首先向build.gradle添加依赖项:

实现“com.squareup.okhttp3:日志记录拦截器:3.12.1”

在使用Kotlin时，你可以像这样添加日志拦截器:

companion object {
    val okHttpClient = OkHttpClient().newBuilder()
            .addInterceptor(HttpLoggingInterceptor().apply {
                level = HttpLoggingInterceptor.Level.BODY
            })
            .build()


    fun getRetrofitInstance(): Retrofit {
        val retrofit = Retrofit.Builder()
                .client(okHttpClient)
                .baseUrl(ScanNShopConstants.BASE_URL)
                .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
                .addConverterFactory(GsonConverterFactory.create())
                .build()

        return retrofit
    }
}

我不知道setLogLevel()是否会在最终2.0版本的Retrofit中返回，但现在你可以使用一个拦截器来记录日志。

一个很好的例子可以在OkHttp wiki上找到:https://github.com/square/okhttp/wiki/Interceptors

OkHttpClient client = new OkHttpClient();
client.interceptors().add(new LoggingInterceptor());

Retrofit retrofit = new Retrofit.Builder()
        .baseUrl("http://www.yourjsonapi.com")
        .addConverterFactory(GsonConverterFactory.create())
        .client(client)
        .build();

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。

在Retrofit 2中做到这一点的最好方法是添加记录器拦截器作为networkInterceptor，这将打印出网络头和您的自定义头。重要的是要记住，拦截器作为一个堆栈工作，并确保在所有的末尾添加记录器。

OkHttpClient.Builder builder = new OkHttpClient.Builder();
builder.addInterceptor(new MyCustomInterceptor());
builder.connectTimeout(60, TimeUnit.SECONDS);
builder.readTimeout(60, TimeUnit.SECONDS);
builder.writeTimeout(60, TimeUnit.SECONDS);
// important line here
builder.addNetworkInterceptor(LoggerInterceptor());

如果您正在使用Retrofit2和okhttp3，那么您需要知道Interceptor是通过队列工作的。所以在你的其他interceptor之后添加loggingInterceptor:

HttpLoggingInterceptor loggingInterceptor = new HttpLoggingInterceptor();
        if (BuildConfig.DEBUG)
            loggingInterceptor.setLevel(HttpLoggingInterceptor.Level.HEADERS);

 new OkHttpClient.Builder()
                .connectTimeout(60, TimeUnit.SECONDS)
                .readTimeout(60, TimeUnit.SECONDS)
                .writeTimeout(60, TimeUnit.SECONDS)
                .addInterceptor(new CatalogInterceptor(context))//first
                .addInterceptor(new OAuthInterceptor(context))//second
                .authenticator(new BearerTokenAuthenticator(context))
                .addInterceptor(loggingInterceptor)//third, log at the end
                .build();

对于Retrofit 2.0.2，代码如下:

HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
        logging.setLevel(HttpLoggingInterceptor.Level.BODY);
        OkHttpClient.Builder httpClient=new OkHttpClient.Builder();
        httpClient.addInterceptor(logging);

        if (retrofit == null) {
            retrofit = new Retrofit.Builder()
                    .baseUrl(BASE_URL)
                    .addConverterFactory(GsonConverterFactory.create())
                    .client(httpClient.build())
                    .build();
        }