第七节第二部分：接口的综合案例

案例分析

代码：

Student类

package com.Interface_Demo;public class Student {private String name;private char sex;private double score;public Student() {}public Student(String name, char sex, double score) {this.name = name;this.sex = sex;this.score = score;}public String getName() {return name;}public void setName(String name) {this.name = name;}public char getSex() {return sex;}public void setSex(char sex) {this.sex = sex;}public double getScore() {return score;}public void setScore(double score) {this.score = score;}
}

StudentOperator（接口）

package com.Interface_Demo;import java.util.ArrayList;public interface StudentOperator {void printAllInfo(ArrayList<Student> students);void printAverageScore(ArrayList<Student> students);
}

StudentOperatorImpl1（继承接口的类，即第一套方案）

package com.Interface_Demo;import java.util.ArrayList;public class StudentOperatorImpl1 implements StudentOperator {@Override//打印全班学生信息public void printAllInfo(ArrayList<Student> students) {System.out.println("---------------全部学生信息如下------------------");for (int i = 0; i < students.size(); i++) {Student s = students.get(i);System.out.println("学生姓名："+s.getName()+"     学生性别："+s.getSex()+"    学生成绩:"+s.getScore());}System.out.println("----------------------------------------------");}@Overridepublic void printAverageScore(ArrayList<Student> students) {double avgScore = 0.0;for (int i = 0; i < students.size(); i++) {Student s = students.get(i);avgScore += s.getScore();}System.out.println("全班学生的平均成绩："+(avgScore/students.size()));}
}

StudentOperatorImpl2（继承接口的类，即第二套方案）

package com.Interface_Demo;import java.util.ArrayList;public class StudentOperatorImpl2 implements StudentOperator {@Override//打印全班学生信息public void printAllInfo(ArrayList<Student> students) {System.out.println("---------------全部学生信息如下------------------");int count1 = 0;int count2 = 0;for (int i = 0; i < students.size(); i++) {Student s = students.get(i);System.out.println("学生姓名："+s.getName()+"     学生性别："+s.getSex()+"    学生成绩:"+s.getScore());if (s.getSex()=='男'){count1++;}else {count2++;}}System.out.println("男生人数："+count1+"     女生人数："+count2);System.out.println("全班人数："+students.size());System.out.println("----------------------------------------------");}@Overridepublic void printAverageScore(ArrayList<Student> students) {double avgScore = 0.0;double max = students.get(0).getScore();double min = students.get(0).getScore();for (int i = 0; i < students.size(); i++) {Student s = students.get(i);avgScore += s.getScore();if (s.getScore()>max) max = s.getScore();if (s.getScore()<min) min = s.getScore();}System.out.println("最高分："+max);System.out.println("最低分："+min);System.out.println("全班学生的平均成绩："+((avgScore-max-min)/(students.size()-2)));}
}

ClassManager类

package com.Interface_Demo;import java.util.ArrayList;public class ClassManager {private ArrayList<Student> students = new ArrayList<>();//利用面向接口，进行方案切换//第一套方案//StudentOperator studentOperator = new StudentOperatorImpl1();//使用第一套方案就是StudentOperatorImpl1，第二套方案就new StudentOperatorImpl2//第二套方案StudentOperator studentOperator = new StudentOperatorImpl2();public ClassManager() {students.add(new Student("飞鸟马时",'女',100));students.add(new Student("枣伊吕波",'女',99));students.add(new Student("伊洛玛丽",'女',98));students.add(new Student("尾刃康纳",'女',99));}//打印全班学生信息public void printInfo(){studentOperator.printAllInfo(students);}//打印全班学生分数public void printScore(){studentOperator.printAverageScore(students);}
}

Test类（运行的主程序）

package com.Interface_Demo;public class Test  {//完成班级学生信息管理案例public static void main(String[] args) {ClassManager classManager = new ClassManager();classManager.printInfo();classManager.printScore();}
}

第一套方案结果

第二套方案结果