Java tutorial
/* * Copyright 2010 Manuel Carrasco Moino. (manuel_carrasco at * users.sourceforge.net) http://code.google.com/p/gwtupload * * 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. */ package gwtupload.server.gae; import com.google.appengine.api.blobstore.BlobKey; import com.google.appengine.api.blobstore.BlobstoreService; import com.google.appengine.api.blobstore.BlobstoreServiceFactory; import org.apache.commons.fileupload.FileItem; import org.apache.commons.fileupload.FileItemFactory; import java.io.IOException; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Map.Entry; import javax.servlet.ServletConfig; import javax.servlet.ServletException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import static gwtupload.shared.UConsts.PARAM_BLOBKEY; import static gwtupload.shared.UConsts.PARAM_CANCEL; import static gwtupload.shared.UConsts.PARAM_ERROR; import static gwtupload.shared.UConsts.PARAM_REDIRECT; import static gwtupload.shared.UConsts.RESP_OK; import static gwtupload.shared.UConsts.TAG_CANCELED; import static gwtupload.shared.UConsts.TAG_ERROR; import static gwtupload.shared.UConsts.TAG_FINISHED; import static gwtupload.shared.UConsts.TAG_MESSAGE; import gwtupload.server.AbstractUploadListener; import gwtupload.server.UploadAction; import gwtupload.server.exceptions.UploadActionException; import gwtupload.server.exceptions.UploadCanceledException; import gwtupload.server.gae.BlobstoreFileItemFactory.BlobstoreFileItem; import gwtupload.shared.UConsts; /** * <p> * Upload servlet for the GwtUpload library's deployed in Google App-engine using blobstore. * </p> * * <p> * Constrains: * <ul> * <li>It seems that the redirected servlet path must be /upload because wildcards don't work.</li> * <li>After of blobstoring, our doPost receives a request size = -1.</li> * <li>If the upload fails, our doPost is never called.</li> * </ul> * * @author Manolo Carrasco Moino * */ public class BlobstoreUploadAction extends UploadAction { private static final long serialVersionUID = -2569300604226532811L; protected static BlobstoreService blobstoreService = BlobstoreServiceFactory.getBlobstoreService(); // See constrain 1 private String servletPath = "/upload"; @Override public void checkRequest(HttpServletRequest request) { logger.debug("BLOB-STORE-SERVLET: (" + request.getSession().getId() + ") procesing a request with size: " + request.getContentLength() + " bytes."); } @Override public boolean isAppEngine() { return true; } @Override public void init(ServletConfig config) throws ServletException { super.init(config); uploadDelay = 0; useBlobstore = true; logger.info("BLOB-STORE-SERVLET: init: maxSize=" + maxSize + ", slowUploads=" + uploadDelay + ", isAppEngine=" + isAppEngine() + ", useBlobstore=" + useBlobstore); } @SuppressWarnings("serial") @Override protected final AbstractUploadListener createNewListener(HttpServletRequest request) { return new MemCacheUploadListener(uploadDelay, request.getContentLength()) { int cont = 1; // In blobStore we cannot know the fileSize emulating progress public long getBytesRead() { return getContentLength() / (isFinished() ? 1 : 10 * (1 + (cont++ % 10))); } public long getContentLength() { return 100; } }; } @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException { if (request.getParameter(PARAM_BLOBKEY) != null) { BlobKey blobKey = new BlobKey(request.getParameter("blob-key")); blobstoreService.serve(blobKey, response); try { logger.info("BLOB-STORE-SERVLET: Serving blobstore file. " + request.getParameter(PARAM_BLOBKEY)); blobstoreService.serve(new BlobKey(request.getParameter(PARAM_BLOBKEY)), response); } catch (Throwable e) { logger.info("BLOB-STORE-SERVLET: Exception accessing blobStoreService:" + e.getMessage()); e.printStackTrace(); renderXmlResponse(request, response, "Error getting blob: " + e.getMessage() + " " + request.getParameter(PARAM_BLOBKEY)); } } else if (request.getParameter(PARAM_REDIRECT) != null) { perThreadRequest.set(request); Map<String, String> stat = new HashMap<String, String>(); if (request.getParameter(PARAM_ERROR) != null) { stat.put(TAG_ERROR, request.getParameter(PARAM_ERROR)); } else if (request.getParameter(PARAM_CANCEL) != null) { stat.put(TAG_CANCELED, request.getParameter(PARAM_CANCEL)); } else { try { getFileItemsSummary(request, stat); String message = executeAction(request, getMySessionFileItems(request)); stat.put(TAG_MESSAGE, message); stat.put(TAG_FINISHED, RESP_OK); } catch (UploadActionException e) { logger.error("ExecuteUploadActionException: " + e); stat.put(TAG_ERROR, e.getMessage()); } } String ret = statusToString(stat); finish(request, ret); logger.debug("BLOB-STORE-SERVLET: (" + request.getSession().getId() + ") redirect \n" + ret); renderXmlResponse(request, response, ret, true); perThreadRequest.set(null); } else { super.doGet(request, response); } } @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException { String error = null; perThreadRequest.set(request); try { error = super.parsePostRequest(request, response); } catch (UploadCanceledException e) { redirect(response, PARAM_CANCEL + "=true"); return; } catch (Exception e) { logger.info("BLOB-STORE-SERVLET: Exception " + e); error = e.getMessage(); } finally { perThreadRequest.set(null); } if (error != null) { removeSessionFileItems(request); redirect(response, PARAM_ERROR + "=" + error); perThreadRequest.set(null); return; } List<FileItem> sessionFiles = getLastReceivedFileItems(request); if (sessionFiles == null) { sessionFiles = new ArrayList<FileItem>(); request.setAttribute(getSessionLastFilesKey(request), sessionFiles); } Map<String, List<BlobKey>> blobs = blobstoreService.getUploads(request); if (blobs != null && blobs.size() > 0) { for (Entry<String, List<BlobKey>> e : blobs.entrySet()) { for (BlobKey blob : e.getValue()) { BlobstoreFileItem bfi = null; if (sessionFiles != null) { for (FileItem i : sessionFiles) { if (i.getFieldName().replaceFirst("-\\d+$", "") .equals(e.getKey().replace(UConsts.MULTI_SUFFIX, ""))) { bfi = (BlobstoreFileItem) i; break; } } } if (bfi == null) { bfi = new BlobstoreFileItem(e.getKey(), "unknown", false, ""); sessionFiles.add(bfi); } bfi.setKey(blob); logger.info("BLOB-STORE-SERVLET: received file: " + e.getKey() + " " + bfi); } } redirect(response, null); } else { redirect(response, PARAM_ERROR + "=" + getMessage("no_data")); } perThreadRequest.set(null); } /** * User can override this for customization. */ public String executeAction(HttpServletRequest request, List<FileItem> sessionFiles) throws UploadActionException { // Let the user whether remove or not file items overriding this method removeSessionFileItems(request, false); return null; } protected void redirect(HttpServletResponse response, String params) throws IOException { String url = servletPath + "?" + PARAM_REDIRECT + "=true" + (params != null ? "&" + params.replaceAll("[\n\r]+", " ") : ""); logger.info("BLOB-STORE-SERVLET: redirecting to -> : " + url); response.sendRedirect(url); } protected String getBlobstorePath(HttpServletRequest request) { String ret = blobstoreService.createUploadUrl(servletPath); logger.info("BLOB-STORE-SERVLET: generated new upload-url -> " + servletPath + " : " + ret); ret = ret.replaceFirst("^https?://[^/]+", ""); return ret; } @Override protected final AbstractUploadListener getCurrentListener(HttpServletRequest request) { return MemCacheUploadListener.current(request.getSession().getId()); } @Override protected final FileItemFactory getFileItemFactory(long requestSize) { return new BlobstoreFileItemFactory(); } }