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对于ArrayList等常用的集合具体业务类，基本上都实现了Comparable接口，即可以用来比较装载的对象实体。
主要用Collections.sort方法对集合类中的对象进行排序
Collections.sort的两种重载方法
1.Collections.sort(list, comparator)方法，通过comparator规则，实现对list的特定排序。
2.Collections.sort(list),list中的对象自身实现comparator接口
Java集合框架：
代码示例（演示Collections.sort(list, comparator)方法）：
注意：本代码均已在`jdk1.6`版本下通过测试
model，Student类
public class Student { private int id; private String name; private int age; /** * @Title: Student * @Description: TODO * @param: * @throws */ public Student(int id, String name, int age) { // TODO Auto-generated constructor stub this.id = id; this.name = name; this.age = age; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public int getId() { return id; } @Override public String toString() { return String.format("Student [age=%s, name=%s, id=%s]", age, name, id); } }
测试类
public static void main(String[] args) { // TODO Auto-generated method stub ArrayList<Student> arrayList = new ArrayList<Student>(); Student s1 = new Student(1, "jack", 20); Student s2 = new Student(2, "jack", 20); Student s3 = new Student(3, "lily", 29); Student s4 = new Student(4, "tom", 30); Student s5 = new Student(5, "rose", 31); Student s6 = new Student(6, "crane", 20); Student s7 = new Student(7, "jack", 25); Student s8 = new Student(8, "rose", 27); Student s9 = new Student(9, "lucy", 18); arrayList.add(s1); arrayList.add(s2); arrayList.add(s3); arrayList.add(s4); arrayList.add(s5); arrayList.add(s6); arrayList.add(s7); arrayList.add(s8); arrayList.add(s9); Comparator<Student> studentComparator = new Comparator<Student>() { /** * * @Title: compare * @Description: 先比较age，再比较name，最后比较id * @param: @param o1 * @param: @param o2 * @param: @return * @return: int * @throws */ @Override public int compare(Student o1, Student o2) { // TODO Auto-generated method stub if (o1.getAge() != o2.getAge()) { return o1.getAge() - o2.getAge(); } else if (!o1.getName().equals(o2.getName())) { return o1.getName().compareTo(o2.getName()); } else if (o1.getId() != o2.getId()) { return o1.getId() - o2.getId(); } return 0; } }; Collections.sort(arrayList, studentComparator); for (Student student : arrayList) { System.out.println(student.toString()); } }
测试结果
Student [age=18, name=lucy, id=9] Student [age=20, name=crane, id=6] Student [age=20, name=jack, id=1] Student [age=20, name=jack, id=2] Student [age=25, name=jack, id=7] Student [age=27, name=rose, id=8] Student [age=29, name=lily, id=3] Student [age=30, name=tom, id=4] Student [age=31, name=rose, id=5]
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原文地址：http://www.cnblogs.com/VioletLove/p/5756145.html
