2. Tutorials
  3. Retrofit — Using the Log Level to Debug Requests

Retrofit — Using the Log Level to Debug Requests

After diving deep into the art of using Retrofit for network requests, we'll look in this post at the debugging capabilities of Retrofit. Let's review the covered topics in our Retrofit series.

Retrofit Series Overview

  1. Getting Started and Creating an Android Client
  2. Basics of API Description
  3. Creating a Sustainable Android Client
  4. URL Handling, Resolution and Parsing
  5. How to Change API Base Url at Runtime
  6. Multiple Server Environments (Develop, Staging, Production)
  7. Share OkHttp Client and Converters between Retrofit Instances
  8. Upgrade Guide from 1.9
  9. Beyond Android: Retrofit for Java Projects
  10. How to use OkHttp 3 with Retrofit 1
  1. Synchronous and Asynchronous Requests
  2. Send Objects in Request Body
  3. Add Custom Request Header
  4. Manage Request Headers in OkHttp Interceptor
  5. Dynamic Request Headers with @HeaderMap
  6. Multiple Query Parameters of Same Name
  7. Optional Query Parameters
  8. Send Data Form-Urlencoded
  9. Send Data Form-Urlencoded Using FieldMap
  10. How to Add Query Parameters to Every Request
  11. Add Multiple Query Parameter With QueryMap
  12. How to Use Dynamic Urls for Requests
  13. Constant, Default and Logic Values for POST and PUT Requests
  14. Cancel Requests
  15. Reuse and Analyze Requests
  16. Optional Path Parameters
  17. How to Send Plain Text Request Body
  18. Customize Network Timeouts
  19. How to Trust Unsafe SSL certificates (Self-signed, Expired)
  20. Dynamic Endpoint-Dependent Interceptor Actions
  21. How to Update Objects on the Server (PUT vs. PATCH)
  22. How to Delete Objects on the Server
  1. Ignore Response Payload with Call<Void>
  2. Receive Plain-String Responses
  3. Crawl HTML Responses with jspoon (Wikipedia Example)
  4. Loading Data into RecyclerView and CardView
  1. Introduction to (Multiple) Converters
  2. Adding & Customizing the Gson Converter
  3. Implementing Custom Converters
  4. How to Integrate XML Converter
  5. Access Mapped Objects and Raw Response Payload
  6. Supporting JSON and XML Responses Concurrently
  7. Handling of Empty Server Responses with Custom Converter
  8. Send JSON Requests and Receive XML Responses (or vice versa)
  9. Unwrapping Envelope Responses with Custom Converter
  10. Wrapping Requests in Envelope with Custom Converter
  11. Define a Custom Response Converter
  1. Simple Error Handling
  2. Error Handling for Synchronous Requests
  3. Catch Server Errors Globally with Response Interceptor
  4. How to Detect Network and Conversion Errors in onFailure
  1. Introduction to Call Adapters
  2. Custom Call Adapter to Separate OnResponse Callback
  3. How to Integrate RxJava 1.x Call Adapter
  4. How to Integrate RxJava 2.x Call Adapter
  5. How to Integrate Guava Call Adapter
  6. Custom Call Adapter to Separate Network and Gson Errors
  1. Pagination Using Query Parameter
  2. Pagination Using Link Header and Dynamic Urls (Like GitHub)
  3. Pagination Using Range Header Fields (Like Heroku)
  1. How to Upload Files to Server
  2. How to Upload Multiple Files to Server
  3. How to Upload a Dynamic Amount of Files to Server
  4. Upload Files with Progress
  5. Passing Multiple Parts Along a File with @PartMap
  6. How to Download Files from Server
  7. Download Files with Progress Updates
  8. How to Upload Files to Server
  1. Basic Authentication on Android
  2. Token Authentication on Android
  3. OAuth on Android
  4. Hawk Authentication on Android
  5. How to Refresh an Access Token
  1. Activate Response Caching (Etag, Last-Modified)
  2. Check Response Origin (Network, Cache, or Both)
  3. Force Server Cache Support with Response Interceptor
  4. Support App Offline Mode by Accessing Response Caches
  5. Analyze Cache Files
  1. Basics of Mocking Server Responses
  2. Customizing Network Behavior of Mocked Server Responses
  3. Mock APIs with JsonServer
  1. Callbacks
  2. Annotations
  3. Fluent Interface with Builders

Logging in Retrofit 2

We’ve published a blog post on how to debug requests using Retrofit 2. If you already jumped on the second major version of Retrofit, please follow the link to the related post.

Request Logging

As you can see by our long list of published posts, we at Future Studio are fans of Retrofit. Just a few days ago we utilized another great feature of Retrofit: the request logging.

If you're having a similar problem and trouble understanding why a request from your Android app does not work the way it is intended, follow this guide for easy trouble shooting (or, at the very least, to be able to blame the API devs).

Activating Retrofit Logging

That we can view the requests and responses can be a nice assistant. However, it's deactivated by default. Luckily, enabling the logging feature is fast and easy:

RestAdapter.Builder builder = new RestAdapter.Builder()  
    .setEndpoint(API_LOCATION)
    .setLogLevel(RestAdapter.LogLevel.FULL) // this is the important line
    .setClient(new OkClient(new OkHttpClient()));

This is all you've to do. Now start the app or the tests and force an execution of the requests in question.

Using the Logs

After the requests were made, take a look at the Android Logcat of your testing device. Retrofit posts a bunch of interesting things:

Retrofit's Logs using Log Level FULL

As you can see, this includes the entire request and response body. While this can be useful and necessary, the information can be too much and clutter up your log.

Knowing the Levels

Not to worry, Retrofit has different logging levels to match the amount of required information without blowing up your logs too much. Let's take a look at the various levels:

  • NONE

Description: No logging.

  • BASIC

Description: Log only the request method and URL and the response status code and execution time.

Example:

Retrofit's Logs using BASIC

  • HEADERS

Description: Log the basic information along with request and response headers.

Example:

Retrofit's Logs using HEADERS

  • HEADERS_AND_ARGS

Description: Log the basic information along with request and response objects via toString().

Example:

Retrofit's Logs using HEADERS_AND_ARGS

  • FULL

Description: Log the headers, body, and metadata for both requests and responses.

Example:

see above at Using the Logs

Utilize Logging

We hope this post gave you a short introduction into a feature of Retrofit, which can be tremendously helpful. Keep it in your mind if you want to debug a specific request or just log all the networking your app is doing.

If you've questions, please let us know at @futurestud_io.

Additional Resources

Norman Peitek

android & node.js dev

https://twitter.com/peitek

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