Java tutorial
/* * Copyright 2013 2015 Ricki Hirner (bitfire web engineering). * All rights reserved. This program and the accompanying materials * are made available under the terms of the GNU Public License v3.0 * which accompanies this distribution, and is available at * http://www.gnu.org/licenses/gpl.html */ package com.granita.icloudcalsync.resource; import android.util.Log; import net.fortuna.ical4j.model.ValidationException; import org.apache.commons.io.IOUtils; import org.apache.http.impl.client.CloseableHttpClient; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.net.URI; import java.net.URISyntaxException; import java.util.LinkedList; import java.util.List; import com.granita.icloudcalsync.URIUtils; import com.granita.icloudcalsync.webdav.DavException; import com.granita.icloudcalsync.webdav.DavMultiget; import com.granita.icloudcalsync.webdav.DavNoContentException; import com.granita.icloudcalsync.webdav.HttpException; import com.granita.icloudcalsync.webdav.HttpPropfind; import com.granita.icloudcalsync.webdav.WebDavResource; import com.granita.icloudcalsync.webdav.WebDavResource.PutMode; import ezvcard.io.text.VCardParseException; import lombok.Cleanup; import lombok.Getter; /** * Represents a remotely stored synchronizable collection (collection as in * WebDAV terminology). * * @param <T> Subtype of Resource that can be stored in the collection */ public abstract class RemoteCollection<T extends Resource> { private static final String TAG = "davdroid.resource"; CloseableHttpClient httpClient; URI baseURI; @Getter WebDavResource collection; abstract protected String memberAcceptedMimeTypes(); abstract protected DavMultiget.Type multiGetType(); abstract protected T newResourceSkeleton(String name, String ETag); public RemoteCollection(CloseableHttpClient httpClient, String baseURL, String user, String password, boolean preemptiveAuth) throws URISyntaxException { this.httpClient = httpClient; baseURI = URIUtils.parseURI(baseURL, false); collection = new WebDavResource(httpClient, baseURI, user, password, preemptiveAuth); } /* collection operations */ public String getCTag() throws URISyntaxException, IOException, HttpException { try { if (collection.getCTag() == null && collection.getMembers() == null) // not already fetched collection.propfind(HttpPropfind.Mode.COLLECTION_CTAG); } catch (DavException e) { return null; } return collection.getCTag(); } /** * Returns a body for the REPORT request that queries all members of the collection * that should be considered. Allows collections to implement remote filters. * @return body for REPORT request or null if PROPFIND shall be used */ public String getMemberETagsQuery() { return null; } /** * Gets the ETags of the resources in a collection. If davQuery is set, it's required to be a * complete addressbook-query or calendar-query XML and will cause getMemberETags() to use REPORT * instead of PROPFIND. * @return array of Resources where only the resource names and ETags are set */ public Resource[] getMemberETags() throws URISyntaxException, IOException, DavException, HttpException { String query = getMemberETagsQuery(); if (query != null) collection.report(query); else collection.propfind(HttpPropfind.Mode.MEMBERS_ETAG); List<T> resources = new LinkedList<T>(); if (collection.getMembers() != null) for (WebDavResource member : collection.getMembers()) resources.add(newResourceSkeleton(member.getName(), member.getETag())); return resources.toArray(new Resource[0]); } @SuppressWarnings("unchecked") public Resource[] multiGet(Resource[] resources) throws URISyntaxException, IOException, DavException, HttpException { try { if (resources.length == 1) return (T[]) new Resource[] { get(resources[0]) }; Log.i(TAG, "Multi-getting " + resources.length + " remote resource(s)"); LinkedList<String> names = new LinkedList<String>(); for (Resource resource : resources) names.add(resource.getName()); LinkedList<T> foundResources = new LinkedList<T>(); collection.multiGet(multiGetType(), names.toArray(new String[0])); if (collection.getMembers() == null) throw new DavNoContentException(); for (WebDavResource member : collection.getMembers()) { T resource = newResourceSkeleton(member.getName(), member.getETag()); try { if (member.getContent() != null) { @Cleanup InputStream is = new ByteArrayInputStream(member.getContent()); resource.parseEntity(is, getDownloader()); foundResources.add(resource); } else Log.e(TAG, "Ignoring entity without content"); } catch (InvalidResourceException e) { Log.e(TAG, "Ignoring unparseable entity in multi-response", e); } } return foundResources.toArray(new Resource[0]); } catch (InvalidResourceException e) { Log.e(TAG, "Couldn't parse entity from GET", e); } return new Resource[0]; } /* internal member operations */ public Resource get(Resource resource) throws URISyntaxException, IOException, HttpException, DavException, InvalidResourceException { WebDavResource member = new WebDavResource(collection, resource.getName()); member.get(memberAcceptedMimeTypes()); byte[] data = member.getContent(); if (data == null) throw new DavNoContentException(); @Cleanup InputStream is = new ByteArrayInputStream(data); try { resource.parseEntity(is, getDownloader()); } catch (VCardParseException e) { throw new InvalidResourceException(e); } return resource; } // returns ETag of the created resource, if returned by server public String add(Resource res) throws URISyntaxException, IOException, HttpException, ValidationException { WebDavResource member = new WebDavResource(collection, res.getName(), res.getETag()); member.setContentType(res.getMimeType()); @Cleanup ByteArrayOutputStream os = res.toEntity(); String eTag = member.put(os.toByteArray(), PutMode.ADD_DONT_OVERWRITE); // after a successful upload, the collection has implicitely changed, too collection.invalidateCTag(); return eTag; } public void delete(Resource res) throws URISyntaxException, IOException, HttpException { WebDavResource member = new WebDavResource(collection, res.getName(), res.getETag()); member.delete(); collection.invalidateCTag(); } // returns ETag of the updated resource, if returned by server public String update(Resource res) throws URISyntaxException, IOException, HttpException, ValidationException { WebDavResource member = new WebDavResource(collection, res.getName(), res.getETag()); member.setContentType(res.getMimeType()); @Cleanup ByteArrayOutputStream os = res.toEntity(); String eTag = member.put(os.toByteArray(), PutMode.UPDATE_DONT_OVERWRITE); // after a successful upload, the collection has implicitely changed, too collection.invalidateCTag(); return eTag; } // helpers Resource.AssetDownloader getDownloader() { return new Resource.AssetDownloader() { @Override public byte[] download(URI uri) throws URISyntaxException, IOException, HttpException, DavException { if (!uri.isAbsolute()) throw new URISyntaxException(uri.toString(), "URI referenced from entity must be absolute"); if (uri.getScheme().equalsIgnoreCase(baseURI.getScheme()) && uri.getAuthority().equalsIgnoreCase(baseURI.getAuthority())) { // resource is on same server, send Authorization WebDavResource file = new WebDavResource(collection, uri); file.get("image/*"); return file.getContent(); } else { // resource is on an external server, don't send Authorization return IOUtils.toByteArray(uri); } } }; } }