JNDI lookup of PostgreSQL database in tomcat

Question

In existing application I am connecting to database using jndi as follows. Please guide me on how I can write effective code for same in Spring based application.

My Current jndi lookup code is

InitialContext context = null;
String welcomeMessage = null;
Integer maxSessionCount = null;

try{
    context = new InitialContext();

    welcomeMessage = (String)context.lookup(
            "java:comp/env/welcomeMessage");
    maxSessionCount = (Integer)context.lookup(
            "java:comp/env/maxSessionCount");
}
catch (NamingException exception){
    exception.printStackTrace();
}

Answer 1

<jee:jndi-lookup id="dbDataSource"
   jndi-name="jdbc/DatabaseName"
   expected-type="javax.sql.DataSource" />

Declare the JNDI resource in tomcat's server.xml using something like this:

<GlobalNamingResources>
  <Resource name="jdbc/DatabaseName" auth="Container" type="javax.sql.DataSource"
              username="dbUsername" password="dbPasswd"
              url="jdbc:postgresql://localhost/dbname"
              driverClassName="org.postgresql.Driver"
              initialSize="5" maxWait="5000"
              maxActive="120" maxIdle="5"
              validationQuery="select 1"
              poolPreparedStatements="true"/>
</GlobalNamingResources/>

And reference the JNDI resource from Tomcat's web context.xml like this:

 <ResourceLink name="jdbc/DatabaseName"
   global="jdbc/DatabaseName"
   type="javax.sql.DataSource"/>

make use of bean dbDatasource in your application.