io.wcm.dam.assetservice.impl.AssetRequestServlet Maven / Gradle / Ivy

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A RESTful service for resolving URLs to DAM assets and renditions.
There is a newer version: 1.5.0
/*
 * #%L
 * wcm.io
 * %%
 * Copyright (C) 2015 wcm.io
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */
package io.wcm.dam.assetservice.impl;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang3.CharEncoding;
import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.api.SlingHttpServletResponse;
import org.apache.sling.api.servlets.SlingSafeMethodsServlet;
import org.apache.sling.commons.json.JSONArray;
import org.apache.sling.commons.json.JSONException;
import org.apache.sling.commons.json.JSONObject;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import io.wcm.handler.media.Media;
import io.wcm.handler.media.MediaHandler;
import io.wcm.handler.media.Rendition;
import io.wcm.wcm.commons.contenttype.ContentType;

/**
 * Implements a simple REST interface that allows resolving DAM asset paths to URLs.
 * For image assets resolving to specific dimensions is supported.
 */
@SuppressWarnings("deprecation")
class AssetRequestServlet extends SlingSafeMethodsServlet {
  private static final long serialVersionUID = 1L;

  private final DamPathHandler damPathHandler;

  private static final Logger log = LoggerFactory.getLogger(AssetRequestServlet.class);

  AssetRequestServlet(DamPathHandler damPathHandler) {
    this.damPathHandler = damPathHandler;
  }

  @SuppressWarnings("null")
  @Override
  protected void doGet(SlingHttpServletRequest request, SlingHttpServletResponse response) throws ServletException, IOException {
    String assetPath = request.getResource().getPath();

    // check if asset path is valid
    if (!damPathHandler.isAllowedAssetPath(assetPath)) {
      log.debug("Asset path not allowed {}", assetPath);
      response.sendError(HttpServletResponse.SC_NOT_FOUND);
      return;
    }

    // get media handler
    MediaHandler mediaHandler = request.getResource().adaptTo(MediaHandler.class);
    if (mediaHandler == null) {
      log.debug("Unable to get media handler for {}", assetPath);
      response.sendError(HttpServletResponse.SC_NOT_FOUND);
      return;
    }

    // build list of asset service requests with optional input parameters
    List requests = AssetRequestParser.getAssetRequests(assetPath, request);

    // resolve asset service requests
    List mediaList = resolveMedia(requests, mediaHandler);
    if (mediaList.isEmpty()) {
      log.debug("No matching assets/renditions found for {}; requests: {}", assetPath, requests);
      response.sendError(HttpServletResponse.SC_NOT_FOUND);
      return;
    }

    // output result json
    try {
      JSONArray resultJson = toResultJson(mediaList);
      response.setContentType(ContentType.JSON);
      response.setCharacterEncoding(CharEncoding.UTF_8);
      response.getWriter().write(resultJson.toString());
    }
    catch (JSONException ex) {
      throw new ServletException("Unable to generate JSON.", ex);
    }
  }

  private List resolveMedia(List requests, MediaHandler mediaHandler) {
    List result = new ArrayList<>();
    for (AssetRequest request : requests) {
      Media media = request.resolve(mediaHandler);
      if (media.isValid()) {
        result.add(media);
      }
    }
    return result;
  }

  private JSONArray toResultJson(List mediaList) throws JSONException {
    JSONArray array = new JSONArray();
    for (Media media : mediaList) {
      Rendition rendition = media.getRendition();
      JSONObject mediaObject = new JSONObject();
      mediaObject.put("assetPath", media.getAsset().getPath());
      mediaObject.put("url", media.getUrl());
      if (rendition.getWidth() > 0 && rendition.getHeight() > 0) {
        mediaObject.put("width", rendition.getWidth());
        mediaObject.put("height", rendition.getHeight());
      }
      if (rendition.getFileSize() > 0) {
        mediaObject.put("fileSize", rendition.getFileSize());
      }
      mediaObject.putOpt("fileExtension", rendition.getFileExtension());
      mediaObject.putOpt("mimeType", rendition.getMimeType());
      array.put(mediaObject);
    }
    return array;
  }

}