OkHttp3 拦截器向请求正文添加字段

Question

由于我的 API 请求都包含一些共同的 json 字段，我想在拦截器中添加这些字段，但我正在努力修改拦截器中的 OkHttp3 RequestBody

这是我的改造构建器：

private val retrofitBuilder by lazy {


        val client = OkHttpClient.Builder().apply {
            addInterceptor(MyInterceptor())
        }.build()

        Retrofit.Builder()
            .baseUrl("https://placeholder.com/")
            .addConverterFactory(GsonConverterFactory.create())
            .client(client)
            .build()

    }

这里是拦截器：

class MyInterceptor : Interceptor {

    override fun intercept(chain: Interceptor.Chain): Response {

        //Is it possible to change it in JSON? Or how do I add paramenters to this body?
        val body: RequestBody? = chain.request().body()

        return chain.proceed(chain.request())
    }
}

如何将“traceId”：“abc123”添加到拦截器内的所有请求正文中？

Answer 1

就我而言：

public class MyInterceptor implements Interceptor {

@Override
public Response intercept(Chain chain) throws IOException {
    Request request = chain.request();
    request = addHeaderFields(request);
    request = modifyRequestBody(request);
    return chain.proceed(request);
}

/**
 * add new Headers
 */
private Request addHeaderFields(Request request) {
    return request.newBuilder()
            .addHeader("timestamp", String.valueOf(new Date().getTime()))
            .addHeader("os", "android")
            .build();
}

/**
 * add new post fields
 */
private Request modifyRequestBody(Request request) {
    if ("POST".equals(request.method())) {
        if (request.body() instanceof FormBody) {
            FormBody.Builder bodyBuilder = new FormBody.Builder();
            FormBody formBody = (FormBody) request.body();
            // Copy the original parameters first
            for (int i = 0; i < formBody.size(); i++) {
                bodyBuilder.addEncoded(formBody.encodedName(i), formBody.encodedValue(i));
            }
            // Add common parameters
            formBody = bodyBuilder
                    .addEncoded("userid", "001")
                    .addEncoded("param2", "value2")
                    .build();
            request = request.newBuilder().post(formBody).build();
        }
    }
    return request;
}

}

Answer 2

带有头部和正文修改的拦截器：

class OkHttpInterceptor() : Interceptor {

    override fun intercept(chain: Interceptor.Chain): Response {
        val request = chain.request()
        val requestWithAndroidHeaders = addHeaderFields(request)
        val response = chain.proceed(requestWithAndroidHeaders)
        return modifyResponseBody(response)
    }

    private fun addHeaderFields(request: Request): Request = request.newBuilder()
                .addHeader("Content-Type", "application/json")
                .addHeader("User-Agent", "Android")
                .addHeader("TraceId", "abc 123")
                .build()

    private fun modifyResponseBody(response: Response): Response {
        val responseString = response.body()?.charStream()?.readText()
        val responseJson = responseString?.let { stringToJson(it) }
        return if (responseJson != null) {
            val contentType: MediaType? = response.body()?.contentType()
            val responseBody = ResponseBody.create(contentType, responseJson.toString())
            response.newBuilder().body(responseBody).build()
        } else {
           response
        }
    }

    private fun stringToJson(responseString: String): JSONObject? = try {
        JSONObject(responseString).put("traceId", "abc 123")
    } catch (e: JSONException) {
        println(e.message)
        null
    }
}

OkHttpClient：

val okHttpInterceptor = OkHttpInterceptor()
val client = OkHttpClient.Builder()
client.interceptors().add(okHttpInterceptor)
client.build()

也许您还想添加 Logging：

val logging = HttpLoggingInterceptor()
if(BuildConfig.DEBUG) {
    logging.level = HttpLoggingInterceptor.Level.BODY
} else {
    logging.level = HttpLoggingInterceptor.Level.NONE
}
val okHttpInterceptor = OkHttpInterceptor()
val client = OkHttpClient.Builder()
client.interceptors().add(okHttpInterceptor)
client.interceptors().add(logging)
client.build()

Answer 3

这应该可以，虽然我是用 java 做的，但认为你应该在 kotlin 中解决它

public Response intercept(@NonNull Chain chain) throws IOException {
             Request original = chain.request();
             // Request customization: add request headers
             Request.Builder requestBuilder = original.newBuilder();
             //requestBuilder.addHeader("key",API_KEY);
             requestBuilder.addHeader("Content-Type","application/json");

             Request request = requestBuilder.build();
             return chain.proceed(request);
         }