Java tutorial
/* * This file is part of the PDF Split And Merge source code * Created on 07/ott/2014 * Copyright 2013-2014 by Andrea Vacondio (andrea.vacondio@gmail.com). * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as * published by the Free Software Foundation, either version 3 of the * License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package org.pdfsam.ui; import static org.apache.commons.lang3.StringUtils.isNotBlank; import java.io.IOException; import java.time.Instant; import java.util.prefs.BackingStoreException; import java.util.prefs.Preferences; import javax.annotation.PreDestroy; import javax.inject.Named; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.fasterxml.jackson.jr.ob.JSON; /** * Statefull implementation of a {@link StageService} using {@link Preferences}. * * @author Andrea Vacondio * */ @Named class StatefullPreferencesStageService implements StageService { private static final Logger LOG = LoggerFactory.getLogger(StatefullPreferencesStageService.class); static final String STAGE_PATH = "/org/pdfsam/stage"; static final String STAGE_STATUS_KEY = "stage.status"; static final String NEWS_STAGE_DISPLAY_TIME_KEY = "news.stage.display.time"; @PreDestroy void flush() { Preferences prefs = Preferences.userRoot().node(STAGE_PATH); try { LOG.trace("Flushing stage information"); prefs.flush(); } catch (BackingStoreException e) { LOG.error("Unable to stage status information", e); } } public void save(StageStatus status) { Preferences node = Preferences.userRoot().node(STAGE_PATH); try { node.put(STAGE_STATUS_KEY, JSON.std.asString(status)); LOG.trace("Stage status saved {}", status); } catch (IOException e) { LOG.error("Unable to increment modules usage statistics", e); } } public StageStatus getLatestStatus() { Preferences node = Preferences.userRoot().node(STAGE_PATH); try { String statusString = node.get(STAGE_STATUS_KEY, ""); if (isNotBlank(statusString)) { return JSON.std.beanFrom(StageStatus.class, statusString); } } catch (IOException e) { LOG.error("Unable to get latest stage status", e); } return StageStatus.NULL; } void clearStageStatus() { Preferences prefs = Preferences.userRoot().node(STAGE_PATH); try { prefs.removeNode(); prefs.flush(); } catch (BackingStoreException e) { LOG.error("Unable to clear stage status", e); } } public void newsStageDisplayed() { Preferences.userRoot().node(STAGE_PATH).putLong(NEWS_STAGE_DISPLAY_TIME_KEY, Instant.now().toEpochMilli()); LOG.trace("Latest news stage display time stored"); } public Instant getLatestNewsStageDisplayInstant() { return Instant.ofEpochMilli(Preferences.userRoot().node(STAGE_PATH).getLong(NEWS_STAGE_DISPLAY_TIME_KEY, Instant.EPOCH.toEpochMilli())); } }