[Java 11] Comparable 数组排序 之一 与 Comparator 数组排序之二

package com.qunar.basicJava.javase.p11CommonlyUsedClass;

import java.util.Arrays;

/**
* Author: libin.chen@qunar.com  Date: 14-5-21 19:59
*/
class Student implements Comparable<Student> { // 指定泛型类型
private String name;
private int age;
private float score;

Student(String name, int age, float score) {
this.name = name;
this.age = age;
this.score = score;
}

@Override
public String toString() {
return "Student{" +
"name='" + name + '\'' +
", age=" + age +
", score=" + score +
'}';
}
public int compareTo(Student stu) { // 覆写 compareTo() 方法
if (this.score > stu.score) {
return -1;
} else if (this.score < stu.score) {
return 1;
} else {
if (this.age > stu.age) {
return 1;
} else if (this.age < stu.age) {
return -1;
} else {
return 0;
}
}
}
}
public class ComparableDemo01 {
public static void main(String[] args) {
Student stu[] = {new Student("张三", 20, 90.0f), new Student("李四", 22, 90.0f), new Student("王五", 20, 99.0f)};
Arrays.sort(stu);
for (int i = 0; i < stu.length; i++) {
System.out.println(stu[i]);
}
}
}

package com.qunar.basicJava.javase.p11CommonlyUsedClass.Comparator;

/**
* Author: libin.chen@qunar.com  Date: 14-5-21 21:32
*/
public class Student {
private String name;
private int age;

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

@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (!(obj instanceof Student)) {
return false;
}
Student stu = (Student)obj;
if (stu.name.equals(this.name) && stu.age == this.age) {
return true;
} else {
return false;
}
}
public String toString() {
return name + "\t\t" + 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;
}
}

package com.qunar.basicJava.javase.p11CommonlyUsedClass.Comparator;

import java.util.Comparator;
/**
* Author: libin.chen@qunar.com  Date: 14-5-21 21:40
*/
public class StudentComparator implements Comparator<Student> {
public int compare(Student s1, Student s2) {
if (s1.equals(s2)) {
return 0;
} else if (s1.getAge() < s2.getAge()) {
return 1;
} else {
return -1;
}
}
}

package com.qunar.basicJava.javase.p11CommonlyUsedClass.Comparator;

import java.util.Arrays;

/**
* Author: libin.chen@qunar.com  Date: 14-5-21 21:38
*/
public class ComparatorDemo {
public static void main(String[] args) {
Student stu[] = {new Student("张三", 30), new Student("李四", 14), new Student("王五", 18)};
Arrays.sort(stu, new StudentComparator());
for (Student student : stu) {
System.out.println(student);
}
}
}