Thx for ur reply, how long u hav been using derby ??
On 2/19/08, musky <[EMAIL PROTECTED]> wrote:
>
>
> i am using derby server itself like a chat server.
>
> i have two programs:they both have a main thread which creates a user
> interface.
> as the user(say bob) enters his messages to the other party(say
> alice),they
> are entered into a table say bobtable.
> there is a thread that is invoked periodically that reads unread messages
> from alicetable and displays them to bob and updates the messages as read
> by
> setting the ID field to 1.
>
> the same logic is for alice.
>
> here are the programs:
>
> bob:
> import java.util.Timer;
>
> import java.util.TimerTask;
> import java.sql.*;
>
> import org.eclipse.swt.*;
> import org.eclipse.swt.events.SelectionAdapter;
> import org.eclipse.swt.events.SelectionEvent;
> import org.eclipse.swt.widgets.*;
>
> import org.eclipse.swt.widgets.Button;
> import org.eclipse.swt.widgets.Display;
> import org.eclipse.swt.widgets.Shell;
> import org.eclipse.swt.widgets.Text;
> public class TestTime {
> DBClass dbobject1=new DBClass();
> static MainClass mc;
> static Statement stmt;
> static Connection conn=null;
> PreparedStatement pstmt=null;
> static PreparedStatement pstmt1=null;
>
> ResultSet rs=null;
> ResultSet rs1=null;
>
> static Display d;
> static Shell s;
> static Button OK;
>
> //int id=0;
>
> public static void main(String[] args) throws Exception {
> TestTime t = new TestTime();
>
>
> DBClass dbobject1=new DBClass();
> conn=dbobject1.createConnection("ChatDB1");
> conn.setAutoCommit(false);
> t.stmt = conn.createStatement();
> t.execute();
> //mc=new MainClass();
>
> d = new Display( );
> s = new Shell(d);
> s.setSize(250,250);
> s.setText("A Text Field Example");
>
> final Text text1 = new Text(s, SWT.MULTI | SWT.BORDER);
> text1.setBounds(0,0,250,150);
> OK = new Button(s, SWT.PUSH);
> OK.setBounds(80,170,75,40);
> OK.setText("OK");
> OK.addSelectionListener(new SelectionAdapter( ) {
> public void widgetSelected(SelectionEvent e)
> {
> String contents = text1.getText( );
> text1.setText("");
>
>
>
> System.out.println("Push Me Was Pushed");
> //System.out.println(contents);
> try
> {
> //stmt.executeUpdate("lock table bobtable in exclusive
> mode");
> pstmt1 = conn.prepareStatement("insert into bobtable
> values(?,?)");
> pstmt1.setInt(1,0);
> pstmt1.setString(2,contents);
>
> pstmt1.executeUpdate();
> System.out.println("inserted "+contents+" into bobtable");
> }
> catch(Exception e1)
> {System.out.println("could not insert"+e1);}
>
> }
>
> });
>
>
> s.open();
>
> while(!s.isDisposed( )){
> if(!d.readAndDispatch( ))
> d.sleep( );
> }
>
> System.out.println("Main Method is finishing");
>
> }
>
> private void execute() throws Exception {
> System.out.println(" Tasks scheduled");
> int initialDelay = 1000; // start after 30 seconds
> int period = 2000; // repeat every 5 seconds
> Timer timer = new Timer();
> System.out.println(" Timer set");
>
> DBClass dbobject2=new DBClass();
> final Connection conn2=dbobject2.createConnection("ChatDB1");
> conn2.setAutoCommit(false);
> stmt = conn2.createStatement();
>
>
> //dbclass db=new dbclass();
>
> timer.scheduleAtFixedRate(new TimerTask ()
> {
> public void run()
> {
> //System.out.println("Task Run");
>
> //conn=dbobject1.createConnection("ChatDB1");
>
>
> try
> {
> //int id=mc.returnflag();
>
> //System.out.println(id);
> // System.out.println("Before ExecuteQuery");
>
> //stmt.executeUpdate("lock table alicetable in share mode");
>
> PreparedStatement pstmt=conn2.prepareStatement("select * from alicetable
> where TID=0");
> //pstmt.setInt(1,id);
>
> rs=pstmt.executeQuery();
> //stmt.executeUpdate("lock table alicetable in exclusive mode");
>
> stmt.executeUpdate("Update alicetable set TID=1 where TID=0");
> //rs1=pstmt.executeQuery();
>
>
> while(rs.next())
> {
> String str=rs.getString(2);
> int str2=rs.getInt(1);
> System.out.println(str2+" "+str);
> }
>
>
> }
>
> catch ( Exception e ) {System.out.println("mhjfdshmnjh "+e);}
>
> }
> }, initialDelay, period);
> }
> }
>
> alice:
> import java.util.Timer;
>
> import java.util.TimerTask;
> import java.sql.*;
>
> import org.eclipse.swt.*;
> import org.eclipse.swt.events.SelectionAdapter;
> import org.eclipse.swt.events.SelectionEvent;
> import org.eclipse.swt.widgets.*;
>
> import org.eclipse.swt.widgets.Button;
> import org.eclipse.swt.widgets.Display;
> import org.eclipse.swt.widgets.Shell;
> import org.eclipse.swt.widgets.Text;
> public class TestTime2 {
> DBClass dbobject1=new DBClass();
> static MainClass mc;
> Statement stmt;
> static Connection conn=null;
> PreparedStatement pstmt=null;
> static PreparedStatement pstmt1=null;
> static Text text1;
> ResultSet rs=null;
> ResultSet rs1=null;
>
> static Display d;
> static Shell s;
> static Button OK;
>
> //int id=0;
>
> public static void main(String[] args) throws Exception {
> TestTime2 t = new TestTime2();
>
>
> DBClass dbobject1=new DBClass();
> conn=dbobject1.createConnection("ChatDB1");
> conn.setAutoCommit(false);
> t.execute();
> //mc=new MainClass();
>
> d = new Display( );
> s = new Shell(d);
> s.setSize(250,250);
> s.setText("A Text Field Example");
>
> text1 = new Text(s, SWT.MULTI | SWT.BORDER);
> text1.setBounds(0,0,250,150);
> OK = new Button(s, SWT.PUSH);
> OK.setBounds(80,170,75,40);
> OK.setText("OK");
>
> OK.addSelectionListener(new SelectionAdapter( ) {
> public void widgetSelected(SelectionEvent e)
> {
> String contents = text1.getText( );
> text1.setText("");
>
>
>
> System.out.println("Push Me Was Pushed");
> //System.out.println(contents);
> try
> {
> pstmt1 = conn.prepareStatement("insert into alicetable
> values(?,?)");
> pstmt1.setInt(1,0);
> pstmt1.setString(2,contents);
>
> pstmt1.executeUpdate();
> System.out.println("inserted "+contents+" into alicetable");
> }
> catch(Exception e1)
> {System.out.println("could not insert"+e1);}
>
> }
>
> });
>
>
> s.open();
>
> while(!s.isDisposed( )){
> if(!d.readAndDispatch( ))
> d.sleep( );
> }
>
> System.out.println("Main Method is finishing");
>
> }
>
> private void execute() throws Exception {
> System.out.println(" Tasks scheduled");
> int initialDelay = 10000; // start after 30 seconds
> int period = 2000; // repeat every 5 seconds
> Timer timer = new Timer();
> System.out.println(" Timer set");
>
> DBClass dbobject2=new DBClass();
> final Connection conn2=dbobject2.createConnection("ChatDB1");
> conn2.setAutoCommit(false);
> stmt = conn2.createStatement();
> //dbclass db=new dbclass();
>
> timer.scheduleAtFixedRate(new TimerTask ()
> {
> public void run()
> {
> try
> {
> PreparedStatement pstmt=conn2.prepareStatement("select * from bobtable
> where
> TID=0");
> //pstmt.setInt(1,id);
>
> rs=pstmt.executeQuery();
> //stmt.executeUpdate("lock table bobtable in exclusive mode");
>
> stmt.executeUpdate("Update bobtable set TID=1 where TID=0");
> //rs1=pstmt.executeQuery();
>
>
> while(rs.next())
> {
> String str=rs.getString(2);
> int str2=rs.getInt(1);
> System.out.println(str2+" "+str);
> //text1.setText(str2+" "+str);
> }
>
>
> }
>
> catch ( Exception e ) {System.out.println("mhjfdshmnjh "+e);}
>
> }
> }, initialDelay, period);
> }
> }
>
> when i run both the programs:i get the following exception:mhjfdshmnjh
> java.sql.SQLTransactionRollbackException: A lock could not be obtained
> within the time requested
>
> please help me.
>
> regards.
> --
> View this message in context:
> http://www.nabble.com/Chat-program-using-derby-tp15561400p15561400.html
> Sent from the Apache Derby Users mailing list archive at Nabble.com.
>
>
--
! ! ! WACK ! ! !
