Re: Something unusual has occured to cause the driver to fail. NullPointerException

Larry,

Shouldn't your connection URL be:

jdbc:postgresql://localhost:5432/testdb

instead of

jdbc:postgresql://localhost:5432?database=testdb

thanks,
--Barry

Larry Rogers wrote:
> Hi all,
>
> I'm having trouble opening a database connection to a test database on a
> fresh PostGreSQL 7.1.3 installation on RedHat 7.1 from the RPMs. I have a
> simple test class TestPostGreSQL that opens a connection, queries for all the
> rows in a table and prints the results to standard output. The driver file
> is in the same directory as the java class, which I execute using
>
> java -classpath .:jdbc7.1-1.2.jar TestPostGreSQL
>
> I get the following error message:
>
> Something unusual has occured to cause the driver to fail. Please report this
> exception: Exception: java.lang.NullPointerException
> Stack Trace:
> java.lang.NullPointerException
> at org.postgresql.Connection.openConnection(Connection.java:148)
> at org.postgresql.Driver.connect(Driver.java:122)
> at java.sql.DriverManager.getConnection(DriverManager.java:517)
> at java.sql.DriverManager.getConnection(DriverManager.java:177)
> at TestPostGreSQL.main(TestPostGreSQL.java:17)
> End of Stack Trace
>
> I created the database using
>
> createdb testdb
>
> and from psql created the table as
>
> create table Person (
> FirstName char(30) not null,
> LastName char(30) not null);
>
> then created the user and password and granted all permissions on the Person
> table.
>
> I start the server with
>
> postmaster -i
>
> to get TCP/IP support. The code for the test class is at the end of this
> message. Note that everything is commented out except for loading the driver
> and opening a connection. I have used JDBC successfully for months with
> Microsoft SQL Server, but I'm anxious to switch over to PostGreSQL!
>
> Thanks in advance for any help!
> Larry Rogers
>
> *****************************
>
> import java.sql.*;
> import java.util.Date;
>
> public class TestPostGreSQL {
>
> public static void main(String[] args) {
>
> final String driver = "org.postgresql.Driver";
> final String url = "jdbc:postgresql://localhost:5432?database=testdb";
> final String login = "TestUser";
> final String password = "TestPass";
> String sql = "SELECT * FROM Person";
>
> try {
> Class.forName(driver);
> Connection connection
> = DriverManager.getConnection(url, login, password);
> /*
>
> Statement statement = connection.createStatement();
> ResultSet result = statement.executeQuery(sql);
>
> while (result.next()) {
> System.out.println(result.getString("FirstName") + " " +
> result.getString("LastName"));
> }
> result.close();
> statement.close();
> */
> connection.close();
>
> } catch(SQLException e) {
> System.out.println(e);
> } catch(ClassNotFoundException e) {
> System.out.println(e);
> }
> }
> }
>
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