datasource for mysql

[divya kundapur]

Hi,

I m using struts1.2.9, tomcat 6 and mysql. I m trying to establish connection pooling and have done the following

in META-INF/context.xml

<Context path="" reloadable="false">
<Resource driverClassName="com.mysql.jdbc.Driver" maxActive="40" maxIdle="5" maxWait="5000" minEvictableIdleTimeMillis="30000" name="jdbc/mydB" password="root123" testOnBorrow="true" testWhileIdle="true" type="javax.sql.DataSource" url="jdbc:mysql://localhost:3306/test?autoReconnect=true&zeroDateTimeBehavior=convertToNull" username="root"/>
<WatchedResource>WEB-INF/web.xml</WatchedResource>
</Context>

wrote a java class

  
import java.io.*;
import javax.servlet.http.*;
import java.sql.*;
import javax.sql.DataSource;
import javax.naming.*;


public class DbConnection
{
    private static DbConnection dbConn  = null;
    private static DataSource ds  = null;

    public static DbConnection getInstance()
    {
        if(dbConn == null)
        {
            dbConn = new DbConnection();
        }
        return dbConn;
    }

    public static void setDataSource(String dataSource) throws NamingException
	{
		Context init = new InitialContext();
		Context ctx = (Context)init.lookup("java:comp/env/jdbc/mydB");
		ds = (DataSource)ctx.lookup(dataSource);
	}
    public static Connection getConnection() throws SQLException
	{
		return ds.getConnection();
	}
}
  

when i try to open db connection i m getting null pointer exception.. What else needs to be configured to get this working. any ideas are welcome.

Thank you

[amit punekar]

Hi,
I am not sure where in you code you are getting the NPE.
But the code below looks wrong, probably you can correct it and check .

    
Line 1: Context ctx = (Context)init.lookup("java:comp/env/jdbc/mydB");  
Line 2: ds = (DataSource)ctx.lookup(dataSource);
 

Line 1 seems wrong and will fetch the resource that is DataSource and not the Context.
Instead you should just have something like

    
Line 1: ds = (DataSource)ctx.lookup(dataSource);
 

Where datasource string can be JNDI Name of the datasource. In your case "java:comp/env/jdbc/mydB".