问题描述
ProjectDetails类：
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JLabel;
import javax.swing.JTextField;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JRadioButton;
import javax.swing.JTextArea;
public class ProjectDetails extends JFrame {
private JPanel contentPane;
private JTextField pid;
private JTextField compName;
private JTextField X;
private JTextField Y;
private String radioResponse="";
private String id="";
private String comp="";
private String x="";
private String y="";
private String r="";
private DBManager db;
private JTextArea remarks;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokelater(new Runnable() {
public void run() {
try {
ProjectDetails frame = new ProjectDetails();
frame.setVisible(true);
} catch (Exception e) {
e.printstacktrace();
}
}
});
}
/**
* Create the frame.
*/
public ProjectDetails() {
setDefaultCloSEOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100,100,450,456);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5,5,5));
setContentPane(contentPane);
contentPane.setLayout(null);
JLabel label = new JLabel("Project_Id");
label.setFont(new Font("Tahoma",Font.PLAIN,12));
label.setBounds(10,74,81,14);
contentPane.add(label);
pid = new JTextField();
pid.setBounds(101,71,282,20);
contentPane.add(pid);
pid.setColumns(10);
JLabel lblNewLabel_1 = new JLabel("Company Name");
lblNewLabel_1.setFont(new Font("Tahoma",12));
lblNewLabel_1.setBounds(10,113,91,14);
contentPane.add(lblNewLabel_1);
compName = new JTextField();
compName.setBounds(101,111,20);
contentPane.add(compName);
compName.setColumns(10);
JLabel lblNewLabel_2 = new JLabel("Project Details");
lblNewLabel_2.setFont(new Font("Tahoma",Font.BOLD,16));
lblNewLabel_2.setBounds(134,11,121,32);
contentPane.add(lblNewLabel_2);
JLabel lblNewLabel_3 = new JLabel("New label");
lblNewLabel_3.setFont(new Font("Tahoma",12));
lblNewLabel_3.setBounds(10,156,14);
contentPane.add(lblNewLabel_3);
X = new JTextField();
X.setBounds(101,154,20);
contentPane.add(X);
X.setColumns(10);
JLabel lblNewLabel_4 = new JLabel("New label");
lblNewLabel_4.setFont(new Font("Tahoma",12));
lblNewLabel_4.setBounds(10,204,14);
contentPane.add(lblNewLabel_4);
Y = new JTextField();
Y.setBounds(101,202,20);
contentPane.add(Y);
Y.setColumns(10);
JRadioButton YesButton = new JRadioButton("Yes");
YesButton.setBounds(101,253,47,23);
contentPane.add(YesButton);
JRadioButton NoButton = new JRadioButton("No");
NoButton.setBounds(231,23);
contentPane.add(NoButton);
ButtonGroup YesNo = new ButtonGroup();
YesNo.add(YesButton);
YesNo.add(NoButton);
JLabel lblNewLabel_5 = new JLabel("Invoice Sent");
lblNewLabel_5.setFont(new Font("Tahoma",12));
lblNewLabel_5.setBounds(10,257,14);
contentPane.add(lblNewLabel_5);
JButton NextButton = new JButton("Next");
NextButton.setEnabled(false);
NextButton.setBounds(203,383,89,23);
contentPane.add(NextButton);
remarks = new JTextArea();
remarks.setEditable(false);
remarks.setEnabled(false);
remarks.setBounds(101,301,61);
contentPane.add(remarks);
ActionListener listener = new ActionListener() {
public void actionPerformed(ActionEvent event) {
JRadioButton button = (JRadioButton) event.getSource();
if (YesButton.isSelected()) {
radioResponse="Yes";
// option Yes is selected
NextButton.setEnabled(true);
remarks.setEditable(false);
remarks.setEnabled(false);
} else if (NoButton.isSelected()) {
radioResponse="No";
// option No is selected
remarks.setEditable(true);
remarks.setEnabled(true);
NextButton.setEnabled(false);
}
}
};
YesButton.addActionListener(listener);
NoButton.addActionListener(listener);
JLabel lblNewLabel_6 = new JLabel("Remarks");
lblNewLabel_6.setFont(new Font("Tahoma",12));
lblNewLabel_6.setLabelFor(remarks);
lblNewLabel_6.setBounds(10,306,14);
contentPane.add(lblNewLabel_6);
JButton AddButton = new JButton("Add");
AddButton.setBounds(59,23);
contentPane.add(AddButton);
AddButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
// Todo Auto-generated method stub
id=pid.getText();
comp=compName.getText();
x=X.getText();
y=Y.getText();
r=remarks.getText();
db.addProject(id,comp,x,y,radioResponse,r);
}
});
}
}
DBManager：
import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.sqlException;
import java.sql.Statement;
import javax.swing.JOptionPane;
public class DBManager {
private String connectionString="jdbc:MysqL://localhost/techno_control_database";
private Connection conn=null;
private Statement st=null;
private ResultSet rs=null;
private int status;
public DBManager() {
}
private void createConnection() {
try {
conn=DriverManager.getConnection(connectionString,"root","");
st=conn.createStatement();
} catch (sqlException e) {
// Todo Auto-generated catch block
e.printstacktrace();
}
}
public void addProject(String id,String company,String x,String y,String invoice,String r) {
createConnection();
String query="Insert into project_details(Project_Id,CompanyName,X,Y,InvoiceSent,Remarks) VALUES ('"+id+"','"+company+"','"+x+"','"+y+"','"+invoice+"','"+r+"')";
try {
st.execute(query);
JOptionPane.showMessageDialog(null,"Added Project :) ");
st.close();
conn.close();
} catch (sqlException e) {
// Todo Auto-generated catch block
e.printstacktrace();
}
}
public static void main(String args[]) {
DBManager test=new DBManager();
}
}
我要解决错误： 我似乎找不到问题： //////////////////////////////////////////////////// //////////////////////////////////////////////////// //////////////////////////////////////////////////// //////////////////////////////////////////////////// ///////////////////////////////////
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at ProjectDetails$3.actionPerformed(ProjectDetails.java:177)
at java.desktop/javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1967)
at java.desktop/javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2308)
at java.desktop/javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:405)
at java.desktop/javax.swing.DefaultButtonModel.setpressed(DefaultButtonModel.java:262)
at java.desktop/javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:279)
at java.desktop/java.awt.Component.processMouseEvent(Component.java:6636)
at java.desktop/javax.swing.JComponent.processMouseEvent(JComponent.java:3342)
at java.desktop/java.awt.Component.processEvent(Component.java:6401)
at java.desktop/java.awt.Container.processEvent(Container.java:2263)
at java.desktop/java.awt.Component.dispatchEventImpl(Component.java:5012)
at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2321)
at java.desktop/java.awt.Component.dispatchEvent(Component.java:4844)
at java.desktop/java.awt.Lightweightdispatcher.retargetMouseEvent(Container.java:4918)
at java.desktop/java.awt.Lightweightdispatcher.processMouseEvent(Container.java:4547)
at java.desktop/java.awt.Lightweightdispatcher.dispatchEvent(Container.java:4488)
at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2307)
at java.desktop/java.awt.Window.dispatchEventImpl(Window.java:2762)
at java.desktop/java.awt.Component.dispatchEvent(Component.java:4844)
at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:772)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:715)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:391)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:95)
at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:745)
at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:743)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:391)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742)
at java.desktop/java.awt.EventdispatchThread.pumpOneEventForFilters(EventdispatchThread.java:203)
at java.desktop/java.awt.EventdispatchThread.pumpEventsForFilter(EventdispatchThread.java:124)
at java.desktop/java.awt.EventdispatchThread.pumpEventsForHierarchy(EventdispatchThread.java:113)
at java.desktop/java.awt.EventdispatchThread.pumpEvents(EventdispatchThread.java:109)
at java.desktop/java.awt.EventdispatchThread.pumpEvents(EventdispatchThread.java:101)
at java.desktop/java.awt.EventdispatchThread.run(EventdispatchThread.java:90)
解决方法
暂无找到可以解决该程序问题的有效方法，小编努力寻找整理中！
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