转载：https://blog.csdn.net/wangtaocsdn/article/details/71500500
有时候需要对对象列表或数组进行排序，下面提供两种简单方式：
方法一：将要排序的对象类实现Comparable<>接口。
首先，创建学生类，我们将根据学生成绩对学生进行排序：
/**
* 学生类
*/
class Student implements Comparable<Student>{
String name;
int age;
int score;
public Student(String name, int age,int score) {
this.name = name;
this.age = age;
this.score = score;
}
@Override
public int compareTo(Studento) {
// TODO Auto-generated method stub
return this.age - o.age;
}
}
public class Test {
public static void main(String[] args) {
// TODO Auto-generated method stub
ArrayList<Student> students = new ArrayList<>();
students.add(new Student("大铭", 19, 89));
students.add(new Student("来福", 26, 90));
students.add(new Student("仓颉", 23, 70));
students.add(new Student("王磊", 18, 80));
System.out.println("排序前:");
for (Student student : students) {
System.out.println("姓名："+student.name+" 年龄："+student.age+" 成绩："+student.score);
}
// 排序
Collections.sort(students);
System.out.println("排序后:");
for (Student student : students) {
System.out.println("姓名："+student.name+" 年龄："+student.age+" 成绩："+student.score);
}
}
}
同理，也可以根据对象的其他属性进行排序。
方法二：使用Comparator匿名内部类实现。
还是使用同一个例子，按成绩将学生排序：
/**
* 学生类
*/
class Student {
String name;
int age;
int score;
public Student(String name, int age,int score) {
this.name = name;
this.age = age;
this.score = score;
}
}
public class Test {
public static void main(String[] args) {
// TODO Auto-generated method stub
ArrayList<Student> students = new ArrayList<>();
students.add(new Student("大铭", 19, 89));
students.add(new Student("来福", 26, 90));
students.add(new Student("仓颉", 23, 70));
students.add(new Student("王磊", 18, 80));
System.out.println("排序前:");
for (Student student : students) {
System.out.println("姓名："+student.name+" 年龄："+student.age+" 成绩："+student.score);
}
Collections.sort(students,new Comparator<Student>() {
@Override
public int compare(Student o1, Student o2) {
// TODO Auto-generated method stub
return o1.age-o2.age;
}
});
System.out.println("排序后:");
for (Student student : students) {
System.out.println("姓名："+student.name+" 年龄："+student.age+" 成绩："+student.score);
}
}
}
也可以实现按对象属性将对象列表排序。