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 for 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 code 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 .
