Thread: java.lang.NullPointerException

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Forgive me if this is the wrong mailing list for this, but it seemed the
most appropriate.

I've got a database up and running under PostgreSQL called kwn.  When I
try to use the following Java code to connect to it:

    try {
      Class.forName("postgresql.Driver");
    }
    catch (Exception e) {
      System.out.println(e);
    }

    postgresql.Connection conn = null;

    try {
      conn =
(postgresql.Connection)DriverManager.getConnection("jdbc:postgresql:kwn");
    }
    catch (Exception e) {
      System.out.println(e);
      e.printStackTrace();
    }

I get the following stack trace from the second try block:

java.lang.NullPointerException:
java.lang.NullPointerException:
        at java.lang.String.<init>(String.java)
        at postgresql.Connection.<init>(Connection.java:71)
        at postgresql.Driver.connect(Driver.java:87)
        at java.sql.DriverManager.getConnection(DriverManager.java:91)
        at java.sql.DriverManager.getConnection(DriverManager.java:149)
        at CookBook.<init>(CookBook.java:165)
        at CookBook.main(CookBook.java:335)

==============================================================================

The program was compiled with the command line:

javac -d . -classpath /usr/share/java/postgresql.jar:/usr/lib/jdk-1.1.3/classes.zip:. test.java

and my CLASSPATH env variable is:
/usr/lib/jdk-1.1.3/lib/classes.zip:/usr/share/java/postgresql.jar:.

As far as I can tell, the Class.forName() call doesn't throw any
exceptions.

Ideas, hints or suggestions greatly appreciated.

Kevin

- --
Kevin Nikiforuk                    knikifor@gpu.srv.ualberta.ca
- ----------------------------------------------------------------------------
    http://pgp5.ai.mit.edu/pks-commands-beta.html for my PGP public key

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On Wed, 20 May 1998, Kevin W. Nikiforuk wrote:

>     try {
>       conn =
> (postgresql.Connection)DriverManager.getConnection("jdbc:postgresql:kwn");
>     }
>     catch (Exception e) {
>       System.out.println(e);
>       e.printStackTrace();
>     }

I managed to correct the problem by changing the argument passed to
getConnection() to:

"jdbc:postgresql:kwn", "kwn", ""

where kwn is my userid on my Linux box.

Kevin

- --
Kevin Nikiforuk                    knikifor@gpu.srv.ualberta.ca
- ----------------------------------------------------------------------------
    http://pgp5.ai.mit.edu/pks-commands-beta.html for my PGP public key

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