1. When using maven as an build tool and for dependency management in your JAVA/J2EE project , If you need source code of the jar file as well(for reading or for debugging the code),Use/Run the following goal in your project’s directory(where pom.xml file is present)

mvn dependency:sources

or if using eclipse IDE,below goal/command can also be used:

mvn eclipse:eclipse -DdownloadSources=true

2.Stub is client side proxy and Skeleton is server side proxy. Stub: local object representing the remote service. Skeleton: is a style of Skeleton programming which means dummy code .

3. DROP and TRUNCATE are DDL commands, whereas DELETE is a DML command. As such, DELETE operations can be rolled back (undone), while DROP and TRUNCATE operations cannot be rolled back.