JavaSE-15.2.4【案例-成绩排序(比较器排序Comparator实现、自然排序Comparable实现)】
作者:互联网
1 package day6.lesson2.anli1; 2 3 import java.util.Comparator; 4 import java.util.TreeSet; 5 6 /* 7 2.4 案例-成绩排序 8 9 用TreeSet集合存储多个学生信息(姓名,语文成绩,数学成绩),并遍历该集合 10 要求:按照总分从高到低出现 11 12 通过 比较器排序Comparator 实现 13 通过 自然排序Comparable 实现 14 */ 15 //通过 比较器排序Comparator 实现 16 public class TreeSetDemo4 { 17 public static void main(String[] args) { 18 TreeSet<Student> ts = new TreeSet<>(new Comparator<Student>() { 19 @Override 20 public int compare(Student s1, Student s2) { 21 // return 0; 22 23 /*int score_s1 = s1.getChinese() + s1.getMath(); 24 int score_s2 = s2.getChinese() + s2.getMath(); 25 int num = score_s2 - score_s1; 26 return num;*/ 27 28 int num = s2.getSum() - s1.getSum(); 29 int num2 = ( num==0 ? s1.getChinese()-s2.getChinese() : num ); 30 int num3 = ( num2==0 ? s1.getName().compareTo(s2.getName()) : num2 ); 31 return num3; 32 } 33 }); 34 35 Student s1 = new Student("tom", 100, 80); 36 Student s2 = new Student("amy", 85, 90); 37 Student s3 = new Student("sam", 79, 100); 38 Student s4 = new Student("jji", 90, 95); 39 Student s5 = new Student("bba", 95, 90); 40 Student s6 = new Student("cca", 95, 90); 41 42 ts.add(s1); 43 ts.add(s2); 44 ts.add(s3); 45 ts.add(s4); 46 ts.add(s5); 47 ts.add(s6); 48 49 for (Student s: ts){ 50 // System.out.println(s.getName() + "," + (s.getChinese()+s.getMath()) ); 51 System.out.println(s.getName() + "," + s.getSum()); 52 } 53 /* 54 jji,185 55 bba,185 56 cca,185 57 tom,180 58 sam,179 59 amy,175 60 */ 61 } 62 }
1 package day6.lesson2.anli1; 2 3 public class Student { 4 5 private String name; 6 private int chinese; 7 private int math; 8 9 public Student() { 10 } 11 12 public Student(String name, int chinese, int math) { 13 this.name = name; 14 this.chinese = chinese; 15 this.math = math; 16 } 17 18 public void setName(String name) { 19 this.name = name; 20 } 21 22 public void setChinese(int chinese) { 23 this.chinese = chinese; 24 } 25 26 public void setMath(int math) { 27 this.math = math; 28 } 29 30 public String getName() { 31 return name; 32 } 33 34 public int getChinese() { 35 return chinese; 36 } 37 38 public int getMath() { 39 return math; 40 } 41 42 public int getSum(){ 43 return this.chinese + this.math; 44 } 45 }
1 package day6.lesson2.anli1_1; 2 3 import java.util.TreeSet; 4 5 //通过 自然排序Comparable 实现 6 public class TreeSetDemo5 { 7 public static void main(String[] args) { 8 TreeSet<Student> ts = new TreeSet<>(); 9 10 Student s1 = new Student("tom", 100, 80); 11 Student s2 = new Student("amy", 85, 90); 12 Student s3 = new Student("sam", 79, 100); 13 Student s4 = new Student("jji", 90, 95); 14 Student s5 = new Student("bba", 95, 90); 15 Student s6 = new Student("cca", 95, 90); 16 17 ts.add(s1); 18 ts.add(s2); 19 ts.add(s3); 20 ts.add(s4); 21 ts.add(s5); 22 ts.add(s6); 23 24 for (Student s: ts){ 25 System.out.println(s.getName() + "," + s.getSum()); 26 } 27 /* 28 jji,185 29 bba,185 30 cca,185 31 tom,180 32 sam,179 33 amy,175 34 */ 35 } 36 }
1 package day6.lesson2.anli1_1; 2 3 public class Student implements Comparable<Student>{ 4 5 private String name; 6 private int chinese; 7 private int math; 8 9 public Student() { 10 } 11 12 public Student(String name, int chinese, int math) { 13 this.name = name; 14 this.chinese = chinese; 15 this.math = math; 16 } 17 18 public void setName(String name) { 19 this.name = name; 20 } 21 22 public void setChinese(int chinese) { 23 this.chinese = chinese; 24 } 25 26 public void setMath(int math) { 27 this.math = math; 28 } 29 30 public String getName() { 31 return name; 32 } 33 34 public int getChinese() { 35 return chinese; 36 } 37 38 public int getMath() { 39 return math; 40 } 41 42 public int getSum(){ 43 return this.chinese + this.math; 44 } 45 46 @Override 47 public int compareTo(Student s) { 48 // return 0; 49 50 int num = s.getSum() - this.getSum(); 51 int num2 = ( num==0 ? this.getChinese()-s.getChinese() : num); 52 int num3 = ( num2==0 ? this.getName().compareTo(s.getName()) : num2 ); 53 return num3; 54 } 55 }
标签:15.2,chinese,Comparator,int,ts,Student,排序,public,math 来源: https://www.cnblogs.com/yppah/p/14836800.html