Java tutorial
/* * Copyright (C) 2014 EBay Software Foundation * * This program and the accompanying materials are made available under the * terms of the Eclipse Public License v1.0 which accompanies this distribution, * and is available at http://www.eclipse.org/legal/epl-v10.html * * Authors : Ashwin Raveendran */ package org.opendaylight.ovsdb.lib.schema; import java.lang.reflect.Constructor; import java.util.HashMap; import java.util.Iterator; import java.util.Map; import java.util.Set; import org.opendaylight.ovsdb.lib.error.ParsingException; import org.opendaylight.ovsdb.lib.notation.Version; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.fasterxml.jackson.databind.JsonNode; import com.google.common.reflect.Invokable; /** * Represents an ovsdb database schema, which is comprised of a set of tables. */ public class DatabaseSchema { public static Logger logger = LoggerFactory.getLogger(DatabaseSchema.class); private String name; private Version version; private Map<String, TableSchema> tables; public DatabaseSchema(Map<String, TableSchema> tables) { this.tables = tables; } public DatabaseSchema(String name, Version version, Map<String, TableSchema> tables) { this.name = name; this.version = version; this.tables = tables; } public Set<String> getTables() { return this.tables.keySet(); } public boolean hasTable(String table) { return this.getTables().contains(table); } public <E extends TableSchema<E>> E table(String tableName, Class<E> clazz) { TableSchema<E> table = tables.get(tableName); if (clazz.isInstance(table)) { return clazz.cast(table); } return createTableSchema(clazz, table); } protected <E extends TableSchema<E>> E createTableSchema(Class<E> clazz, TableSchema<E> table) { Constructor<E> declaredConstructor = null; try { declaredConstructor = clazz.getDeclaredConstructor(TableSchema.class); } catch (NoSuchMethodException e) { String message = String .format("Class %s does not have public constructor that accepts TableSchema object", clazz); throw new IllegalArgumentException(message, e); } Invokable<E, E> invokable = Invokable.from(declaredConstructor); try { return invokable.invoke(null, table); } catch (Exception e) { String message = String.format("Not able to create instance of class %s using public constructor " + "that accepts TableSchema object", clazz); throw new IllegalArgumentException(message, e); } } //todo : this needs to move to a custom factory public static DatabaseSchema fromJson(String dbName, JsonNode json) { if (!json.isObject() || !json.has("tables")) { throw new ParsingException("bad DatabaseSchema root, expected \"tables\" as child but was not found"); } if (!json.isObject() || !json.has("version")) { throw new ParsingException("bad DatabaseSchema root, expected \"version\" as child but was not found"); } Version dbVersion = Version.fromString(json.get("version").asText()); Map<String, TableSchema> tables = new HashMap<>(); for (Iterator<Map.Entry<String, JsonNode>> iter = json.get("tables").fields(); iter.hasNext();) { Map.Entry<String, JsonNode> table = iter.next(); logger.trace("Read schema for table[{}]:{}", table.getKey(), table.getValue()); //todo : this needs to done by a factory tables.put(table.getKey(), new GenericTableSchema().fromJson(table.getKey(), table.getValue())); } return new DatabaseSchema(dbName, dbVersion, tables); } public String getName() { return name; } public void setName(String name) { this.name = name; } public Version getVersion() { return version; } public void setVersion(Version version) { this.version = version; } public void populateInternallyGeneratedColumns() { for (TableSchema tableSchema : tables.values()) { tableSchema.populateInternallyGeneratedColumns(); } } }