Re: [Rapla-developers] Using container datasource

[Carlos A. V. <lo...@un...>]

Hi all,

These are the changes I found neccesary to use container datasource. 
These are the steps using tomcat. Step 1 should be the same for any 
container and 2 & 3 are almost standard in any container (differences 
normally are the locations of the files that hold the values)

Sorry for being brief, I do not have much time, but I think it could 
help as is. I think that using container datasource is worth using and 
has many benefits. Hope you find it useful.

Carlos



****** 1) Code changes:

I get it working changing org.rapla.storage.dbsql.DBOperator.java. Just 
two methods are necesary to change: createConnection() and 
DBOperator(RaplaContext context, Configuration config)

Three new imports are needed for using datasource

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.sql.DataSource;

createConnection returns a connection from datasource pool:

    public Connection createConnection() throws RaplaException {
    
     Connection myConn = null;  
     try
      {
       Context cxt = new InitialContext();
       if ( cxt == null )
         { throw new Exception("Unable to get context"); }
      
       DataSource ds = (DataSource) cxt.lookup( 
"java:/comp/env/jdbc/RaplaDB" );

       if ( ds == null )
         {throw new Exception("Datasource not found"); }
        else 
         {myConn = ds.getConnection();}
     
       if (myConn == null)
         throw new RaplaDBException("Unable to connect to DB \nCheck 
datasource!");

       bSupportsTransactions = myConn.getMetaData().supportsTransactions();
       if (bSupportsTransactions)
         {
          myConn.setAutoCommit( false );
          }
         else
         {
          getLogger().warn("No Transaction support");
         }
        }
        catch (Throwable ex) {
             if ( ex instanceof RaplaDBException)
             {
                 throw (RaplaDBException) ex;
             }
             ex.printStackTrace();
             throw new RaplaDBException("DB-Connection aborted",ex);
        }
    
     return myConn;                      
       
    }


DBOperator does not need now to register driver. Just remove all the 
lines of that.

DBOperator(RaplaContext context, Configuration config) throws 
RaplaException {
        super( context );
    }




(Steps 2 and 3 are about container datasource conf. If you need more 
info, thay are explained at tomcat website -and in most containers) Be 
sure  of being coherent when naming datasource. i.e. raplaDB and RaplaDB 
are not same)

****** 2) at WEB-INF/web.xml

  <resource-ref>
      <description>DB Connection</description>
      <res-ref-name>jdbc/RaplaDB</res-ref-name>
      <res-type>javax.sql.DataSource</res-type>
      <res-auth>Container</res-auth>
  </resource-ref>


****** 3) at {catalina.base} conf/Catalina/localhost a rapla.xml file

<Context path="/rapla" docBase="rapla" >

<Resource name="jdbc/RaplaDB" auth="Container" type="javax.sql.DataSource"
               maxActive="10" maxIdle="3" maxWait="10"
               username="raplauser" password="somepass" 
driverClassName="oracle.jdbc.driver.OracleDriver"
               url="jdbc:oracle:thin:@yourHost:yourListnrPort:yourDB" 
               connectionProperties="SetBigStringTryClob=true" />

</Context>