Networking

API Integration Skill

Quick Start

Retrofit Setup

interface UserApi {
    @GET("/users/{id}")
    suspend fun getUser(@Path("id") id: Int): UserDto
    
    @POST("/users")
    suspend fun createUser(@Body user: UserDto): UserDto
}

val retrofit = Retrofit.Builder()
    .baseUrl("https://api.example.com/")
    .addConverterFactory(GsonConverterFactory.create())
    .build()

val api = retrofit.create(UserApi::class.java)

OkHttp Configuration

val client = OkHttpClient.Builder()
    .addInterceptor(HttpLoggingInterceptor())
    .connectTimeout(30, TimeUnit.SECONDS)
    .certificatePinner(CertificatePinner.Builder()
        .add("api.example.com", "sha256/...").build())
    .build()

Error Handling

sealed class Result<T> {
    data class Success<T>(val data: T) : Result<T>()
    data class Error<T>(val exception: Exception) : Result<T>()
}

Key Concepts

HTTP Methods

• GET: Fetch data
• POST: Create resource
• PUT/PATCH: Update
• DELETE: Remove

Retrofit Features

• Type-safe interfaces
• Automatic serialization
• Suspend function support
• Error callbacks

Network Security

• HTTPS/TLS enforcement
• SSL pinning
• Certificate validation
• Secure token storage

Best Practices

✅ Use HTTPS always ✅ Implement SSL pinning ✅ Handle errors gracefully ✅ Optimize request/response size ✅ Cache when possible

Resources

• Retrofit Guide
• OkHttp Documentation