For Java-based extensions, first use the Server SDK to create and build the extension bundle as described in the Server SDK documentation. Then, install it using the manage-extension tool as follows:
$ bin/manage-extension --install/path/to/extension.zip

The Java-based extension may then be configured for use in the server using dsconfig or the Administrative Console. Create a new Third Party HTTP Servlet Extension, specifying the fully-qualified name for the HTTPServletExtension subclass in the extension-class property, and providing any appropriate arguments in the extension-argument property.

Note: Web Application and Servlet extensions run in a shared embedded web application server environment. Incompatiblities or conflicts may arise from use of different versions of commonly used jars or including frameworks such as loggers, Spring components, JAX-RS implementations or other resources which may require a dedicated Java Virtual Machine (JVM) environment. After introducing a custom extension, check the server error log for an indication that the extension loaded successfully. The error log may also contain debug information if the extension failed to load with an initialization exception or did not complete initialization.