跟踪执行和继承 Java

Question

我是Java的新手。如何跟踪此程序的执行情况？这个程序是否正确地传达了继承，或者它只是传达了一个没有继承的正常封装？

我

只是想知道我是否真的在这些类中传达了继承。非常感谢您的回复。

这是第一堂课，TestMembers：

public class TestMembers {
    public static void main (String args []){
        Members Ailee=new Members("Ailee","52213116028","BRS",2,1.6,45);
        Members Amy=new Members("Amy","52213116032","BDR",2,1.63,57);
        Members Jack=new Members("Jack","52213116201","BRE",2,1.75,82);
        String[] member = { "Ailee","Amy", "Jack"};
        JFrame frame = new JFrame();
        String teammembers = (String) JOptionPane.showInputDialog(frame, "Team 
        Members","Team members",
        JOptionPane.QUESTION_MESSAGE,null,member, member[0]);
        if (teammembers==member[0]){
            JOptionPane.showMessageDialog(null,Ailee,"Member Profile", 
            JOptionPane.INFORMATION_MESSAGE);
        } else if (teammembers==member[1]){
            JOptionPane.showMessageDialog(null,Amy,"Member Profile", 
            JOptionPane.INFORMATION_MESSAGE);
        } else if (teammembers==member[2]){
            JOptionPane.showMessageDialog(null,Jack,"Member Profile", 
            JOptionPane.INFORMATION_MESSAGE);
        }
        System.exit(0);
    }
}

这是另一个类，Person：

public class Person {
    private String name;
    private double height;
    private double weight;
    public void setPersonname(String name){
        this.name=name;
    }
    public String getPersonname(){
        return name;
    }
    public void setPersonHeight(double height){
        this.height=height;
    }
    public double getPersonHeight(){
        return height;
    }
    public void setPersonWeight(double weight){
        this.weight=weight;
    }
    public double getPersonWeight(){
        return weight;
    }
}

这是第三类，Student：

public class Student extends Person{
    private String id_number;
    private String course;
    private int semester;
    public void setStudentIdNumber(String id_number){
        this.id_number=id_number;
    }
    public String getStudentIdNumber(){
        return id_number;
    }
    public void setStudentCourse(String course){
        this.course=course;
    }
    public String getStudentCourse(){
        return course;
    }
    public void setStudentSemester(int semester){
        this.semester=semester;
    }
    public int getStudentSemester(){
        return semester;
    }
}

这是第四类，Members：

public class Members extends Student{
    private double bmi;
    private String bmistatus;
    public Members(String name,String id_number, String course, int semester, 
        double height, double weight){
        setPersonname(name);
        setStudentIdNumber(id_number);
        setStudentCourse(course);
        setStudentSemester(semester);
        setPersonHeight(height);
        setPersonWeight(weight);
    }
    public double getMemberBMI(){
        bmi= getPersonWeight()/(getPersonHeight()*getPersonHeight());
        DecimalFormat twoDForm = new DecimalFormat("#.00");
        return Double.valueOf(twoDForm.format(bmi));
    }
    public String BMIstatus(){
        if (bmi>= 18.5 & bmi <= 25.0){
            return bmistatus= "Optimal weight";
        } else if (bmi<18.5){
            return bmistatus="Underweight";
        } else if (bmi>25.0){
            return bmistatus="Overweight";
        }
        return bmistatus;
    }
    public String toString() {
        return "Name: " + getPersonname() + "nID: " + getStudentIdNumber() 
        +"nCourse: 
        " + getStudentCourse()+
        "nSem: " + getStudentSemester()+"nHeight: "+getPersonHeight()+" metre"+
        "nWeight: "+getPersonWeight()+" kg"+"nBMI:"+getMemberBMI()+"nBMI         status 
        :"+BMIstatus();
    }
}

Answer 1

我认为，继承在语法上是正确的。从设计的角度来看，这取决于更广泛的背景。

关于软件设计，没有简单的方法来学习它。您可能想阅读有关清洁代码，重构或设计模式的书籍(按此顺序(。他们会教你很多基本规则。但是，您也需要从日常工作中学习，这样您就可以学习如何应用这些规则。

关于描摹，你可以使用Logger，或者简单地使用System.out，例如：

private static final Logger logger = Logger.getInstance(TestMembers.class);
...
if (teammembers==member[0]) {
    logger.debug("first member");
}
...

另外，我建议删除尾随System.exit(0);还有其他方法可以做到这一点。