java实现比较功能的类,有两种解决方案。分别继承comparable和compartor接口。
1 继承comparable
实现比较功能的类直接继承该接口,并重写compareTo方法。相关代码如下:
public class BookCook implements Comparable<BookCook>{
/**
* 主题
*/
private String title;
/**
* 价格
*/
private Double price;
public BookCook(String title, Double price) {
this.title = title;
this.price = price;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public Double getPrice() {
return price;
}
public void setPrice(Double price) {
this.price = price;
}
@Override
public int compareTo(BookCook o) {
if (this.price > o.price) {
return 1;
} else if (this.price < o.price) {
return -1;
}
return 0;
}
@Override
public String toString() {
return "书名:"+this.title+",价格:"+this.price;
}
}
// 测试接口
public static void main(String[] args) {
BookCook[] bookCooks = new BookCook[]{
new BookCook("书籍1", (double) 20),
new BookCook("书籍2", (double) 30),
new BookCook("书籍3", (double) 10),
new BookCook("书籍4", (double) 70),
new BookCook("书籍5", (double) 50)
};
Arrays.sort(bookCooks);
for (BookCook bookCook : bookCooks) {
System.out.println(bookCook);
}
}
2 继承compartor
不改变比较类的前提下,只需要写一个xxxCompartor(命名随意)来实现Compartor接口即可,同时重写compare方法。相关代码如下所示:
// 比较类
public class Student {
/**
* 学生姓名
*/
private String name;
/**
* 学生得分
*/
private Double score;
public Student(String name, Double score) {
this.name = name;
this.score = score;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Double getScore() {
return score;
}
public void setScore(Double score) {
this.score = score;
}
@Override
public String toString() {
return "姓名:"+this.name+",分数:"+this.score;
}
}
public class StudentComparator implements Comparator<Student> {
@Override
public int compare(Student o1, Student o2) {
if (o1.getScore()>o2.getScore()) {
return 1;
} else if (o1.getScore()<o2.getScore()) {
return -1;
}
return 0;
}
}
// 测试接口
public static void main(String[] args) {
Student[] sts = new Student[]{
new Student("小戴", (double) 60),
new Student("小王", (double) 90),
new Student("老王", (double) 80),
new Student("小萱", (double) 95)
};
Arrays.sort(sts, new StudentComparator());
System.out.println(Arrays.toString(sts));
}