import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

/**
 * {@link <a href=
 * "https://[Log in to view URL]"
 * target= "_blank">interfaccia funzionale Comparator<T></a>}
 * 
 * @author itammb ( Italia Massimiliano Buscati )
 * @version JDK 1.15
 *
 */
class Main {
	public static class Student 
	{
	    private int id;
	    private String name, address;
	    
	    public Student( int id, String name, String address )
	    {	 
	        this.id = id;
	        this.name = name;
	        this.address = address;
	    }
	    
	    @Override
	    public String toString()
	    {
	        return this.id + " " + this.name + " " + this.address;
	    }	 

	} 
	 
	/**
	 * @see Comparator
	 *
	 */
	public static class SortById implements Comparator<Student> 
	{
		//  0: a = b
		// -1: a < b
		// +1: a > b
	    public int compare( Student a, Student b ) { return a.id - b.id; }
	}

	/**
	 * @see List
	 * @see ArrayList
	 * @see Collections#sort(List, Comparator)
	 */
	public static void main(String args[]) throws Exception {
		// Unit test - interfaccia funzionale Comparator<T>

	    List<Student> archive = new ArrayList<Student>();
	    	 
	    archive.add( new Student(111, "Pippo", "Treviglio, Via Giovanni Verga N21, Italia"));
	    archive.add( new Student(131, "Pluto", "Milano, Via Tito Livio N1, Italia"));
	    archive.add( new Student(121, "Paperino", "Genova, Via Marco Polo N53, Italia"));
	    archive.add( new Student(101, "Minni", "Roma, Via Misano N3, Italia"));
	   	 
	     for( Student student : archive )
	    	 System.out.println( student );
	
	     Collections.sort( archive, new SortById() );

	     for( Student student : archive )
	    	 System.out.println( "-- " + student );
	}
}