java简单源代码百度盘 java编程源码( 六 )


//要实现对象间的比较,就必须实现Comparable接口,它里面有个compareTo方法
//Comparable最好使用泛型,这样,无论是速度还是代码量都会减少
@SuppressWarnings("unchecked")
class Student implements ComparableStudent{
private String studentNo; //学号
private String studentName; //姓名
private double englishScore; //英语成绩
private double computerScore; //计算机成绩
private double mathScore; //数学成绩
private double totalScore; //总成绩
//空构造函数
public Student() {}
//构造函数
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;
}
//计算总成绩
public double sum() {
this.totalScore = englishScore+computerScore+mathScore;
return totalScore;
}
//计算评测成绩
public double testScore() {
return sum()/3;
}
//实现compareTO方法
@Override
public int compareTo(Student student) {
double studentTotal = student.getTotalScore();
return totalScore==studentTotal?0:(totalScorestudentTotal?1:-1);
}
//重写toString方法
public String toString(){
return "学号:"+this.getStudentNo()+" 姓名:"+this.getStudentName()+" 英语成绩:"+this.getEnglishScore()+" 数学成绩:"+this.getMathScore()+" 计算机成绩:"+this.getComputerScore()+" 总成绩:"+this.getTotalScore();
}
//重写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())) { //照现实来说,比较是不是同一个学生 , 应该只是看他的学号是不是相同
return true;
} else {
return false;
}
}
/*以下为get和set方法,我个人认为,totalScore的set的方法没必要要,因为它是由其它成绩计算出来的
在set方法中,没设置一次值,调用一次sum方法,即重新计算总成绩
*/
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子类学习委员类的实现
class StudentXW extends Student {
//重写父类Student的testScore()方法
@Override
public double testScore() {
return sum()/3+3;
}
public StudentXW() {}
//StudentXW的构造函数
public StudentXW(String studentNo,String studentName,double englishSocre,double computerScore,double mathScore) {
super(studentNo,studentName,englishSocre,computerScore,mathScore);
}
}
//Student子类班长类的实现
class StudentBZ extends Student {

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