PairTest3.java Source code

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Here is the source code for PairTest3.java

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/*
   This program is a part of the companion code for Core Java 8th ed.
   (http://horstmann.com/corejava)
    
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
    
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
    
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

import java.util.Date;
import java.util.GregorianCalendar;

/**
 * @version 1.00 2004-05-10
 * @author Cay Horstmann
 */
public class PairTest3 {
    public static void main(String[] args) {
        Manager ceo = new Manager("Gus Greedy", 800000, 2003, 12, 15);
        Manager cfo = new Manager("Sid Sneaky", 600000, 2003, 12, 15);
        Pair<Manager> buddies = new Pair<Manager>(ceo, cfo);
        printBuddies(buddies);

        ceo.setBonus(1000000);
        cfo.setBonus(500000);
        Manager[] managers = { ceo, cfo };

        Pair<Employee> result = new Pair<Employee>();
        minmaxBonus(managers, result);
        System.out.println("first: " + result.getFirst().getName() + ", second: " + result.getSecond().getName());
        maxminBonus(managers, result);
        System.out.println("first: " + result.getFirst().getName() + ", second: " + result.getSecond().getName());
    }

    public static void printBuddies(Pair<? extends Employee> p) {
        Employee first = p.getFirst();
        Employee second = p.getSecond();
        System.out.println(first.getName() + " and " + second.getName() + " are buddies.");
    }

    public static void minmaxBonus(Manager[] a, Pair<? super Manager> result) {
        if (a == null || a.length == 0)
            return;
        Manager min = a[0];
        Manager max = a[0];
        for (int i = 1; i < a.length; i++) {
            if (min.getBonus() > a[i].getBonus())
                min = a[i];
            if (max.getBonus() < a[i].getBonus())
                max = a[i];
        }
        result.setFirst(min);
        result.setSecond(max);
    }

    public static void maxminBonus(Manager[] a, Pair<? super Manager> result) {
        minmaxBonus(a, result);
        PairAlg.swapHelper(result); // OK--swapHelper captures wildcard type
    }
}

class PairAlg {
    public static boolean hasNulls(Pair<?> p) {
        return p.getFirst() == null || p.getSecond() == null;
    }

    public static void swap(Pair<?> p) {
        swapHelper(p);
    }

    public static <T> void swapHelper(Pair<T> p) {
        T t = p.getFirst();
        p.setFirst(p.getSecond());
        p.setSecond(t);
    }
}

class Employee {
    public Employee(String n, double s, int year, int month, int day) {
        name = n;
        salary = s;
        GregorianCalendar calendar = new GregorianCalendar(year, month - 1, day);
        hireDay = calendar.getTime();
    }

    public String getName() {
        return name;
    }

    public double getSalary() {
        return salary;
    }

    public Date getHireDay() {
        return hireDay;
    }

    public void raiseSalary(double byPercent) {
        double raise = salary * byPercent / 100;
        salary += raise;
    }

    private String name;
    private double salary;
    private Date hireDay;
}

class Manager extends Employee {
    /**
       @param n the employee's name
       @param s the salary
       @param year the hire year
       @param month the hire month
       @param day the hire day
    */
    public Manager(String n, double s, int year, int month, int day) {
        super(n, s, year, month, day);
        bonus = 0;
    }

    public double getSalary() {
        double baseSalary = super.getSalary();
        return baseSalary + bonus;
    }

    public void setBonus(double b) {
        bonus = b;
    }

    public double getBonus() {
        return bonus;
    }

    private double bonus;
}

/*
   This program is a part of the companion code for Core Java 8th ed.
   (http://horstmann.com/corejava)
    
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
    
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
    
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

/**
 * @version 1.00 2004-05-10
 * @author Cay Horstmann
 */
class Pair<T> {
    public Pair() {
        first = null;
        second = null;
    }

    public Pair(T first, T second) {
        this.first = first;
        this.second = second;
    }

    public T getFirst() {
        return first;
    }

    public T getSecond() {
        return second;
    }

    public void setFirst(T newValue) {
        first = newValue;
    }

    public void setSecond(T newValue) {
        second = newValue;
    }

    private T first;
    private T second;
}