how to register an error ?

[Bob Matthews]

Hi

Output as expected:-
File Name: C:/Dukascopylog/USD_JPY 2019_7_10_2.txt
DOW: 4, Hour: 2
date_current: 2019-7-10; time_current: 2
Open_price: 108.901
High_price: 108.933
Low_price: 108.883
Close_price: 108.899
DerbyApp starting in embedded mode
Loaded the appropriate driver
Connected to database C:/Users/aaaa/us_copiosus_USDJPY_1525
Number of records in table HOURLY_HISTORY: 21922
Number of records in table PROTOTYPES: 3823
***********************************************************
Output - not as expected
File Name: C:/Dukascopylog/GBP_CHF 2019_7_10_2.txt
DOW: 4, Hour: 2
date_current: 2019-7-10; time_current: 2
Open_price: 1.23774
High_price: 1.23786
Low_price: 1.23721
Close_price: 1.23721
DerbyApp starting in embedded mode
Loaded the appropriate driver
**********************************************************

private class DerbyApp {

        /* the default framework is embedded*/
        private String framework = "embedded";
        private String driver = "org.apache.derby.jdbc.EmbeddedDriver";
        private String protocol = "jdbc:derby:";

        @SuppressWarnings("UnusedAssignment")
        void go(String[] args_derby) {

            /* parse the arguments to determine which framework is desired*/
            parseArguments(args_derby);

            fw.writetoFile(("DerbyApp starting in " + framework + " mode"), File_Name);

            /* load the desired JDBC driver */
            loadDriver();

            ArrayList statements = new ArrayList(); // list of Statements, PreparedStatements
            @SuppressWarnings("UnusedAssignment")
            PreparedStatement ps = null;
            @SuppressWarnings("UnusedAssignment")
            PreparedStatement psInsert = null;
            @SuppressWarnings("UnusedAssignment")
            PreparedStatement psUpdate = null;
            PreparedStatement psDelete = null;

            fw.writetoFile(("DerbyApp starting in " + framework + " mode"), File_Name);

            try {
                Properties props = new Properties(); // connection properties
                // providing a user name and password is optional in the embedded and derbyclient frameworks
                props.put("user", "xxxBobM");
                props.put("password", "yyyy");

                
                String dbName = "C:/Users/zzzz/us_copiosus_NZDUSD_1525"; // the name of the database

                conn = DriverManager.getConnection(protocol + dbName, props);

                fw.writetoFile(("Connected to database " + dbName), File_Name);

The above code is used to connect to an Apache derby database

In the first output above, all is well
But in the second example - output is halted with no line saying "Connected to database................

BUT I don't get any error messages ???

How do I find out what is going wrong ?

Bob M

[Dave Tolls]

That output does not match the logging lines in the code.
In the code you have two lines that output "DerbyApp starting in...", both of which have to come out if the loadDriver call works (and it has in both).

That they haven't come out in either runs indicates that the code provided is not hte cod that was executed to produce that output.

[Bob Matthews]

Apologies...............

I had deleted the second occurrance of the same line

Bob M

[Campbell Ritchie]

Bob Matthews wrote: . . . I had deleted the second occurrance of the same line . . .

Please don't; editing posts after a response can make the reponse look like nonsense. I shall reinstate the missing line.

[Bob Matthews]

as a further confusing issue..............

After a reboot, the output may come right again

It may last for 1 or 2 or 3 hours (the program activates on the hour) but then we go back to restricted output again

Bob M

[Dave Tolls]

So can you post the actual code, and the output?
As a new post (don't edit the first post).

That way we can see exactly where it thinks it is going wrong.
As it stands I cannot tell what is happening at all.

Also, can you include in that the whole of the try/catch/finally block, not just the first bit of the try part?

[Bob Matthews]

private class DerbyApp {

        /* the default framework is embedded*/
        private String framework = "embedded";
        private String driver = "org.apache.derby.jdbc.EmbeddedDriver";
        private String protocol = "jdbc:derby:";

        @SuppressWarnings("UnusedAssignment")
        void go(String[] args_derby) {

            /* parse the arguments to determine which framework is desired*/
            parseArguments(args_derby);

            fw.writetoFile(("DerbyApp starting in " + framework + " mode"), File_Name);

            /* load the desired JDBC driver */
            loadDriver();

            ArrayList statements = new ArrayList(); // list of Statements, PreparedStatements
            @SuppressWarnings("UnusedAssignment")
            PreparedStatement ps = null;
            @SuppressWarnings("UnusedAssignment")
            PreparedStatement psInsert = null;
            @SuppressWarnings("UnusedAssignment")
            PreparedStatement psUpdate = null;
            PreparedStatement psDelete = null;

            try {
                Properties props = new Properties(); // connection properties
                // providing a user name and password is optional in the embedded and derbyclient frameworks
                props.put("user", "xxx");
                props.put("password", "yyy");

                /* By default, the schema APP will be used when no username is provided.
                 * Otherwise, the schema name is the same as the user name (in this
                 * case "user1" or USER1.)
                 *
                 * Note that user authentication is off by default, meaning that any
                 * user can connect to your database using any password. To enable
                 * authentication, see the Derby Developer's Guide.
                 */
                String dbName = "C:/Users/.../USDJPY..."; // the name of the database

                conn = DriverManager.getConnection(protocol + dbName, props);

                fw.writetoFile(("Connected to database " + dbName), File_Name);

                // We want to control transactions manually. Autocommit is on by
                // default in JDBC.
                conn.setAutoCommit(false);

                /* Creating a statement object that we can use for running various
                * SQL statements commands against the database.*/
                s = conn.createStatement();
                statements.add(s);

                // get the number of records in the Hourly_History table
                rs = s.executeQuery("SELECT COUNT(*) FROM HOURLY_HISTORY");
                rs.next();
                int Count_Table1 = rs.getInt(1);
                // get the number of records in the Prototypes table
                rs = s.executeQuery("SELECT COUNT(*) FROM PROTOTYPES");
                rs.next();
                int Count_Table2 = rs.getInt(1);

                fw.writetoFile(("Number of records in table HOURLY_HISTORY: " + Count_Table1), File_Name);
                fw.writetoFile(("Number of records in table PROTOTYPES: " + Count_Table2), File_Name);

//******************************************************************************
                herein lies several lines of code - calculations etc
		several records in database are updated...
//************************************************************************
                if (framework.equals("embedded")) {
                    try {
                    // the shutdown=true attribute shuts down Derby
                        DriverManager.getConnection("jdbc:derby:;shutdown=true");
                    } catch (SQLException se) {
                        if (((se.getErrorCode() == 50000)
                                && ("XJ015".equals(se.getSQLState())))) {
                            // we got the expected exception
                            myConsole.getOut().println("Derby shut down normally");
                            fw.writetoFile(("Derby shut down normally"), File_Name);

                            // Note that for single database shutdown, the expected
                            // SQL state is "08006", and the error code is 45000.
                        } else {
                            // if the error code or SQLState is different, we have
                            // an unexpected exception (shutdown failed)
                            myConsole.getOut().println("Derby did not shut down normally");
                            fw.writetoFile(("Derby did not shut down normally"), File_Name);

                            printSQLException(se);
                        }
                    }
                }
            } catch (SQLException e) {
                e.printStackTrace();
            } finally {
                // release all open resources to avoid unnecessary memory usage

                // ResultSet
                try {
                    if (rs != null) {
                        rs.close();
                        rs = null;
                    }
                } catch (SQLException sqle) {
                    printSQLException(sqle);
                }

                // Statements and PreparedStatements
                int i = 0;
                while (!statements.isEmpty()) {
                    // PreparedStatement extend Statement
                    Statement st = (Statement) statements.remove(i);
                    try {
                        if (st != null) {
                            st.close();
                            st = null;
                        }
                    } catch (SQLException sqle) {
                        printSQLException(sqle);
                    }
                }

                //Connection
                try {
                    if (conn != null) {
                        conn.close();
                        conn = null;
                    }
                } catch (SQLException sqle) {
                    printSQLException(sqle);
                }
            }
        } // end of go args-derby

        private void loadDriver() {
            try {
                Class.forName(driver).newInstance();
                fw.writetoFile(("Loaded the appropriate driver"), File_Name);
            } catch (ClassNotFoundException cnfe) {
                fw.writetoFile(("\nUnable to load the JDBC driver " + driver), File_Name);
                fw.writetoFile(("Please check your CLASSPATH."), File_Name);
                cnfe.printStackTrace(System.err);
            } catch (InstantiationException ie) {
                fw.writetoFile(("\nUnable to instantiate the JDBC driver " + driver), File_Name);
                ie.printStackTrace(System.err);
            } catch (IllegalAccessException iae) {
                fw.writetoFile(("\nNot allowed to access the JDBC driver " + driver), File_Name);
                iae.printStackTrace(System.err);
            }
        } // end of loadDriver

        /**
         * Reports a data verification failure to System.err with the given
         * message.
         *
         * @param message A message describing what failed.
         */
        private void reportFailure(String message) {
            fw.writetoFile(("\nData verification failed:"), File_Name);
            fw.writetoFile(('\t' + message), File_Name);
        } // end of reportFailure

        /**
         * Prints details of an SQLException chain to <code>System.err</code>.
         * Details included are SQL State, Error code, Exception message.
         *
         * @param e the SQLException from which to print details.
         */
        private void printSQLException(SQLException e) {
        // Unwraps the entire exception chain to unveil the real cause of the Exception
            while (e != null) {
                fw.writetoFile(("\n----- SQLException -----"), File_Name);
                fw.writetoFile((" SQL State: " + e.getSQLState()), File_Name);
                fw.writetoFile((" Error Code: " + e.getErrorCode()), File_Name);
                fw.writetoFile((" Message: " + e.getMessage()), File_Name);
                // for stack traces, refer to derby.log or uncomment this: 
                e.printStackTrace(System.err);
                e = e.getNextException();
            }
        } // end of print SQLException

        private void parseArguments(String[] args_derby) {
            if (args_derby.length > 0) {
                if (args_derby[0].equalsIgnoreCase("derbyclient")) {
                    framework = "derbyclient";
                    driver = "org.apache.derby.jdbc.ClientDriver";
                    protocol = "jdbc:derby://localhost:1527/";
                }
            }
        } // end of parseArguments
    } // end of class DerbyApp

Example of output - good !
File Name: C:/Dukascopylog/USD_JPY 2019_7_10_2.txt
DOW: 4, Hour: 2
date_current: 2019-7-10; time_current: 2
Open_price: 108.901
High_price: 108.933
Low_price: 108.883
Close_price: 108.899
DerbyApp starting in embedded mode
Loaded the appropriate driver
Connected to database C:/Users/zzzzUSDJPY.....
Number of records in table HOURLY_HISTORY: 220
Number of records in table PROTOTYPES: 38
then follows evidence of calculations being done and database records being updated

Example of output - not good !
File Name: C:/Dukascopylog/GBP_CHF 2019_7_10_2.txt
DOW: 4, Hour: 2
date_current: 2019-7-10; time_current: 2
Open_price: 1.23774
High_price: 1.23786
Low_price: 1.23721
Close_price: 1.23721
DerbyApp starting in embedded mode
Loaded the appropriate driver

Bob M