JNDI Datasource Tomcat

JNDI Datasource Tomcat

This tutorial will show you how to configure JNDI data source to tomcat server and get connection through your program using configured JNDI name. (Note: below example has been done for MySQL database)

Before you proceed to configure JNDI Datasource Tomcat, don’t forget to copy the JDBC Driver’s jar into $CATALINA_HOME/lib.

MySQL configuration

Create a new test user, a new database and a single test table. Your MySQL user must have a password assigned. The driver will fail if you try to connect with an empty password.

mysql> GRANT ALL PRIVILEGES ON *.* TO javauser@localhost 
    ->   IDENTIFIED BY 'javadude' WITH GRANT OPTION;
mysql> create database javatest;
mysql> use javatest;
mysql> create table testdata (
    ->   id int not null auto_increment primary key,
    ->   foo varchar(25), 
    ->   bar int);

 

Note: the above user should be removed once testing is complete!
Next insert some test data into the testdata table.

mysql> insert into testdata values(null, 'hello', 12345);
Query OK, 1 row affected (0.00 sec)

mysql> select * from testdata;
+----+-------+-------+
| ID | FOO   | BAR   |
+----+-------+-------+
|  1 | hello | 12345 |
+----+-------+-------+
1 row in set (0.00 sec)

mysql>

 

Context configuration

Configure the JNDI Datasource Tomcat by adding a declaration for your resource to your server Context.(File location : tomcate_home/conf/context.xml and eclipse: \Servers\Tomcat v7.0 Server at localhost-config\context.xml)

Example:

<Context>

    <!-- maxActive: Maximum number of database connections in pool. Make sure you
         configure your mysqld max_connections large enough to handle
         all of your db connections. Set to -1 for no limit.
         -->

    <!-- maxIdle: Maximum number of idle database connections to retain in pool.
         Set to -1 for no limit.  See also the DBCP documentation on this
         and the minEvictableIdleTimeMillis configuration parameter.
         -->

    <!-- maxWait: Maximum time to wait for a database connection to become available
         in ms, in this example 10 seconds. An Exception is thrown if
         this timeout is exceeded.  Set to -1 to wait indefinitely.
         -->

    <!-- username and password: MySQL username and password for database connections  -->

    <!-- driverClassName: Class name for the old mm.mysql JDBC driver is
         org.gjt.mm.mysql.Driver - we recommend using Connector/J though.
         Class name for the official MySQL Connector/J driver is com.mysql.jdbc.Driver.
         -->

    <!-- url: The JDBC connection url for connecting to your MySQL database.
         -->

  <Resource name="jdbc/TestDB" auth="Container" type="javax.sql.DataSource"
               maxActive="100" maxIdle="30" maxWait="10000"
               username="javauser" password="javadude" driverClassName="com.mysql.jdbc.Driver"
               url="jdbc:mysql://localhost:3306/javatest"/>

</Context>

 

web.xml configuration

Now add to WEB-INF/web.xml to test this in application forĀ JNDI Datasource Tomcat

<web-app xmlns="http://java.sun.com/xml/ns/j2ee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"
    version="2.4">
  <description>MySQL Test App</description>
  <resource-ref>
      <description>DB Connection</description>
      <res-ref-name>jdbc/TestDB</res-ref-name>
      <res-type>javax.sql.DataSource</res-type>
      <res-auth>Container</res-auth>
  </resource-ref>
</web-app>

 

Test codeĀ JNDI Datasource Tomcat

Now create a simple test.jsp page for use later.

<%@ taglib uri="http://java.sun.com/jsp/jstl/sql" prefix="sql" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>

<sql:query var="rs" dataSource="jdbc/TestDB">
select id, foo, bar from testdata
</sql:query>

<html>
  <head>
    <title>DB Test</title>
  </head>
  <body>

  <h2>Results</h2>

<c:forEach var="row" items="${rs.rows}">
    Foo ${row.foo}<br/>
    Bar ${row.bar}<br/>
</c:forEach>

  </body>
</html>

 

That JSP page makes use of JSTL’s SQL and Core taglibs. You can get it from Apache Tomcat Taglibs – Standard Tag Library project. Once you have JSTL, copy jstl.jar and standard.jar to your web app’s WEB-INF/lib directory.

Finally deploy your web app into $CATALINA_BASE/webapps either as a warfile called DBTest.war or into a sub-directory called DBTest

Once deployed, point a browser at http://localhost:8080/DBTest/test.jsp to view and get information form data base .

 

 

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