Student外部比较器比较年龄，身高，名字

落日映苍穹つ 2024-03-16 10:22 42阅读 0赞

实体类和外部比较器类代码如下所示：

package com.test.Test09;
    
    
    import java.util.Comparator;
    
    public class Student{
        private int age;
        private double height;
        private String name;
    
        public int getAge() {
            return age;
        }
    
        public void setAge(int age) {
            this.age = age;
        }
    
        public double getHeight() {
            return height;
        }
    
        public void setHeight(double height) {
            this.height = height;
        }
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
        public Student(int age, double height, String name) {
            this.age = age;
            this.height = height;
            this.name = name;
        }
    
        @Override
        public String toString() {
            return "Student{" +
                    "age=" + age +
                    ", height=" + height +
                    ", name='" + name + '\'' +
                    '}';
        }
    
    
    }
    
    class BiJiao01 implements Comparator<Student> {
    
    
        @Override
        public int compare(Student o1, Student o2) {
            //return 0;
            //比较年龄
            return o1.getAge()-o2.getAge();
        }
    }
    
    class BiJiao02 implements Comparator<Student> {
        @Override
        public int compare(Student o1, Student o2) {
            //比较姓名
            return o1.getName().compareTo(o2.getName());
        }
    }
    
    class BiJiao03 implements Comparator<Student> {
        @Override
        public int compare(Student o1, Student o2) {
            //在年龄相同的情况下比较身高，年龄不同比较年龄
            if(o1.getAge()-o2.getAge() == 0) {
                return ((Double)(o1.getHeight())).compareTo((Double)(o2.getHeight()));
            }else{ //年龄不一样
                return o1.getAge()-o2.getAge();
            }
        }
    }
    
    测试类如下所示：

package com.test.Test09;
    
    import com.test.Test09.Student;
    
    public class Test02 {
        public static void main(String[] args) {
            //比较两个学生
            Student s1 = new Student(9, 160.2, "alili");
            Student s2 = new Student(14, 170.5, "bnana");
            /*//获取外部比较器
            BiJiao01 bj1 = new BiJiao01();
            //1.比较年龄
            System.out.println(bj1.compare(s1,s2)); //0 -5*/
    
            /*//获取外部比较器
            BiJiao02 bj2 = new BiJiao02();
            //2.比较姓名
            System.out.println(bj2.compare(s1,s2)); // 2 -1*/
    
            //3.在年龄相同的情况下比较身高，年龄不同比较年龄
            BiJiao03 bj3 = new BiJiao03();
            System.out.println(bj3.compare(s1,s2));//-5
        }
    }