Android网络库：Volley、Retrofit、OkHttp和HttpURLConnection的比较与应用

import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;

// ...

RequestQueue queue = Volley.newRequestQueue(this);
String url = "https://api.example.com/data";

StringRequest stringRequest = new StringRequest(Request.Method.GET, url,
        new Response.Listener<String>() {
            @Override
            public void onResponse(String response) {
                // 处理响应
                Log.d("Response", response);
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                // 处理错误
                Log.e("Error", error.toString());
            }
        });

queue.add(stringRequest);

import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;
import retrofit2.Retrofit;
import retrofit2.converter.gson.GsonConverterFactory;
import retrofit2.http.GET;

// 定义API接口
public interface ApiService {
    @GET("data")
    Call<String> getData();
}

// ...

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

ApiService apiService = retrofit.create(ApiService.class);
Call<String> call = apiService.getData();

call.enqueue(new Callback<String>() {
    @Override
    public void onResponse(Call<String> call, Response<String> response) {
        // 处理响应
        Log.d("Response", response.body());
    }

    @Override
    public void onFailure(Call<String> call, Throwable t) {
        // 处理错误
        Log.e("Error", t.toString());
    }
});

import java.io.IOException;
import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

// ...

OkHttpClient client = new OkHttpClient();
String url = "https://api.example.com/data";

Request request = new Request.Builder()
        .url(url)
        .build();

client.newCall(request).enqueue(new Callback() {
    @Override
    public void onFailure(Call call, IOException e) {
        // 处理错误
        Log.e("Error", e.toString());
    }

    @Override
    public void onResponse(Call call, Response response) throws IOException {
        // 处理响应
        Log.d("Response", response.body().string());
    }
});

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

public class NetworkUtil {
    public static String sendGetRequest(String urlString) throws IOException {
        URL url = new URL(urlString);
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.setRequestMethod("GET");
        connection.connect();

        int responseCode = connection.getResponseCode();
        if (responseCode == HttpURLConnection.HTTP_OK) {
            BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            StringBuilder response = new StringBuilder();
            String line;
            while ((line = reader.readLine()) != null) {
                response.append(line);
            }
            reader.close();
            return response.toString();
        } else {
            return "Error: HTTP response code: " + responseCode;
        }
    }
}