我在内部实例化一个 class 后得到 StackOverflowError
I get a StackOverflowError after I instantiate a class inside itself
我在这个 class 的第 12 行和第 65 行得到一个 WhosebugError：
package studInfoAndSubj; // Information Window
import javax.swing.*;
import javax.swing.border.*;
import java.awt.*;
import java.awt.event.*;
public class StudInfo extends JFrame
{
// This Class
private StudInfo studInfo = new StudInfo(); // this is Line 12
// Subjects Window Class
private StudSubj studSubj = new StudSubj();
// Labels
private JLabel nameL = new JLabel("Student Name: ", SwingConstants.CENTER);
private JLabel snameL = new JLabel("(Surname)", SwingConstants.CENTER);
private JLabel fnameL = new JLabel("(First Name)", SwingConstants.CENTER);
private JLabel mnameL = new JLabel("(Middle Name)", SwingConstants.CENTER);
private JLabel courseL = new JLabel("Course: ", SwingConstants.CENTER);
private JLabel yearL = new JLabel("Year: ", SwingConstants.CENTER);
private JLabel semesterL = new JLabel("Semester: ", SwingConstants.CENTER);
// Text Fields
private JTextField snameTF = new JTextField(10);
private JTextField fnameTF = new JTextField(10);
private JTextField mnameTF = new JTextField(10);
// Text Value Handlers
private String snameS, fnameS, mnameS, courseS, yearS, semesterS;
// Buttons
private JButton nextB = new JButton("Next");
private JButton cancelB = new JButton("Cancel");
private NextButtonHandler nextBH = new NextButtonHandler();
private CancelButtonHandler cancelBH = new CancelButtonHandler();
// Layouts ((components + rows - 1) / rows)
private Container pane = getContentPane();
private Container one = new JPanel(new GridLayout(0, 6));
// Combo Boxes
private String[] course = {"BSIT"};
private String[] year = {"I"};
private String[] semester = {"1ST", "2ND"};
private JComboBox<String> courseCB = new JComboBox<>(course);
private JComboBox<String> yearCB = new JComboBox<>(year);
private JComboBox<String> semesterCB = new JComboBox<>(semester);
// Spaces
private JLabel blank1 = new JLabel("");
private JLabel blank2 = new JLabel("");
private JLabel blank3 = new JLabel("");
private JLabel blank4 = new JLabel("");
private JLabel blank5 = new JLabel("");
private JLabel blank6 = new JLabel("");
private JLabel blank7 = new JLabel("");
// Window Size
private static final int WIDTH = 1000;
private static final int HEIGHT = 250;
public StudInfo() // and this is line 65
{
DefaultListCellRenderer dlcr1 = new DefaultListCellRenderer();
dlcr1.setHorizontalAlignment(DefaultListCellRenderer.CENTER);
courseCB.setRenderer(dlcr1);
yearCB.setRenderer(dlcr1);
semesterCB.setRenderer(dlcr1);
snameTF.setHorizontalAlignment(JTextField.CENTER);
fnameTF.setHorizontalAlignment(JTextField.CENTER);
mnameTF.setHorizontalAlignment(JTextField.CENTER);
snameL.setVerticalAlignment(SwingConstants.TOP);
fnameL.setVerticalAlignment(SwingConstants.TOP);
mnameL.setVerticalAlignment(SwingConstants.TOP);
nextB.addActionListener(nextBH);
cancelB.addActionListener(cancelBH);
Border border1 = BorderFactory.createLineBorder(Color.BLUE, 1);
courseL.setBorder(border1);
yearL.setBorder(border1);
semesterL.setBorder(border1);
pane.add(one);
one.add(blank1);
one.add(nameL);
one.add(snameTF);
one.add(fnameTF);
one.add(mnameTF);
one.add(blank2);
one.add(blank3);
one.add(blank4);
one.add(snameL);
one.add(fnameL);
one.add(mnameL);
one.add(blank5);
one.add(courseL);
one.add(courseCB);
one.add(yearL);
one.add(yearCB);
one.add(semesterL);
one.add(semesterCB);
one.add(blank6);
one.add(blank7);
one.add(cancelB);
one.add(nextB);
setTitle("Student Information");
setSize(WIDTH, HEIGHT);
setLocationRelativeTo(null);
setVisible(true);
setResizable(false);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public String getSemValue()
{
return semesterS;
}
public String[] getSemCBValue()
{
return semester;
}
private class NextButtonHandler implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
snameS = snameTF.getText();
fnameS = fnameTF.getText();
mnameS = mnameTF.getText();
courseS = courseCB.getSelectedItem().toString();
yearS = yearCB.getSelectedItem().toString();
semesterS = semesterCB.getSelectedItem().toString();
studInfo.setVisible(false);
studSubj.setVisible(true);
}
}
private class CancelButtonHandler implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
System.exit(0);
}
}
public static void main(String[] args)
{
StudInfo studInfo = new StudInfo();
}
}
这是我的另一个 class:
package studInfoAndSubj; // Subjects Window
import javax.swing.*;
import javax.swing.border.*;
import java.awt.*;
import java.awt.event.*;
public class StudSubj extends JFrame
{
// This class
private StudSubj studSubj = new StudSubj();
// Information Window Class
private StudInfo studInfo = new StudInfo();
// Labels
private JLabel addSubjL = new JLabel("Add Subject: ", SwingConstants.CENTER);
// Buttons
private JButton doneB = new JButton("Done");
private JButton backB = new JButton("Back");
private DoneButtonHandler doneBH = new DoneButtonHandler();
private BackButtonHandler backBH = new BackButtonHandler();
// Text Value Handlers
private String semesterS = studInfo.getSemValue();
private String[] semester = studInfo.getSemCBValue();
private int selectedSubj;
private String selectedSubjTime;
// Subject Lists
private String[] sem1Subj = {"College Algebra\nMWF\n12:00PM-1:00PM",
"Communication Arts 1\nMWF\n9:00AM-10:00AM",
"Information Technology Fundamentals - Lec\nTTH\n7:30AM-8:30AM",
"Information Technology Fundamentals - Lab\nT\n9:00AM-12:00PM",
"Programming 1\nMWF\n7:00AM-9:00AM"};
private String[] sem1AddSubj = {"", "Filipino Christian Living\nMWF\n7:00AM-9:00AM",
"Foundation of Physical Education\nTH\n10:00AM-12:00PM",
"Komunikasyon sa Akademikong Filipino\nMWF\n9:00AM-10:00AM"};
private String[] sem2Subj = {"Trigonometry\nMWF\n7:00AM-8:00AM",
"Communication Arts 2\nTTH\n9:00AM-10:30AM",
"Programming 2\nMWF\n9:00AM-11:00AM",
"Database Management Systems\nMWF\n8:00AM-9:00AM",
"Network Management\nTTH\n7:30AM-9:00AM"};
private String[] sem2AddSubj = {"", "Environmental Science\nMWF\n8:00AM-9:00AM",
"Social Dances\nM\n12:00PM-2:00PM",
"General Psychology\nT\n12:00PM-1:00PM"};
// Subject Time
private String[] sem1SubjTime = {"MWF12:00PM-1:00PM", "MWF9:00AM-10:00AM", "TTH7:30AM-8:30AM",
"T9:00AM-12:00PM", "MWF7:00AM-9:00AM"};
private String[] sem1AddSubjTime = {"", "MWF7:00AM-9:00AM", "TH10:00AM-12:00PM", "MWF9:00AM-10:00AM"};
private String[] sem2SubjTime = {"MWF7:00AM-8:00AM", "TTH9:00AM-10:30AM", "MWF9:00AM-11:00AM",
"MWF8:00AM-9:00AM", "TTH7:30AM-9:00AM"};
private String[] sem2AddSubjTime = {"", "MWF8:00AM-9:00AM", "M12:00PM-2:00PM", "T12:00PM-1:00PM"};
// Layouts ((components + rows - 1) / rows)
private Container pane = getContentPane();
private Container two = new JPanel(new GridLayout(0, 2));
// Combo Boxes
private JComboBox<String> sem1AddSubjCB = new JComboBox<>(sem1AddSubj);
private JComboBox<String> sem2AddSubjCB = new JComboBox<>(sem2AddSubj);
// Window Size
private static final int WIDTH = 1000;
private static final int HEIGHT = 250;
public StudSubj()
{
DefaultListCellRenderer dlcr2 = new DefaultListCellRenderer();
dlcr2.setHorizontalAlignment(DefaultListCellRenderer.CENTER);
sem1AddSubjCB.setRenderer(dlcr2);
sem2AddSubjCB.setRenderer(dlcr2);
doneB.addActionListener(doneBH);
backB.addActionListener(backBH);
// 1st Semester Subjects
JLabel sem1Subj1 = new JLabel(sem1Subj[0]);
JLabel sem1Subj2 = new JLabel(sem1Subj[1]);
JLabel sem1Subj3 = new JLabel(sem1Subj[2]);
JLabel sem1Subj4 = new JLabel(sem1Subj[3]);
JLabel sem1Subj5 = new JLabel(sem1Subj[4]);
// 2nd Semester Subjects
JLabel sem2Subj1 = new JLabel(sem2Subj[0]);
JLabel sem2Subj2 = new JLabel(sem2Subj[1]);
JLabel sem2Subj3 = new JLabel(sem2Subj[2]);
JLabel sem2Subj4 = new JLabel(sem2Subj[3]);
JLabel sem2Subj5 = new JLabel(sem2Subj[4]);
Border border2 = BorderFactory.createLineBorder(Color.BLUE, 1);
sem1Subj1.setBorder(border2); sem2Subj1.setBorder(border2);
sem1Subj2.setBorder(border2); sem2Subj2.setBorder(border2);
sem1Subj3.setBorder(border2); sem2Subj3.setBorder(border2);
sem1Subj4.setBorder(border2); sem2Subj4.setBorder(border2);
sem1Subj5.setBorder(border2); sem2Subj5.setBorder(border2);
addSubjL.setBorder(border2);
pane.add(two);
if(semesterS.equals(semester[0]))
{
setTitle("(BSIT - I - 1st Semester) List Of Subjects");
two.add(sem1Subj1);
two.add(sem1Subj2);
two.add(sem1Subj3);
two.add(sem1Subj4);
two.add(sem1Subj5);
two.add(addSubjL);
two.add(sem1AddSubjCB);
}else if(semesterS.equals(semester[1]))
{
setTitle("(BSIT - I - 2nd Semester) List Of Subjects");
two.add(sem2Subj1);
two.add(sem2Subj2);
two.add(sem2Subj3);
two.add(sem2Subj4);
two.add(sem2Subj5);
two.add(addSubjL);
two.add(sem2AddSubjCB);
}
two.add(backB);
two.add(doneB);
setSize(WIDTH, HEIGHT);
setLocationRelativeTo(null);
setResizable(false);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
private class DoneButtonHandler implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
int ctr;
if(semesterS.equals(semester[0]))
{
selectedSubj = sem1AddSubjCB.getSelectedIndex();
selectedSubjTime = sem1AddSubj[selectedSubj];
for(ctr = 0; ctr <= sem1AddSubj.length; ctr++)
{
if(selectedSubjTime.equals(sem1AddSubjTime[ctr]))
{
JOptionPane.showMessageDialog(null, "Choosen Subject has same time with the others!", "Error", 0);
}else{
sem1AddSubjCB.getSelectedItem();
}
}
}else if(semesterS.equals(semester[1]))
{
selectedSubj = sem2AddSubjCB.getSelectedIndex();
selectedSubjTime = sem2AddSubj[selectedSubj];
for(ctr = 0; ctr <= sem1AddSubj.length; ctr++)
{
if(selectedSubjTime.equals(sem2AddSubjTime[ctr]))
{
JOptionPane.showMessageDialog(null, "Choosen Subject has same time with the others!", "Error", 0);
}else{
sem2AddSubjCB.getSelectedItem();
}
}
}
}
}
private class BackButtonHandler implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
studSubj.setVisible(false);
studInfo.setVisible(true);
}
}
public static void main(String[] args)
{
StudSubj studSubj = new StudSubj();
}
}
当我 运行 main:
时出现此错误
Exception in thread "main" java.lang.WhosebugError
at sun.awt.Win32GraphicsConfig.getBounds(Native Method)
at sun.awt.Win32GraphicsConfig.getBounds(Unknown Source)
at java.awt.Window.init(Unknown Source)
at java.awt.Window.(Unknown Source)
at java.awt.Frame.(Unknown Source)
at java.awt.Frame.(Unknown Source)
at javax.swing.JFrame.(Unknown Source)
at studInfoAndSubj.StudInfo.(StudInfo.java:65)
at studInfoAndSubj.StudInfo.(StudInfo.java:12)
at studInfoAndSubj.StudInfo.(StudInfo.java:12)
at studInfoAndSubj.StudInfo.(StudInfo.java:12)
at studInfoAndSubj.StudInfo.(StudInfo.java:12)
at studInfoAndSubj.StudInfo.(StudInfo.java:12)
at studInfoAndSubj.StudInfo.(StudInfo.java:12)
at studInfoAndSubj.StudInfo.(StudInfo.java:12)
为什么会这样？我可以修复它吗？
您的问题包括尝试在 StudInfo class 中实例化两次：
private StudInfo studInfo = new StudInfo(); // this is Line 12
并在：
public static void main(String[] args)
{
StudInfo studInfo = new StudInfo();
}
这一行：
private StudInfo studInfo = new StudInfo();
调用自 main:
StudSubj studSubj = new StudSubj();
创建一个新的 StudInfo 对象，该对象具有相同类型的字段。
创建 StudInfo 的第一个实例时，也会实例化 other 的实例。那个 也 有一个实例化 另一个 StudInfo 的字段，依此类推...
如果不抛出 WhosebugError，这将永远持续下去。
您需要避免创建 class 本身的对象作为成员或字段。
正如其他人所说，您创建了太多 StudInfo 的实例，但即使修复了该问题，您也会遇到更多异常。要解决您的问题，请参阅修改后的代码。
StudInfo.java
package studInfoAndSubj;
import javax.swing.*;
import javax.swing.border.*;
import java.awt.*;
import java.awt.event.*;
public class StudInfo extends JFrame {
private StudSubj sJ;
// Labels
private JLabel nameL = new JLabel("Student Name: ", SwingConstants.CENTER);
private JLabel snameL = new JLabel("(Surname)", SwingConstants.CENTER);
private JLabel fnameL = new JLabel("(First Name)", SwingConstants.CENTER);
private JLabel mnameL = new JLabel("(Middle Name)", SwingConstants.CENTER);
private JLabel courseL = new JLabel("Course: ", SwingConstants.CENTER);
private JLabel yearL = new JLabel("Year: ", SwingConstants.CENTER);
private JLabel semesterL = new JLabel("Semester: ", SwingConstants.CENTER);
// Text Fields
private JTextField snameTF = new JTextField(10);
private JTextField fnameTF = new JTextField(10);
private JTextField mnameTF = new JTextField(10);
// Text Value Handlers
private String snameS, fnameS, mnameS, courseS, yearS, semesterS;
// Buttons
private JButton nextB = new JButton("Next");
private JButton cancelB = new JButton("Cancel");
private ButtonHandler bH = new ButtonHandler();
// Layouts ((components + rows - 1) / rows)
private Container pane = getContentPane();
private Container one = new JPanel(new GridLayout(0, 6));
// Combo Boxes
private String[] course = {"BSIT"};
private String[] year = {"I"};
private String[] semester = {"1ST", "2ND"};
private JComboBox<String> courseCB = new JComboBox<>(course);
private JComboBox<String> yearCB = new JComboBox<>(year);
private JComboBox<String> semesterCB = new JComboBox<>(semester);
// Spaces
private JLabel blank1 = new JLabel("");
private JLabel blank2 = new JLabel("");
private JLabel blank3 = new JLabel("");
private JLabel blank4 = new JLabel("");
private JLabel blank5 = new JLabel("");
private JLabel blank6 = new JLabel("");
private JLabel blank7 = new JLabel("");
// Window Size
private static final int WIDTH = 1000;
private static final int HEIGHT = 250;
public StudInfo() // and this is line 65
{
DefaultListCellRenderer dlcr1 = new DefaultListCellRenderer();
dlcr1.setHorizontalAlignment(DefaultListCellRenderer.CENTER);
courseCB.setRenderer(dlcr1);
yearCB.setRenderer(dlcr1);
semesterCB.setRenderer(dlcr1);
snameTF.setHorizontalAlignment(JTextField.CENTER);
fnameTF.setHorizontalAlignment(JTextField.CENTER);
mnameTF.setHorizontalAlignment(JTextField.CENTER);
snameL.setVerticalAlignment(SwingConstants.TOP);
fnameL.setVerticalAlignment(SwingConstants.TOP);
mnameL.setVerticalAlignment(SwingConstants.TOP);
nextB.addActionListener(bH);
cancelB.addActionListener(bH);
Border border1 = BorderFactory.createLineBorder(Color.BLUE, 1);
courseL.setBorder(border1);
yearL.setBorder(border1);
semesterL.setBorder(border1);
pane.add(one);
one.add(blank1);
one.add(nameL);
one.add(snameTF);
one.add(fnameTF);
one.add(mnameTF);
one.add(blank2);
one.add(blank3);
one.add(blank4);
one.add(snameL);
one.add(fnameL);
one.add(mnameL);
one.add(blank5);
one.add(courseL);
one.add(courseCB);
one.add(yearL);
one.add(yearCB);
one.add(semesterL);
one.add(semesterCB);
one.add(blank6);
one.add(blank7);
one.add(cancelB);
one.add(nextB);
setTitle("Student Information");
setSize(WIDTH, HEIGHT);
setLocationRelativeTo(null);
setVisible(true);
setResizable(false);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
sJ = new StudSubj(this);
}
public String getSemValue()
{
return semesterS;
}
public String[] getSemCBValue()
{
return semester;
}
private class ButtonHandler implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
if(e.getSource() == nextB) {
snameS = snameTF.getText();
fnameS = fnameTF.getText();
mnameS = mnameTF.getText();
courseS = courseCB.getSelectedItem().toString();
yearS = yearCB.getSelectedItem().toString();
semesterS = semesterCB.getSelectedItem().toString();
setVisible(false);
sJ.build();
} else if(e.getSource() == cancelB) {
System.exit(0);
}
}
}
public static void main(String[] args)
{
StudInfo studInfo = new StudInfo();
}
}
StudSubj.java
package studInfoAndSubj;
import javax.swing.*;
import javax.swing.border.*;
import java.awt.*;
import java.awt.event.*;
public class StudSubj extends JFrame {
private StudInfo sI;
// Labels
private JLabel addSubjL = new JLabel("Add Subject: ", SwingConstants.CENTER);
// Buttons
private JButton doneB = new JButton("Done");
private JButton backB = new JButton("Back");
private ButtonHandler bH = new ButtonHandler();
// Text Value Handlers
private String semesterS;
private String[] semester;
private int selectedSubj;
private String selectedSubjTime;
// Subject Lists
private String[] sem1Subj = {"College Algebra\nMWF\n12:00PM-1:00PM",
"Communication Arts 1\nMWF\n9:00AM-10:00AM",
"Information Technology Fundamentals - Lec\nTTH\n7:30AM-8:30AM",
"Information Technology Fundamentals - Lab\nT\n9:00AM-12:00PM",
"Programming 1\nMWF\n7:00AM-9:00AM"};
private String[] sem1AddSubj = {"", "Filipino Christian Living\nMWF\n7:00AM-9:00AM",
"Foundation of Physical Education\nTH\n10:00AM-12:00PM",
"Komunikasyon sa Akademikong Filipino\nMWF\n9:00AM-10:00AM"};
private String[] sem2Subj = {"Trigonometry\nMWF\n7:00AM-8:00AM",
"Communication Arts 2\nTTH\n9:00AM-10:30AM",
"Programming 2\nMWF\n9:00AM-11:00AM",
"Database Management Systems\nMWF\n8:00AM-9:00AM",
"Network Management\nTTH\n7:30AM-9:00AM"};
private String[] sem2AddSubj = {"", "Environmental Science\nMWF\n8:00AM-9:00AM",
"Social Dances\nM\n12:00PM-2:00PM",
"General Psychology\nT\n12:00PM-1:00PM"};
// Subject Time
private String[] sem1SubjTime = {"MWF12:00PM-1:00PM", "MWF9:00AM-10:00AM", "TTH7:30AM-8:30AM",
"T9:00AM-12:00PM", "MWF7:00AM-9:00AM"};
private String[] sem1AddSubjTime = {"MWF7:00AM-9:00AM", "TH10:00AM-12:00PM", "MWF9:00AM-10:00AM"};
private String[] sem2SubjTime = {"MWF7:00AM-8:00AM", "TTH9:00AM-10:30AM", "MWF9:00AM-11:00AM",
"MWF8:00AM-9:00AM", "TTH7:30AM-9:00AM"};
private String[] sem2AddSubjTime = {"MWF8:00AM-9:00AM", "M12:00PM-2:00PM", "T12:00PM-1:00PM"};
// Layouts ((components + rows - 1) / rows)
private Container pane = getContentPane();
private Container two = new JPanel(new GridLayout(0, 2));
// Combo Boxes
private JComboBox<String> sem1AddSubjCB = new JComboBox<>(sem1AddSubj);
private JComboBox<String> sem2AddSubjCB = new JComboBox<>(sem2AddSubj);
// Window Size
private static final int WIDTH = 1000;
private static final int HEIGHT = 250;
private JLabel sem1Subj1 = new JLabel(sem1Subj[0]);
private JLabel sem1Subj2 = new JLabel(sem1Subj[1]);
private JLabel sem1Subj3 = new JLabel(sem1Subj[2]);
private JLabel sem1Subj4 = new JLabel(sem1Subj[3]);
private JLabel sem1Subj5 = new JLabel(sem1Subj[4]);
// 2nd Semester Subjects
private JLabel sem2Subj1 = new JLabel(sem2Subj[0]);
private JLabel sem2Subj2 = new JLabel(sem2Subj[1]);
private JLabel sem2Subj3 = new JLabel(sem2Subj[2]);
private JLabel sem2Subj4 = new JLabel(sem2Subj[3]);
private JLabel sem2Subj5 = new JLabel(sem2Subj[4]);
public StudSubj(StudInfo sI)
{
this.sI = sI;
DefaultListCellRenderer dlcr2 = new DefaultListCellRenderer();
doneB.addActionListener(bH);
backB.addActionListener(bH);
dlcr2.setHorizontalAlignment(DefaultListCellRenderer.CENTER);
sem1AddSubjCB.setRenderer(dlcr2);
sem2AddSubjCB.setRenderer(dlcr2);
setResizable(false);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Border border2 = BorderFactory.createLineBorder(Color.BLUE, 1);
sem1Subj1.setBorder(border2);
sem2Subj1.setBorder(border2);
sem1Subj2.setBorder(border2);
sem2Subj2.setBorder(border2);
sem1Subj3.setBorder(border2);
sem2Subj3.setBorder(border2);
sem1Subj4.setBorder(border2);
sem2Subj4.setBorder(border2);
sem1Subj5.setBorder(border2);
sem2Subj5.setBorder(border2);
addSubjL.setBorder(border2);
}
public void build() {
pane.add(two);
semesterS = sI.getSemValue();
semester = sI.getSemCBValue();
if(semesterS.equals(semester[0])) {
setTitle("(BSIT - I - 1st Semester) List Of Subjects");
two.add(sem1Subj1);
two.add(sem1Subj2);
two.add(sem1Subj3);
two.add(sem1Subj4);
two.add(sem1Subj5);
two.add(addSubjL);
two.add(sem1AddSubjCB);
} else if(semesterS.equals(semester[1])) {
setTitle("(BSIT - I - 2nd Semester) List Of Subjects");
two.add(sem2Subj1);
two.add(sem2Subj2);
two.add(sem2Subj3);
two.add(sem2Subj4);
two.add(sem2Subj5);
two.add(addSubjL);
two.add(sem2AddSubjCB);
}
two.add(backB);
two.add(doneB);
repaint();
revalidate();
setSize(WIDTH, HEIGHT);
setLocationRelativeTo(null);
setVisible(true);
}
private class ButtonHandler implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
if(e.getSource() == doneB) {
int ctr;
if(semesterS.equals(semester[0]))
{
selectedSubj = sem1AddSubjCB.getSelectedIndex()-1;
selectedSubjTime = sem1AddSubjTime[selectedSubj];
for(ctr = 0; ctr < sem1SubjTime.length; ctr++)
{
if(selectedSubjTime.equals(sem1SubjTime[ctr])) {
JOptionPane.showMessageDialog(null, "Choosen Subject has same time with the others!", "Error", 0);
} else {
sem1AddSubjCB.getSelectedItem();
}
}
} else if(semesterS.equals(semester[1])) {
selectedSubj = sem2AddSubjCB.getSelectedIndex()-1;
selectedSubjTime = sem2AddSubjTime[selectedSubj];
for(ctr = 0; ctr < sem2SubjTime.length; ctr++)
{
if(selectedSubjTime.equals(sem2SubjTime[ctr]))
{
JOptionPane.showMessageDialog(null, "Choosen Subject has same time with the others!", "Error", 0);
} else {
sem2AddSubjCB.getSelectedItem();
}
}
}
} else if(e.getSource() == backB) {
setVisible(false);
sI.setVisible(true);
}
}
}
}
注意：我从 StudSubj class 中删除了 main function 所以你需要 运行 StudInfo 才能让它工作
变更日志，很抱歉没有明确说明变更。
现在每个 class 只有一个实例，当单击正确的按钮时它们会在彼此之间切换。
在每个 class 中有两个 Action Listeners 而现在只有一个可以识别哪个 JButton 触发了 Action Event 然后跟随相应的代码。这是通过 e.getSource().
创建了一个新函数 build() 以便在单击 nextB 时它采用在 JComboBoxes
稍微修改了数组sem1AddSubjTime和sem2AddSubjTime并更改了
原创
int ctr;
if(semesterS.equals(semester[0]))
{
selectedSubj = sem1AddSubjCB.getSelectedIndex();
selectedSubjTime = sem1AddSubj[selectedSubj];
for(ctr = 0; ctr <= sem1AddSubj.length; ctr++)
{
if(selectedSubjTime.equals(sem1AddSubjTime[ctr]))
{
JOptionPane.showMessageDialog(null, "Choosen Subject has same time with the others!", "Error", 0);
}else{
sem1AddSubjCB.getSelectedItem();
}
}
}else if(semesterS.equals(semester[1]))
{
selectedSubj = sem2AddSubjCB.getSelectedIndex();
selectedSubjTime = sem2AddSubj[selectedSubj];
for(ctr = 0; ctr <= sem1AddSubj.length; ctr++)
{
if(selectedSubjTime.equals(sem2AddSubjTime[ctr]))
{
JOptionPane.showMessageDialog(null, "Choosen Subject has same time with the others!", "Error", 0);
}else{
sem2AddSubjCB.getSelectedItem();
}
}
}
已修改
int ctr;
if(semesterS.equals(semester[0]))
{
selectedSubj = sem1AddSubjCB.getSelectedIndex()-1;
selectedSubjTime = sem1AddSubjTime[selectedSubj];
for(ctr = 0; ctr < sem1SubjTime.length; ctr++)
{
if(selectedSubjTime.equals(sem1SubjTime[ctr])) {
JOptionPane.showMessageDialog(null, "Choosen Subject has same time with the others!", "Error", 0);
} else {
sem1AddSubjCB.getSelectedItem();
}
}
} else if(semesterS.equals(semester[1])) {
selectedSubj = sem2AddSubjCB.getSelectedIndex()-1;
selectedSubjTime = sem2AddSubjTime[selectedSubj];
for(ctr = 0; ctr < sem2SubjTime.length; ctr++)
{
if(selectedSubjTime.equals(sem2SubjTime[ctr]))
{
JOptionPane.showMessageDialog(null, "Choosen Subject has same time with the others!", "Error", 0);
} else {
sem2AddSubjCB.getSelectedItem();
}
}
}
我在这个 class 的第 12 行和第 65 行得到一个 WhosebugError：
package studInfoAndSubj; // Information Window
import javax.swing.*;
import javax.swing.border.*;
import java.awt.*;
import java.awt.event.*;
public class StudInfo extends JFrame
{
// This Class
private StudInfo studInfo = new StudInfo(); // this is Line 12
// Subjects Window Class
private StudSubj studSubj = new StudSubj();
// Labels
private JLabel nameL = new JLabel("Student Name: ", SwingConstants.CENTER);
private JLabel snameL = new JLabel("(Surname)", SwingConstants.CENTER);
private JLabel fnameL = new JLabel("(First Name)", SwingConstants.CENTER);
private JLabel mnameL = new JLabel("(Middle Name)", SwingConstants.CENTER);
private JLabel courseL = new JLabel("Course: ", SwingConstants.CENTER);
private JLabel yearL = new JLabel("Year: ", SwingConstants.CENTER);
private JLabel semesterL = new JLabel("Semester: ", SwingConstants.CENTER);
// Text Fields
private JTextField snameTF = new JTextField(10);
private JTextField fnameTF = new JTextField(10);
private JTextField mnameTF = new JTextField(10);
// Text Value Handlers
private String snameS, fnameS, mnameS, courseS, yearS, semesterS;
// Buttons
private JButton nextB = new JButton("Next");
private JButton cancelB = new JButton("Cancel");
private NextButtonHandler nextBH = new NextButtonHandler();
private CancelButtonHandler cancelBH = new CancelButtonHandler();
// Layouts ((components + rows - 1) / rows)
private Container pane = getContentPane();
private Container one = new JPanel(new GridLayout(0, 6));
// Combo Boxes
private String[] course = {"BSIT"};
private String[] year = {"I"};
private String[] semester = {"1ST", "2ND"};
private JComboBox<String> courseCB = new JComboBox<>(course);
private JComboBox<String> yearCB = new JComboBox<>(year);
private JComboBox<String> semesterCB = new JComboBox<>(semester);
// Spaces
private JLabel blank1 = new JLabel("");
private JLabel blank2 = new JLabel("");
private JLabel blank3 = new JLabel("");
private JLabel blank4 = new JLabel("");
private JLabel blank5 = new JLabel("");
private JLabel blank6 = new JLabel("");
private JLabel blank7 = new JLabel("");
// Window Size
private static final int WIDTH = 1000;
private static final int HEIGHT = 250;
public StudInfo() // and this is line 65
{
DefaultListCellRenderer dlcr1 = new DefaultListCellRenderer();
dlcr1.setHorizontalAlignment(DefaultListCellRenderer.CENTER);
courseCB.setRenderer(dlcr1);
yearCB.setRenderer(dlcr1);
semesterCB.setRenderer(dlcr1);
snameTF.setHorizontalAlignment(JTextField.CENTER);
fnameTF.setHorizontalAlignment(JTextField.CENTER);
mnameTF.setHorizontalAlignment(JTextField.CENTER);
snameL.setVerticalAlignment(SwingConstants.TOP);
fnameL.setVerticalAlignment(SwingConstants.TOP);
mnameL.setVerticalAlignment(SwingConstants.TOP);
nextB.addActionListener(nextBH);
cancelB.addActionListener(cancelBH);
Border border1 = BorderFactory.createLineBorder(Color.BLUE, 1);
courseL.setBorder(border1);
yearL.setBorder(border1);
semesterL.setBorder(border1);
pane.add(one);
one.add(blank1);
one.add(nameL);
one.add(snameTF);
one.add(fnameTF);
one.add(mnameTF);
one.add(blank2);
one.add(blank3);
one.add(blank4);
one.add(snameL);
one.add(fnameL);
one.add(mnameL);
one.add(blank5);
one.add(courseL);
one.add(courseCB);
one.add(yearL);
one.add(yearCB);
one.add(semesterL);
one.add(semesterCB);
one.add(blank6);
one.add(blank7);
one.add(cancelB);
one.add(nextB);
setTitle("Student Information");
setSize(WIDTH, HEIGHT);
setLocationRelativeTo(null);
setVisible(true);
setResizable(false);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public String getSemValue()
{
return semesterS;
}
public String[] getSemCBValue()
{
return semester;
}
private class NextButtonHandler implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
snameS = snameTF.getText();
fnameS = fnameTF.getText();
mnameS = mnameTF.getText();
courseS = courseCB.getSelectedItem().toString();
yearS = yearCB.getSelectedItem().toString();
semesterS = semesterCB.getSelectedItem().toString();
studInfo.setVisible(false);
studSubj.setVisible(true);
}
}
private class CancelButtonHandler implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
System.exit(0);
}
}
public static void main(String[] args)
{
StudInfo studInfo = new StudInfo();
}
}
这是我的另一个 class:
package studInfoAndSubj; // Subjects Window
import javax.swing.*;
import javax.swing.border.*;
import java.awt.*;
import java.awt.event.*;
public class StudSubj extends JFrame
{
// This class
private StudSubj studSubj = new StudSubj();
// Information Window Class
private StudInfo studInfo = new StudInfo();
// Labels
private JLabel addSubjL = new JLabel("Add Subject: ", SwingConstants.CENTER);
// Buttons
private JButton doneB = new JButton("Done");
private JButton backB = new JButton("Back");
private DoneButtonHandler doneBH = new DoneButtonHandler();
private BackButtonHandler backBH = new BackButtonHandler();
// Text Value Handlers
private String semesterS = studInfo.getSemValue();
private String[] semester = studInfo.getSemCBValue();
private int selectedSubj;
private String selectedSubjTime;
// Subject Lists
private String[] sem1Subj = {"College Algebra\nMWF\n12:00PM-1:00PM",
"Communication Arts 1\nMWF\n9:00AM-10:00AM",
"Information Technology Fundamentals - Lec\nTTH\n7:30AM-8:30AM",
"Information Technology Fundamentals - Lab\nT\n9:00AM-12:00PM",
"Programming 1\nMWF\n7:00AM-9:00AM"};
private String[] sem1AddSubj = {"", "Filipino Christian Living\nMWF\n7:00AM-9:00AM",
"Foundation of Physical Education\nTH\n10:00AM-12:00PM",
"Komunikasyon sa Akademikong Filipino\nMWF\n9:00AM-10:00AM"};
private String[] sem2Subj = {"Trigonometry\nMWF\n7:00AM-8:00AM",
"Communication Arts 2\nTTH\n9:00AM-10:30AM",
"Programming 2\nMWF\n9:00AM-11:00AM",
"Database Management Systems\nMWF\n8:00AM-9:00AM",
"Network Management\nTTH\n7:30AM-9:00AM"};
private String[] sem2AddSubj = {"", "Environmental Science\nMWF\n8:00AM-9:00AM",
"Social Dances\nM\n12:00PM-2:00PM",
"General Psychology\nT\n12:00PM-1:00PM"};
// Subject Time
private String[] sem1SubjTime = {"MWF12:00PM-1:00PM", "MWF9:00AM-10:00AM", "TTH7:30AM-8:30AM",
"T9:00AM-12:00PM", "MWF7:00AM-9:00AM"};
private String[] sem1AddSubjTime = {"", "MWF7:00AM-9:00AM", "TH10:00AM-12:00PM", "MWF9:00AM-10:00AM"};
private String[] sem2SubjTime = {"MWF7:00AM-8:00AM", "TTH9:00AM-10:30AM", "MWF9:00AM-11:00AM",
"MWF8:00AM-9:00AM", "TTH7:30AM-9:00AM"};
private String[] sem2AddSubjTime = {"", "MWF8:00AM-9:00AM", "M12:00PM-2:00PM", "T12:00PM-1:00PM"};
// Layouts ((components + rows - 1) / rows)
private Container pane = getContentPane();
private Container two = new JPanel(new GridLayout(0, 2));
// Combo Boxes
private JComboBox<String> sem1AddSubjCB = new JComboBox<>(sem1AddSubj);
private JComboBox<String> sem2AddSubjCB = new JComboBox<>(sem2AddSubj);
// Window Size
private static final int WIDTH = 1000;
private static final int HEIGHT = 250;
public StudSubj()
{
DefaultListCellRenderer dlcr2 = new DefaultListCellRenderer();
dlcr2.setHorizontalAlignment(DefaultListCellRenderer.CENTER);
sem1AddSubjCB.setRenderer(dlcr2);
sem2AddSubjCB.setRenderer(dlcr2);
doneB.addActionListener(doneBH);
backB.addActionListener(backBH);
// 1st Semester Subjects
JLabel sem1Subj1 = new JLabel(sem1Subj[0]);
JLabel sem1Subj2 = new JLabel(sem1Subj[1]);
JLabel sem1Subj3 = new JLabel(sem1Subj[2]);
JLabel sem1Subj4 = new JLabel(sem1Subj[3]);
JLabel sem1Subj5 = new JLabel(sem1Subj[4]);
// 2nd Semester Subjects
JLabel sem2Subj1 = new JLabel(sem2Subj[0]);
JLabel sem2Subj2 = new JLabel(sem2Subj[1]);
JLabel sem2Subj3 = new JLabel(sem2Subj[2]);
JLabel sem2Subj4 = new JLabel(sem2Subj[3]);
JLabel sem2Subj5 = new JLabel(sem2Subj[4]);
Border border2 = BorderFactory.createLineBorder(Color.BLUE, 1);
sem1Subj1.setBorder(border2); sem2Subj1.setBorder(border2);
sem1Subj2.setBorder(border2); sem2Subj2.setBorder(border2);
sem1Subj3.setBorder(border2); sem2Subj3.setBorder(border2);
sem1Subj4.setBorder(border2); sem2Subj4.setBorder(border2);
sem1Subj5.setBorder(border2); sem2Subj5.setBorder(border2);
addSubjL.setBorder(border2);
pane.add(two);
if(semesterS.equals(semester[0]))
{
setTitle("(BSIT - I - 1st Semester) List Of Subjects");
two.add(sem1Subj1);
two.add(sem1Subj2);
two.add(sem1Subj3);
two.add(sem1Subj4);
two.add(sem1Subj5);
two.add(addSubjL);
two.add(sem1AddSubjCB);
}else if(semesterS.equals(semester[1]))
{
setTitle("(BSIT - I - 2nd Semester) List Of Subjects");
two.add(sem2Subj1);
two.add(sem2Subj2);
two.add(sem2Subj3);
two.add(sem2Subj4);
two.add(sem2Subj5);
two.add(addSubjL);
two.add(sem2AddSubjCB);
}
two.add(backB);
two.add(doneB);
setSize(WIDTH, HEIGHT);
setLocationRelativeTo(null);
setResizable(false);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
private class DoneButtonHandler implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
int ctr;
if(semesterS.equals(semester[0]))
{
selectedSubj = sem1AddSubjCB.getSelectedIndex();
selectedSubjTime = sem1AddSubj[selectedSubj];
for(ctr = 0; ctr <= sem1AddSubj.length; ctr++)
{
if(selectedSubjTime.equals(sem1AddSubjTime[ctr]))
{
JOptionPane.showMessageDialog(null, "Choosen Subject has same time with the others!", "Error", 0);
}else{
sem1AddSubjCB.getSelectedItem();
}
}
}else if(semesterS.equals(semester[1]))
{
selectedSubj = sem2AddSubjCB.getSelectedIndex();
selectedSubjTime = sem2AddSubj[selectedSubj];
for(ctr = 0; ctr <= sem1AddSubj.length; ctr++)
{
if(selectedSubjTime.equals(sem2AddSubjTime[ctr]))
{
JOptionPane.showMessageDialog(null, "Choosen Subject has same time with the others!", "Error", 0);
}else{
sem2AddSubjCB.getSelectedItem();
}
}
}
}
}
private class BackButtonHandler implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
studSubj.setVisible(false);
studInfo.setVisible(true);
}
}
public static void main(String[] args)
{
StudSubj studSubj = new StudSubj();
}
}
当我 运行 main:
Exception in thread "main" java.lang.WhosebugError at sun.awt.Win32GraphicsConfig.getBounds(Native Method) at sun.awt.Win32GraphicsConfig.getBounds(Unknown Source) at java.awt.Window.init(Unknown Source) at java.awt.Window.(Unknown Source) at java.awt.Frame.(Unknown Source) at java.awt.Frame.(Unknown Source) at javax.swing.JFrame.(Unknown Source) at studInfoAndSubj.StudInfo.(StudInfo.java:65) at studInfoAndSubj.StudInfo.(StudInfo.java:12) at studInfoAndSubj.StudInfo.(StudInfo.java:12) at studInfoAndSubj.StudInfo.(StudInfo.java:12) at studInfoAndSubj.StudInfo.(StudInfo.java:12) at studInfoAndSubj.StudInfo.(StudInfo.java:12) at studInfoAndSubj.StudInfo.(StudInfo.java:12) at studInfoAndSubj.StudInfo.(StudInfo.java:12)
为什么会这样？我可以修复它吗？
您的问题包括尝试在 StudInfo class 中实例化两次：
private StudInfo studInfo = new StudInfo(); // this is Line 12
并在：
public static void main(String[] args)
{
StudInfo studInfo = new StudInfo();
}
这一行：
private StudInfo studInfo = new StudInfo();
调用自 main:
StudSubj studSubj = new StudSubj();
创建一个新的 StudInfo 对象，该对象具有相同类型的字段。
创建 StudInfo 的第一个实例时，也会实例化 other 的实例。那个 也 有一个实例化 另一个 StudInfo 的字段，依此类推...
如果不抛出 WhosebugError，这将永远持续下去。
您需要避免创建 class 本身的对象作为成员或字段。
正如其他人所说，您创建了太多 StudInfo 的实例，但即使修复了该问题，您也会遇到更多异常。要解决您的问题，请参阅修改后的代码。
StudInfo.java
package studInfoAndSubj;
import javax.swing.*;
import javax.swing.border.*;
import java.awt.*;
import java.awt.event.*;
public class StudInfo extends JFrame {
private StudSubj sJ;
// Labels
private JLabel nameL = new JLabel("Student Name: ", SwingConstants.CENTER);
private JLabel snameL = new JLabel("(Surname)", SwingConstants.CENTER);
private JLabel fnameL = new JLabel("(First Name)", SwingConstants.CENTER);
private JLabel mnameL = new JLabel("(Middle Name)", SwingConstants.CENTER);
private JLabel courseL = new JLabel("Course: ", SwingConstants.CENTER);
private JLabel yearL = new JLabel("Year: ", SwingConstants.CENTER);
private JLabel semesterL = new JLabel("Semester: ", SwingConstants.CENTER);
// Text Fields
private JTextField snameTF = new JTextField(10);
private JTextField fnameTF = new JTextField(10);
private JTextField mnameTF = new JTextField(10);
// Text Value Handlers
private String snameS, fnameS, mnameS, courseS, yearS, semesterS;
// Buttons
private JButton nextB = new JButton("Next");
private JButton cancelB = new JButton("Cancel");
private ButtonHandler bH = new ButtonHandler();
// Layouts ((components + rows - 1) / rows)
private Container pane = getContentPane();
private Container one = new JPanel(new GridLayout(0, 6));
// Combo Boxes
private String[] course = {"BSIT"};
private String[] year = {"I"};
private String[] semester = {"1ST", "2ND"};
private JComboBox<String> courseCB = new JComboBox<>(course);
private JComboBox<String> yearCB = new JComboBox<>(year);
private JComboBox<String> semesterCB = new JComboBox<>(semester);
// Spaces
private JLabel blank1 = new JLabel("");
private JLabel blank2 = new JLabel("");
private JLabel blank3 = new JLabel("");
private JLabel blank4 = new JLabel("");
private JLabel blank5 = new JLabel("");
private JLabel blank6 = new JLabel("");
private JLabel blank7 = new JLabel("");
// Window Size
private static final int WIDTH = 1000;
private static final int HEIGHT = 250;
public StudInfo() // and this is line 65
{
DefaultListCellRenderer dlcr1 = new DefaultListCellRenderer();
dlcr1.setHorizontalAlignment(DefaultListCellRenderer.CENTER);
courseCB.setRenderer(dlcr1);
yearCB.setRenderer(dlcr1);
semesterCB.setRenderer(dlcr1);
snameTF.setHorizontalAlignment(JTextField.CENTER);
fnameTF.setHorizontalAlignment(JTextField.CENTER);
mnameTF.setHorizontalAlignment(JTextField.CENTER);
snameL.setVerticalAlignment(SwingConstants.TOP);
fnameL.setVerticalAlignment(SwingConstants.TOP);
mnameL.setVerticalAlignment(SwingConstants.TOP);
nextB.addActionListener(bH);
cancelB.addActionListener(bH);
Border border1 = BorderFactory.createLineBorder(Color.BLUE, 1);
courseL.setBorder(border1);
yearL.setBorder(border1);
semesterL.setBorder(border1);
pane.add(one);
one.add(blank1);
one.add(nameL);
one.add(snameTF);
one.add(fnameTF);
one.add(mnameTF);
one.add(blank2);
one.add(blank3);
one.add(blank4);
one.add(snameL);
one.add(fnameL);
one.add(mnameL);
one.add(blank5);
one.add(courseL);
one.add(courseCB);
one.add(yearL);
one.add(yearCB);
one.add(semesterL);
one.add(semesterCB);
one.add(blank6);
one.add(blank7);
one.add(cancelB);
one.add(nextB);
setTitle("Student Information");
setSize(WIDTH, HEIGHT);
setLocationRelativeTo(null);
setVisible(true);
setResizable(false);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
sJ = new StudSubj(this);
}
public String getSemValue()
{
return semesterS;
}
public String[] getSemCBValue()
{
return semester;
}
private class ButtonHandler implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
if(e.getSource() == nextB) {
snameS = snameTF.getText();
fnameS = fnameTF.getText();
mnameS = mnameTF.getText();
courseS = courseCB.getSelectedItem().toString();
yearS = yearCB.getSelectedItem().toString();
semesterS = semesterCB.getSelectedItem().toString();
setVisible(false);
sJ.build();
} else if(e.getSource() == cancelB) {
System.exit(0);
}
}
}
public static void main(String[] args)
{
StudInfo studInfo = new StudInfo();
}
}
StudSubj.java
package studInfoAndSubj;
import javax.swing.*;
import javax.swing.border.*;
import java.awt.*;
import java.awt.event.*;
public class StudSubj extends JFrame {
private StudInfo sI;
// Labels
private JLabel addSubjL = new JLabel("Add Subject: ", SwingConstants.CENTER);
// Buttons
private JButton doneB = new JButton("Done");
private JButton backB = new JButton("Back");
private ButtonHandler bH = new ButtonHandler();
// Text Value Handlers
private String semesterS;
private String[] semester;
private int selectedSubj;
private String selectedSubjTime;
// Subject Lists
private String[] sem1Subj = {"College Algebra\nMWF\n12:00PM-1:00PM",
"Communication Arts 1\nMWF\n9:00AM-10:00AM",
"Information Technology Fundamentals - Lec\nTTH\n7:30AM-8:30AM",
"Information Technology Fundamentals - Lab\nT\n9:00AM-12:00PM",
"Programming 1\nMWF\n7:00AM-9:00AM"};
private String[] sem1AddSubj = {"", "Filipino Christian Living\nMWF\n7:00AM-9:00AM",
"Foundation of Physical Education\nTH\n10:00AM-12:00PM",
"Komunikasyon sa Akademikong Filipino\nMWF\n9:00AM-10:00AM"};
private String[] sem2Subj = {"Trigonometry\nMWF\n7:00AM-8:00AM",
"Communication Arts 2\nTTH\n9:00AM-10:30AM",
"Programming 2\nMWF\n9:00AM-11:00AM",
"Database Management Systems\nMWF\n8:00AM-9:00AM",
"Network Management\nTTH\n7:30AM-9:00AM"};
private String[] sem2AddSubj = {"", "Environmental Science\nMWF\n8:00AM-9:00AM",
"Social Dances\nM\n12:00PM-2:00PM",
"General Psychology\nT\n12:00PM-1:00PM"};
// Subject Time
private String[] sem1SubjTime = {"MWF12:00PM-1:00PM", "MWF9:00AM-10:00AM", "TTH7:30AM-8:30AM",
"T9:00AM-12:00PM", "MWF7:00AM-9:00AM"};
private String[] sem1AddSubjTime = {"MWF7:00AM-9:00AM", "TH10:00AM-12:00PM", "MWF9:00AM-10:00AM"};
private String[] sem2SubjTime = {"MWF7:00AM-8:00AM", "TTH9:00AM-10:30AM", "MWF9:00AM-11:00AM",
"MWF8:00AM-9:00AM", "TTH7:30AM-9:00AM"};
private String[] sem2AddSubjTime = {"MWF8:00AM-9:00AM", "M12:00PM-2:00PM", "T12:00PM-1:00PM"};
// Layouts ((components + rows - 1) / rows)
private Container pane = getContentPane();
private Container two = new JPanel(new GridLayout(0, 2));
// Combo Boxes
private JComboBox<String> sem1AddSubjCB = new JComboBox<>(sem1AddSubj);
private JComboBox<String> sem2AddSubjCB = new JComboBox<>(sem2AddSubj);
// Window Size
private static final int WIDTH = 1000;
private static final int HEIGHT = 250;
private JLabel sem1Subj1 = new JLabel(sem1Subj[0]);
private JLabel sem1Subj2 = new JLabel(sem1Subj[1]);
private JLabel sem1Subj3 = new JLabel(sem1Subj[2]);
private JLabel sem1Subj4 = new JLabel(sem1Subj[3]);
private JLabel sem1Subj5 = new JLabel(sem1Subj[4]);
// 2nd Semester Subjects
private JLabel sem2Subj1 = new JLabel(sem2Subj[0]);
private JLabel sem2Subj2 = new JLabel(sem2Subj[1]);
private JLabel sem2Subj3 = new JLabel(sem2Subj[2]);
private JLabel sem2Subj4 = new JLabel(sem2Subj[3]);
private JLabel sem2Subj5 = new JLabel(sem2Subj[4]);
public StudSubj(StudInfo sI)
{
this.sI = sI;
DefaultListCellRenderer dlcr2 = new DefaultListCellRenderer();
doneB.addActionListener(bH);
backB.addActionListener(bH);
dlcr2.setHorizontalAlignment(DefaultListCellRenderer.CENTER);
sem1AddSubjCB.setRenderer(dlcr2);
sem2AddSubjCB.setRenderer(dlcr2);
setResizable(false);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Border border2 = BorderFactory.createLineBorder(Color.BLUE, 1);
sem1Subj1.setBorder(border2);
sem2Subj1.setBorder(border2);
sem1Subj2.setBorder(border2);
sem2Subj2.setBorder(border2);
sem1Subj3.setBorder(border2);
sem2Subj3.setBorder(border2);
sem1Subj4.setBorder(border2);
sem2Subj4.setBorder(border2);
sem1Subj5.setBorder(border2);
sem2Subj5.setBorder(border2);
addSubjL.setBorder(border2);
}
public void build() {
pane.add(two);
semesterS = sI.getSemValue();
semester = sI.getSemCBValue();
if(semesterS.equals(semester[0])) {
setTitle("(BSIT - I - 1st Semester) List Of Subjects");
two.add(sem1Subj1);
two.add(sem1Subj2);
two.add(sem1Subj3);
two.add(sem1Subj4);
two.add(sem1Subj5);
two.add(addSubjL);
two.add(sem1AddSubjCB);
} else if(semesterS.equals(semester[1])) {
setTitle("(BSIT - I - 2nd Semester) List Of Subjects");
two.add(sem2Subj1);
two.add(sem2Subj2);
two.add(sem2Subj3);
two.add(sem2Subj4);
two.add(sem2Subj5);
two.add(addSubjL);
two.add(sem2AddSubjCB);
}
two.add(backB);
two.add(doneB);
repaint();
revalidate();
setSize(WIDTH, HEIGHT);
setLocationRelativeTo(null);
setVisible(true);
}
private class ButtonHandler implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
if(e.getSource() == doneB) {
int ctr;
if(semesterS.equals(semester[0]))
{
selectedSubj = sem1AddSubjCB.getSelectedIndex()-1;
selectedSubjTime = sem1AddSubjTime[selectedSubj];
for(ctr = 0; ctr < sem1SubjTime.length; ctr++)
{
if(selectedSubjTime.equals(sem1SubjTime[ctr])) {
JOptionPane.showMessageDialog(null, "Choosen Subject has same time with the others!", "Error", 0);
} else {
sem1AddSubjCB.getSelectedItem();
}
}
} else if(semesterS.equals(semester[1])) {
selectedSubj = sem2AddSubjCB.getSelectedIndex()-1;
selectedSubjTime = sem2AddSubjTime[selectedSubj];
for(ctr = 0; ctr < sem2SubjTime.length; ctr++)
{
if(selectedSubjTime.equals(sem2SubjTime[ctr]))
{
JOptionPane.showMessageDialog(null, "Choosen Subject has same time with the others!", "Error", 0);
} else {
sem2AddSubjCB.getSelectedItem();
}
}
}
} else if(e.getSource() == backB) {
setVisible(false);
sI.setVisible(true);
}
}
}
}
注意：我从 StudSubj class 中删除了 main function 所以你需要 运行 StudInfo 才能让它工作
变更日志，很抱歉没有明确说明变更。
现在每个 class 只有一个实例，当单击正确的按钮时它们会在彼此之间切换。
在每个 class 中有两个
Action Listeners而现在只有一个可以识别哪个JButton触发了Action Event然后跟随相应的代码。这是通过e.getSource(). 完成的
创建了一个新函数
build()以便在单击nextB时它采用在JComboBoxes稍微修改了数组
sem1AddSubjTime和sem2AddSubjTime并更改了
原创
int ctr;
if(semesterS.equals(semester[0]))
{
selectedSubj = sem1AddSubjCB.getSelectedIndex();
selectedSubjTime = sem1AddSubj[selectedSubj];
for(ctr = 0; ctr <= sem1AddSubj.length; ctr++)
{
if(selectedSubjTime.equals(sem1AddSubjTime[ctr]))
{
JOptionPane.showMessageDialog(null, "Choosen Subject has same time with the others!", "Error", 0);
}else{
sem1AddSubjCB.getSelectedItem();
}
}
}else if(semesterS.equals(semester[1]))
{
selectedSubj = sem2AddSubjCB.getSelectedIndex();
selectedSubjTime = sem2AddSubj[selectedSubj];
for(ctr = 0; ctr <= sem1AddSubj.length; ctr++)
{
if(selectedSubjTime.equals(sem2AddSubjTime[ctr]))
{
JOptionPane.showMessageDialog(null, "Choosen Subject has same time with the others!", "Error", 0);
}else{
sem2AddSubjCB.getSelectedItem();
}
}
}
已修改
int ctr;
if(semesterS.equals(semester[0]))
{
selectedSubj = sem1AddSubjCB.getSelectedIndex()-1;
selectedSubjTime = sem1AddSubjTime[selectedSubj];
for(ctr = 0; ctr < sem1SubjTime.length; ctr++)
{
if(selectedSubjTime.equals(sem1SubjTime[ctr])) {
JOptionPane.showMessageDialog(null, "Choosen Subject has same time with the others!", "Error", 0);
} else {
sem1AddSubjCB.getSelectedItem();
}
}
} else if(semesterS.equals(semester[1])) {
selectedSubj = sem2AddSubjCB.getSelectedIndex()-1;
selectedSubjTime = sem2AddSubjTime[selectedSubj];
for(ctr = 0; ctr < sem2SubjTime.length; ctr++)
{
if(selectedSubjTime.equals(sem2SubjTime[ctr]))
{
JOptionPane.showMessageDialog(null, "Choosen Subject has same time with the others!", "Error", 0);
} else {
sem2AddSubjCB.getSelectedItem();
}
}
}