Help with a project

[80mins]

Hey there I am having trouble with my project,
and now as I am overdue Im asking for help.

My project is sending a unusual amount of nullpointerexceptions.
I know what these exceptions are, I just have no idea how to find them.

I am ready to give up but as this is the last hurdle before I can graduate I wish to finish what
I have started.

I dont know how to upload my project to this site. but if anybody can spear some time
to help me. I can email them a copy of the project.

Cheers julian.

juliancassidy@hotmail.com

[Tolls]

There will be a stack trace with your exceptions.
That stack trace will point you to the line of code that is throwing the exception.
If you aren't getting a stack trace then it is probably because you are doing something like:

catch (Exception e) {
    System.out.println(e.getMessage());
}

instead of:

catch (Exception e) {
    e.printStackTrace();
}

[80mins]

hey Tolls I have done what you sujested.

but as i am only newish to java I dont understand how to read the output.

I get this when trying to delete a field.

run:
Running ok
Sent location to propertiesC:\Users\Julian Cassidy\Desktop\db-2x2.db
Error in findRecord java.io.EOFException
Error in getFileRecords java.lang.NullPointerException
Error connect in ClientSocketjava.net.ConnectException: Connection refused: connect
sending data over sockets
Error connect in ClientSocketjava.net.ConnectException: Connection refused: connect
java.lang.NullPointerException
Error send in ClientSocket java.lang.NullPointerException
at sjdsuncertify.Socket.ClientSocket.send(ClientSocke t.java:303)
at sjdsuncertify.Socket.ClientSocket.lock(ClientSocke t.java:212)
at sjdsuncertify.GUI.MainGUI.btnDeleteActionPerformed (MainGUI.java:434)
at sjdsuncertify.GUI.MainGUI.access$400(MainGUI.java: 23)
at sjdsuncertify.GUI.MainGUI$5.actionPerformed(MainGU I.java:198)
at javax.swing.AbstractButton.fireActionPerformed(Abs tractButton.java:1995)
at javax.swing.AbstractButton$Handler.actionPerformed (AbstractButton.java:2318)
at javax.swing.DefaultButtonModel.fireActionPerformed (DefaultButtonModel.java:387)
at javax.swing.DefaultButtonModel.setPressed(DefaultB uttonModel.java:242)
at javax.swing.plaf.basic.BasicButtonListener.mouseRe leased(BasicButtonListener.java:236)
at java.awt.Component.processMouseEvent(Component.jav a:6267)
at javax.swing.JComponent.processMouseEvent(JComponen t.java:3267)
at java.awt.Component.processEvent(Component.java:603 2)
at java.awt.Container.processEvent(Container.java:204 1)
at java.awt.Component.dispatchEventImpl(Component.jav a:4630)
at java.awt.Container.dispatchEventImpl(Container.jav a:2099)
at java.awt.Component.dispatchEvent(Component.java:44 60)
at java.awt.LightweightDispatcher.retargetMouseEvent( Container.java:4577)
at java.awt.LightweightDispatcher.processMouseEvent(C ontainer.java:4238)
at java.awt.LightweightDispatcher.dispatchEvent(Conta iner.java:4168)
at java.awt.Container.dispatchEventImpl(Container.jav a:2085)
at java.awt.Window.dispatchEventImpl(Window.java:2478 )
at java.awt.Component.dispatchEvent(Component.java:44 60)
Error disconnect in ClientSOcketjava.lang.NullPointerException
at java.awt.EventQueue.dispatchEvent(EventQueue.java: 599)
Error lock in ClientSocket java.lang.NullPointerException
at java.awt.EventDispatchThread.pumpOneEventForFilter s(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(E ventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarch y(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThre ad.java:122)
java.lang.NullPointerException
at sjdsuncertify.Socket.ClientSocket.lock(ClientSocke t.java:212)
at sjdsuncertify.GUI.MainGUI.btnDeleteActionPerformed (MainGUI.java:434)
at sjdsuncertify.GUI.MainGUI.access$400(MainGUI.java: 23)
at sjdsuncertify.GUI.MainGUI$5.actionPerformed(MainGU I.java:198)
at javax.swing.AbstractButton.fireActionPerformed(Abs tractButton.java:1995)
at javax.swing.AbstractButton$Handler.actionPerformed (AbstractButton.java:2318)
at javax.swing.DefaultButtonModel.fireActionPerformed (DefaultButtonModel.java:387)
at javax.swing.DefaultButtonModel.setPressed(DefaultB uttonModel.java:242)
at javax.swing.plaf.basic.BasicButtonListener.mouseRe leased(BasicButtonListener.java:236)
at java.awt.Component.processMouseEvent(Component.jav a:6267)
at javax.swing.JComponent.processMouseEvent(JComponen t.java:3267)
at java.awt.Component.processEvent(Component.java:603 2)
at java.awt.Container.processEvent(Container.java:204 1)
at java.awt.Component.dispatchEventImpl(Component.jav a:4630)
at java.awt.Container.dispatchEventImpl(Container.jav a:2099)
at java.awt.Component.dispatchEvent(Component.java:44 60)
at java.awt.LightweightDispatcher.retargetMouseEvent( Container.java:4577)
at java.awt.LightweightDispatcher.processMouseEvent(C ontainer.java:4238)
at java.awt.LightweightDispatcher.dispatchEvent(Conta iner.java:4168)
at java.awt.Container.dispatchEventImpl(Container.jav a:2085)
at java.awt.Window.dispatchEventImpl(Window.java:2478 )
at java.awt.Component.dispatchEvent(Component.java:44 60)
at java.awt.EventQueue.dispatchEvent(EventQueue.java: 599)
sending data over sockets
at java.awt.EventDispatchThread.pumpOneEventForFilter s(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(E ventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarch y(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThre ad.java:122)
Error connect in ClientSocketjava.net.ConnectException: Connection refused: connect
java.lang.NullPointerException
Error send in ClientSocket java.lang.NullPointerException
at sjdsuncertify.Socket.ClientSocket.send(ClientSocke t.java:303)
at sjdsuncertify.Socket.ClientSocket.delete(ClientSoc ket.java:145)
at sjdsuncertify.GUI.MainGUI.btnDeleteActionPerformed (MainGUI.java:434)
at sjdsuncertify.GUI.MainGUI.access$400(MainGUI.java: 23)
at sjdsuncertify.GUI.MainGUI$5.actionPerformed(MainGU I.java:198)
at javax.swing.AbstractButton.fireActionPerformed(Abs tractButton.java:1995)
at javax.swing.AbstractButton$Handler.actionPerformed (AbstractButton.java:2318)
at javax.swing.DefaultButtonModel.fireActionPerformed (DefaultButtonModel.java:387)
at javax.swing.DefaultButtonModel.setPressed(DefaultB uttonModel.java:242)
at javax.swing.plaf.basic.BasicButtonListener.mouseRe leased(BasicButtonListener.java:236)
at java.awt.Component.processMouseEvent(Component.jav a:6267)
at javax.swing.JComponent.processMouseEvent(JComponen t.java:3267)
at java.awt.Component.processEvent(Component.java:603 2)
at java.awt.Container.processEvent(Container.java:204 1)
at java.awt.Component.dispatchEventImpl(Component.jav a:4630)
at java.awt.Container.dispatchEventImpl(Container.jav a:2099)
at java.awt.Component.dispatchEvent(Component.java:44 60)
at java.awt.LightweightDispatcher.retargetMouseEvent( Container.java:4577)
at java.awt.LightweightDispatcher.processMouseEvent(C ontainer.java:4238)
at java.awt.LightweightDispatcher.dispatchEvent(Conta iner.java:4168)
at java.awt.Container.dispatchEventImpl(Container.jav a:2085)
at java.awt.Window.dispatchEventImpl(Window.java:2478 )
at java.awt.Component.dispatchEvent(Component.java:44 60)
at java.awt.EventQueue.dispatchEvent(EventQueue.java: 599Error disconnect in ClientSOcketjava.lang.NullPointerException
)
at java.awt.EventDispatchThread.pumpOneEventForFilter s(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(E ventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarch y(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThre ad.java:122)
Error in findRecord java.io.EOFException
Error in getFileRecords java.lang.NullPointerException

I do realise that this could be because my laptop wont let me run the socket on the one computer.

[Tolls]

Error send in ClientSocket java.lang.NullPointerException
at sjdsuncertify.Socket.ClientSocket.send(ClientSocke t.java:303)

Somethign on that line is null.

Considering prior to this you have:
Error connect in ClientSocketjava.net.ConnectException: Connection refused: connect

I'm guessing it's your connection object.

[80mins]

i am currently trying to run it on another computer.

[80mins]

after looking more into this problem.

I have descovered the reason for everything starts with my find record method. which is throwing a EOFException. on line 7.

 private Record findRecord(long locationInFile, RandomAccessFile raf)
    throws IOException{
       final byte[] input = new byte[Record.TOTAL_LENGTH];

       Record returned = null;

       try{
           
           raf.seek(locationInFile);
           System.out.println("input = " + input);
           raf.readFully(input);
           
           
           
           
              
       class InputReader{
           private int offset = 0;
           
           String read(int length) throws UnsupportedEncodingException{
               String newString = new String(input, offset, length);
               
               offset += length;
               return newString.trim();
           }
       }
           InputReader inputReader = new InputReader();

           String name = inputReader.read(Record.LENGTH_NAME);
           String location = inputReader.read(Record.LENGTH_LOCATION);
           String specialties = inputReader.read(Record.LENGTH_SPECIALTIES);
           int size = Integer.parseInt(inputReader.read(Record.LENGTH_SIZE));
           String rate = inputReader.read(Record.LENGTH_RATE);
           String owner = inputReader.read(Record.LENGTH_OWNER);
           
       
           returned  = new Record(recNo, name, location, specialties, size,
                       rate, owner);
       }
       catch(Exception ex){
           System.out.println("Error in findRecord  " + ex.toString());
           System.out.println("location in file: " + locationInFile);
           System.out.println("input = " + input);
       }
           return returned;
   }

I need a way to tell the computer that it should stop reading as the database is at the end of the file.

the output of this code is.

run:
Running ok
Sent location to propertiesC:\Users\Julian Cassidy\Desktop\db-2x2.db
input = [B@148cc8c
input = [B@152544e
input = [B@1cdeff
input = [B@17471e0
input = [B@1e04cbf
input = [B@cec0c5
input = [B@1d2068d
input = [B@1ac2f9c
input = [B@169ca65
input = [B@66e815
input = [B@ece65
input = [B@106082
input = [B@1301ed8
input = [B@3901c6
input = [B@a37368
input = [B@edc3a2
input = [B@1c6f579
input = [B@11ddcde
input = [B@18fb1f7
input = [B@ed0338
input = [B@6e70c7
input = [B@ae506e
input = [B@228a02
input = [B@192b996
input = [B@1d63e39
input = [B@8f4fb3
input = [B@b988a6
input = [B@ba6c83
input = [B@12a1e44
Error in findRecord  java.io.EOFException
location in file: 5221
input = [B@12a1e44
Error in getFileRecords java.lang.NullPointerException
Error connect in ClientSocketjava.net.ConnectException: Connection refused: connect
BUILD SUCCESSFUL (total time: 19 seconds)

So my question is,
is there a way to tell the computer to stop trying to read when it reaches the end of file.

[Tolls]

Print stack traces!

       catch(Exception ex){
           System.out.println("Error in findRecord  " + ex.toString());
           System.out.println("location in file: " + locationInFile);
           System.out.println("input = " + input);
       }

This is losing you so much information.
Like where this is being thrown from.

And when you know that then you can highlight the line for us.