编辑代码

class Main {
	public static void main(String[] args) {
        //JSRUN引擎2.0，支持多达30种语言在线运行，全仿真在线交互输入输出。
		System.out.println("Hello world!   - java.jsrun.net ");
	}
}

 class Student implements Comparable<Student>{
 
	private Integer id;
	private String name;
	private int age;
 
	/**
	 * get和set方法
	 * @param id
	 */
	public Integer getId() {
		return id;
	}
	
	public void setId(Integer id) {
		this.id = id;
	}
	
	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;
	}
 
	/**
	 * hashCode()方法
	 */
	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + age;
		result = prime * result + ((id == null) ? 0 : id.hashCode());
		result = prime * result + ((name == null) ? 0 : name.hashCode());
		return result;
	}
 
	/**
	 * equals()方法
	 */
	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		Student other = (Student) obj;
		if (age != other.age)
			return false;
		if (id == null) {
			if (other.id != null)
				return false;
		} else if (!id.equals(other.id))
			return false;
		if (name == null) {
			if (other.name != null)
				return false;
		} else if (!name.equals(other.name))
			return false;
		return true;
	}
 
	@Override
	public String toString() {
		return "Student [id=" + id + ", name=" + name + ", age=" + age + "]";
	}
 
	public Student(Integer id, String name, int age) {
		super();
		this.id = id;
		this.name = name;
		this.age = age;
	}
 
	
	public int compareTo(Student o) {
		if(this.getAge()-o.getAge()==0) {
			return this.getId()-o.getId();
		}
		return this.getAge() - o.getAge();
	}
 
	
 
	
}