comparetor和comparable的区别

package mycomparator;


import java.util.Arrays;
import java.util.Comparator;
class Person
{
//   private int age;
private int id;
public Person(int id)
{
// this.age=age;
this.id=id;
}
public int getId()
{
return id;
}
}
class Person1 implements Comparable
{
//   private int age;
private int id;
public Person1(int id)
{
// this.age=age;
this.id=id;
}
public int getId()
{
return id;
}
@Override
public int compareTo(Object a) {
// TODO Auto-generated method stub
return ((Person1)a).getId()-this.id;  //降序 this.id-a.id 为升序
}
}
class Percompare implements Comparator
{


@Override
public int compare(Object a, Object b) {
// TODO Auto-generated method stub
return ((Person)b).getId()-((Person)a).getId();  //降序 a-b为升序
}

}
public class Mycomparator {


public static void main(String[] args) {
// TODO Auto-generated method stub
Person1[] myPerson=new Person1[10];
for(int i=0;i<10;++i)
{
myPerson[i]=new Person1(i);
}
// Arrays.sort(myPerson,new Percompare());    //对于list<class>  要用Collections.sort(list,new Percompare())
Arrays.sort(myPerson);
for(Person1 t:myPerson)
{
System.out.println(t.getId());
}
}

}

上述的比较器都必须是在类下进行比较，对于基本类型，不适用。