Connectivity issue-MySQL and Java

[Pragya]

Hi

There is a problem in JDBC connectivity.I have downloaded the JDBC

Connector/J for MySQL connectivity with java. I've changed the

CLASSPATH environment variable, made changes in the code and tried

and tested with several modifications. But it still doesn't work.

Here is the source code.

import java.sql.*;

public class Check
{
public static void main(String args[])
{
Connection conn=null;

try
{
String url="jdbc:mysql://localhost/example";
Class.forName("com.jdbc.mysql.Driver").newInstance ();
conn=DriverManager.getConnection(url);
System.out.println("Database connection established");
}
catch(Exception e)
{
System.out.println("Cannot connect to server");
}
finally
{
if(conn!=null)
{
try
{
conn.close();
System.out.println("Database connection terminated");
}
catch(Exception e)
{ }
}
}
}
}

It compiles and displays "Cannot connect to database" when run on the

command prompt.

Here are some specifications:

(1) My JDK is in C:\ drive
(2) MySQL is in Program Files.
(3) The Connector/J is in C:\jdk1.6.0_16\jre\lib\ext
The ext folder has the mysql-connector-java-5.1.10-bin.jar file.

Hence the CLASSPATH environment variable includes :

C:\jdk1.6.0_16\jre\lib\ext\mysql-connector-java-5.1.10-bin.jar

Please help me with this so that I can move on...

[FON]

Add this line to your code
and post all Exception here please:

catch(Exception e)
{
e.printStackTrace();
System.out.println("Cannot connect to server");
}


Maybe you must specify port like 3306
jdbc:mysql://localhost:3306/mydb

[Pragya]

Thanks

In which Exception block do I make the changes?
Making the changes you suggested within the paranthesis of the first exception and adding :3306 after local host didn't help. It still gives the same exception.

[masijade]

In all of them.

[Tolls]

Yes. Always print a stack trace, otherwise you're simply losing all the important exception information.

[Pragya]

Here's what comes on printing the stack trace :

java.lang.ClassNotFoundException : com.jdbc.mysql.Driver
at java.net.URLCClassLoader$1.run(URLClassLoader.java :200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net,URLClassLoader.findClass(URLClassLoader.j ava:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:3 07)
at sun.misc.Launcher$AppClassLoader.loadClass(Launche r.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:2 52)
at java.lang.ClassLoader.loadClassInternal(ClassLoade r.java:320)
at java.lang.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
at Check.main(Check.java:12)
Cannot connect to database
How do I verify whether SQL is running or not?

[Tolls]

The connector/J jar file isn't on your classpath.

[Pragya]

What should the classpath be so that Connector/J is included?

[masijade]

What should the classpath be so that Connector/J is included?

It should include the complete path to the Driver jarfile, of course.

[cjr9968]

Try moving the jar into your project directory.
If you're using netbeans you can just drag the .jar file under the "Libraries" folder in your project. That worked for me.