Retrofit2：在 OkHttp 拦截器中修改请求正文

Question

我在 Android 应用程序中使用带有 OkHttp 客户端的 Retrofit 2 (2.0.0-beta3)，到目前为止一切顺利。但目前我正面临 OkHttp 拦截器的问题。我正在与之通信的服务器正在请求正文中获取访问令牌，因此当我拦截添加身份验证令牌的请求或在需要添加更新的身份验证令牌时在 Authenticator 的身份验证方法中时，我需要为此修改请求正文.但看起来我只能在标头中添加数据，而不能在正在进行的请求的正文中添加数据。目前我写的代码如下：

client.interceptors().add(new Interceptor() {
            @Override
            public Response intercept(Chain chain) throws IOException {
                Request request = chain.request();
                if (UserPreferences.ACCESS_TOKEN != null) {
                    // need to add this access token in request body as encoded form field instead of header
                    request = request.newBuilder()
                            .header("access_token", UserPreferences.ACCESS_TOKEN))
                            .method(request.method(), request.body())
                            .build();
                }
                Response response = chain.proceed(request);
                return response;
            }
        });

谁能指出我正确的方向，即如何修改请求正文以添加我的访问令牌（第一次或在令牌刷新后更新）？任何指向正确方向的指针将不胜感激。

Answer 1

我使用它来将 post 参数添加到现有的。

 OkHttpClient client = new OkHttpClient.Builder()
                    .protocols(protocols)
                    .addInterceptor(new Interceptor() {
                        @Override
                        public Response intercept(Chain chain) throws IOException {
                            Request request = chain.request();
                            Request.Builder requestBuilder = request.newBuilder();
RequestBody formBody = new FormEncodingBuilder()
            .add("email", "Jurassic@Park.com")
            .add("tel", "90301171XX")
            .build();
                            String postBodyString = Utils.bodyToString(request.body());
                            postBodyString += ((postBodyString.length() > 0) ? "&" : "") +  Utils.bodyToString(formBody);
                            request = requestBuilder
                                    .post(RequestBody.create(MediaType.parse("application/x-www-form-urlencoded;charset=UTF-8"), postBodyString))
                                    .build();
                            return chain.proceed(request);
                        }
                    })
                    .build();

public static String bodyToString(final RequestBody request){
        try {
            final RequestBody copy = request;
            final Buffer buffer = new Buffer();
            if(copy != null)
                copy.writeTo(buffer);
            else
                return "";
            return buffer.readUtf8();
        }
        catch (final IOException e) {
            return "did not work";
        }
    }

OkHttp3：

RequestBody formBody = new FormBody.Builder()
                .add("email", "Jurassic@Park.com")
                .add("tel", "90301171XX")
                .build();

Answer 2

我将使用 Dagger 分享我的 @Fabian 答案的 Kotlin 实现。我希望将origin=app 添加到 GET 请求的请求 url，并添加到表单编码的 POST 请求的正文中

@Provides
@Singleton
fun providesRequestInterceptor() =
        Interceptor {
            val request = it.request()

            it.proceed(when (request.method()) {
                "GET" -> {
                    val url = request.url()
                    request.newBuilder()
                            .url(url.newBuilder()
                                    .addQueryParameter("origin", "app")
                                    .build())
                            .build()
                }
                "POST" -> {
                    val body = request.body()
                    request.newBuilder()
                            .post(RequestBody.create(body?.contentType(),
                                    body.bodyToString() + "&origin=app"))
                            .build()
                }
                else -> request
            })
        }

fun RequestBody?.bodyToString(): String {
    if (this == null) return ""
    val buffer = okio.Buffer()
    writeTo(buffer)
    return buffer.readUtf8()
}

Answer 3

因为这不能写在@Fabian 上一个答案的 cmets 中，所以我将这个作为单独的答案发布。这个答案既涉及“应用程序/json”，也涉及表单数据。

import android.content.Context;

import org.json.JSONException;
import org.json.JSONObject;

import java.io.IOException;

import okhttp3.FormBody;
import okhttp3.Interceptor;
import okhttp3.MediaType;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;
import okio.Buffer;

/**
 * Created by debanjan on 16/4/17.
 */

public class TokenInterceptor implements Interceptor {
    private Context context; //This is here because I needed it for some other cause 

    //private static final String TOKEN_IDENTIFIER = "token_id";
    public TokenInterceptor(Context context) {
        this.context = context;
    }

    @Override
    public Response intercept(Chain chain) throws IOException {
        Request request = chain.request();
        RequestBody requestBody = request.body();
        String token = "toku";//whatever or however you get it.
        String subtype = requestBody.contentType().subtype();
        if(subtype.contains("json")){
            requestBody = processApplicationJsonRequestBody(requestBody, token);
        }
        else if(subtype.contains("form")){
            requestBody = processFormDataRequestBody(requestBody, token);
        }
        if(requestBody != null) {
            Request.Builder requestBuilder = request.newBuilder();
            request = requestBuilder
                    .post(requestBody)
                    .build();
        }

        return chain.proceed(request);
    }
    private String bodyToString(final RequestBody request){
        try {
            final RequestBody copy = request;
            final Buffer buffer = new Buffer();
            if(copy != null)
                copy.writeTo(buffer);
            else
                return "";
            return buffer.readUtf8();
        }
        catch (final IOException e) {
            return "did not work";
        }
    }
    private RequestBody processApplicationJsonRequestBody(RequestBody requestBody,String token){
        String customReq = bodyToString(requestBody);
        try {
            JSONObject obj = new JSONObject(customReq);
            obj.put("token", token);
            return RequestBody.create(requestBody.contentType(), obj.toString());
        } catch (JSONException e) {
            e.printStackTrace();
        }
        return null;
    }
    private RequestBody processFormDataRequestBody(RequestBody requestBody, String token){
        RequestBody formBody = new FormBody.Builder()
                .add("token", token)
                .build();
        String postBodyString = bodyToString(requestBody);
        postBodyString += ((postBodyString.length() > 0) ? "&" : "") +  bodyToString(formBody);
        return RequestBody.create(requestBody.contentType(), postBodyString);
    }

}

Answer 4

您可以通过以下方法编辑请求正文，传递请求和参数进行编辑。

private fun editBody(request: Request, parameter: String): RequestBody {
           
  val oldBody = request.body //retrieve the current request body
  val buffer =  Buffer()
  oldBody?.writeTo(buffer)

  val strOldBody = buffer.readUtf8() // String representation of the current request body
  buffer.clear()
  buffer.close()

  val strNewBody = JSONObject(strOldBody).put("parameter", parameter).toString()
  return strNewBody.toRequestBody(request.body?.contentType()) // New request body with the encrypted/modified string of the current request body

}

现在您可以使用更新的请求正文再次请求

override fun intercept(chain: Interceptor.Chain): Response {
      val request: Request = chain.request()
      return chain.proceed(requestWithUpdatedParameter(request, "parameter"))
    
}
    
private fun requestWithUpdatedParameter(req: Request, parameter: String): Request {
                val newRequest: Request
                val body = editBody(req, parameter)
                newRequest = req.newBuilder().method(req.method, body).build()
                return newRequest
}

Answer 5

private static class NetworkInterceptor implements Interceptor {

@Override
public Response intercept(Chain chain) throws IOException {
    
    Request request = chain.request();
    RequestBody oldBody = request.body(); //retrieve the current request body
    Buffer buffer = new Buffer();
    oldBody.writeTo(buffer);
    String strOldBody = buffer.readUtf8(); // String representation of the current request body
    buffer.clear();
    buffer.close();

    MediaType mediaType = MediaType.parse("application/json; charset=UTF-8");
    String strNewBody = enDecService.encryptBody(strOldBody); // Your encryption/ modification logic 
    RequestBody body = RequestBody.create(mediaType, strNewBody); // New request body with the encrypted/modified string of the current request body

    request = request.newBuilder()
            .header("Content-Type", "application/json")
            .header("Content-Length", String.valueOf(body.contentLength()))
            .header("Authorization", "Bearer " + "your token")
            .method(request.method(), body).build();


    long t1 = System.nanoTime();
    Log.d(TAG, String.format("Sending request %s on %s", request.url(), request.headers()));

    Response response = chain.proceed(request); // sending req. to server. current req. body is a encrypted string.
    int maxAge = 6000; // read from cache for 6000 seconds even if there is internet connection
    response.header("Cache-Control", "public, max-age=" + maxAge);
    response = response.newBuilder().removeHeader("Pragma").build();


    long t2 = System.nanoTime();
    Log.d(TAG, String.format("Received response for %s in %.1fms  %s", response.request().url(), (t2 - t1) / 1e6d, response.toString()));

    try {
        String s = response.body().string(); // retrieve string representation of encrypted response assuming your response is encrypted.
        ResponseBody responseBody = ResponseBody.create(mediaType, enDecService.decryptBody(s)); // decrypt the encrypted response or make other modifications.yor decryption/modifications logic goes here.
        response = response.newBuilder().body(responseBody).build(); // build a new response with the decrypted response body.
    } catch (JOSEException e) {

    } catch (ParseException e) {

    }
    return response;
}

}

Answer 6

我正在使用这种方式来验证我的令牌

final OkHttpClient okHttpClient = new OkHttpClient.Builder()
                .connectTimeout(30, TimeUnit.SECONDS) //retrofit default 10 seconds
                .writeTimeout(30, TimeUnit.SECONDS) //retrofit default 10 seconds
                .readTimeout(30, TimeUnit.SECONDS) //retrofit default 10 seconds
                .addInterceptor(logging.setLevel(HttpLoggingInterceptor.Level.BODY))
                .addInterceptor(new BasicAuthInterceptor())
                .build();

这里我通过 BasicAuthInterceptor 发送令牌

public class MyServiceInterceptor implements Interceptor {

private String HEADER_NAME="Authorization";
private String OBJECT_NAME="Bearer";
private String SPACE="  ";
@Override public Response intercept(Chain chain) throws IOException {
    Request request = chain.request();

    Request.Builder requestBuilder = request.newBuilder();

    String token= PreferenceManager.getInstance().getString(PreferenceManager.TOKEN);
        if (token != null) { {
            requestBuilder.addHeader(HEADER_NAME, OBJECT_NAME+SPACE+ token);
        }
}

    return chain.proceed(requestBuilder.build());

} }