<GlobalNamingResources>
  <Resource name="jdbc/ApplicationContext_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/>

<Context path="/ApplicationContext" ... >
  <!--
    "global" attribute links to GlobalNamingResources in the ${catalina.base}/conf/server.xml (server administrator team)
    "name" attribute is relative to the application-private JNDI context java:comp/env/ and is looked up from the java web application (application developer team)
  -->
  <ResourceLink global="jdbc/ApplicationContext_DatabaseName" name="jdbc/DatabaseName" type="javax.sql.DataSource"/>
</Context>

<resource-ref>
    <description>DatabaseName's Datasource</description>
    <res-ref-name>jdbc/DatabaseName</res-ref-name>
    <res-type>javax.sql.DataSource</res-type>
    <res-auth>Container</res-auth>
</resource-ref>

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

<GlobalNamingResources>
  <Resource name="jdbc/ApplicationContext_DatabaseName1" ... />
  <Resource name="jdbc/ApplicationContext_DatabaseName2" ... />
  ...
</GlobalNamingResources/>

<Context path="/ApplicationContext" ... >
  <ResourceLink global="jdbc/ApplicationContext_DatabaseName1" name="jdbc/DatabaseName1" ... />
  <ResourceLink global="jdbc/ApplicationContext_DatabaseName2" name="jdbc/DatabaseName2" ... />
  ...
</Context>

<resource-ref>
    <description>DatabaseName1's Datasource</description>
    <res-ref-name>jdbc/DatabaseName1</res-ref-name> ...
</resource-ref>
<resource-ref>
    <description>DatabaseName2's Datasource</description>
    <res-ref-name>jdbc/DatabaseName2</res-ref-name> ...
</resource-ref>
...

<jee:jndi-lookup id="DatabaseName1DataSource"
   jndi-name="jdbc/DatabaseName1" ... />
<jee:jndi-lookup id="DatabaseName2DataSource"
   jndi-name="jdbc/DatabaseName2" ... />
...

<GlobalNamingResources>
  <Resource name="jdbc/ApplicationContextX_DatabaseName1" ... />
  <Resource name="jdbc/ApplicationContextX_DatabaseName2" ... />
  <Resource name="jdbc/ApplicationContextY_DatabaseName1" ... />
  <Resource name="jdbc/ApplicationContextY_DatabaseName2" ... />
  ...
</GlobalNamingResources/>

<GlobalNamingResources>
  <Resource name="jdbc/ApplicationContextX_DatabaseName" ... />
  <Resource name="jdbc/ApplicationContextY_DatabaseName" ... />

<Context path="/ApplicationContextX" ... >
  <ResourceLink global="jdbc/ApplicationContextX_DatabaseName" name="jdbc/DatabaseName" ... />
</Context>

<Context path="/ApplicationContextY" ... >
  <ResourceLink global="jdbc/ApplicationContextY_DatabaseName" name="jdbc/DatabaseName" ... />
</Context>

<Context path="/ApplicationContextX" ... >
  <ResourceLink global="jdbc/ApplicationContextX_DatabaseName" name="jdbc/applicationXprivateDatabaseName" ... />
</Context>

<Context path="/ApplicationContextY" ... >
  <ResourceLink global="jdbc/ApplicationContextY_DatabaseName" name="jdbc/applicationYprivateDatabaseName" ... />
</Context>

<context:property-placeholder location="classpath:app.properties"/>

<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
    <property name="driverClassName" value="oracle.jdbc.OracleDriver"/>
    <property name="url" value="jdbc:oracle:thin:@${db.host}:${db.port}:${db.user}"/>
    <property name="username" value="${db.user}"/>
    <property name="password" value="${db.pass}"/>
</bean>

@Value("${db.user}") String defaultSchema;

@Inject ApplicationContext context;
Enviroment env = context.getEnvironment();
String defaultSchema = env.getProperty("db.user");

@Value('${db.user:testdb}') private String dbUserName;

<property name='username' value='${db.user.${env}}'/>

<Loader className="org.apache.catalina.loader.VirtualWebappLoader"
        virtualClasspath="/srv/web/app/"/>

<Context>
...
<Resource auth="Container" factory="com.benasmussen.jndi.url.URLFactory"
name="url/MyUrl" type="java.net.URL" url="file:///your/path/to/file"/>
...
</Context>

<jee:jndi-lookup id="myUrl" jndi-name="java:comp/env/url/MyUrl" expected-type="java.net.URL" />