我不确定此代码的问题是什么，但每当我运行它时，我得到java.lang.StackOverflowError。我该如何解决？这是netbeans的输出控制台中显示的内容：
run:
Exception in thread "AWT-EventQueue-0" java.lang.StackOverflowError
at sun.awt.Win32GraphicsConfig.getBounds(Native Method)
at sun.awt.Win32GraphicsConfig.getBounds(Win32GraphicsConfig.java:222) at sun.awt.Win32GraphicsConfig.getBounds(Win32GraphicsConfig.java:222)
at java.awt.Window.init(Window.java:497)
at java.awt.Window.<init>(Window.java:536)
at java.awt.Frame.<init>(Frame.java:420)
at java.awt.Frame.<init>(Frame.java:385)
at javax.swing.JFrame.<init>(JFrame.java:180)
码
import java.awt.Color;
import java.awt.Font;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Scanner;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.ButtonGroup;
import javax.swing.JOptionPane;
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
/**
*
* @author Nicholas Ferretti
*/
public class Section2 extends javax.swing.JFrame {
Section2 s2Frame = new Section2();
Section3 s3Frame = new Section3();
ResultSet section2Questions;
DB connection = new DB();
/**
* Creates new form Section2Question1
*/
TimerFrame timerFrame;
int timeRemaining = 60;
int s2QuestionNumber = 1;
public Section2() {
this.timerFrame = new TimerFrame(this);
initComponents();
groupButton();
section2QuestionBox.setEditable(false);
s2QuestionNumberLabel.setText("Question "+s2QuestionNumber+":");
try {
section2Questions=connection.queryTbl("SELECT * FROM tblQuestions WHERE Section = 2");
section2Questions.next();
String firstQuestion = section2Questions.getString("Questions");
System.out.println(firstQuestion);
section2QuestionBox.setText(firstQuestion);
String firstAnswers = section2Questions.getString("AllPossibleAnswers");
Scanner scLine = new Scanner(firstAnswers).useDelimiter(",");
while(scLine.hasNext()){
String answer1 = scLine.next();
S2Answer1.setText(answer1);
System.out.println(answer1);
String answer2 = scLine.next();
S2Answer2.setText(answer2);
System.out.println(answer2);
String answer3 = scLine.next();
S2Answer3.setText(answer3);
System.out.println(answer3);
String answer4 = scLine.next();
S2Answer4.setText(answer4);
System.out.println(answer4);
}
} catch (SQLException ex) {
Logger.getLogger(Section1.class.getName()).log(Level.SEVERE, null, ex);
System.out.println("Error with SQL firstQuestion");
}
/*boolean t = timerFrame.timer(Section2Timer, timeRemaining);
if(t == false){
JOptionPane.showMessageDialog(null, "Time up for section.");
s2Frame.setVisible(false);
//s3Frame.setVisible(true);
}*/
}
private void groupButton() {
ButtonGroup buttons = new ButtonGroup();
buttons.add(S2Answer2);
buttons.add(S2Answer3);
buttons.add(S2Answer1);
buttons.add(S2Answer4);
}
private void timer() {
try {
Score time = new Score();
int timeRemaining = time.getTime();
while(timeRemaining>0){
Section2Timer.setText(timeRemaining+"");
Section2Timer.setFont(new Font("Serif", Font.BOLD, 32));
Section2Timer.setForeground(Color.RED);
Thread.sleep(1000);
timeRemaining--;
if(timeRemaining==0){
time.setTime(60);
}
time.setTime(timeRemaining);
}
} catch (InterruptedException e) {
e.printStackTrace();
// handle the exception...
// For example consider calling Thread.currentThread().interrupt(); here.
}
}
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jLabel7 = new javax.swing.JLabel();
s2QuestionNumberLabel = new javax.swing.JLabel();
jLabel9 = new javax.swing.JLabel();
jScrollPane3 = new javax.swing.JScrollPane();
section2QuestionBox = new javax.swing.JTextArea();
S2Answer1 = new javax.swing.JRadioButton();
S2Answer2 = new javax.swing.JRadioButton();
S2Answer3 = new javax.swing.JRadioButton();
S2Answer4 = new javax.swing.JRadioButton();
nextS2Question = new javax.swing.JButton();
Section2Timer = new javax.swing.JLabel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jLabel7.setFont(new java.awt.Font("Tahoma", 1, 36)); // NOI18N
jLabel7.setText("SECTION 2:");
s2QuestionNumberLabel.setFont(new java.awt.Font("Tahoma", 1, 18)); // NOI18N
s2QuestionNumberLabel.setText("QUESTION 1:");
jLabel9.setText("Answers:");
section2QuestionBox.setColumns(20);
section2QuestionBox.setRows(5);
section2QuestionBox.setText("At a conference, 12 memeber shook hands with each other \nbefore & after the meeting. How many total number of\nhand shakes occurred?");
jScrollPane3.setViewportView(section2QuestionBox);
S2Answer1.setText("Monday");
S2Answer1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
S2Answer1ActionPerformed(evt);
}
});
S2Answer2.setText("Tuesday");
S2Answer2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
S2Answer2ActionPerformed(evt);
}
});
S2Answer3.setText("Wednesday");
S2Answer3.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
S2Answer3ActionPerformed(evt);
}
});
S2Answer4.setText("Friday");
S2Answer4.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
S2Answer4ActionPerformed(evt);
}
});
nextS2Question.setText("Next");
nextS2Question.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
nextS2QuestionActionPerformed(evt);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addGroup(javax.swing.GroupLayout.Alignment.LEADING, layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(jLabel7, javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.LEADING, layout.createSequentialGroup()
.addGap(125, 125, 125)
.addComponent(s2QuestionNumberLabel)))
.addGap(0, 0, Short.MAX_VALUE))
.addGroup(javax.swing.GroupLayout.Alignment.LEADING, layout.createSequentialGroup()
.addGap(217, 217, 217)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jScrollPane3, javax.swing.GroupLayout.Alignment.TRAILING)
.addGroup(layout.createSequentialGroup()
.addComponent(jLabel9)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(S2Answer1)
.addGap(53, 53, 53)
.addComponent(S2Answer2)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 56, Short.MAX_VALUE)
.addComponent(S2Answer3)
.addGap(45, 45, 45)
.addComponent(S2Answer4))
.addComponent(nextS2Question, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))))
.addGap(139, 139, 139)
.addComponent(Section2Timer, javax.swing.GroupLayout.PREFERRED_SIZE, 101, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap())
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(Section2Timer, javax.swing.GroupLayout.PREFERRED_SIZE, 54, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel7, javax.swing.GroupLayout.PREFERRED_SIZE, 74, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(0, 0, 0)
.addComponent(s2QuestionNumberLabel, javax.swing.GroupLayout.PREFERRED_SIZE, 40, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addComponent(jScrollPane3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(50, 50, 50)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel9)
.addComponent(S2Answer1)
.addComponent(S2Answer2)
.addComponent(S2Answer3)
.addComponent(S2Answer4))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 140, Short.MAX_VALUE)
.addComponent(nextS2Question)
.addGap(125, 125, 125))
);
pack();
}// </editor-fold>
String answer = "";
private void S2Answer1ActionPerformed(java.awt.event.ActionEvent evt) {
answer = S2Answer1.getText();
}
private void S2Answer2ActionPerformed(java.awt.event.ActionEvent evt) {
answer = S2Answer2.getText();
}
private void S2Answer3ActionPerformed(java.awt.event.ActionEvent evt) {
answer = S2Answer3.getText();
}
private void S2Answer4ActionPerformed(java.awt.event.ActionEvent evt) {
answer = S2Answer4.getText();
}
private void nextS2QuestionActionPerformed(java.awt.event.ActionEvent evt) {
Score score = new Score();
try {
String actualAnswer = section2Questions.getString("Answer");
int currentScore = score.getS2Score();
if(answer.equalsIgnoreCase(actualAnswer)){
currentScore+=5;
score.setS2Score(currentScore);
}
} catch (SQLException ex) {
Logger.getLogger(Section1.class.getName()).log(Level.SEVERE, null, ex);
System.out.println("Error in Next Question method");
}
if(s2QuestionNumber ==4){
int timeLeft = score.getTime();
int currentBonusPoints = score.getBonusPoints();
score.setBonusPoints(timeLeft+currentBonusPoints);
s2Frame.setVisible(false);
s3Frame.setVisible(true);
}
try {
section2Questions.next();
String nextQuestion = section2Questions.getString("Questions");
section2QuestionBox.setText(nextQuestion);
s2QuestionNumber++;
s2QuestionNumberLabel.setText("Question "+s2QuestionNumber+":");
} catch (SQLException ex) {
Logger.getLogger(Section1.class.getName()).log(Level.SEVERE, null, ex);
System.out.println("Error in Next Question method");
}
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(Section2.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(Section2.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(Section2.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(Section2.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Section2().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JRadioButton S2Answer1;
private javax.swing.JRadioButton S2Answer2;
private javax.swing.JRadioButton S2Answer3;
private javax.swing.JRadioButton S2Answer4;
private javax.swing.JLabel Section2Timer;
private javax.swing.JLabel jLabel7;
private javax.swing.JLabel jLabel9;
private javax.swing.JScrollPane jScrollPane3;
private javax.swing.JButton nextS2Question;
private javax.swing.JLabel s2QuestionNumberLabel;
private javax.swing.JTextArea section2QuestionBox;
// End of variables declaration
}
答案 0 :(得分：10)
班级Section2中的第一行会导致问题。
你有Section2 s2Frame = new Section2();，这意味着，每次为Section2创建一个对象时，你想创建另一个Section2对象（这将创建另一个对象......并且sooooooooo上...）
因此stackoverflow异常......