How to determine errors in java
- by user225269
I'm just a java beginner. Do you have any tips there on how to determine errors. I'm trying to connect to mysql derby database.
I don't know how to determine the error, there is no red line, but there is a message box that shows up when I try to run the program.
All I want to do is to display the first record in the database.
All I get is this in the output:
E:\Users\users.netbeans\6.8\var\cache\executor-snippets\run.xml:45:
package Employees;
import java.sql.Statement;
import javax.swing.JOptionPane;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.ResultSet;
/**
*
* @author Nrew
*/
public class Students extends javax.swing.JFrame {
Connection con;
Statement stmt;
ResultSet rs;
/** Creates new form Students */
public Students() {
initComponents();
DoConnect();
}
public void DoConnect(){
try {
String host= "jdbc:derby://localhost:1527/YURA";
String uname = "bart";
String pword = "12345";
con = DriverManager.getConnection(host, uname, pword);
stmt = con.createStatement( );
String SQL = "SELECT * FROM APP.XROSS";
rs = stmt.executeQuery(SQL);
rs.next();
rs.next( );
int ids = rs.getInt("IDNUM");
String idz = Integer.toString(ids);
String fname = rs.getString("FNAME");
String lname = rs.getString("LNAME");
String course = rs.getString("COURSE");
String skul = rs.getString("SCHOOL");
String gen = rs.getString("GENDER");
TextIDNUM.setText(idz);
TextFNAME.setText(fname);
TextLNAME.setText(lname);
textCOURSE.setText(course);
textSCHOOL.setText(skul);
textGENDER.setText(gen);
}
catch (SQLException err) {
JOptionPane.showMessageDialog(Students.this, err.getMessage());
}
}
/** 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() {
TextIDNUM = new javax.swing.JTextField();
TextFNAME = new javax.swing.JTextField();
TextLNAME = new javax.swing.JTextField();
textCOURSE = new javax.swing.JTextField();
textSCHOOL = new javax.swing.JTextField();
textGENDER = new javax.swing.JTextField();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(116, 116, 116)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
.addComponent(textGENDER, javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(textSCHOOL, javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(textCOURSE, javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(TextLNAME, javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(TextFNAME, javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(TextIDNUM, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, 151, Short.MAX_VALUE))
.addContainerGap(243, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(37, 37, 37)
.addComponent(TextIDNUM, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addComponent(TextFNAME, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addComponent(TextLNAME, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addComponent(textCOURSE, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(textSCHOOL, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(textGENDER, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(67, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Students().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JTextField TextFNAME;
private javax.swing.JTextField TextIDNUM;
private javax.swing.JTextField TextLNAME;
private javax.swing.JTextField textCOURSE;
private javax.swing.JTextField textGENDER;
private javax.swing.JTextField textSCHOOL;
// End of variables declaration
}
