// Retrofit
implementation 'com.squareup.retrofit2:retrofit:2.6.0'
implementation 'com.squareup.retrofit2:converter-gson:2.6.0'
implementation "com.squareup.okhttp3:logging-interceptor:4.5.0"// FULL EXAMPLE FOR RETROFIT
//add Retrofit dependencies to gradle file
//file build.gradele
implementation 'com.squareup.retrofit2:retrofit:2.9.0'
implementation 'com.squareup.retrofit2:converter-gson:2.9.0'
implementation 'com.squareup.okhttp3:okhttp:5.0.0-alpha.10'
// create an interface for more flexibility
// file MyAPI.kt
interface MyAPI(){
// function calling to server
// @Field("your_name_of_field") under this name we will receive our request on the server
// Like if(isset($_POST("your_name_of_field"))){ do something } //PHP
@FormUrlEncoded // required annotation
@POST("server.php") // address of the page to which we send data and from which we receive a response
fun SendAndGetPost(
@Field("name") userName: String?
@Field("password") userPass: String?
):Call<ResponsedData?>? // class ResponsedData.kt
companion object{
private val client = OkHttpClient.Builder().build()
operator fun invoke():MyAPI{
return Retrofit.Builder()
// https://google.com/folder/ (path example)
.baseUrl("https://yor_server_path/")
.addConverterFactory(GsonConverterFactory.create())
.client(client)
.build()
.create(MyAPI::class.java)
}
}
}
// create a class to receive our response from the server
// file ResponsedData.kt
class ResponsedData{
val email: String? = null
val age: String? = null
//variable names must match the names sent from the server !
}
// ActivityMain calls the function and get the data
class ActivityMain : AppCompatActivity(){
override fun onCreate(savedInstance: Bundle){
super.onCreate(savedInstance)
setContentView(R.layout.activity_main)
val name = "myName"
val password = "1234567"
MyAPI().SendAndGetPost(name, password)?enqueue(
object: CalBack<ResponsedData?>{
override fun onResponse(
call: Call<ResponsedData?>,
response: Response<ResponsedData?>)
{
if(!response.isSuccessful){
Log.e("API-ERROR", response.code().toString())
return
}else{
// val answer: ResponsedData
val answer = response.body()
email.name
age.password
// data for use
}
}
override fun onFalure(
call: Call<ResponsedData?>,
t: Throwable)
{
Log.e("API-ERROR", t.printStackTrace())
}
})
}
}
--------------------- SERVER SIDE -------------------------------------------
// this is how the file on the server looks like
// the path to which we registered in the interface of our application
// file server.php
<?php
// Data Base includes
// or any sources
if(isset($_POST("name")) && isset($_POST("password"))){
$js = array(
'email'=>"some data from DB",
'age'=>"some data from DB"
);
echo json_encode($js);
exit();
}
// all examples are taken from here
// https://square.github.io/retrofit/implementation 'com.squareup.retrofit2:retrofit:2.6.0'- intoduction
1. post is used to send data to server
- exapmle
"simple post"
@POST("posts")
Call<Post> createPost(@Body Post post);
"post with from url encoded "
@FormUrlEncoded
@POST("posts")
Call<Post> createPost( @Field("userId") int userid ,
@Field("title") String title,
@Field("body") String body );
"using map"
@FormUrlEncoded
@POST("posts")
Call<Post> createPost(@FieldMap Map<String,String> postMap);
- INTERFACE
public interface MyWebService {
String BASE_URL = "https://jsonplaceholder.typicode.com/";
String FEED = "posts";
Retrofit retrofit = new Retrofit.Builder()
.baseUrl(BASE_URL)
.addConverterFactory(GsonConverterFactory.create())
.build();
@GET(FEED)
Call<List<Post>> getPosts();
}
- MODEL CLASS
public class Post {
private int userId;
private int id;
private String title;
private String body;
public int getUserId() {
return userId;
}
public void setUserId(int userId) {
this.userId = userId;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getBody() {
return body;
}
public void setBody(String body) {
this.body = body;
}
}
- IN ACTIVITY WHERE TO SEND POST REQUEST
Post post = new Post(1,"Post Title","this is post body");
Map<String,String> postmap = new HashMap<>();
postmap.put("userId","33");
postmap.put("title","My post title");
postmap.put("body","this is my post body in the map");
Call<Post> postCall = myWebService.createPost(postmap);
postCall.enqueue(new Callback<Post>() {
@Override
public void onResponse(Call<Post> call, Response<Post> response) {
if (response.isSuccessful()){
textView.setText(String.valueOf(response.code()));
show(response.body());
}
}
@Override
public void onFailure(Call<Post> call, Throwable t) {
}
});