Re: JDBC Emit SQLError code for communication errors

Please consider this version of the patch. The extra cases
(postgresql.stream.ioerror:An I/O error occurred while reading from
backend) also should result in "08S01"s.

I left postgresql.updateable.ioerror:Input Stream Error as the "08S01"
does not seem completely appropriate for those.

Regards,
Fernando

Fernando Nasser wrote:
> Applications can't rely on the text of the SQLException error message to
> detect that there was a communication error as it is localized (and
> error messages are prone to change anyway). So, a JDBC application
> cannot take the appropriate actions when an IO error occurs.
>
> This patch makes the JDBC driver report an eof and other communication
> errors using the standard SQLSTATE value:
>
> "08S01" (connection exception-communication link failure)
>
> which can be safely tested for in applications. Without this patch we
> get null, instead of the "08S01" string, when calling getSQLState() as
> the driver never sets that value.
>
> The behavior of applications when we lose connection with the backend is
> currently very bad, as there is no way to distinguish this problem from
> a regular SQL error.
>
>
> ------------------------------------------------------------------------
>
> Index: src/interfaces/jdbc/org/postgresql/PG_Stream.java
> ===================================================================
> RCS file: /projects/cvsroot/pgsql-server/src/interfaces/jdbc/org/postgresql/PG_Stream.java,v
> retrieving revision 1.17
> diff -c -p -r1.17 PG_Stream.java
> *** src/interfaces/jdbc/org/postgresql/PG_Stream.java 2002/08/20 04:26:02 1.17
> --- src/interfaces/jdbc/org/postgresql/PG_Stream.java 2002/11/19 22:21:33
> *************** public class PG_Stream
> *** 137,143 ****
> {
> c = pg_input.read();
> if (c < 0)
> ! throw new PSQLException("postgresql.stream.eof");
> }
> catch (IOException e)
> {
> --- 137,143 ----
> {
> c = pg_input.read();
> if (c < 0)
> ! throw new PSQLException("postgresql.stream.eof", "08S01");
> }
> catch (IOException e)
> {
> *************** public class PG_Stream
> *** 164,170 ****
> int b = pg_input.read();
>
> if (b < 0)
> ! throw new PSQLException("postgresql.stream.eof");
> n = n | (b << (8 * i)) ;
> }
> }
> --- 164,170 ----
> int b = pg_input.read();
>
> if (b < 0)
> ! throw new PSQLException("postgresql.stream.eof", "08S01");
> n = n | (b << (8 * i)) ;
> }
> }
> *************** public class PG_Stream
> *** 193,199 ****
> int b = pg_input.read();
>
> if (b < 0)
> ! throw new PSQLException("postgresql.stream.eof");
> n = b | (n << 8);
> }
> }
> --- 193,199 ----
> int b = pg_input.read();
>
> if (b < 0)
> ! throw new PSQLException("postgresql.stream.eof", "08S01");
> n = b | (n << 8);
> }
> }
> *************** public class PG_Stream
> *** 227,233 ****
> {
> int c = pg_input.read();
> if (c < 0)
> ! throw new PSQLException("postgresql.stream.eof");
> else if (c == 0)
> {
> rst[s] = 0;
> --- 227,233 ----
> {
> int c = pg_input.read();
> if (c < 0)
> ! throw new PSQLException("postgresql.stream.eof", "08S01");
> else if (c == 0)
> {
> rst[s] = 0;
> *************** public class PG_Stream
> *** 330,336 ****
> {
> int w = pg_input.read(b, off + s, siz - s);
> if (w < 0)
> ! throw new PSQLException("postgresql.stream.eof");
> s += w;
> }
> }
> --- 330,336 ----
> {
> int w = pg_input.read(b, off + s, siz - s);
> if (w < 0)
> ! throw new PSQLException("postgresql.stream.eof", "08S01");
> s += w;
> }
> }
> Index: src/interfaces/jdbc/org/postgresql/core/QueryExecutor.java
> ===================================================================
> RCS file: /projects/cvsroot/pgsql-server/src/interfaces/jdbc/org/postgresql/core/QueryExecutor.java,v
> retrieving revision 1.17
> diff -c -p -r1.17 QueryExecutor.java
> *** src/interfaces/jdbc/org/postgresql/core/QueryExecutor.java 2002/11/14 05:35:45 1.17
> --- src/interfaces/jdbc/org/postgresql/core/QueryExecutor.java 2002/11/19 22:21:33
> *************** public class QueryExecutor
> *** 156,162 ****
> }
> catch (IOException e)
> {
> ! throw new PSQLException("postgresql.con.ioerror", e);
> }
> }
>
> --- 156,162 ----
> }
> catch (IOException e)
> {
> ! throw new PSQLException("postgresql.con.ioerror", "08S01", e);
> }
> }
>
> Index: src/interfaces/jdbc/org/postgresql/util/PSQLException.java
> ===================================================================
> RCS file: /projects/cvsroot/pgsql-server/src/interfaces/jdbc/org/postgresql/util/PSQLException.java,v
> retrieving revision 1.7
> diff -c -p -r1.7 PSQLException.java
> *** src/interfaces/jdbc/org/postgresql/util/PSQLException.java 2001/11/19 22:33:39 1.7
> --- src/interfaces/jdbc/org/postgresql/util/PSQLException.java 2002/11/19 22:21:33
> *************** public class PSQLException extends SQLEx
> *** 21,26 ****
> --- 21,37 ----
> }
>
> /*
> + * Like the above, but sets SQLState
> + * @param error Error string
> + * @param sqlstate SQLState string
> + */
> + public PSQLException(String error, String sqlstate)
> + {
> + super("", sqlstate);
> + translate(error, null);
> + }
> +
> + /*
> * A more generic entry point.
> * @param error Error string or standard message id
> * @param args Array of arguments
> *************** public class PSQLException extends SQLEx
> *** 50,55 ****
> --- 61,95 ----
> public PSQLException(String error, Exception ex)
> {
> super();
> +
> + Object[] argv = new Object[1];
> +
> + try
> + {
> + ByteArrayOutputStream baos = new ByteArrayOutputStream();
> + PrintWriter pw = new PrintWriter(baos);
> + pw.println("Exception: " + ex.toString() + "\nStack Trace:\n");
> + ex.printStackTrace(pw);
> + pw.println("End of Stack Trace");
> + pw.flush();
> + argv[0] = baos.toString();
> + pw.close();
> + baos.close();
> + }
> + catch (Exception ioe)
> + {
> + argv[0] = ex.toString() + "\nIO Error on stack trace generation! " + ioe.toString();
> + }
> +
> + translate(error, argv);
> + }
> +
> + /*
> + * Like the above, but sets the SQLState
> + */
> + public PSQLException(String error, String sqlstate, Exception ex)
> + {
> + super("", sqlstate);
>
> Object[] argv = new Object[1];
>
>
>
> ------------------------------------------------------------------------
>
>
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--
Fernando Nasser
Red Hat Canada Ltd. E-Mail: fnasser(at)redhat(dot)com
2323 Yonge Street, Suite #300
Toronto, Ontario M4P 2C9