Consume PHP Webservice using Java/Android

Question

I built following the guidance of a friend a webservice using php (actually is a web application that returns to all requests made via post a string in format json).

First what I’d like to know is whether what I’ve done is in fact a webservice?

Second, what I wanted to do now was consume this webservice using an application made in java, more precisely android.

I have no idea what to do to consume this webservice.

So I would expect you to explain to me what needs to be done and indicate some tutorials on the Internet or even make a code available for me to base.

Thank you for your cooperation!

Answer 1

In general terms, a webservice is a function that can be accessed by another program using the web protocol (HTTP), ie if your program returns an html that can be viewed by a human, this is not a webservice, however, if it is returning a JSON that will be consumed by another program, then yes we can say that it is a webservice

This is a brief definition and there’s a whole more elaborate concept behind it.

To send http requests using Android, I use the library Volley, it is present in the official Android documentation that you can check here.

A simple request example using Volley:

// Criamos a fila de requisições
RequestQueue fila = Volley.newRequestQueue(this);
String endpoint = "https://api.punkapi.com/v2/beers";

// Criamos a request string a partir da URL
StringRequest stringRequest = new StringRequest(Request.Method.GET, endpoint, 
    new Response.Listener<String>() {
        @Override
        public void onResponse(String response) {
            Log.d("Response", "is: "+ response);
        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            Log.d("Response Error", "Erro na requisição!");
        }
    });
    // Adicionamos a requisição a fila de requisições
    fila.add(stringRequest);

Answer 2

Basically, you will need to run calls via HTTP pro web address that is running the webservice application.

You can call the webservice manually, using a tool like Curl, Postman, etc, to better understand how it works.

To do it in Java you can use a library that abstracts a lot of logic for you, like https://github.com/OpenFeign/feign and implement as required in your programme.