Networking and APIs
Networking in software development often involves connecting to the internet, making HTTP requests, and working with APIs. Below is an overview of these concepts, focusing on HTTP requests, JSON parsing, and working with REST APIs using Retrofit and OkHttp in Android development.
Connecting to the Internet
To interact with the internet, you need to establish a connection and make HTTP requests. Two common methods are GET and POST:
- GET Requests: Retrieve data from a server.
- POST Requests: Send data to a server to create or update resources.
Making HTTP Requests (GET, POST)
Parsing JSON Data
Once you receive a response from the server, it is often in JSON format. To parse JSON data in Java or Kotlin, you can use libraries like Gson or JSONObject.
Working with REST APIs
REST (Representational State Transfer) APIs allow communication between clients and servers using HTTP. In Android, the Retrofit library is popular for handling API calls.
Using Retrofit Library for API Calls
Retrofit simplifies the process of making HTTP requests by abstracting many complexities. It works seamlessly with OkHttp for handling HTTP connections and Gson for JSON parsing.
- Setup Retrofit in your Android project
- Define an API interface
- Create a Retrofit instance
- Make an API call
Handling Asynchronous Tasks with Retrofit and OkHttp
Retrofit uses OkHttp for network operations, which provides asynchronous request handling. This is critical for keeping the UI thread responsive.
- Asynchronous Calls:
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- Use enqueue() method for asynchronous execution of API calls.
- Handle the response or failure within the provided callback methods.
- Synchronous Calls:
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- Use execute() method for synchronous execution, which blocks the main thread—generally discouraged in Android apps.
