Getting java.lang.ClassNotFoundException: com.mysql.jdbc.Driver while connecting to external MYSQL database

[Vinutha Vasan]

Hi All,

I have written a plugin which read data from external mysql database.

I have copied the "mysql-connector-java-5.1.10-bin.jar" jar to 'jira\webapp\WEB-INF\lib' folde on my plugin enevironmet directory.

But while executoing the plugin i am getting ClassNotFoundException exception for com.mysql.jdbc.Driver.

Please find the stack trace below,

java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
at org.apache.felix.framework.ModuleImpl.findClassOrResourceByDelegation(ModuleImpl.java:772)
at org.apache.felix.framework.ModuleImpl.access$200(ModuleImpl.java:73)
at org.apache.felix.framework.ModuleImpl$ModuleClassLoader.loadClass(ModuleImpl.java:1690)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
at com.microchip.jira.plugins.versionManagement.dao.DatabaseValuesViewHelper.<init>(DatabaseValuesViewHelper.java:43)
at com.microchip.jira.plugins.versionManagement.restservice.VersionManagementResource.updateLineageData(VersionManagementResource.java:725)
at com.microchip.jira.plugins.versionManagement.restservice.VersionManagementResource.createIpVersion(VersionManagementResource.java:651)
at com.microchip.jira.plugins.versionManagement.action.AddIpProject.doExecute(AddIpProject.java:506)
at webwork.action.ActionSupport.execute(ActionSupport.java:165)
at com.atlassian.jira.action.JiraActionSupport.execute(JiraActionSupport.java:76)
at webwork.interceptor.DefaultInterceptorChain.proceed(DefaultInterceptorChain.java:39)

Could any let me know what should i do to fix it?

Is that i sould set it to classpath explicitly? Is not this jar will be accessible from 'jira\webapp\WEB-INF\lib' folder?

Thanks,

Vinutha

[Wojciech Seliga · Accepted solution]

Hi,

JIRA comes with JDBC drivers located in <insatllation-dir>/lib. IIRC due to licensing requirements, SDK does not include this libraries (that's why you are putting them to WEB-INF/lib). But that two different locations wrt classloaders.

How we handle it in JIRA Importers Plugin:

...
import com.atlassian.core.util.ClassLoaderUtils;
...
    private Driver loadDriver(final String driverName) throws SQLException {
        try {
            final Class clazz = ClassLoaderUtils.loadClass(driverName, JdbcConnection.class);
            return (Driver) clazz.newInstance();
        } catch (ClassNotFoundException e) {
            throw new SQLException("JDBC driver class not found: " + driverName, e);
        } catch (Exception e) {
            throw new SQLException("Cannot instantiate JDBC driver class " + driverName + ": " + e.getMessage(), e);
        }
    }
...

Then to streamline dev process we have a special test profile in our pom.xml (not used when releasing a plugin):

...
    <profiles>
        <profile>
            <id>test</id>
            <activation>
                <property>
                    <name>environment</name>
                    <value>test</value>
                </property>
            </activation>
            <dependencies>
                <dependency>
                    <groupId>mysql</groupId>
                    <artifactId>mysql-connector-java</artifactId>
                    <version>5.1.13</version>
                    <scope>runtime</scope>
                </dependency>
            </dependencies>
...
        </profile>

I hope it helps.

Cheers,
Wojtek

[Vinutha Vasan]

Hi Wojciech,

Yes, It sovled my problem. Thank you.

Cheers,

Vinutha