将项目保存到JAR中并发生错误…通过NetBeans完美运行它

Question

I've got an application with database connection etc, which is working correctly in NetBeans, although I want to test the application on different PC etc... so I've created a Jar File, and somehow when opening it it gives an error, straight after trying to connect to the database I'm guessing as GUI is functioning although I can't retrieve or save any data to the database. What could be the problem?

public View_HomePage() {
        initComponents();
        String date = new SimpleDateFormat("dd-MM-yyyy").format(new Date());
               lblDate.setText(date);

        String[][] rowData = new String[0][4];
        String[] columns = {"ID", "Name", "Surname", "Registration", "Make", "Model", "Engine", "Year", "Mileage", "Type", "Date", "Time", "Postcode", "Number"};
        resultModel = new DefaultTableModel(rowData,columns);
        jTable1.setAutoCreateRowSorter(true); 

         try{
            Model_Customer[] appointment = Controller_ManageCustomer.FindCustomers2(lblDate.getText());
            resultModel.setRowCount(0);
            for(int i = 0; i < appointment.length; i++)
                resultModel.insertRow(i,new Object[]{appointment[i].GetID(),appointment[i].GetFName(), appointment[i].GetLName(), appointment[i].GetRegistration(), appointment[i].GetMake(), appointment[i].GetModel(), appointment[i].GetEngine(), appointment[i].GetYear(), appointment[i].GetMileage(), appointment[i].GetType(), appointment[i].GetDate(), appointment[i].GetTime(), appointment[i].GetPostcode(), appointment[i].GetNumber()});

         if (jTable1 == null) {
        jTable1 = new JTable(resultModel);
        add(new JScrollPane(jTable1));
    } else {
        jTable1.setModel(resultModel);
    }

}
         catch(Exception ex){
            JOptionPane.showMessageDialog(this,ex.getMessage(),"Error Problem",JOptionPane.ERROR_MESSAGE);
        }

    }

Error in CMD shows as =

Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation.  All rights reserved.

C:\Users\IMPREZA>cd Documents

C:\Users\IMPREZA\Documents>cd attachments

C:\Users\IMPREZA\Documents\attachments>java -jar LPGExerts.jar
ClassNotFoundException: org.postgresql.Driver
Fatalnull
null


Import java.sql.*;
import java.util.concurrent.*;

public class Database 
{
    private static Connection con;
    private static String url = "jdbc:postgresql://lpgexperts.heliohost.org:5432/*****";
    private static String user = "****";
    private static String pass = "***"
    static{
        try{
            Class.forName("org.postgresql.Driver"); 
            Database.con = DriverManager.getConnection(Database.url, Database.user, Database.pass);
        }
        catch (ClassNotFoundException ex) {System.err.println("ClassNotFoundException: " + ex.getMessage());}
        catch (SQLException ex)           {System.err.println("SQLException: " + ex.getMessage());}

        //Ping every minute, keep alive

        // Create a service with 3 threads.
        ScheduledExecutorService execService = Executors.newScheduledThreadPool(3);

        // Schedule a task to run every 5 seconds with no initial delay.
        execService.scheduleAtFixedRate(new Runnable() {
            public void run() {
                try{
                    Connection c = Database.GetConnection();
                    Statement stmt = c.createStatement();
                    ResultSet rs = stmt.executeQuery("SELECT 1");
                }catch(Exception e){
                    System.out.println("Fatal" + e.getMessage());
                    System.out.println(e.getCause());
                }
            }
        }, 0L, 60L, TimeUnit.SECONDS);
    }

    /**
     * Get connection interface
     * 
     * @return Connection instance
     */
    public static Connection GetConnection(){
        return Database.con;
    }

Update: Made it Work!!! Opened project properties in NetBeans... and found that in Libraries there was nothing about PGDriver... added the driver to the library saved and compiled the jar file and woop woop works :)

Answer 1

You need to have the PostGresql driver on your classpath when you run it as a jar on a different machine.

Say your driver jar is named pg.jar. It is kept at -

c:\Users\IMPREZA\Documents\jars

then

C:\Users\IMPREZA\Documents\attachments>java -classpath c:\Users\IMPREZA\Documents\jars\pg.jar;. -jar LPGExerts.jar

Update: Even though you are running it on same machine, do specify classpath. It should work. Try it and let me know.

Update 2: >> but how can i run the jar then not from cmd but by double click?

NetBeans adds the jar to your classpath before running it. You have added the driver jar to the project in NetBeans. Let me know the result!

Update 3:

Yes. do check the spellings. Make sure you use double quotes for paths that contain spaces.

Try this -

java -classpath C:\Users\IMPREZA\Documents\attachments\lib\postgresql-9.2-1002.jdbc4.jar;.\LPGExerts.jar -jar LPGExerts.jar

with quotes (just a shot, no need since I dont see spaces in paths)

java -classpath "C:\Users\IMPREZA\Documents\attachments\lib\postgresql-9.2-1002.jdbc4.jar;.\LPGExerts.jar" -jar LPGExerts.jar

Update 4:

Now, i cant say anything. has to be a spelling mistake. Check all spellings, paths, etc.

1. Use the exact same jar as in Netbeans, and remember to update your -classpath argument to match the file name of the jar you added to your project in Netbeans. I am just making sure that we have a working jar in classpath. The jar you added in Netbeans is working.

2. Make sure your LPGExerts.jar is being rebuilt after every code change you made.

Do let me know if you find a solution.

Update 5: You are welcome