Java tutorial
/* * The MIT License * * Copyright 2014 Lachlan Phillips. * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ package me.lachlanap.summis.update; import com.google.api.client.http.*; import com.google.api.client.http.javanet.NetHttpTransport; import com.google.api.client.util.ExponentialBackOff; import com.google.gson.JsonArray; import com.google.gson.JsonElement; import com.google.gson.JsonObject; import com.google.gson.JsonParser; import java.io.IOException; import java.util.ArrayList; import java.util.Collections; import java.util.Comparator; import java.util.List; import java.util.concurrent.*; import me.lachlanap.config.Configuration; import me.lachlanap.summis.MemoryUnit; import me.lachlanap.summis.UpdateInformation; import me.lachlanap.summis.UpdateInformation.FileInfo; import me.lachlanap.summis.UpdateInformation.FileSet; import me.lachlanap.summis.Version; /** * * @author Lachlan Phillips */ public class UpdateInformationGrabber { private static final int FORMAT_VERSION = 1; private final ExecutorService EXECUTOR = Executors.newSingleThreadExecutor(new ThreadFactory() { @Override public Thread newThread(Runnable r) { Thread thread = new Thread(r); thread.setDaemon(true); thread.setName("Summis Client: Update Information HTTP Executor"); return thread; } }); private final Configuration config; private Future<Void> future; private final List<VersionInfo> versions; public UpdateInformationGrabber(Configuration config) { this.config = config; this.versions = new ArrayList<>(); } public void begin() { future = EXECUTOR.submit(new Callable<Void>() { @Override public Void call() throws Exception { getVersionInformation(config); return null; } }); } private void getVersionInformation(Configuration config) throws IOException { String serverAddress = config.getString("server.address"); String project = config.getString("server.project"); final int VERSION = 1; String updateSourceUrl = serverAddress + String.format("%d/project/%s/%s.json", VERSION, project, project); HttpRequestFactory factory = new NetHttpTransport().createRequestFactory(); try { HttpRequest request = factory.buildGetRequest(new GenericUrl(updateSourceUrl)); request.setUnsuccessfulResponseHandler( new HttpBackOffUnsuccessfulResponseHandler(new ExponentialBackOff())); request.setReadTimeout(3000); HttpResponse response = request.execute(); process(response.parseAsString()); response.disconnect(); } catch (HttpResponseException hre) { if (hre.getStatusCode() == 404) { System.out.println(updateSourceUrl + " does not exist"); } } } private void process(String allText) { JsonObject json = new JsonParser().parse(allText).getAsJsonObject(); if (json.get("version").getAsInt() != FORMAT_VERSION) throw new RuntimeException("Format version " + json.get("version").getAsInt() + " is not supported."); versions.clear(); for (JsonElement element : json.getAsJsonArray("versions")) { versions.add(parseVersion(element.getAsJsonObject())); } // Sort latest to earliest Collections.sort(versions, new Comparator<VersionInfo>() { @Override public int compare(VersionInfo o1, VersionInfo o2) { return -o1.version.compareTo(o2.version); } }); } private VersionInfo parseVersion(JsonObject versionJson) { Version version = Version.parse(versionJson.get("number").getAsString()); String description = versionJson.get("description").getAsString(); FileSet diffSet = parseFileSet(versionJson.getAsJsonArray("diff")); FileSet fullSet = parseFileSet(versionJson.getAsJsonArray("full")); return new VersionInfo(version, description, diffSet, fullSet); } private FileSet parseFileSet(JsonArray fileSetJson) { List<FileInfo> infos = new ArrayList<>(); for (JsonElement element : fileSetJson) { JsonObject fileInfoJson = element.getAsJsonObject(); infos.add(new FileInfo(fileInfoJson.get("name").getAsString(), new MemoryUnit(fileInfoJson.get("size").getAsLong()), fileInfoJson.get("url").getAsString(), fileInfoJson.get("md5").getAsString(), fileInfoJson.get("sha1").getAsString())); } return new FileSet(infos); } public UpdateInformation get(Version current) throws InterruptedException { try { future.get(); } catch (ExecutionException ee) { if (ee.getCause() instanceof RuntimeException) throw (RuntimeException) ee.getCause(); else throw new RuntimeException(ee.getCause()); } VersionInfo latest = versions.get(0); FileSet diffSet = computeDiffSet(current, latest); UpdateInformation info = new UpdateInformation(latest.version, current, diffSet, latest.fullSet); return info; } private FileSet computeDiffSet(Version current, VersionInfo latest) { List<FileInfo> diffSetList = new ArrayList<>(); for (VersionInfo aVersion : versions) { if (!aVersion.version.isGreaterThan(current)) break; for (FileInfo aFile : aVersion.diffSet.getFiles()) { boolean alreadyInDiffSet = false; for (FileInfo check : diffSetList) if (aFile.getName().equals(check.getName())) alreadyInDiffSet = true; if (!alreadyInDiffSet && latest.fullSet.getFiles().contains(aFile)) diffSetList.add(aFile); } } return new FileSet(diffSetList); } private static class VersionInfo { final Version version; final String description; final FileSet diffSet; final FileSet fullSet; public VersionInfo(Version version, String description, FileSet diffSet, FileSet fullSet) { this.version = version; this.description = description; this.diffSet = diffSet; this.fullSet = fullSet; } } }