java - JDBC connection pool to MySQL on OpenShift -

first of all, i'm computer science student, , i'm not computer science world yet (i.e. i've little experience doing stuff on own). sorry not having knowledge possible on it.

then, in 1 of classes learnt how create web application java (jsp, beans, etc.) plus client-side stuff (html, css, javascript, ect.).

i work on netbeans ide.

to connect mysql database, use connection pooling in way:

1) add mysql jdbc driver jar

2) dbconnect.java java class method returns connection:

public static connection getconnection() {     /* jndi query locate datasource object */     context initcontext;     try {         initcontext = new initialcontext();         context envcontext = (context) initcontext.lookup("java:/comp/env"); // jndi standard naming root         datasource ds = (datasource) envcontext.lookup("jdbc/aname");          /* ask datasource connection */         connection conn;         try {             conn = ds.getconnection();             return conn;         } catch (sqlexception ex) {             logger.getlogger(dbconnect.class.getname()).log(level.severe, null, ex);             throw new runtimeexception("cannot open connection", ex);         }     } catch (namingexception ex) {         logger.getlogger(dbconnect.class.getname()).log(level.severe, null, ex);         throw new runtimeexception("cannot find datasource reference", ex);     } } 

3) web.xml:

<?xml version="1.0" encoding="utf-8"?> <web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/xmlschema-instance" xsi:schemalocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">  <resource-ref>     <description>resource reference datasource managing connection pool.</description>     <res-ref-name>jdbc/aname</res-ref-name>     <res-type>javax.sql.datasource</res-type>     <res-auth>container</res-auth> </resource-ref>  </web-app> 

4) context.xml

<?xml version="1.0" encoding="utf-8"?> <context antijarlocking="true" path="/myapp">     <resource       auth="container"       driverclassname="com.mysql.jdbc.driver"       maxactive="100"       maxidle="30"       maxwait="10000"       name="jdbc/aname"       username="username"       password="password"       type="javax.sql.datasource"       url="jdbc:mysql://"whateverhost":"whateverport"/dbschema?autoreconnect=true"/> </context> 

now, created small project , wanted publish online free. ran openshift , managed push files on (even if folders' schema different).

the problem connection pooling doesn't work, , don't have clue on do.

running application, these exceptions:

java.lang.runtimeexception: cannot open connection ....  org.apache.tomcat.dbcp.dbcp.sqlnestedexception: cannot create jdbc driver of class '' connect url 'null' ....  java.sql.sqlexception: no suitable driver .... 

mysql-connector jar in /web_inf/lib , pom.xml has:

<dependency>     <groupid>mysql</groupid>     <artifactid>mysql-connector-java</artifactid>     <version>5.1.25</version> </dependency> 

maybe solution quite simple don't know do. thank you.

i think problem web.xml file. it's redundant. context.xml specifies data source appropriate configuration , web.xml specifies 1 without url or driver class name.

try removing resource-ref block web.xml , try again:

<resource-ref>     <description>resource reference datasource managing connection pool.</description>     <res-ref-name>jdbc/aname</res-ref-name>     <res-type>javax.sql.datasource</res-type>     <res-auth>container</res-auth> </resource-ref> 

you have quotes in url attribute in context.xml:

url="jdbc:mysql://"whateverhost":"whateverport"/dbschema?autoreconnect=true"/> 

make this:

url="jdbc:mysql://whateverhost:whateverport/dbschema?autoreconnect=true"/>