Comparable接口与Comparator接口的对比
1. Comparable接口与Comparator接口的对比
comparable指定了比较方法在待比较的类中，直接利用Collections.sort()或Arrays.sort()排序就可以了。
comparator则是指定了比较的行为，可以作为Collections.sort()或Arrays.sort()方法的参数

2.代码：
Comparable

public class Person implements Comparable<Person>{private Integer id;private String name;private Integer age;public Person(){}public Person(Integer id, String name, Integer age){this.id = id;this.name = name;this.age = age;}public Integer getId(){return id;}public void setId( Integer id ){this.id = id;}public String getName(){return name;}public void setName( String name ){this.name = name;}public Integer getAge(){return age;}public void setAge( Integer age ){this.age = age;}@Overridepublic int compareTo( Person o ){return this.getAge().compareTo( o.getAge() );}}

import java.util.Comparator;public class PersonComparetor implements Comparator<Person>{@Overridepublic int compare( Person o1, Person o2 ){return o1.getAge().compareTo( o2.getAge() );}}

import java.util.ArrayList;import java.util.List;public class PersonsSingle{private static List<Person> persons = null;private PersonsSingle(){}public static List<Person> getPersons(){persons = new ArrayList<Person>();persons.add( new Person( 1, "张三",26 ) );persons.add( new Person( 2, "王五",20 ) );persons.add( new Person( 3, "赵六",29 ) );persons.add( new Person( 4, "李四",26 ) );persons.add( new Person( 5, "周公",50 ) );return persons;}}

import java.util.ArrayList;import java.util.Collections;import java.util.List;public class CollectionsTest{public void sort(){double array[] = {112, 111, 23, 456, 231 }; List list = new ArrayList();for (int i = 0; i < array.length; i++) { list.add(new Double(array[i])); } Collections.sort(list); for (int i = 0; i < array.length; i++) {    System.out.println(list.get(i)); }  System.out.println();}public void sortOne(){List<Person> list = PersonsSingle.getPersons();Collections.sort(list); for (Person p: list) {    System.out.println(p.getId() + "\t" + p.getName() + "\t" + p.getAge()); }  System.out.println();}public void sortTwo(){List<Person> list = PersonsSingle.getPersons();Collections.sort(list, new PersonComparetor()); for (Person p: list) {    System.out.println(p.getId() + "\t" + p.getName() + "\t" + p.getAge()); }  System.out.println();}public void shuffling(){List<Person> list = PersonsSingle.getPersons();//Collections.shuffling(list);Collections.shuffle(list); for (Person p: list) {    System.out.println(p.getId() + "\t" + p.getName() + "\t" + p.getAge()); }  System.out.println();}public void reverse(){List<Person> list = PersonsSingle.getPersons();Collections.reverse( list );for (Person p: list) {    System.out.println(p.getId() + "\t" + p.getName() + "\t" + p.getAge()); }  System.out.println();}public void fill(){List<Person> list = PersonsSingle.getPersons();Collections.fill( list, new Person(6,"傻根", 34) ); for (Person p: list) {    System.out.println(p.getId() + "\t" + p.getName() + "\t" + p.getAge()); }  System.out.println();}public void minOne(){List<Person> list = PersonsSingle.getPersons();Person p = Collections.min( list );System.out.println(p.getId() + "\t" + p.getName() + "\t" + p.getAge()); System.out.println();}public void minTwo(){List<Person> list = PersonsSingle.getPersons();Person p = Collections.min( list, new PersonComparetor() );System.out.println(p.getId() + "\t" + p.getName() + "\t" + p.getAge()); System.out.println();}public void maxOne(){List<Person> list = PersonsSingle.getPersons();Person p = Collections.max( list );System.out.println(p.getId() + "\t" + p.getName() + "\t" + p.getAge()); System.out.println();}public void maxTwo(){List<Person> list = PersonsSingle.getPersons();Person p = Collections.max( list, new PersonComparetor() );System.out.println(p.getId() + "\t" + p.getName() + "\t" + p.getAge()); System.out.println();}public void lastIndexOfSubList(){//int count = Collections.lastIndexOfSubList(list,li); double array[] = {112, 111, 23, 456, 231 }; List list = new ArrayList(); List li = new ArrayList(); for (int i = 0; i < array.length; i++) { list.add(new Double(array[i])); } double arr[] = {111}; String str[] = {"dd","aa","bb","cc","ee"}; for(int j=0;j<arr.length;j++){ li.add(new Double(arr[j])); } int locations = Collections.lastIndexOfSubList (list,li); System.out.println("====="+ locations); }public void indexOfSubList(){//int count = Collections.indexOfSubList(list,li); double array[] = {112, 111, 23, 456, 231 }; List list = new ArrayList(); List li = new ArrayList(); for (int i = 0; i < array.length; i++) { list.add(new Double(array[i])); } double arr[] = {111}; String str[] = {"dd","aa","bb","cc","ee"}; for(int j=0;j<arr.length;j++){ li.add(new Double(arr[j])); } int locations = Collections.indexOfSubList(list,li); System.out.println("====="+ locations); }public void rotate(){double array[] = {112, 111, 23, 456, 231 }; List list = new ArrayList(); for (int i = 0; i < array.length; i++) { list.add(new Double(array[i])); } Collections.rotate(list,-1); for (int i = 0; i <list.size(); i++) { System.out.println("list[" + i + "]=" + list.get(i)); } }/** * @desc  * @param args */public static void main( String[] args ){// TODO Auto-generated method stubCollectionsTest test = new CollectionsTest();//排序test.sort();test.sortOne();test.sortTwo();//混排test.shuffling();//反转test.reverse();//填充test.fill();//最小test.minOne();test.minTwo();//最大test.maxOne();test.maxTwo();//test.lastIndexOfSubList();//test.indexOfSubList();//test.rotate();}}