DataSourceRealm with JNDI Resource on context.xml

If you declare a <Resource/> into context.xml you must use
localDataSource="true"
with <Realm/>

EXAMPLE

driverClassName="org.gjt.mm.mysql.Driver"
maxActive="10"
maxIdle="4"
maxWait="5000"
name="jdbc/testlogin"
password="test"
type="javax.sql.DataSource"
url="jdbc:mysql://localhost/testlogin"
username="test"/>

<Realm className="org.apache.catalina.realm.DataSourceRealm" debug="99"
dataSourceName="jdbc/testlogin"
userTable="users" userNameCol="user_name" userCredCol="user_pass"
userRoleTable="user_roles" roleNameCol="role_name"
localDataSource="true"/>

Thank to:
http://www.junlu.com/msg/108880.html