I'm using Websphere Portal 7.0 and creating a portlet with RAD 8.0. My portlet is trying to make a db2 connection to a remote server. I wrote a java program locally to do a basic JDBC connection to the server and get records from a table. The code works fine; however, when I add the code to my portlet as well as the db2jcc4.jar, the connection doesn't work. I'm using the basic:
Connection connection = DriverManager.getConnection("jdbc:db2://server:port/db:user=user;password=pw;");
I figure that using the Websphere datasource is the right way to go. I know the JNDI name for the datasource, but I'm not finding clear cut examples on how to make a connection. Several examples use a DataSource class (I typed this in and this doesn't seem like it comes from a native java package so what import do I use here?) coupled with a Context. I've come across code like:
Context ctx = new InitialContext();
ctx.lookup("jdbc/xxxx");
... Can someone break this down for me?
EDIT 1
I've updated my code per the answers listed. I really think I'm getting closer. Here is my getConnection() method:
private Connection getConnection() throws SQLException {
javax.naming.InitialContext ctx = null;
javax.sql.DataSource ds = null;
System.out.println("Attempting connection..." + DateUtil.now() );
try {
ctx = new javax.naming.InitialContext();
ds = (javax.sql.DataSource) ctx.lookup("java:comp/env/jdbc/db");
connection = ds.getConnection();
} catch (NamingException e) {
System.out.println("peformanceappraisalstatus: COULDN'T CREATE CONNECTION!");
e.printStackTrace();
}
System.out.println("connection: " + connection.getClass().getName() + " at " + DateUtil.now());
return connection;
}
My entire web.xml file looks like:
<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_ID" version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<display-name>PeformanceAppraisalStatus</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<resource-ref>
<description>
Datasource connection to Db</description>
<res-ref-name>jdbc/db</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
<res-sharing-scope>Shareable</res-sharing-scope>
</resource-ref>
</web-app>
I am seeing an error that describes the very thing you guys are telling me Websphere should prompt me to do, but doesn't:
SRVE0169I: Loading Web Module: PeformanceAppraisalStatus.
[8/23/11 18:08:02:166 CDT] 00000009 InjectionProc E CWNEN0044E: A resource reference binding could not be found for the jdbc/db resource reference, defined for the PeformanceAppraisalStatus component.
[8/23/11 18:08:02:169 CDT] 00000009 InjectionEngi E CWNEN0011E: The injection engine failed to process bindings for the metadata.
Yes, I know that I've mispelled performance as peformance throughout the app.
SOLUTION
I was so very close. Here are the missing bits that made it all fall into place:
web.xml:
<resource-ref>
<description>
Datasource connection to db</description>
<res-ref-name>jdbc/db</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
<res-sharing-scope>Shareable</res-sharing-scope>
<mapped-name>jdbc/db</mapped-name>
</resource-ref>
ibm-web-bnd.xml:
<?xml version="1.0" encoding="UTF-8"?>
<web-bnd
xmlns="http://websphere.ibm.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://websphere.ibm.com/xml/ns/javaee http://websphere.ibm.com/xml/ns/javaee/ibm-web-bnd_1_0.xsd"
version="1.0">
<virtual-host name="default_host" />
<resource-ref name="jdbc/db" binding-name="jdbc/mydatasource" />
</web-bnd>
It appears that the ibm-web-bnd.xml file handles the binding between the project resource name and the datasource in websphere. Once I added the line:
<resource-ref name="jdbc/db" binding-name="jdbc/mydatasource" />
Websphere Portal seemed appeased. My code is working and connecting to the database now.
You need to define a resource reference in your application and then map that logical resource reference to the physical resource (data source) during deployment.
In your web.xml
, add the following configuration (modifying the names and properties as appropriate):
<resource-ref>
<description>Resource reference to my database</description>
<res-ref-name>jdbc/MyDB</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
<res-sharing-scope>Shareable</res-sharing-scope>
</resource-ref>
Then, during application deployment, WAS will prompt you to map this resource reference (jdbc/MyDB
) to the data source you created in WAS.
In your code, you can obtain the DataSource similar to how you've shown it in your example; however, the JNDI name you'll use to look it up should actually be the resource reference's name you defined (res-ref-name
), rather than the JNDI name of the physical data source. Also, you'll need to prefix the res-ref-name with the application naming context (java:comp/env/
).
Context ctx = new InitialContext();
DataSource dataSource = (DataSource) ctx.lookup("java:comp/env/jdbc/MyDB");