Sorting

public class Person implements Comparable<Person>{

    private int salary;
    private String name;

    public Person(String name, int salary) {
        this.name = name;
        this.salary = salary;
    }

    public String getName() {
        return name;
    }

    public int getSalary() {
        return salary;
    }


    @Override
    public int compareTo(Person person) {
        return this.salary - person.getSalary();
    }


    @Override
    public String toString() {
        return name + " " + salary;
    }
}




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

public class Main {

    public static void main(String[] args) {
        List<Person> people = new ArrayList<Person>();
        people.add(new Person("Matti", 150000));
        people.add(new Person("Pekka", 3000));
        people.add(new Person("Mikko", 300));
        people.add(new Person("Arto", 10));
        people.add(new Person("Merja", 500));
        people.add(new Person("Pertti", 80));

        System.out.println(people);

        /*
         * When you have implemented the compareTo-method, remove comment below.
         */

        Collections.sort(people);

        System.out.println(people);
    }
}


// Error
warning: [options] bootstrap class path not set in conjunction with -source 1.6
C:\Users\Laptop\Documents\NetBeansProjects\2013-OOProgrammingWithJava-PART2\week8-week8_13.RichFirstPoorLast\src\Person.java:2: error: type Comparable does not take parameters
public class Person implements Comparable<Person>{
C:\Users\Laptop\Documents\NetBeansProjects\2013-OOProgrammingWithJava-PART2\week8-week8_13.RichFirstPoorLast\src\Main.java:23: error: no suitable method found for sort(List<Person>)
        Collections.sort(people);
                   ^
    method Collections.<T#1>sort(List<T#1>,Comparator<? super T#1>) is not applicable
      (cannot instantiate from arguments because actual and formal argument lists differ in length)
    method Collections.<T#2>sort(List<T#2>) is not applicable
      (inferred type does not conform to declared bound(s)
        inferred: Person
        bound(s): Comparable<? super Person>)
  where T#1,T#2 are type-variables:
    T#1 extends Object declared in method <T#1>sort(List<T#1>,Comparator<? super T#1>)
    T#2 extends Comparable<? super T#2> declared in method <T#2>sort(List<T#2>)
C:\Users\Laptop\Documents\NetBeansProjects\2013-OOProgrammingWithJava-PART2\week8-week8_13.RichFirstPoorLast\src\Person.java:21: error: method does not override or implement a method from a supertype
    @Override
    ^
3 errors
1 warning
C:\Users\Laptop\Documents\NetBeansProjects\2013-OOProgrammingWithJava-PART2\week8-week8_13.RichFirstPoorLast\nbproject\build-impl.xml:603: The following error occurred while executing this line:
C:\Users\Laptop\Documents\NetBeansProjects\2013-OOProgrammingWithJava-PART2\week8-week8_13.RichFirstPoorLast\nbproject\build-impl.xml:245: Compile failed; see the compiler error output for details.
BUILD FAILED (total time: 0 seconds)