Thread: Catching postgres exceptions - functions returning error values?
What would be the preffered way of catching postgres exceptions within
Java code?
For instance, I have an application where user types in database name
he/she wishes to connect to. So, when user enters the database name, I
try to connect to it. If that database does not exists, I'm thrown an
exception, something like this:
org.postgresql.util.PSQLException: Backend start-up failed:
org.postgresql.util.PSQLException: FATAL: database "testdb" does not
exist
Now, if the database server is unavailable, I get something like this:
org.postgresql.util.PSQLException: Connection refused. Check that the
hostname and port are correct and that the postmaster is accepting
TCP/IP connections.
I would like to know, in my code, what happened, and inform user
apropriatley, I don't want just to print the exception to the user.
I could parse the return from printStackTrace method, but that just
doesn't seem right.
Also, some of the functions need to return errorcode of some sort. If
the function is returning SETOF, I can't use OUT parametars. So, I'm
asking for a recomendation here.
I'm using postgres 8.1 with latest JDBC driver.
Thank you in advance,
Mario
--
Mario Splivalo
Mob-Art
mario.splivalo@mobart.hr
"I can do it quick, I can do it cheap, I can do it well. Pick any two."
Mario Splivalo <mario.splivalo@mobart.hr> writes: > Now, if the database server is unavailable, I get something like this: > > org.postgresql.util.PSQLException: Connection refused. Check that the > hostname and port are correct and that the postmaster is accepting > TCP/IP connections. > > I would like to know, in my code, what happened, and inform user > apropriatley, I don't want just to print the exception to the user. What would like to substitute to the above message for instance? Is this just a language issue? > I could parse the return from printStackTrace method, but that just > doesn't seem right. > > Also, some of the functions need to return errorcode of some sort. If > the function is returning SETOF, I can't use OUT parametars. So, I'm > asking for a recomendation here. Maybe you want to use the SQLState http://www.postgresql.org/docs/8.1/interactive/errcodes-appendix.html http://www.easysoft.com/developer/interfaces/odbc/sqlstate_status_return_codes.html http://msdn.microsoft.com/library/default.asp?url=/library/en-us/odbc/htm/odbcodbc_error_codes.asp http://www.opengroup.org/bookstore/catalog/c451.htm (appendix A) http://www.opengroup.org/bookstore/catalog/c449.htm (appendix B)
On Wed, 2006-08-30 at 18:27 +0200, Marc Herbert wrote: > > Also, some of the functions need to return errorcode of some sort. If > > the function is returning SETOF, I can't use OUT parametars. So, I'm > > asking for a recomendation here. > > Maybe you want to use the SQLState > > http://www.postgresql.org/docs/8.1/interactive/errcodes-appendix.html > > http://www.easysoft.com/developer/interfaces/odbc/sqlstate_status_return_codes.html > http://msdn.microsoft.com/library/default.asp?url=/library/en-us/odbc/htm/odbcodbc_error_codes.asp > > http://www.opengroup.org/bookstore/catalog/c451.htm (appendix A) > http://www.opengroup.org/bookstore/catalog/c449.htm (appendix B) > Thank you! :) Although I've found out that errcodes-appendix.html from postgresql manual doesn't contain some errors, for instance: org.postgresql.util.PSQLException: Connection refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections. at org.postgresql.jdbc1.AbstractJdbc1Connection.openConnection(AbstractJdbc1Connection.java:204) at org.postgresql.Driver.connect(Driver.java:139) at java.sql.DriverManager.getConnection(DriverManager.java:525) at java.sql.DriverManager.getConnection(DriverManager.java:171) at Example1.main(Example1.java:31) -------------------------- Message: Connection refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections. SQLState: 08004 ErrorCode: 0 This, 08004 is not listed there. Then, if I throw some 'custom' exception from postgres (using plpgsql RAISE EXCEPTION), I'll get SQLState code P0001 from getSQLState(). If I want to know what realy happened, I need to parse what getMessage() returns. Is there another way? Mario -- Mario Splivalo Mob-Art mario.splivalo@mobart.hr "I can do it quick, I can do it cheap, I can do it well. Pick any two."