这个项目的目标是创建四个类：Student类，GradStudent类，Manager类和GUI类。在GUI中有两个单选按钮：一个用于学生，一个用于GradStudent。根据选择的是哪一个，Manager类应该负责通过使用两个数组来创建和存储Student或GradStudent对象。我还在GUI中添加了一个按钮，用于打印所有以“计算机科学”为主要内容的学生。但是，我在如何编写此方法时遇到了麻烦。任何有关此问题的帮助将不胜感激。我将在下面发布我的课程。谢谢！
学生班级
public class Student {
protected String name;
protected String address;
protected double balance;
protected String major;
// Constructs fields
public Student(String name, String address, String balance, String major) {
this.name = name;
this.address = address;
this.major = major;
try {
this.balance = Double.parseDouble(balance);
}
catch(NumberFormatException e) {
this.balance = 0;
}
}
public String setName(String name) {
return name;
}
public String setAddress(String address) {
return address;
}
public double setBalance(double balance) {
return balance;
}
public String setMajor(String major) {
return major;
}
public String toString() {
return ("Name: " + this.name + " Address: " + this.address
+ " Balance: " + this.balance + " Major: " + this.major);
}
}
GradStudent Class
public class GradStudent extends Student {
public GradStudent(String name, String address, String balance, String major) {
super(name, address, balance, major);
}
public String toString() {
return ("Name: " + this.name + " Address: " + this.address
+ " Balance: " + this.balance + " Major: " + this.major);
}
}
经理类
public class Manager {
public Student[] students = new Student[50];
public int counter1 = 0;
public GradStudent[] gradStudents = new GradStudent[50];
public int counter2 = 0;
public Manager() {
}
public void addStudent(String name, String address, String balance, String major) {
Student student1 = new Student(name, address, balance, major);
students[counter1] = student1;
counter1++;
}
public String getLastStudent() {
return "Student added: " + students[counter1-1] +"\n";
}
public void addGradStudent(String name, String address, String balance, String major) {
GradStudent student2 = new GradStudent(name, address, balance, major);
gradStudents[counter2] = student2;
counter2++;
}
public String getLastGradStudent() {
return "Graduate Student added: " + gradStudents[counter2-1] +"\n";
}
public String getAverageBalance(){
double sum = 0;
for (int i = 0; i < counter1; i++) {
sum += students[i].setBalance(counter1);
}
for(int i = 0; i < counter2; i++) {
sum+= students[i].setBalance(counter2);
}
double average = sum / (counter1+counter2);
return average+"";
}
}
GUI类
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.JRadioButton;
import javax.swing.ButtonGroup;
public class GUI extends JFrame {
private JRadioButton jrbStudent = new JRadioButton("Student");
private JRadioButton jrbGraduate = new JRadioButton("Graduate");
private JTextField name = new JTextField(20);
private JTextField address = new JTextField(20);
private JTextField balance = new JTextField(20);
private JTextField major = new JTextField(20);
private JButton jbtSubmit = new JButton("Submit");
private JTextArea echoStudent = new JTextArea();
private JButton printStudentNames = new JButton("Print Student's Names");
private JButton printGradStudentNames = new JButton(
"Print Graduate Student's Names");
private JButton calcBalance = new JButton(
"Calculate Average Balance of All Students");
private JButton compSciMajor = new JButton(
"Displays Computer Science Major Students");
private Manager m1 = new Manager();
public GUI() {
// Creates panel P1 and adds the components
JPanel p1 = new JPanel(new GridLayout(9, 1, 10, 10));
p1.add(new JLabel("Name: "));
p1.add(name);
p1.add(new JLabel("Address: "));
p1.add(address);
p1.add(new JLabel("Balance: "));
p1.add(balance);
p1.add(new JLabel("Major: "));
p1.add(major);
p1.add(jrbStudent);
p1.add(jrbGraduate);
p1.add(new JLabel("Submit Button: "));
p1.add(jbtSubmit);
p1.add(printStudentNames);
p1.add(printGradStudentNames);
p1.add(calcBalance);
p1.add(compSciMajor);
p1.add(new JLabel("Submitted Text: "));
// Creates a radio-button group to group both buttons
ButtonGroup group = new ButtonGroup();
group.add(jrbStudent);
group.add(jrbGraduate);
// Adds the panel and text area to the frame
add(p1);
p1.add(echoStudent);
echoStudent.setEditable(false);
// Creates a listener and registers it with the submit button
SubmitListener l1 = new SubmitListener();
jbtSubmit.addActionListener(l1);
// Creates a listener and registers it with the radio buttons
JRBListener l2 = new JRBListener();
jrbStudent.addActionListener(l2);
jrbGraduate.addActionListener(l2);
// Creates a listener and registers it with the PrintStudentNames button
StudentListener l3 = new StudentListener();
printStudentNames.addActionListener(l3);
// Creates a listener and registers it with the PrintGradStudentNames button
GradStudentListener l4 = new GradStudentListener();
printGradStudentNames.addActionListener(l4);
// Creates a listener and registers it with the calcBalance button
CalcBalanceListener l5 = new CalcBalanceListener();
calcBalance.addActionListener(l5);
}
// Class to handle the submit button
class SubmitListener implements ActionListener {
public void actionPerformed(ActionEvent a) {
Student[] students = new Student[50];
int arrayLocation = 0;
Student student1 = new Student(name.getText(), address.getText(),
balance.getText(), major.getText());
// Checks remaining array space
if (arrayLocation < 50) {
students[arrayLocation] = student1;
++arrayLocation;
}
// Echos back entered text while storing the previous text
echoStudent.setText(echoStudent.getText() + "\n"
+ student1.toString());
}
}
// Class to handle the radio buttons
class JRBListener implements ActionListener {
public void actionPerformed(ActionEvent b) {
if (b.getSource() == jrbStudent) {
m1.addStudent(name.getText(), address.getText(),
balance.getText(), major.getText());
echoStudent
.setText("Created Student: \n" + m1.getLastStudent());
}
if (jrbGraduate.isSelected()) {
m1.addGradStudent(name.getText(), address.getText(),
balance.getText(), major.getText());
echoStudent.setText("Created Graduate Student: \n"
+ m1.getLastGradStudent());
}
}
}
// Class to handle the "Print Student's Names" button
class StudentListener extends Manager implements ActionListener {
public void actionPerformed(ActionEvent c) {
echoStudent.setText(m1.students[counter1].name);
}
}
// Class to handle the "Print Graduate Student's Names" button
class GradStudentListener extends Manager implements ActionListener {
public void actionPerformed(ActionEvent d) {
echoStudent.setText(m1.gradStudents[counter2].name);
}
}
// Class to handle the "Calculate Average Balance of All Students" button
class CalcBalanceListener extends Manager implements ActionListener {
public void actionPerformed(ActionEvent e) {
echoStudent.setText(getAverageBalance());
}
}
// Class to handle the "Displays Computer Science Major Students" button
class CompSciMajorListener extends Manager implements ActionListener {
public void actionPerformed(ActionEvent f) {
}
}
public static void main(String[] args) {
GUI frame = new GUI();
frame.setTitle("Information Interface");
frame.setSize(1200, 900);
frame.setLocationRelativeTo(null); // Center the frame
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
}
答案 0 :(得分：0)
对我而言，您应该执行以下操作： 在一个方法中，你将需要遍历学生阵列（你称之为学生），让每个学生，检查分配给它的专业（与“计算机科学”相比）并打印那些做CS的学生。
这将是一致的：
private static void checkMajor(Student [] studentList) {
for(Student s : studentList){
if(s.major.equals("Computer Science"){
System.out.println(s);
}
}
}
或者您可以将方法的返回类型从void更改为student，如果要在GUI中显示或使用它执行某些操作（我的代码将其打印到命令行），则将println语句更改为返回s。 / p>