对对象按对象的某个属性进行排序

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public class Student<T> implements Comparable<T> {

   private int age;
   private String name;

   public Student() {
       super();
   }

   public Student(int age, String name) {
       super();
       this.age = age;
       this.name = name;
   }

   public int getAge() {
       return age;
   }

   public void setAge(int age) {
       this.age = age;
   }

   public String getName() {
       return name;
   }

   public void setName(String name) {
       this.name = name;
   }

   @Override
   public int compareTo(Object o) {

       if (o == null) {
           try {
               throw new Exception("该对象为空！");
           } catch (Exception e) {
               e.printStackTrace();
           }
       }

       if (!(this.getClass().getName().equals(o.getClass().getName()
               .toString()))) {
           try {
               throw new Exception("该对象的类名不一致！");
           } catch (Exception e) {
               e.printStackTrace();
           }
       }

       if (!(o instanceof Student)) {
           try {
               throw new Exception("该对象不是Student的实例！");
           } catch (Exception e) {
               e.printStackTrace();
           }
       }
       Student student = (Student) o;

       return this.getAge() - student.getAge();
   }
}

对某个对象按照对象的某个属性进行排序，没必要自己写一些方法，进行排序。

利用JDK的Collections的排序方法即可，

1、该对象的实现Comparable<T>接口

2、重写public int compareTo(Object o)方法。

3、测试方法

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class Test {

   /**
   * @param args
   */
   public static void main(String[] args) {
       List<Student> students = new ArrayList<Student>();
       students.add(new Student(29, "张三"));
       students.add(new Student(28, "张三"));
       students.add(new Student(30, "张三"));
       students.add(new Student(31, "张三"));
       students.add(new Student(24, "张三"));
       students.add(new Student(25, "张三"));
       students.add(new Student(27, "张三"));
       // 进对象集合进行排序
       Collections.sort(students);

       // 遍历集合
       for (Student s : students) {
           System.out.println("age:" + s.getAge() + " name:" + s.getName());
       }

   }

}