в 17:43, 31 мая 2010

2010-05-31T17:43:48Z

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2010-05-31T14:40:43Z

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== implements Comparable ==



<source lang="java">

import java.util.Arrays;
import java.util.ruparator;
class Person implements Comparable {
private String firstName;
private String lastName;
private int age;
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public int compareTo(Object anotherPerson) throws ClassCastException {
if (!(anotherPerson instanceof Person)) {
throw new ClassCastException("A Person object expected.");
}
int anotherPersonAge = ((Person) anotherPerson).getAge();
return this.age - anotherPersonAge;
}
}
class LastNameComparator implements Comparator {
public int compare(Object person, Object anotherPerson) {
String lastName1 = ((Person) person).getLastName().toUpperCase();
String firstName1 = ((Person) person).getFirstName().toUpperCase();
String lastName2 = ((Person) anotherPerson).getLastName().toUpperCase();
String firstName2 = ((Person) anotherPerson).getFirstName().toUpperCase();

if (lastName1.equals(lastName2)) {
return firstName1.rupareTo(firstName2);
} else {
return lastName1.rupareTo(lastName2);
}
}
}
class FirstNameComparator implements Comparator {
public int compare(Object person, Object anotherPerson) {
String lastName1 = ((Person) person).getLastName().toUpperCase();
String firstName1 = ((Person) person).getFirstName().toUpperCase();
String lastName2 = ((Person) anotherPerson).getLastName().toUpperCase();
String firstName2 = ((Person) anotherPerson).getFirstName().toUpperCase();
if (firstName1.equals(firstName2)) {
return lastName1.rupareTo(lastName2);
} else {
return firstName1.rupareTo(firstName2);
}
}
}
public class Main {
public static void main(String[] args) {
Person[] persons = new Person[4];
persons[0] = new Person();
persons[0].setFirstName("A");
persons[0].setLastName("X");
persons[0].setAge(56);
persons[1] = new Person();
persons[1].setFirstName("S");
persons[1].setLastName("C");
persons[1].setAge(8);
persons[2] = new Person();
persons[2].setFirstName("E");
persons[2].setLastName("H");
persons[2].setAge(16);
persons[3] = new Person();
persons[3].setFirstName("B");
persons[3].setLastName("Q");
persons[3].setAge(69);
System.out.println("Natural Order");
for (int i = 0; i < 4; i++) {
Person person = persons[i];
String lastName = person.getLastName();
String firstName = person.getFirstName();
int age = person.getAge();
System.out.println(lastName + ", " + firstName + ". Age:" + age);
}
Arrays.sort(persons, new LastNameComparator());
System.out.println();
System.out.println("Sorted by last name");
for (int i = 0; i < 4; i++) {
Person person = persons[i];
String lastName = person.getLastName();
String firstName = person.getFirstName();
int age = person.getAge();
System.out.println(lastName + ", " + firstName + ". Age:" + age);
}
Arrays.sort(persons, new FirstNameComparator());
System.out.println();
System.out.println("Sorted by first name");
for (int i = 0; i < 4; i++) {
Person person = persons[i];
String lastName = person.getLastName();
String firstName = person.getFirstName();
int age = person.getAge();
System.out.println(lastName + ", " + firstName + ". Age:" + age);
}
Arrays.sort(persons);
System.out.println();
System.out.println("Sorted by age");
for (int i = 0; i < 4; i++) {
Person person = persons[i];
String lastName = person.getLastName();
String firstName = person.getFirstName();
int age = person.getAge();
System.out.println(lastName + ", " + firstName + ". Age:" + age);
}
}
}

</source>



== implements java.lang.Comparable ==



<source lang="java">

import java.util.Arrays;
import java.util.ruparator;
class Person implements Comparable<Person> {
public Person(String firstName, String surname) {
this.firstName = firstName;
this.surname = surname;
}
public String getFirstName() {
return firstName;
}
public String getSurname() {
return surname;
}
public String toString() {
return firstName + " " + surname;
}
public int compareTo(Person person) {
int result = surname.rupareTo(person.surname);
return result == 0 ? firstName.rupareTo(((Person) person).firstName) : result;
}
private String firstName;
private String surname;
}
class ComparePersons implements Comparator<Person> {

public int compare(Person person1, Person person2) {
int result = -person1.getSurname().rupareTo(person2.getSurname());
return result == 0 ? -person1.getFirstName().rupareTo(person2.getFirstName()) : result;
}

public boolean equals(Object collator) {
if (this == collator) {
return true;
}
if (collator == null) {
return false;
}
return getClass() == collator.getClass();
}
}
public class Main {
public static void main(String[] args) {
Person[] authors = { new Person("A", "S"),
new Person("J", "G"),
new Person("T", "C"),
new Person("C", "S"),
new Person("P", "C"),
new Person("B", "B") };
System.out.println("Original order:");
for (Person author : authors) {
System.out.println(author);
}
Arrays.sort(authors, new ComparePersons());
System.out.println("\nOrder after sorting using comparator:");
for (Person author : authors) {
System.out.println(author);
}
Arrays.sort(authors); // Sort using Comparable method
System.out.println("\nOrder after sorting using Comparable method:");
for (Person author : authors) {
System.out.println(author);
}
}
}

</source>

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