye Liangchen, Age: 22, Height: 171, School: Lanxiang, Mathematics Achievement: 85, English Achievement: 88