Generating a Provider Proxy 
To provide a Web service, a provider proxy needs to be created.
Prerequisites
Provider proxies are created and implemented in the ABAP back-end system, in which the service will be provided.
To generate a provider proxy, the following objects must already have been designed in the Enterprise Services Repository:
Data types
Message types
Service interface and its operations
A provider proxy is based on an inbound service interface.
Procedure
You work with the Enterprise Services Repository Browser in the ABAP back-end system and follow the general procedure for generating proxies.
More information: ABAP Proxy Generation - General Procedure
Perform the following steps:
Generate a provider proxy for an inbound service interface.
Activate the provider proxy.
When the provider proxy is activated, all the underlying data types and message types will also be activated.
Implement the provider proxy.
To implement a provider proxy, you need to add application coding.
To be able to call a Web service, you have to create a runtime configuration.
To do this, use the SAP NetWeaver Administrator. Start this tool from the SOA Manager (transaction code SOAMANAGER).
Result
An active provider proxy now exists in the ABAP back-end system, in which the service will be provided.
The provider proxy comprises the following:
An ABAP proxy interface
An implementing class that uses the proxy interface
The implementing class contains the operations that were modeled in the Enterprise Services Repository as methods.
A template for the implementing class is created during proxy generation. A developer must add the appropriate application code to the implementing class. The ABAP proxy interface is not changed.
Example
Below is an example of an implementation of a method that returns an echo of imported data:
Syntax
1. METHOD ZMY_II_SYNCHRON_INBOUND_INTERF~EXECUTE_SYNCHRONOUS.
2. **** INSERT IMPLEMENTATION HERE ****
3. OUTPUT-RESPONSE_MESSAGE_TYPE-SIMPLE =
4. INPUT-REQUEST_MESSAGE_TYPE-SIMPLE.
5. ENDMETHOD.