square/okhttp · error · IOException

Unexpected code

Error message

Unexpected code 

What it means

UploadProgress.java:75 throws 'Unexpected code ' when the POST to https://api.imgur.com/3/image returns non-2xx. The recipe authenticates with a hardcoded Client-ID '9199fdef135c122' (line 32) via the Authorization header, and POSTs docs/images/logo-square.png wrapped in a ProgressRequestBody that counts bytes via a ForwardingSink. The isSuccessful() guard runs after the body has been fully transmitted, so progress completes before the error is raised.

Source

Thrown at samples/guide/src/main/java/okhttp3/recipes/UploadProgress.java:75

          if (contentLength != -1) {
            System.out.format("%d%% done\n", (100 * bytesWritten) / contentLength);
          }
        }
      }
    };

    RequestBody requestBody = RequestBody.create(
      new File("docs/images/logo-square.png"),
      MEDIA_TYPE_PNG);

    Request request = new Request.Builder()
      .header("Authorization", "Client-ID " + IMGUR_CLIENT_ID)
      .url("https://api.imgur.com/3/image")
      .post(new ProgressRequestBody(requestBody, progressListener))
      .build();

    Response response = client.newCall(request).execute();
    if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

    System.out.println(response.body().string());
  }

  public static void main(String... args) throws Exception {
    new UploadProgress().run();
  }

  private static class ProgressRequestBody extends RequestBody {

    private final ProgressListener progressListener;
    private final RequestBody delegate;

    public ProgressRequestBody(RequestBody delegate, ProgressListener progressListener) {
      this.delegate = delegate;
      this.progressListener = progressListener;
    }

View on GitHub (pinned to 4fc0831380)

Solutions

1. Register an Imgur application at https://api.imgur.com/oauth2/addclient and replace IMGUR_CLIENT_ID with your own Client-ID.
2. Inspect response.code(), response.header('X-RateLimit-ClientRemaining'), and response.body().string() to differentiate 401/403/429/400.
3. Verify the file exists before building the request: java.nio.file.Files.exists(Path.of("docs/images/logo-square.png")) — a missing file throws FileNotFoundException, not this error.
4. If running many uploads, sleep based on X-RateLimit-Userreset to stay under the Imgur quota and avoid 429.

Example fix

// before
Response response = client.newCall(request).execute();
if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);
System.out.println(response.body().string());

// after
try (Response response = client.newCall(request).execute()) {
  if (!response.isSuccessful()) {
    throw new IOException("Imgur upload failed: HTTP " + response.code()
        + " remaining=" + response.header("X-RateLimit-ClientRemaining")
        + " body=" + response.peekBody(1024).string());
  }
  System.out.println(response.body().string());
}

java.nio.file.Path image = java.nio.file.Paths.get("docs/images/logo-square.png");
if (!java.nio.file.Files.exists(image)) {
  throw new java.io.FileNotFoundException(image.toString());
}
String clientId = System.getenv("IMGUR_CLIENT_ID");
if (clientId == null || clientId.isBlank()) {
  throw new IllegalStateException("IMGUR_CLIENT_ID env var not set");
}
// Build the request only after both guards pass.

try (Response response = client.newCall(request).execute()) {
  switch (response.code()) {
    case 401, 403 -> throw new IOException("Imgur auth failed (" + response.code()
        + "); check Client-ID");
    case 429 -> throw new IOException("Imgur rate limited; reset at "
        + response.header("X-RateLimit-Userreset"));
  }
  if (!response.isSuccessful()) {
    throw new IOException("Imgur " + response.code() + ": " + response.peekBody(1024).string());
  }
  handle(response.body().string());
}

When it happens

Trigger: Imgur returns 401/403 when the Client-ID is unknown/revoked; 429 when the application exceeds the per-client rate limit; 400 when the uploaded PNG is rejected (corrupt/oversized) or when docs/images/logo-square.png is missing (the RequestBody.create at line 64 throws FileNotFoundException before reaching the network). Imgur's migration to requiring registered apps (post-2020) makes the legacy anonymous Client-ID invalid, yielding 403.

Common situations: Reusing the sample's Client-ID after Imgur revoked anonymous upload access; running the recipe from a directory that does not contain docs/images/logo-square.png; hitting Imgur's per-IP or per-app post quota in a CI loop; uploading from a country Imgur geo-blocks.

Related errors

• Unexpected code
• Unexpected code
• Unexpected code
• Unexpected code
• Unexpected code

AI-assisted analysis of square/okhttp@4fc0831380 (2026-08-04). Data as JSON: /data/errors/4368d499451ca672.json. Report an issue: GitHub.