Re: AS/400 JDBC Connection

[Narayanan R Pillai <strqst400@xxxxxxxxx>]

If you are planning to use Tomcat, then use the DataSource Interface. In 
your deployment xml ( 
%CATALINA_HOME%\conf\Catalina\localhost\<your-app>..xml ) add the following:

        <Resource name="jdbc/AS400" auth="Container" type="javax.sql.DataSource" 
/>
        <ResourceParams name="jdbc/AS400">

                <!-- Parameter factory   -->
                <parameter>
                        <name>factory</name>
                        <value>
                                org.apache.commons.dbcp.BasicDataSourceFactory
                        </value>
                </parameter>

                <!-- dB username and password for dB connections  -->
                <parameter>
                        <name>maxActive</name>
                        <value>40</value>
                </parameter>
                <parameter>
                        <name>maxIdle</name>
                        <value>4</value>
                </parameter>

                <parameter>
                        <name>username</name>
                        <value>userid</value>
                </parameter>
                <parameter>
                        <name>password</name>
                        <value>password</value>
                </parameter>


                <parameter>
                        <name>driverClassName</name>
                        <value>com.ibm.as400.access.AS400JDBCDriver</value>
                </parameter>
                <parameter>
                        <name>url</name>
                         
<value>jdbc:as400://Nameofas400here;naming=system;errors=full;access=all;translate 
binary=true;extended dynamic=true;package=CSI;package cache=true;</value>
                </parameter>

                <parameter>
                        <name>removeAbandoned</name>
                        <value>true</value>
                </parameter>
                <parameter>
                        <name>removeAbandonedTimeout</name>
                        <value>6000</value>
                </parameter>
                <parameter>
                        <name>logAbandoned</name>
                        <value>true</value>
                </parameter>

                <parameter>
                        <name>testWhileIdle</name>
                        <value>true</value>
                </parameter>

                <parameter>
                        <name>timeBetweenEvictionRunsMillis</name>
                        <value>1800000</value>
                </parameter>
                <parameter>
                        <name>numTestsPerEvictionRun</name>
                        <value>4</value>
                </parameter>


                <parameter>
                        <name>validationQuery</name>
                        <value>select current date from sysibm/sysdummy1</value>
                </parameter>

Now this can be accessed from within an application, like so:

Context initCtx = new InitialContext();
Context envCtx  = ( Context ) initCtx.lookup( "java:comp/env" );
DataSource dataSource = = (DataSource)envCtx.lookup( "jdbc/AS400" );


Now a connection is just:

Connection conn = dataSource.getConnection();


If you do a conn.close(); the connection is returned to the datasource 
pool.

ps: Most of this technique is a straight lift from the Tomcat JNDI/Howto 
( 
http://tomcat.apache.org/tomcat-4.1-doc/jndi-datasource-examples-howto.html 
).


Regards,
Narayanan R Pillai

RPower@xxxxxxxxxx wrote:

> I'm trying to figure out if I should be creating and closing my 
> connections to the JDBC each time a servlet is called or should I just 
> open it once and leave it open?  ie:
>        public void performTask(HttpServletRequest req, 
> HttpServletResponse resp) {
>                sess = req.getSession(true);
>                customer = (Customer) sess.getAttribute("customer");
>                createAuditTrail = false;
>                try {
>                        //!---New code put in Jun 2, 2005
>                        if (ds == null)
>                                getDS();
>                        conn = ds.getConnection();
>                        dmd = conn.getMetaData();
>
> code here.....
>
>
>                conn.close();
>
> is this efficient or am I wasting valuable resources?  Thanks,
>
> Ron Power
> Programmer
> Information Services
> City Of St. John's, NL
> P.O. Box 908
> St. John's, NL
> A1C 5M2
> 709-576-8132
> rpower@xxxxxxxxxx
> http://www.stjohns.ca/
> ___________________________________________________________________________
> Success is going from failure to failure without a loss of enthusiasm. - 
> Sir Winston Churchill
>
>
>
>
>
> This email communication and accompanying documents is intended only for the 
> individual or entity to which it is addressed and may contain information that 
> is confidential, privileged or exempt from disclosure under applicable law. Any 
> use of this information by individuals or entities other than the intended 
> recipient is strictly prohibited. If you have received this in error, please 
> notify the sender and delete all the copies (electronic or otherwise) 
> immediately.
>