Java tutorial
/* * Copyright (c) 2015. Qubole Inc * 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.qubole.quark.plugins.jdbc; import org.apache.commons.lang.Validate; import com.google.common.collect.ImmutableMap; import com.qubole.quark.QuarkException; import com.qubole.quark.plugin.DataSource; import com.qubole.quark.plugin.DataSourceFactory; import java.lang.reflect.InvocationTargetException; import java.util.Arrays; import java.util.Map; /** * Created by rajatv on 11/12/15. */ public class JdbcFactory implements DataSourceFactory { // Static Registry for JDBC DB plugin private static final Map<String, Class<? extends JdbcDB>> DB_PLUGINS = new ImmutableMap.Builder<String, Class<? extends JdbcDB>>() .put("HIVE", EMRDb.class).put("REDSHIFT", RedShiftDb.class).put("H2", H2Db.class) .put("MYSQL", MysqlDb.class).put("ORACLE", OracleDb.class).put("GENERIC", GenericDb.class).build(); public DataSource create(Map<String, Object> properties) throws QuarkException { validate(properties); String type = (String) properties.get("type"); Class dbClass = DB_PLUGINS.get(type.toUpperCase()); Validate.notNull(dbClass, "Invalid DataSource type: " + type + " Please specify one of these: " + Arrays.toString(DB_PLUGINS.keySet().toArray())); return getDataSource(properties, dbClass); } private DataSource getDataSource(Map<String, Object> properties, Class dbClass) throws QuarkException { try { return (DataSource) (dbClass.getConstructor(Map.class).newInstance(properties)); } catch (NoSuchMethodException | IllegalAccessException | InstantiationException e) { throw new QuarkException(new Throwable("Invoking invalid constructor on class " + "specified for type " + properties.get("type") + ": " + dbClass.getCanonicalName())); } catch (InvocationTargetException e) { throw new QuarkException(e.getTargetException()); } } private void validate(Map<String, Object> properties) { Validate.notNull(properties.get("type"), "Field \"type\" specifying type of DataSource endpoint needs " + "to be defined for JDBC Data Source in JSON"); } }