Code:

import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.SQLException;

public class JDBCExample {

	public static void main(String[] argv) {

		System.out.println("-------- PostgreSQL "
				+ "JDBC Connection Testing ------------");

		try {

			Class.forName("org.postgresql.Driver");

		} catch (ClassNotFoundException e) {

			System.out.println("Where is your PostgreSQL JDBC Driver? "
					+ "Include in your library path!");
			e.printStackTrace();
			return;

		}

		System.out.println("PostgreSQL JDBC Driver Registered!");

		Connection connection = null;

		try {

			connection = DriverManager.getConnection(
					"jdbc:postgresql://127.0.0.1:5432/pim", "postgres",
					"pass");

		} catch (SQLException e) {

			System.out.println("Connection Failed! Check output console");
			e.printStackTrace();
			return;

		}

		if (connection != null) {
			System.out.println("You made it, take control your database now!");
		} else {
			System.out.println("Failed to make connection!");
		}
	}

}

Output:

saurabh@linux-jt69:~/PIM> classpath=postgresql-9.0-801.jdbc3.jar
saurabh@linux-jt69:~/PIM> export classpath
saurabh@linux-jt69:~/PIM> echo $classpath
postgresql-9.0-801.jdbc3.jar
saurabh@linux-jt69:~/PIM> javac JDBCExample.java
saurabh@linux-jt69:~/PIM> ls
JDBCExample.class             Personal Information Manager.zip
JDBCExample.java              postgresql-9.0-801.jdbc3.jar
Personal Information Manager
saurabh@linux-jt69:~/PIM> java JDBCExample
-------- PostgreSQL JDBC Connection Testing ------------
Where is your PostgreSQL JDBC Driver? Include in your library path!
java.lang.ClassNotFoundException: org.postgresql.Driver
	at java.net.URLClassLoader$1.run(URLClassLoader.java:217)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
	at java.lang.Class.forName0(Native Method)
	at java.lang.Class.forName(Class.java:186)
	at JDBCExample.main(JDBCExample.java:14)