Thread

1. java.lang.NullPointerException

   Kevin W. Nikiforuk <kwn@sethanon.remote.ualberta.ca> — 1998-05-20T19:09:22Z

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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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2. Re: [GENERAL] java.lang.NullPointerException

   Kevin W. Nikiforuk <kwn@sethanon.remote.ualberta.ca> — 1998-05-20T21:37:57Z

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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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