Java tutorial
// Copyright (C) 2015 The Android Open Source Project // // 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 com.googlesource.gerrit.plugins.verifystatus.server.schema; import static java.util.concurrent.TimeUnit.MILLISECONDS; import static java.util.concurrent.TimeUnit.SECONDS; import com.google.common.base.Strings; import com.google.gerrit.common.Nullable; import com.google.gerrit.extensions.annotations.PluginName; import com.google.gerrit.extensions.events.LifecycleListener; import com.google.gerrit.extensions.persistence.DataSourceInterceptor; import com.google.gerrit.metrics.CallbackMetric1; import com.google.gerrit.metrics.Description; import com.google.gerrit.metrics.Field; import com.google.gerrit.metrics.MetricMaker; import com.google.gerrit.server.config.ConfigUtil; import com.google.gerrit.server.config.PluginConfig; import com.google.gerrit.server.config.SitePaths; import com.google.gwtorm.jdbc.SimpleDataSource; import com.google.inject.Inject; import com.google.inject.Provider; import com.google.inject.ProvisionException; import com.google.inject.Singleton; import java.io.File; import java.io.IOException; import java.lang.reflect.Constructor; import java.lang.reflect.InvocationTargetException; import java.sql.SQLException; import java.util.Properties; import javax.sql.DataSource; import org.apache.commons.dbcp.BasicDataSource; import org.eclipse.jgit.errors.ConfigInvalidException; import org.eclipse.jgit.storage.file.FileBasedConfig; import org.eclipse.jgit.util.FS; /** Provides access to the DataSource. */ @Singleton public class CiDataSourceProvider implements Provider<DataSource>, LifecycleListener { public static final int DEFAULT_POOL_LIMIT = 8; private final MetricMaker metrics; private final Context ctx; private final CiDataSourceType dst; private final PluginConfig config; private DataSource ds; @Inject protected CiDataSourceProvider(SitePaths site, @PluginName String pluginName, @Nullable MetricMaker metrics, Context ctx, CiDataSourceType dst) { File file = site.gerrit_config.toFile(); FileBasedConfig cfg = new FileBasedConfig(file, FS.DETECTED); try { cfg.load(); } catch (IOException | ConfigInvalidException e) { throw new ProvisionException(e.getMessage(), e); } this.config = new PluginConfig(pluginName, cfg); this.metrics = metrics; this.ctx = ctx; this.dst = dst; } @Override public synchronized DataSource get() { if (ds == null) { ds = open(ctx, dst); } return ds; } @Override public void start() { } @Override public synchronized void stop() { if (ds instanceof BasicDataSource) { try { ((BasicDataSource) ds).close(); } catch (SQLException e) { // Ignore the close failure. } } } public static enum Context { SINGLE_USER, MULTI_USER } private DataSource open(Context context, CiDataSourceType dst) { // ConfigSection dbs = new ConfigSection(cfg, "database"); String driver = config.getString("driver"); if (Strings.isNullOrEmpty(driver)) { driver = dst.getDriver(); } String url = config.getString("dbUrl"); if (Strings.isNullOrEmpty(url)) { url = dst.getUrl(); } String username = config.getString("username"); String password = config.getString("password"); String interceptor = config.getString("dataSourceInterceptorClass"); boolean usePool; if (context == Context.SINGLE_USER) { usePool = false; } else { usePool = config.getBoolean("connectionpool", dst.usePool()); } if (usePool) { final BasicDataSource ds = new BasicDataSource(); ds.setDriverClassName(driver); ds.setUrl(url); if (username != null && !username.isEmpty()) { ds.setUsername(username); } if (password != null && !password.isEmpty()) { ds.setPassword(password); } ds.setMaxActive(config.getInt("poollimit", DEFAULT_POOL_LIMIT)); ds.setMinIdle(config.getInt("poolminidle", 4)); ds.setMaxIdle(config.getInt("poolmaxidle", 4)); String valueString = config.getString("poolmaxwait"); if (Strings.isNullOrEmpty(valueString)) { ds.setMaxWait(MILLISECONDS.convert(30, SECONDS)); } else { ds.setMaxWait(ConfigUtil.getTimeUnit(valueString, MILLISECONDS.convert(30, SECONDS), MILLISECONDS)); } ds.setInitialSize(ds.getMinIdle()); exportPoolMetrics(ds); return intercept(interceptor, ds); } // Don't use the connection pool. try { Properties p = new Properties(); p.setProperty("driver", driver); p.setProperty("url", url); if (username != null) { p.setProperty("user", username); } if (password != null) { p.setProperty("password", password); } return intercept(interceptor, new SimpleDataSource(p)); } catch (SQLException se) { throw new ProvisionException("Database unavailable", se); } } private void exportPoolMetrics(final BasicDataSource pool) { final CallbackMetric1<Boolean, Integer> cnt = metrics.newCallbackMetric("sql/connection_pool/connections", Integer.class, new Description("SQL database connections").setGauge().setUnit("connections"), Field.ofBoolean("active")); metrics.newTrigger(cnt, new Runnable() { @Override public void run() { synchronized (pool) { cnt.set(true, pool.getNumActive()); cnt.set(false, pool.getNumIdle()); } } }); } private DataSource intercept(String interceptor, DataSource ds) { if (interceptor == null) { return ds; } try { Constructor<?> c = Class.forName(interceptor).getConstructor(); DataSourceInterceptor datasourceInterceptor = (DataSourceInterceptor) c.newInstance(); return datasourceInterceptor.intercept("CiDb", ds); } catch (ClassNotFoundException | SecurityException | NoSuchMethodException | IllegalArgumentException | InstantiationException | IllegalAccessException | InvocationTargetException e) { throw new ProvisionException("Cannot intercept datasource", e); } } }