LocalAwareHttpFactory.java

import java.io.FileNotFoundException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.io.InputStreamResource;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Service;

import com.openhtmltopdf.extend.FSStream;
import com.openhtmltopdf.extend.FSStreamFactory;
import com.XXX.service.ImageService;

import lombok.RequiredArgsConstructor;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

@RequiredArgsConstructor
@Service
public class LocalAwareHttpFactory implements FSStreamFactory {

	private final OkHttpClient client = new OkHttpClient();
	private final ImageService imageService;

	private static final String LOCALHOST = "http://localhost";
	Logger logger = LoggerFactory.getLogger(LocalAwareHttpFactory.class);

	@Override
	public FSStream getUrl(String url) {

		if (url.toLowerCase().startsWith(LOCALHOST)) {
			// no HTTP is required, we can stream directly through the ImageService
			try {
				return handleLocalFile(url);
			} catch (FileNotFoundException e) {
				logger.error("Failed to get local file '{}' via ImageService",url,e);
				return null;
			}
		} else {
			return handleNwGet(url);
		}

	}

	private FSStream handleNwGet(String url) {
		try {
			Request request = new Request.Builder().url(url).build();
			final Response response = client.newCall(request).execute();
			logger.info("Doing network call to {}", url);
			return new FSStream() {
				@Override
				public InputStream getStream() {
					return response.body().byteStream();
				}

				@Override
				public Reader getReader() {
					return response.body().charStream();
				}

			};
		} catch (Exception e) {
			logger.error("Failed to get URL {}", url, e);
		}
		return null;
	}

	private FSStream handleLocalFile(String url) throws FileNotFoundException {
		int lastIndex = url.lastIndexOf('/');
		String fileName = (lastIndex != -1) ? url.substring(lastIndex + 1) : url;
		ResponseEntity<InputStreamResource> responseEntity = imageService.retrieve(fileName);
		logger.info("Doing local call to {} -> {}", url, fileName);
		return new FSStream() {
			@Override
			public InputStream getStream() {
				try {
					InputStreamResource body = responseEntity.getBody();
					if (body != null) {
						return body.getInputStream();
					}
				} catch (Exception e) {
					logger.error("Failed to get URL " + url, e);
				}
				return null;
			}

			@Override
			public Reader getReader() {
				try {
					InputStreamResource body = responseEntity.getBody();
					if (body != null) {
						return new InputStreamReader(body.getInputStream());
					}
				} catch (Exception e) {
					logger.error("Failed to get URL {}", url, e);
				}
				return null;
			}
		};
	}
}