Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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 org.waveprotocol.box.webclient.search; import com.google.common.base.Preconditions; import com.google.gwt.http.client.Request; import com.google.gwt.http.client.RequestBuilder; import com.google.gwt.http.client.RequestCallback; import com.google.gwt.http.client.RequestException; import com.google.gwt.http.client.Response; import com.google.gwt.http.client.URL; import org.waveprotocol.box.search.SearchRequest; import org.waveprotocol.box.search.SearchResponse; import org.waveprotocol.box.search.SearchResponse.Digest; import org.waveprotocol.box.search.jso.SearchRequestJsoImpl; import org.waveprotocol.box.search.jso.SearchResponseJsoImpl; import org.waveprotocol.box.webclient.search.SearchService.Callback; import org.waveprotocol.box.webclient.search.SearchService.DigestSnapshot; import org.waveprotocol.wave.client.debug.logger.DomLogger; import org.waveprotocol.wave.common.logging.LoggerBundle; import org.waveprotocol.wave.communication.gwt.JsonMessage; import org.waveprotocol.wave.communication.json.JsonException; import org.waveprotocol.wave.model.id.WaveId; import org.waveprotocol.wave.model.util.CollectionUtils; import org.waveprotocol.wave.model.wave.ParticipantId; import java.util.List; /** * Helper class to perform searches. * * @author vega113@gmail.com (Yuri Z.) */ public final class JsoSearchBuilderImpl implements SearchBuilder { private static final LoggerBundle LOG = new DomLogger("SearchBuilder"); /** The base search URL. */ private static final String SEARCH_URL_BASE = "/search"; /** Holds search request data. */ private SearchRequest searchRequest; private JsoSearchBuilderImpl() { } /** Static factory method */ public static SearchBuilder create() { return new JsoSearchBuilderImpl(); } @Override public SearchBuilder newSearch() { searchRequest = SearchRequestJsoImpl.create(); return this; } @Override public SearchBuilder setQuery(String query) { searchRequest.setQuery(query); return this; } @Override public SearchBuilder setIndex(int index) { searchRequest.setIndex(index); return this; } @Override public SearchBuilder setNumResults(int numResults) { searchRequest.setNumResults(numResults); return this; } @Override public Request search(final Callback callback) { Preconditions.checkArgument(searchRequest != null, "call SearchBuilder.newSearch method to construct a new query"); Preconditions.checkArgument(searchRequest.getQuery() != null, "new query should be set"); String url = getUrl(searchRequest); LOG.trace().log("Performing a search query: [Query: ", searchRequest.getQuery(), ", Index: ", searchRequest.getIndex(), ", NumResults: ", searchRequest.getNumResults(), "]"); RequestBuilder requestBuilder = new RequestBuilder(RequestBuilder.GET, url); requestBuilder.setCallback(new RequestCallback() { @Override public void onResponseReceived(Request request, Response response) { LOG.trace().log("Search response received: ", response.getText()); if (response.getStatusCode() != Response.SC_OK) { callback.onFailure("Got back status code " + response.getStatusCode()); } else if (!response.getHeader("Content-Type").startsWith("application/json")) { callback.onFailure("Search service did not return json"); } else { SearchResponseJsoImpl searchResponse; try { searchResponse = JsonMessage.parse(response.getText()); } catch (JsonException e) { callback.onFailure(e.getMessage()); return; } List<DigestSnapshot> digestSnapshots = SearchBuilderUtils .deserializeSearchResponse(searchResponse); callback.onSuccess(searchResponse.getTotalResults(), digestSnapshots); } } @Override public void onError(Request request, Throwable exception) { LOG.error().log("Search error: ", exception); callback.onFailure(exception.getMessage()); } }); try { return requestBuilder.send(); } catch (RequestException e) { callback.onFailure(e.getMessage()); return null; } } private static class SearchBuilderUtils { /** * Constructs a list of {@link org.waveprotocol.box.webclient.search.Digest} * from {@link SearchResponse}. */ private static List<DigestSnapshot> deserializeSearchResponse(SearchResponse searchResponse) { List<DigestSnapshot> digestSnapshots = CollectionUtils.newArrayList(); int i = 0; for (SearchResponse.Digest digest : searchResponse.getDigests()) { DigestSnapshot digestSnapshot = deserializeDigest(digest); digestSnapshots.add(i, digestSnapshot); i++; } return digestSnapshots; } private static DigestSnapshot deserializeDigest(Digest digest) { List<ParticipantId> participantIds = CollectionUtils.newArrayList(); for (String participant : digest.getParticipants()) { participantIds.add(ParticipantId.ofUnsafe(participant)); } DigestSnapshot digestSnapshot = new DigestSnapshot(digest.getTitle(), digest.getSnippet(), WaveId.deserialise(digest.getWaveId()), ParticipantId.ofUnsafe(digest.getAuthor()), participantIds, digest.getLastModified(), digest.getUnreadCount(), digest.getBlipCount()); return digestSnapshot; } } private static String getUrl(SearchRequest searchRequest) { String query = URL.encodeQueryString(searchRequest.getQuery()); String params = "?query=" + query + "&index=" + searchRequest.getIndex() + "&numResults=" + searchRequest.getNumResults(); return SEARCH_URL_BASE + "/" + params; } @Override public String toString() { return "[Query: " + searchRequest.getQuery() + ", Index: " + searchRequest.getIndex() + ", NumResults: " + searchRequest.getNumResults() + "]"; } }