好的，所以我做了javac dicebot.java，它工作正常，但是当我做了java dicebot.java我得到了这个： 考虑到我不知道这些错误是什么意思，我真的不知道能解释得多好多少。所以任何帮助都会很棒，谢谢！
与你在那里提出的问题不同，因为它与它无关。这是一个完全不同的问题，它的错误是独一无二的......
java.lang.NullPointerException
at java.awt.Container.addImpl(Container.java:1086)
at java.awt.Container.add(Container.java:966)
at dicebot.<init>(dicebot.java:67)
at dicebot$1.run(dicebot.java:26)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:733)
at java.awt.EventQueue.access$200(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:694)
at java.awt.EventQueue$3.run(EventQueue.java:692)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:703)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)
这是我制作并尝试运行的编码：
import javax.swing.*;
import javax.swing.border.EmptyBorder;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class dicebot extends JFrame implements ActionListener {
static final long serialVersionUID = 1L;
private JPanel contentPane;
private JTextField textField;
public static JComboBox combo;
public static JButton btnConfirm;
public static JTextField txtUserName;
public static JTextField txtStartBid;
public static JTextField txtMultiplier;
public static JTextField txtMinRemaining;
public static JTextField txtPassword;
public static JTextField txtOdds;
public static JTextField txtMaxBet;
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
dicebot frame = new dicebot();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
public dicebot() {
setTitle("Dice Bot");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
contentPane.setLayout(new BorderLayout(0, 0));
setContentPane(contentPane);
JPanel panel = new JPanel();
contentPane.add(panel, BorderLayout.WEST);
GridBagLayout gbl_panel = new GridBagLayout();
gbl_panel.columnWidths = new int[]{0, 0};
gbl_panel.rowHeights = new int[]{0, 0};
gbl_panel.columnWeights = new double[]{0.0, 1.0};
gbl_panel.rowWeights = new double[]{0.0, Double.MIN_VALUE};
panel.setLayout(gbl_panel);
//Every new Label however needs every part that says "user" or on the Password: "pass" changed to something unique.
JLabel userTag = new JLabel("Username:");
GridBagConstraints gbc_userTag = new GridBagConstraints();
gbc_userTag.insets = new Insets(0, 0, 0, 5);
gbc_userTag.anchor = GridBagConstraints.EAST;
gbc_userTag.gridx = 0;//Here are your x + y coords
gbc_userTag.gridy = 0;//Adding to x moves left, adding to y moves down
panel.add(userTag, gbc_userTag);
//Every new textfield needs only the * part to change for it to be valid. (gbc_* =)
txtUserName = new JTextField();
GridBagConstraints txtUserName = new GridBagConstraints();
txtUserName.fill = GridBagConstraints.HORIZONTAL;
txtUserName.gridx = 1;
txtUserName.gridy = 0;
panel.add(textField,txtUserName);
textField.setColumns(10);
JLabel startTag = new JLabel("Starting Bid:");
GridBagConstraints gbc_startTag = new GridBagConstraints();
gbc_startTag.insets = new Insets(0, 0, 0, 5);
gbc_startTag.anchor = GridBagConstraints.EAST;
gbc_startTag.gridx = 0;
gbc_startTag.gridy = 2;
panel.add(startTag, gbc_startTag);
txtStartBid = new JTextField();
GridBagConstraints txtStartBid = new GridBagConstraints();
txtStartBid.fill = GridBagConstraints.HORIZONTAL;
txtStartBid.gridx = 1;
txtStartBid.gridy = 2;
panel.add(textField, txtStartBid);
textField.setColumns(10);
JLabel multTag = new JLabel("Multiplier:");
GridBagConstraints gbc_multTag = new GridBagConstraints();
gbc_multTag.insets = new Insets(0, 0, 0, 5);
gbc_multTag.anchor = GridBagConstraints.EAST;
gbc_multTag.gridx = 0;
gbc_multTag.gridy = 3;
panel.add(multTag, gbc_multTag);
txtMultiplier = new JTextField();
GridBagConstraints txtMultiplier = new GridBagConstraints();
txtMultiplier.fill = GridBagConstraints.HORIZONTAL;
txtMultiplier.gridx = 1;
txtMultiplier.gridy = 3;
panel.add(textField, txtMultiplier);
textField.setColumns(10);
JLabel minTag = new JLabel("Min Remaining:");
GridBagConstraints gbc_minTag = new GridBagConstraints();
gbc_minTag.insets = new Insets(0, 0, 0, 5);
gbc_minTag.anchor = GridBagConstraints.EAST;
gbc_minTag.gridx = 0;
gbc_minTag.gridy = 4;
panel.add(minTag, gbc_minTag);
txtMinRemaining = new JTextField();
GridBagConstraints txtMinRemaining = new GridBagConstraints();
txtMinRemaining.fill = GridBagConstraints.HORIZONTAL;
txtMinRemaining.gridx = 1;
txtMinRemaining.gridy = 4;
panel.add(textField, txtMinRemaining);
textField.setColumns(10);
txtPassword = new JTextField();
GridBagConstraints txtPassword = new GridBagConstraints();
txtPassword.fill = GridBagConstraints.HORIZONTAL;
txtPassword.gridx = 1;
txtPassword.gridy = 1;
panel.add(textField, txtPassword);
textField.setColumns(10);
JLabel passTag = new JLabel("Password:");
GridBagConstraints gbc_passTag = new GridBagConstraints();
gbc_passTag.insets = new Insets(0, 0, 0, 5);
gbc_passTag.anchor = GridBagConstraints.EAST;
gbc_passTag.gridx = 0;
gbc_passTag.gridy = 1;
panel.add(passTag, gbc_passTag);
txtOdds = new JTextField();
GridBagConstraints txtOdds = new GridBagConstraints();
txtOdds.fill = GridBagConstraints.HORIZONTAL;
txtOdds.gridx = 1;
txtOdds.gridy = 5;
panel.add(textField, txtOdds);
textField.setColumns(10);
JLabel oddsTag = new JLabel("Odds %:");
GridBagConstraints gbc_oddsTag = new GridBagConstraints();
gbc_oddsTag.insets = new Insets(0, 0, 0, 5);
gbc_oddsTag.anchor = GridBagConstraints.EAST;
gbc_oddsTag.gridx = 0;
gbc_oddsTag.gridy = 5;
panel.add(oddsTag, gbc_oddsTag);
txtMaxBet = new JTextField();
GridBagConstraints txtMaxBet = new GridBagConstraints();
txtMaxBet.fill = GridBagConstraints.HORIZONTAL;
txtMaxBet.gridx = 1;
txtMaxBet.gridy = 6;
panel.add(textField, txtMaxBet);
textField.setColumns(10);
//This is the Combo Box
combo = new JComboBox<String>(new String[]{"BTC","LTC","PPC","NMC","XPM","FTC","ANC","DOGE","NXT"});
combo.addActionListener(this);
GridBagConstraints gbc_list = new GridBagConstraints();
gbc_list.fill = GridBagConstraints.HORIZONTAL;
gbc_list.gridx = 1;
gbc_list.gridy = 7;
panel.add(combo, gbc_list);
JLabel maxTag = new JLabel("MaxBet:");
GridBagConstraints gbc_maxTag = new GridBagConstraints();
gbc_maxTag.insets = new Insets(0, 0, 0, 5);
gbc_maxTag.anchor = GridBagConstraints.EAST;
gbc_maxTag.gridx = 0;
gbc_maxTag.gridy = 6;
panel.add(maxTag, gbc_maxTag);
JPanel panel_1 = new JPanel();
contentPane.add(panel_1, BorderLayout.SOUTH);
panel_1.setLayout(new FlowLayout(FlowLayout.RIGHT, 5, 5));
btnConfirm = new JButton("Turn Up");
btnConfirm.addActionListener(this);
panel_1.add(btnConfirm);
JScrollPane scrollPane = new JScrollPane();
contentPane.add(scrollPane, BorderLayout.CENTER);
JTextArea textArea = new JTextArea("Current Balance");
textArea.setColumns(1);
scrollPane.setViewportView(textArea);
JScrollPane scrollPanel1 = new JScrollPane();//This will hold the information the bot sends over such as win/loose or error
contentPane.add(scrollPane, BorderLayout.CENTER);
JTextArea textAreal = new JTextArea("Input bot information here...");
textArea.setColumns(20);
scrollPane.setViewportView(textArea);
pack();
}
@Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == combo) {
System.out.println(combo.getSelectedIndex()+1);
}
}
}
答案 0 :(得分：2)
NullPointerException表示有些东西试图调用方法或访问null对象的变量。
根据你的评论，
会抛出异常panel.add(textField,txtUserName);
现在，txtUserName之前被初始化了几行，因此它不应该是原因，textField变量怎么样？
答案 1 :(得分：0)
正如杰克指出的那样，textField未初始化。