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Java接口案例

news 来源：原创 2024/9/20 2:53:06

一案例要求：

二代码：(换方案只需要将操作类第二行的new新对象修改就能更改项目)

Ⅰ：（主函数）

package d1;public class test {public static void main(String[] args) {operator a=new operator();a.show();a.average();}
}

Ⅱ：（实体类）

package d1;public class student {private String name;private String sex;private double score;public student() {}public student(String name, String 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 String getSex() {return sex;}public void setSex(String sex) {this.sex = sex;}public double getScore() {return score;}public void setScore(double score) {this.score = score;}
}

Ⅲ：（操作类）

package d1;import java.util.ArrayList;public class operator {private ArrayList<student> arrayList=new ArrayList<>();private choice a=new oper2();public operator() {arrayList.add(new student("孙悟空","男",12));arrayList.add(new student("紫霞","女",66));arrayList.add(new student("牛魔王","男",6));arrayList.add(new student("山神","男",99));}public void show(){a.show(arrayList);}public void average(){a.average(arrayList);}
}

Ⅳ：（接口）

package d1;import java.util.ArrayList;public interface choice {public void show(ArrayList<student> arrayList);public void average(ArrayList<student> arrayList);
}

Ⅴ：（实现类1）

package d1;import java.util.ArrayList;public class oper1 implements choice{@Overridepublic void show(ArrayList<student> arrayList) {for (int i = 0; i < arrayList.size(); i++) {System.out.println("姓名 "+arrayList.get(i).getName()+"    性别 "+arrayList.get(i).getSex()+"    成绩 "+arrayList.get(i).getScore());}}@Overridepublic void average(ArrayList<student> arrayList) {double sum=0;for (int i = 0; i < arrayList.size(); i++) {sum+=arrayList.get(i).getScore();}System.out.println("平均成绩为  "+sum/arrayList.size());}
}

Ⅵ：（实现类2）

package d1;import java.util.ArrayList;public class oper2 implements choice {@Overridepublic void show(ArrayList<student> arrayList) {int a1=0,a2=0;for (int i = 0; i < arrayList.size(); i++) {System.out.println("姓名 "+arrayList.get(i).getName()+"    性别 "+arrayList.get(i).getSex()+"    成绩 "+arrayList.get(i).getScore());if (arrayList.get(i).getSex().equals("男")){a1++;}else a2++;}System.out.println("男生人数  "+a1+"  女生人数  "+a2);}@Overridepublic void average(ArrayList<student> arrayList) {double sum=0,max=arrayList.get(0).getScore(),min=arrayList.get(0).getScore();for (int i = 0; i < arrayList.size(); i++) {sum+=arrayList.get(i).getScore();if (arrayList.get(i).getScore()>=max){max=arrayList.get(i).getScore();}if(arrayList.get(i).getScore()<=min){min=arrayList.get(i).getScore();}}System.out.println("平均成绩为  "+(sum-max-min)/(arrayList.size()-2));}
}