//要實現對象間的比較，就必須實現Comparable接口，它裏面有個compareTo方法
//Comparable最好使用泛型，這樣，無論是速度還是代碼量都會減少
@SuppressWarnings("unchecked")
class Student implements Comparable<Student>{
private String studentNo; //學號
private String studentName; //姓名
private double englishScore; //英語成績
private double computerScore; //計算機成績
private double mathScore; //數學成績
private double totalScore; //總成績
//空構造函數
public Student() {}
//構造函數
public Student(String studentNo,String studentName,double englishSocre,double computerScore,double mathScore) {
this.studentNo = studentNo;
this.studentName = studentName;
this.englishScore = englishSocre;
this.computerScore = computerScore;
this.mathScore = mathScore;
}
//計算總成績
public double sum() {
this.totalScore = englishScore+computerScore+mathScore;
return totalScore;
}
//計算評測成績
public double testScore() {
return sum()/3;
}
//實現compareTO方法
@Override
public int compareTo(Student student) {
double studentTotal = student.getTotalScore();
return totalScore==studentTotal?0:(totalScore>studentTotal?1:-1);
}
//重寫toString方法
public String toString(){
return "學號："+this.getStudentNo()+" 姓名："+this.getStudentName()+" 英語成績："+this.getEnglishScore()+" 數學成績："+this.getMathScore()+" 計算機成績："+this.getComputerScore()+" 總成績："+this.getTotalScore();
}
//重寫equals方法
public boolean equals(Object obj) {
if(obj == null){
return false;
}
if(!(obj instanceof Student)){
return false;
}
Student student = (Student)obj;
if(this.studentNo.equals(student.getStudentName())) { //照現實來說，比較是不是同壹個學生，應該只是看他的學號是不是相同
return true;
} else {
return false;
}
}
/*以下為get和set方法，我個人認為，totalScore的set的方法沒必要要，因為它是由其它成績計算出來的
在set方法中，沒設置壹次值，調用壹次sum方法，即重新計算總成績
*/
public String getStudentNo() {
return studentNo;
}
public void setStudentNo(String studentNo) {
this.studentNo = studentNo;
sum();
}
public String getStudentName() {
return studentName;
}
public void setStudentName(String studentName) {
this.studentName = studentName;
sum();
}
public double getEnglishScore() {
return englishScore;
}
public void setEnglishScore(double englishScore) {
this.englishScore = englishScore;
sum();
}
public double getComputerScore() {
return computerScore;
}
public void setComputerScore(double computerScore) {
this.computerScore = computerScore;
sum();
}
public double getMathScore() {
return mathScore;
}
public void setMathScore(double mathScore) {
this.mathScore = mathScore;
sum();
}
public double getTotalScore() {
return totalScore;
}
}
//Student子類學習委員類的實現
class StudentXW extends Student {
//重寫父類Student的testScore()方法
@Override
public double testScore() {
return sum()/3+3;
}
public StudentXW() {}
//StudentXW的構造函數
public StudentXW(String studentNo,String studentName,double englishSocre,double computerScore,double mathScore) {
super(studentNo,studentName,englishSocre,computerScore,mathScore);
}
}
//Student子類班長類的實現
class StudentBZ extends Student {
//重寫父類Student的testScore()方法
@Override
public double testScore() {
return sum()/3+5;
}
public StudentBZ() {}
//StudentXW的構造函數
public StudentBZ(String studentNo,String studentName,double englishSocre,double computerScore,double mathScore) {
super(studentNo,studentName,englishSocre,computerScore,mathScore);
}
}
//測試類
public class Test {
public static void main(String[] args) {
//生成若幹個student類、StudentXW類、StudentBZ類
Student student1 = new Student("s001","張三",70.5,50,88.5);
Student student2 = new Student("s002","李四",88,65,88.5);
Student student3 = new Student("s003","王五",67,77,90);
StudentXW student4 = new StudentXW("s004","李六",99,88,99.5);
StudentBZ student5 = new StudentBZ("s005","朱漆",56,65.6,43.5);
Student[] students = {student1,student2,student3,student4,student5};
for(int i = 0 ; i<students.length; i++){
double avgScore = students[i].testScore();
System.out.println(students[i].getStudentName()+"學生的評測成績為："+ avgScore+"分");
}
}
}
運行結果為：
張三學生的評測成績為：69.66666666666667分
李四學生的評測成績為：80.5分
王五學生的評測成績為：78.0分
李六學生的評測成績為：98.5分
朱漆學生的評測成績為：60.03333333333333分