Java JDNI Database Access
April 12, 2010
Here's the Java code and config required to set up a database connection in tomcat, and then refer to it from a WAR file.
Java Code
This code lives inside the WAR file. It looks at Tomcat's config to work out which database to connect to, connects, and then returns a connection object.
public static Connection getConnection() { Connection lConnection = null; try { InitialContext lContext = new InitialContext(); String lLookupURI = "java:comp/env/jdbc/DataSourceDS"; Object lDataSource = lContext.lookup(lLookupURI); lConnection = ((javax.sql.DataSource) lDataSource).getConnection(); lConnection.setAutoCommit(false); } catch (Exception lException) { throw new RuntimeException(lException.getMessage(), lException); } return lConnection; }
web.xml
This is also inside the war file, and advertises the fact that the WAR file needs a database datasource of this name setting up.
<resource-ref> <res-ref-name>jdbc/DataSourceDS</res-ref-name> <res-type>javax.sql.DataSource</res-type> <res-auth>Container</res-auth> </resource-ref>
Tomcat 6 server.xml
The server.xml file in Tomcat is changed to supply details for the database connection called DataSourceDS.
<Resource auth="Container" name="jdbc/DataSourceDS" type="javax.sql.DataSource" url="jdbc:postgresql://server:5432/database" password="password" maxActive="4" maxWait="5000" driverClassName="org.postgresql.Driver" username="username" maxIdle="2" />
Tomcat 6 context.xml
We also need to link this in the context.xml file of Tomcat 6.
<ResourceLink name="jdbc/DataSourceDS" global="jdbc/DataSourceDS" type="javax.sql.DataSource" />
