Several ways to invoke a web service

1. SOAP calling method: It involves using the SOAP protocol to communicate, sending XML requests and receiving XML responses to call a webservice. Typically, this method involves building and sending SOAP requests using a SOAP client.
2. REST call method: Communication is done through the use of the HTTP protocol, which involves sending HTTP requests (such as GET, POST, PUT, DELETE, etc.) and receiving HTTP responses in order to invoke the webservice. This approach typically involves using an HTTP client to construct and send the HTTP requests.
3. JSON-RPC calls involve using the JSON-RPC protocol to communicate, making requests in JSON format and receiving responses in JSON format to call a webservice. This method typically utilizes a JSON-RPC client to create and send the JSON-RPC requests.
4. The method of making XML-RPC calls involves communication using the XML-RPC protocol, where requests are sent in XML format and responses are received in XML format to call a webservice. Typically, an XML-RPC client is used to build and send XML-RPC requests in this manner.
5. The method of calling JAX-RS: Communicating using Java API for RESTful Web Services (JAX-RS) to invoke a RESTful style webservice by sending HTTP requests and receiving HTTP responses. This approach typically involves using JAX-RS clients (such as Jersey, RestEasy, etc.) to build and send HTTP requests.

The above are several common ways of calling a webservice, the specific choice depends on the implementation and requirements of the webservice.