Hello all, THE GENERAL PROBLEM I am a novice in programming with GWT and I started developing a test application which communicates with the server side via GWT-RPC . The servlet in turn tries to establish a connection with a Derby Database. But, however, no matter which mode the servlet uses - either embedded or client/server mode - nothing works. If the servlet tries to communicate with the Apache Derby Database in embedded mode, it gets the following exception stack: ... Caused by: java.lang.NoClassDefFoundError: java.io.FileOutputStream is a restricted class. Please see the Google App Engine developer's guide for more details. ... If it tries to communicate with the Apache Derby Database in client/server mode, it gets the following exception stack: ... Caused by: java.lang.NoClassDefFoundError: javax.net.SocketFactory is a restricted class. Please see the Google App Engine developer's guide for more details. ... MY LOCAL CONFIGURATION Operating System: Windows 7 JDK: Jdk1.6.0_21 IDE: Eclipse Java EE 3.6 (Helios) GWT Version: 2.3 Derby DB Version: 10.8.1.2 My CODE SNIPPET In order to formulate database requests I decided to use JDBC (4.0 or higher). I did not explicitely initialize the according database driver, since I am using JDK 6. The code snippet looks like the following: // .implement --------------------------------------------------------------- ... public UserAccount[] retrieveAllUserAccounts () throws WrapperException { // Get database connection ------------------------------------------------ Connection l_sConn = null; try { // l_sConn = DriverManager.getConnection ("jdbc:derby:D:\\db-derby-10.8.1.2-bin\\DERBYTUTOR\\userManagement"); l_sConn = DriverManager.getConnection("jdbc:derby://localhost:1527/userManagement"); } catch (SQLException ex) { // // Try to make a shutdown and throw exception again --------------------- // try // { // DriverManager.getConnection ("jdbc:derby:;shutdown=true"); // } // catch (SQLException se) // {}
throw new WrapperException (ex.getMessage (), ex.getStackTrace().toString (), ex.getCause ().getMessage()); }
try { // perform SELECT statement ----------------------------------------------- Statement l_selectStatement = l_sConn.createStatement(); ResultSet l_setOfUsers = l_selectStatement.executeQuery ("select * from USERACCOUNTS"); List<UserAccount> l_lUserAccounts = new ArrayList<UserAccount>();
while (l_setOfUsers.next()) { UserAccount l_boUserAccount = new UserAccount (l_setOfUsers.getString (1), l_setOfUsers.getString (2), l_setOfUsers.getString (3));
l_lUserAccounts.add (l_boUserAccount); }
// release resources and return ------------------------------------------- l_selectStatement.close (); l_setOfUsers .close (); l_sConn .close ();
// { // DriverManager.getConnection("jdbc:derby:;shutdown=true"); // } // catch (SQLException se) // { // if (! se.getSQLState ().equals ("XJ015")) // { // throw se; // } // }
} catch (SQLException ex) { throw new WrapperException (ex.getMessage (), ex.getStackTrace ().toString (), ex.getCause ().getMessage ()); }
} // End Method retrieveAllUserAccounts ------------------------------------- -- You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-web-toolkit?hl=en. |
ExceptionStack_ClientServer_Mode.txt
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ExceptionStack_Embedded_Mode.txt
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