I am new in google cloud endpoints. I had successfully created some endpoints. Now I want to use APIs from these endpoints in other projects. For that, I will be needing APIs classes. Is there any way to compile my backend in other projects and get the API classes in other projects.
You need clients for your API. You can use the Google Endpoints documentation to generate Java clients, or you can use the OpenAPI spec from your API to generate clients with a tool like swagger-codegen.