Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/JDBC_DBO]]

You are missing commons-digester3-3.2.jar from Apache Commons Digester. If you are using Maven you can add:

<dependency>
    <groupId>commons-digester</groupId>
    <artifactId>commons-digester</artifactId>
    <version>2.1</version>
</dependency>

to your project dependencies.

Update: The jar from the latest download page has a slightly different package structure to what your application expects. You can use this older jar instead.

I had the same problem in my tomcat server but when i check deeply i found that i add a new tag in my web.xml file and the server doesn't accept it so check your file to if any update happened then restart your tomcat and will be good .