接口：综合案例

package com.Demo4;

public class Test {
    public static void main(String[] args) {
        //目标：完成学生信息管理的实例
        ClassManage classManage=new ClassManage();
        classManage.printInfo();
        classManage.printScore();
    }
}

package com.Demo4;

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;
    }
}

package com.Demo4;

import java.util.ArrayList;

public interface StuentOperator {
    void printAllInfo(ArrayList<Student> students);
    void printAverageScore(ArrayList<Student> students);
}

package com.Demo4;

import java.util.ArrayList;

public class ClassManage {
    private ArrayList<Student> students=new ArrayList<>();
    private StuentOperator stuentOperator=new StuentOperatorlmp1();
    //切换第二套方案                        改成 StydentOperatorImpl2
    public ClassManage(){
        students.add(new Student("迪丽热巴",'女',99));
        students.add(new Student("古力娜扎",'女',100));
        students.add(new Student("马儿扎哈",'男',89));
        students.add(new Student("卡尔扎巴",'男',80));
        students.add(new Student("德莱文",'男',60));
    }

    //打印全部学生信息
    public void printInfo(){
        stuentOperator.printAllInfo(students);
    }
    //打印全班全部学生的平均分
    public void printScore(){
        stuentOperator.printAverageScore(students);
    }
}

package com.Demo4;

import java.util.ArrayList;

public class StuentOperatorlmp1 implements StuentOperator {

    @Override
    public void printAllInfo(ArrayList<Student> students) {
        System.out.println("-----------------全班全部学生信息如下--------------");
        for (int i = 0; i < students.size(); i++) {
            Student s=students.get(i);
            System.out.println("姓名："+ s.getName()+"，性别："+s.getSex()+"，成绩："+s.getScore());
        }
        System.out.println("------------------------------------------------");
    }

    @Override
    public void printAverageScore(ArrayList<Student> students) {
        double allScore=0.0;
        for (int i = 0; i < students.size(); i++) {
            Student s=students.get(i);
            allScore+=s.getScore();
        }
        System.out.println("平均分："+(allScore)/students.size());

    }
}

package com.Demo4;

import java.util.ArrayList;

public class StydentOperatorImpl2 implements StuentOperator{
    @Override
    public void printAllInfo(ArrayList<Student> students) {
        System.out.println("-----------------全班全部学生信息如下--------------");
        int count1=0;
        int count2=0;
        for (int i = 0; i < students.size(); i++) {
            Student s=students.get(i);
            System.out.println("姓名："+ s.getName()+"，性别："+s.getSex()+"，成绩："+s.getScore());
            if (s.getSex()=='男'){
                count1++;
            }else {
                count2++;
            }
        }
        System.out.println("男生人数为："+count1+"，女生人数为："+count2);
        System.out.println("全班人数为："+students.size());
        System.out.println("------------------------------------------------");
    }

    @Override
    public void printAverageScore(ArrayList<Student> students) {
        double allScore=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);
            if (s.getScore()>max )  max=s.getScore();
            if (s.getScore()<min )  min=s.getScore();
            allScore+=s.getScore();
        }
        System.out.println("学生的最高分是："+max);
        System.out.println("学生的最低分是："+min);
        System.out.println("平均分："+(allScore-max-min) / (students.size()-2));

    }
}