package Firm;
//사원 직급, 월급, 입사날자, 이름, 나이, 성별, 성과
// Gik,Pay,Day,name,old,gender,did
//전부 수정이랑, 직급 수정 월급 수정 따로따로 가능하게 업데이트
//월급별 정렬, 날자별 정렬, 직급별 정렬, 나이별 정렬(많은순 적은순), 성별별 정렬
//사원 월급 합계 나오게
//성과를 기존 데이터를 나두고 추가가 가능하게
//ArrayList 사용,try and catch 사용, 이중메뉴 사용
//직급별 찾기 ,이름별 찾기

public interface FirmInterface {

public int input();

public void printPay();
public void printDay();
public void printGik();
public void printOlder();
public void printYounger();
public void printGender();

public void delete();

public void updateAll();
public void updateGik();
public void updatePay();

public void plusDid();

public void findGik();
public void findName();

}

---------------------------------

package Firm;

public class Worker {

private int pay;
private int day;
private int old;

private String gik;
private String name;
private String gender;
private String did;

public Worker(int pay, int day, int old, String gik, String name,
String gender, String did) {
super();
this.pay = pay;
this.day = day;
this.old = old;
this.gik = gik;
this.name = name;
this.gender = gender;
this.did = did;
}

public int getPay() {
return pay;
}

public void setPay(int pay) {
this.pay = pay;
}

public int getDay() {
return day;
}

public void setDay(int day) {
this.day = day;
}

public int getOld() {
return old;
}

public void setOld(int old) {
this.old = old;
}

public String getGik() {
return gik;
}

public void setGik(String gik) {
this.gik = gik;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public String getGender() {
return gender;
}

public void setGender(String gender) {
this.gender = gender;
}

public String getDid() {
return did;
}

public void setDid(String did) {
this.did = did;
}

@Override
public String toString() {
String str;

str = ("직책: " + gik + "이름: " + name + "나이: " + old
+ "성별: " + gender + "입사날자: " + day + "월급: " + pay
+ "연봉: "+ pay * 12 +"성과: " + did );
return str;

}


}


--------------------------------------

package Firm;
//사원들 총 월급 합쳐진것 나와야함 totpay
//월급하고 연봉 따로나와야함
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.Scanner;

public class FirmImple implements FirmInterface {

ArrayList<Worker> arr = new ArrayList<Worker>();
Scanner [...] new Scanner(System.in);
Iterator<Worker> it = arr.iterator();

Worker wo = new Worker(0, 0, 0, null, null, null, null);
@Override
public int input() {

System.out.print("이름: ");
wo.setName([...].next());
System.out.print("직책: ");
wo.setGik([...].next());
System.out.print("나이: ");
wo.setOld([...].nextInt());
System.out.print("성별: ");
wo.setGender([...].next());
System.out.print("입사날자(ex)20130101: ");
wo.setDay([...].nextInt());
System.out.print("월급: ");
wo.setPay([...].nextInt());
System.out.print("성과: ");
wo.setDid([...].next());
arr.add(wo);
System.out.println(wo.toString());
System.out.println("추가완료!!");

return 1;
}

@Override
public void printPay() {
for(int it = 0; it <arr.size();it++){
wo = arr.get(it);
System.out.println(wo);
}

}

@Override
public void printDay() {
// TODO Auto-generated method stub

}

@Override
public void printGik() {
// TODO Auto-generated method stub

}

@Override
public void printOlder() {
// TODO Auto-generated method stub

}

@Override
public void printYounger() {
// TODO Auto-generated method stub

}

@Override
public void printGender() {
// TODO Auto-generated method stub

}

@Override
public void delete() {
// TODO Auto-generated method stub

}

@Override
public void updateAll() {
// TODO Auto-generated method stub

}

@Override
public void updateGik() {
// TODO Auto-generated method stub

}

@Override
public void updatePay() {
// TODO Auto-generated method stub

}

@Override
public void plusDid() {
// TODO Auto-generated method stub

}

@Override
public void findGik() {
// TODO Auto-generated method stub

}

@Override
public void findName() {
// TODO Auto-generated method stub

}

}
------

여기서

public void printPay() {
for(int it = 0; it <arr.size();it++){
wo = arr.get(it);
System.out.println(wo);
}

이 메소드에서
페이가 높은 순으로 정렬을 하려는데 어떻게 해야 할지 모르겠음 ㅜㅡ 도와주심