我也陷入了类似的情况，setLevel()方法没有到来，当我试图用HttpLoggingInterceptor的实例调用它时， 是这样的:

HttpLoggingInterceptor loggingInterceptor = new HttpLoggingInterceptor();
loggingInterceptor.setLevel(HttpLoggingInterceptor.Level.BODY);

这是我解决它的方法，为Retrofit2生成日志，

我猜你增加了依赖关系，

implementation "com.squareup.okhttp3:logging-interceptor:4.7.2"

对于最新的版本，你可以查看，这个链接:

https://github.com/square/okhttp/tree/master/okhttp-logging-interceptor)

这里他们也解释了如何添加。

我创建了一个名为AddLoggingInterceptor的类， 这是我的代码，

public class AddLoggingInterceptor {

    public static OkHttpClient setLogging(){
        HttpLoggingInterceptor loggingInterceptor = new HttpLoggingInterceptor();
        loggingInterceptor.setLevel(HttpLoggingInterceptor.Level.BODY);

        OkHttpClient okHttpClient = new OkHttpClient.Builder()
                .addInterceptor(loggingInterceptor)
                .build();

        return okHttpClient;
    }
}

然后，在我们实例化我们的Retrofit时，

 public static Retrofit getRetrofitInstance() {
    if (retrofit == null) {
        retrofit = new retrofit2.Retrofit.Builder()
                .baseUrl(BASE_URL)
                .addConverterFactory(GsonConverterFactory.create())
                .client(AddLoggingInterceptor.setLogging()) // here the method is called inside client() method, with the name of class, since it is a static method.
                .build();
    }
    return retrofit;
}

现在你可以看到日志生成在你的Android工作室，你可能需要搜索，okHttp过滤过程。这对我很管用。如果有任何问题，你可以给我发短信。

下面是一个拦截器，它同时记录请求和响应体(使用Timber，基于OkHttp文档中的一个例子和其他一些SO答案):

public class TimberLoggingInterceptor implements Interceptor {
    @Override
    public Response intercept(Chain chain) throws IOException {
        Request request = chain.request();

        long t1 = System.nanoTime();
        Timber.i("Sending request %s on %s%n%s", request.url(), chain.connection(), request.headers());
        Timber.v("REQUEST BODY BEGIN\n%s\nREQUEST BODY END", bodyToString(request));

        Response response = chain.proceed(request);

        ResponseBody responseBody = response.body();
        String responseBodyString = response.body().string();

        // now we have extracted the response body but in the process
        // we have consumed the original reponse and can't read it again
        // so we need to build a new one to return from this method

        Response newResponse = response.newBuilder().body(ResponseBody.create(responseBody.contentType(), responseBodyString.getBytes())).build();

        long t2 = System.nanoTime();
        Timber.i("Received response for %s in %.1fms%n%s", response.request().url(), (t2 - t1) / 1e6d, response.headers());
        Timber.v("RESPONSE BODY BEGIN:\n%s\nRESPONSE BODY END", responseBodyString);

        return newResponse;
    }

    private static String bodyToString(final Request request){

        try {
            final Request copy = request.newBuilder().build();
            final Buffer buffer = new Buffer();
            copy.body().writeTo(buffer);
            return buffer.readUtf8();
        } catch (final IOException e) {
            return "did not work";
        }
    }
}

试试这个:

Request request = chain.request();
Buffer buffer = new Buffer();
request.body().writeTo(buffer);
String body = buffer.readUtf8();

在此之后，在正文中有您感兴趣的JSON。

在改装2中，你应该使用HttpLoggingInterceptor。

向build.gradle添加依赖项。截至2019年10月的最新版本为:

implementation 'com.squareup.okhttp3:logging-interceptor:4.2.1'

创建一个Retrofit对象，如下所示:

HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
interceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
OkHttpClient client = new OkHttpClient.Builder().addInterceptor(interceptor).build();

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

return retrofit.create(ApiClient.class);

如果出现弃用警告，只需将setLevel更改为:

interceptor.level(HttpLoggingInterceptor.Level.BODY);

上面的解决方案为您提供的logcat消息非常类似于

setLogLevel(RestAdapter.LogLevel.FULL)

对于java.lang.ClassNotFoundException:

旧的Retrofit版本可能需要旧的日志拦截器版本。详情请看评论部分。

下面的代码对我来说没有任何问题

Gradle

// Retrofit
implementation 'com.squareup.retrofit2:retrofit:2.5.0'
implementation 'com.squareup.retrofit2:converter-gson:2.5.0'
implementation 'com.squareup.okhttp3:logging-interceptor:3.12.1'

RetrofitClient

HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
logging.setLevel(HttpLoggingInterceptor.Level.BODY);

OkHttpClient client = new OkHttpClient.Builder()
        .addInterceptor(logging)
        .build();

retrofit = new Retrofit.Builder()
        .baseUrl(BASE_URL)
        .addConverterFactory(GsonConverterFactory.create())
        .client(client)
        .build();

你也可以通过进入Android Studio底部的Profiler标签来验证结果，然后点击+号开始一个新的会话，然后在“网络”中选择所需的峰值。在那里你可以得到所有的东西，但是又麻烦又慢。请看下图。

这将创建一个带有Logging的改装对象。不需要创建单独的对象。

 private static final Retrofit retrofit = new Retrofit.Builder()
            .baseUrl(BASE_URL)
            .client(new OkHttpClient().newBuilder()
                    .addInterceptor(new HttpLoggingInterceptor().setLevel(HttpLoggingInterceptor.Level.BODY))
                    .readTimeout(READ_TIMEOUT_SECONDS, TimeUnit.SECONDS)
                    .writeTimeout(WRITE_TIMEOUT_SECONDS, TimeUnit.SECONDS)
                    .connectTimeout(CONNECTION_TIMEOUT_SECONDS, TimeUnit.SECONDS)
                    .build())
            .addConverterFactory(GsonConverterFactory.create())
            .build();