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I can't use JNDI in tomcat to connect MySQL

I did everything in this :
how to connect tomcat 7 and mysql
But it still isn't working..... why? What have I missed?
Enviroment
OS : Win7
Eclipse : J2EE Mars
Tomcat : tomcat 8.0
java : 1.8.0_73
db name : test
username: root
password: 123
controller:
writeDB testDB = new writeDB(tablename);
writeDB.java
....
Class.forName("com.mysql.jdbc.Driver");
try{
Context initContext = new InitialContext();
Context envContext = (Context)initContext.lookup("java:/comp/env");
//-------error-------
dataSource = (DataSource) envContext.lookup("jdbc/test");
//-------error-------
}catch(NamingException ex)
{
throw new RuntimeException(ex);
}
web.xml (in my project)
<!-- MySQL JNDI -->
<resource-ref>
<description>MySQL DB</description>
<res-ref-name>jdbc/test</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
</resource-ref>
context.xml
(in TOMCAT_HOME/conf)
(Also in workspace\Servers\Tomcat v8.0 Server at localhost-config)
<?xml version="1.0" encoding="UTF-8"?>
<Context antiJARLocking="true" path="/eatST">
<Resource
name="jdbc/test"
auth="Container"
type="javax.sql.DataSource"
maxActice="100"
maxIdle="30"
maxWait="10000"
username="root"
password="123"
driverClassName="com.mysql.jdbc.Driver"
url="jdbc:mysql://localhost:3306/test?
useUnicode=true&characterEncoding=UTF8"
factory="org.apache.tomcat.jdbc.pool.DataSourceFactory"
/>
</Context>
Logs
Servlet.service() for servlet [commentCtr] in context
with path [/eatST] threw exception
java.lang.ClassCastException: org.apache.tomcat.dbcp.dbcp2.BasicDataSource
cannot be cast to javax.activation.DataSource
at com.joe.db.writeDB.<init>(writeDB.java:58)
at com.joe.servlet.CommentCtr.doPost(CommentCtr.java:38)
at ............

You've imported (and presumable programmed to) an incorrect DataSource. Your exception (java.lang.ClassCastException ... cannot be cast to javax.activation.DataSource) is telling you that you have usedjavax.activation.DataSource, but you wanted javax.sql.DataSource. Modify com.joe.db.writeDB and change
import javax.activation.DataSource;
to
import javax.sql.DataSource;
Also, you don't need Class.forName("com.mysql.jdbc.Driver"); (it doesn't hurt anything, but JDBC drivers register themselves now).

Embedded tomcat jndi definition

I'm using spring with embedded tomcat. I don't want application.properties to be used anymore, since it should be published to a webserver running tomcat and there I'm now using a JNDI dataSource from a context.xml which works very well. Now I want to define that JNDI resource for embedded tomcat, but it does not work.
What I've tried:
context.xml
<?xml version='1.0' encoding='utf-8'?>
<Context>
<Resource name="jdbc/db" auth="Container" type="javax.sql.DataSource"
maxActive="100" maxIdle="30" maxWait="10000"
username="root" password="root" driverClassName="com.mysql.jdbc.Driver"
url="jdbc:mysql://localhost:3306/db"/>
</Context>
Configuration.java
#Bean
public DataSource dataSource() {
final JndiDataSourceLookup lookup = new JndiDataSourceLookup();
lookup.setResourceRef(true);
return lookup.getDataSource("jdbc/db");
}
#Bean
public TomcatEmbeddedServletContainerFactory tomcatFactory() {
return new TomcatEmbeddedServletContainerFactory() {
#Override
protected TomcatEmbeddedServletContainer getTomcatEmbeddedServletContainer(Tomcat tomcat) {
tomcat.enableNaming();
return super.getTomcatEmbeddedServletContainer(tomcat);
}
};
}
and I'm getting:
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.sql.DataSource]:
Factory method 'dataSource' threw exception; nested exception is org.springframework.jdbc.datasource.lookup.DataSourceLookupFailureException: Failed to look up JNDI DataSource with name 'jdbc/db';
nested exception is javax.naming.NameNotFoundException: Name [jdbc/db] is not bound in this Context. Unable to find [jdbc].
Please help me, thanks :)

Try with
lookup.getDataSource("java:/comp/env/jdbc/db");
without java:comp, jndi can not be found."comp" is short for component and is bound to root context.

java.sql.SQLException: Connection has already been closed

We are getting java.sql.SQLException: Connection has already been closed. exception intermittently while performing a transaction. We are using tomcat 7.X and below is the configuration.
<Context docBase="ROOT" reloadable="true" antiJARLocking="true">
<Resource
name="jdbc/DS"
auth="Container"
type="javax.sql.DataSource"
driverClassName="org.postgresql.Driver"
url="jdbc:postgresql://XXXXXXX"
factory="org.apache.tomcat.jdbc.pool.DataSourceFactory"
username="XXXXXX"
password="XXXXXX"
maxActive="20"
maxIdle="3"
minIdle="3"
maxWait="10000"
removeAbandoned="true"/>
</Context>
Probably we are missing some configuration or property here that is causing the issue.
Please suggest a way fix this issue or help to find out the root cause.

Following configuration worked for me
<Context context="ROOT" debug="0" reloadable="false" useHttpOnly="true" cacheMaxSize="40960" cacheTTL="60000" cachingAllowed="true" antiJARLocking="true">
<Resource name="XYZ" auth="Container"
description="Exchange DB Connection"
dataSourceClassName="org.postgresql.ds.PGSimpleDataSource"
dataSource.serverName="XXXXX"
dataSource.databaseName="XXXX"
dataSource.portNumber="XXXX"
dataSource.user="xyz"
dataSource.password="xyz"
maximumPoolSize="20"
minimumIdle="5"
connectionTimeout="300000"
factory="com.zaxxer.hikari.HikariJNDIFactory"
registerMbeans="true"
type="javax.sql.DataSource" />
The key value here is connectionTimeout.
The factory which you are currently using has a default timeout, after that it forces session to close.
The connection timeout value above worked for me , for your application scenarios you'll have to experiment a bit to get the right value.

add below value:
removeAbandonedTimeout="600"

JDBC connection pooling with Struts 2

I am using connection pooling in Struts2 application but after some request, I am not getting any result even though I am closing the connection in our application. Please give me proper solution.
Context.xml
<Resource name="jdbc/abbas"
auth="Container"
type="javax.sql.DataSource"
username="myuser"
password="pass#123"
driverClassName="com.mysql.jdbc.Driver"
url="jdbc:mysql://192.168.14.65/abbas"
maxActive="15"
maxIdle="3"/>

Tomcat, Java & Oracle9. org.apache.naming.NamingContext lookup

I am using Tomcat and Java (through Eclipse) and Oracle Database 9.2.1
I am getting
org.apache.naming.NamingContext lookup
WARNING: Unexpected exception resolving reference
java.sql.SQLException: oracle.jdbc.OracleDriver
at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver
(PooledConnection.java:243)
My code is
context.xml
<Resource type="javax.sql.DataSource" auth="Container"
name="jdbc/charmDB"
factory="org.apache.tomcat.jdbc.pool.DataSourceFactory"
driverClassName="oracle.jdbc.OracleDriver"
url="jdbc:oracle:thin:#localhost:1521:db"
username="db" password="db" maxActive="20" maxIdle="10"
/>
<Resource name="jdbc/charmDB" auth="Container"
type="javax.sql.DataSource"
description="My Database"/>
Java code
InitialContext ic = new InitialContext();
DataSource ds = (DataSource) ic.lookup("java:comp/env/jdbc/charmDB");
Connection con = ds.getConnection();
Does anyone know what's wrong?
Thanks!

Your context.xml appears to have two resources with the same name: jdbc/charmDB.
Try resolving this issue first.
EDIT: Make sure your Oracle JDBC driver jar is in the Tomcat lib directory.