day 18

day 13, day 14, day 15, day 16, day 17 빼먹음

 

 

레트로핏 예제

package com.example.retrofit_test_3

import com.google.gson.JsonElement
import retrofit2.Call
import retrofit2.http.Field
import retrofit2.http.FormUrlEncoded
import retrofit2.http.POST

interface IRetro {
    @FormUrlEncoded
    @POST("/login")
    fun loginRequest(
        @Field("username")username:String,
        @Field("password")password:String
    ): Call<JsonElement>
}

@Field
@Body
URL을 동적으로 지정 @Path : 
쿼리를 지정@Query, @QueryMap : 
HEADER 지정하기 @Header
메소드 : @GET, @POST, @PUT, @DELETE, @HEAD
DTO를 사용할 때  : @SerializedName("request"), @SerializedName("response") 
등등이 있습니다.

 

JsonElement를 받도록 인터페이스를 작성해줍니다.

 

package com.example.retrofit_test_3

enum class LoginResponse {
    OK,
    FAIL
}

 

package com.example.temp_retrofit

import android.util.Log
import okhttp3.OkHttpClient
import okhttp3.logging.HttpLoggingInterceptor
import retrofit2.Retrofit
import retrofit2.converter.gson.GsonConverterFactory
import java.util.concurrent.TimeUnit

//싱글톤 패턴의 적용되어 객체가 한 번만 생성됨
object RetrofitClient {
    private var retrofit:Retrofit? = null
    private val TAG:String = "로그"

    fun getClient(baseUrl:String) :Retrofit?{
        val okclientBuilder = OkHttpClient.Builder()

        val loggingInterceptor = HttpLoggingInterceptor(object : HttpLoggingInterceptor.Logger{
            override fun log(message:String){
                Log.d(TAG, "Retrofit Client - log: $message")
            }
        })

        loggingInterceptor.setLevel(HttpLoggingInterceptor.Level.BODY)
        okclientBuilder.addInterceptor(loggingInterceptor)

        okclientBuilder.connectTimeout(10, TimeUnit.SECONDS)
        //커넥션은 만들어졌지만 작업이 길어질때
        okclientBuilder.readTimeout(10, TimeUnit.SECONDS)
        //커넥션은 만들어졌지만 클라이언트가 데이터를 보내는 시간이 길어질때
        okclientBuilder.writeTimeout(10, TimeUnit.SECONDS)
        okclientBuilder.retryOnConnectionFailure(true)

        if(retrofit == null){
            retrofit = Retrofit.Builder()
                .baseUrl(baseUrl)
                .addConverterFactory(GsonConverterFactory.create())
                .client(okclientBuilder.build())
                .build();
        }

        return retrofit
    }
}

object로 클래스를 정의하면, 싱클턴(Singleton) 패턴이 적용되어 객체가 한번만 생성되도록 합니다. 
object는 익명객체를 생성할 때도 사용됩니다.

 

 

package com.example.retrofit_test_3

import com.google.gson.JsonElement
import retrofit2.Call
import retrofit2.Callback
import retrofit2.Response

class RetrofitManager {

    private val BASE_URL = "http://192.168.21.126:5000";
    private val TAG = "로그"

    companion object{
        val instance = RetrofitManager()
    }

    private val iRetrofit:IRetro? 
        = RetrofitClient.getClient(BASE_URL)?.create(IRetro::class.java)

    fun login(username:String, password:String, completion:(LoginResponse, String)->Unit){
        val call = iRetrofit?.loginRequest(username, password)?:return

        call.enqueue(object: Callback<JsonElement> {
            override fun onFailure(call:Call<JsonElement>, t:Throwable){
                completion(LoginResponse.FAIL, t.toString())
            }

            override fun onResponse(call: Call<JsonElement>, response: Response<JsonElement>){
                if(response.code()!=200){
                    completion(LoginResponse.FAIL, response.body().toString())
                }else{
                    completion(LoginResponse.OK, response.body().toString())
                }
            }
        })

    }

}

 

package com.example.retrofit_test_3

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.util.Log
import androidx.appcompat.app.AlertDialog
import com.example.retrofit_test_3.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {
    val TAG = "태그"
    lateinit var binding:ActivityMainBinding
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)

        binding.loginButton.setOnClickListener {
            Log.d(TAG, "loginbutton click" )

            val username = binding.usernameInput.text.toString()
            val password = binding.passwordInput.text.toString()

            loginRequest(username, password)

        }
    }

    fun loginRequest(username:String, password:String){
        val dialogBuilder = AlertDialog.Builder(this@MainActivity)
        if(username.isEmpty() || password.isEmpty()){
            dialogBuilder.setTitle("알림")
            dialogBuilder.setMessage("빈칸을 전부 채워주세요")
            dialogBuilder.setPositiveButton("확인",null)
            dialogBuilder.show()
        }else{
            RetrofitManager.instance.login(username=username, password=password, completion = {
                loginResponse, response ->
                    when(loginResponse){
                        LoginResponse.FAIL->{
                            dialogBuilder.setTitle("알림")
                            dialogBuilder.setMessage("로그인 실패")
                            dialogBuilder.setPositiveButton("확인", null)
                            dialogBuilder.show()
                        }
                        LoginResponse.OK -> {
                            dialogBuilder.setTitle("알림")
                            dialogBuilder.setMessage("로그인성공")
                            dialogBuilder.setPositiveButton("확인",null)
                            dialogBuilder.show()
                        }
                    }
            })
        }
    }
}

this@MainActivity)  는 qualified this 입니다.