Libraries with only an SPI layer are missing documentation

[gguuss]

Issue

Documentation is missing for the most critical APIs for Java Cloud Vision.

Repro

See the Java documentation and try to find the most important classes for the Cloud Vision API, most notably:

• com.google.cloud.vision.v1.AnnotateImageRequest
• com.google.cloud.vision.v1.AnnotateImageResponse
• com.google.cloud.vision.v1.BatchAnnotateImagesResponse
• com.google.cloud.vision.v1.ColorInfo
• com.google.cloud.vision.v1.DominantColorsAnnotation
• com.google.cloud.vision.v1.EntityAnnotation
• com.google.cloud.vision.v1.FaceAnnotation
• com.google.cloud.vision.v1.Feature
• com.google.cloud.vision.v1.Feature.Type
• com.google.cloud.vision.v1.Image

None of these features have documentation and are necessary to understand when using the Cloud Vision client library.

Fix

Please generate and publish the documentation for the com.google.cloud.vision.* APIs.

It may also be helpful to include a nice little snippet demonstrating usage:

  public static void detectFaces(String filePath, PrintStream out) throws IOException {
    List<AnnotateImageRequest> requests = new ArrayList<>();

    FileInputStream file = new FileInputStream(filePath);
    ByteString imgBytes = ByteString.copyFrom(toByteArray(file));

    Image img = Image.newBuilder().setContent(imgBytes).build();
    Feature feat = Feature.newBuilder().setType(Type.FACE_DETECTION).build();
    AnnotateImageRequest request = AnnotateImageRequest.newBuilder()
        .addFeatures(feat)
        .setImage(img)
        .build();
    requests.add(request);

    BatchAnnotateImagesResponse response = visionApi.batchAnnotateImages(requests);
    List<AnnotateImageResponse> responses = response.getResponsesList();

    for (AnnotateImageResponse res : responses) {
      if (res.hasError()) {
        out.printf("Error: %s\n", res.getError().getMessage());
      }

      for (FaceAnnotation annotation : res.getFaceAnnotationsList()) {
        out.printf("anger: %s\njoy: %s\nsurprise: %s\n",
            annotation.getAngerLikelihood(),
            annotation.getJoyLikelihood(),
            annotation.getSurpriseLikelihood());
      }
    }
  }

[garrettjonesgoogle]

• This affects all APIs which only have an spi layer. We are currently working on this.
• There are example apps here:

https://github.com/GoogleCloudPlatform/java-docs-samples

For Vision specifically:

https://github.com/GoogleCloudPlatform/java-docs-samples/tree/master/vision/text/src/main/java/com/google/cloud/vision/samples/text

I think there could be clearer pointers to the example apps.