While running a web application on server I am getting the below exception:
Server Used : Apache Tomcat 8.5
Exception : java.sql.SQLException: Unable to load class: com.mysql.jdbc.Driver from ClassLoader
I have tried lot of things including putting ojdbc6.jar in WEB-INF/lib folder, putting jar in apache tomcat lib folder,in build path of project i have manually added the jar, also based on google findings attempted few turnarounds which didn't worked out in my case.
From the perspective of a web application, class or resource loading looks in the following repositories, in this order:
I have the jar in /WEB-INF/lib/ folder.
Complete stack trace.
java.sql.SQLException: Unable to load class: com.mysql.jdbc.Driver from ClassLoader:java.net.URLClassLoader@76ed5528;ClassLoader:ParallelWebappClassLoader
context: ROOT
delegate: false
----------> Parent Classloader:
java.net.URLClassLoader@76ed5528
at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:283)
at org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:203)
at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:718)
at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:650)
at org.apache.tomcat.jdbc.pool.ConnectionPool.init(ConnectionPool.java:468)
at org.apache.tomcat.jdbc.pool.ConnectionPool.<init>(ConnectionPool.java:143)
at org.apache.tomcat.jdbc.pool.DataSourceProxy.pCreatePool(DataSourceProxy.java:118)
at org.apache.tomcat.jdbc.pool.DataSourceProxy.createPool(DataSourceProxy.java:107)
at org.apache.tomcat.jdbc.pool.DataSourceFactory.createDataSource(DataSourceFactory.java:554)
at org.apache.tomcat.jdbc.pool.DataSourceFactory.getObjectInstance(DataSourceFactory.java:241)
at org.apache.naming.factory.FactoryBase.getObjectInstance(FactoryBase.java:94)
at javax.naming.spi.NamingManager.getObjectInstance(NamingManager.java:321)
at org.apache.naming.NamingContext.lookup(NamingContext.java:839)
at org.apache.naming.NamingContext.lookup(NamingContext.java:173)
at org.apache.catalina.core.NamingContextListener.addResource(NamingContextListener.java:1091)
at org.apache.catalina.core.NamingContextListener.createNamingContext(NamingContextListener.java:661)
at org.apache.catalina.core.NamingContextListener.lifecycleEvent(NamingContextListener.java:249)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:94)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5087)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1404)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1394)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.ClassNotFoundException: Unable to load class: com.mysql.jdbc.Driver from ClassLoader:java.net.URLClassLoader@76ed5528;ClassLoader:ParallelWebappClassLoader
context: ROOT
delegate: false
----------> Parent Classloader:
java.net.URLClassLoader@76ed5528
at org.apache.tomcat.jdbc.pool.ClassLoaderUtil.loadClass(ClassLoaderUtil.java:56)
at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:271)
... 25 more
Caused by: java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1285)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1119)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:348)
at org.apache.tomcat.jdbc.pool.ClassLoaderUtil.loadClass(ClassLoaderUtil.java:38)
... 26 more
May 07, 2019 4:04:12 PM org.apache.naming.NamingContext lookup
WARNING: Unexpected exception resolving reference
java.sql.SQLException: Unable to load class: com.mysql.jdbc.Driver from ClassLoader:java.net.URLClassLoader@76ed5528;ClassLoader:ParallelWebappClassLoader
context: ROOT
delegate: false
----------> Parent Classloader:
java.net.URLClassLoader@76ed5528
at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:283)
at org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:203)
at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:718)
at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:650)
at org.apache.tomcat.jdbc.pool.ConnectionPool.init(ConnectionPool.java:468)
at org.apache.tomcat.jdbc.pool.ConnectionPool.<init>(ConnectionPool.java:143)
at org.apache.tomcat.jdbc.pool.DataSourceProxy.pCreatePool(DataSourceProxy.java:118)
at org.apache.tomcat.jdbc.pool.DataSourceProxy.createPool(DataSourceProxy.java:107)
at org.apache.tomcat.jdbc.pool.DataSourceFactory.createDataSource(DataSourceFactory.java:554)
at org.apache.tomcat.jdbc.pool.DataSourceFactory.getObjectInstance(DataSourceFactory.java:241)
at org.apache.naming.factory.FactoryBase.getObjectInstance(FactoryBase.java:94)
at javax.naming.spi.NamingManager.getObjectInstance(NamingManager.java:321)
at org.apache.naming.NamingContext.lookup(NamingContext.java:839)
at org.apache.naming.NamingContext.lookup(NamingContext.java:173)
at org.apache.catalina.core.NamingContextListener.addResource(NamingContextListener.java:1091)
at org.apache.catalina.core.NamingContextListener.createNamingContext(NamingContextListener.java:661)
at org.apache.catalina.core.NamingContextListener.lifecycleEvent(NamingContextListener.java:249)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:94)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5087)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1404)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1394)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.ClassNotFoundException: Unable to load class: com.mysql.jdbc.Driver from ClassLoader:java.net.URLClassLoader@76ed5528;ClassLoader:ParallelWebappClassLoader
context: ROOT
delegate: false
----------> Parent Classloader:
java.net.URLClassLoader@76ed5528
at org.apache.tomcat.jdbc.pool.ClassLoaderUtil.loadClass(ClassLoaderUtil.java:56)
at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:271)
... 25 more
Caused by: java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1285)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1119)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:348)
at org.apache.tomcat.jdbc.pool.ClassLoaderUtil.loadClass(ClassLoaderUtil.java:38)
... 26 more
May 07, 2019 4:04:12 PM org.apache.catalina.core.NamingContextListener addResource
WARNING: Failed to register in JMX: javax.naming.NamingException: Unable to load class: com.mysql.jdbc.Driver from ClassLoader:java.net.URLClassLoader@76ed5528;ClassLoader:ParallelWebappClassLoader
cont8ext: ROOT
delegate: false
----------> Parent Classloader:
java.net.URLClassLoader@76ed552
Expected Result : It Must not throw any exception of jar as jar is already present in the /WEB-INF/lib/, as well as in tomcat/lib folder.
Actual Result : It is throwing Exception as stated above.
I want to post an answer after few more brainstorming(atleast in my case).
WEB-INF/lib folder should contains both jars, if in case it is not picked from there by class loader in some strange scenario(my case), copy the same in tomcat/lib folder.
It worked it for me, so posting an answer, I am open for any other views.