| // Copyright 2008 Google 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.google.gwtorm.jdbc; |
| |
| import com.google.gwtorm.client.KeyUtil; |
| import com.google.gwtorm.client.OrmException; |
| import com.google.gwtorm.client.Schema; |
| import com.google.gwtorm.client.SchemaFactory; |
| import com.google.gwtorm.jdbc.gen.GeneratedClassLoader; |
| import com.google.gwtorm.jdbc.gen.SchemaFactoryGen; |
| import com.google.gwtorm.jdbc.gen.SchemaGen; |
| import com.google.gwtorm.schema.SchemaModel; |
| import com.google.gwtorm.schema.java.JavaSchemaModel; |
| import com.google.gwtorm.schema.sql.DialectH2; |
| import com.google.gwtorm.schema.sql.DialectMySQL; |
| import com.google.gwtorm.schema.sql.DialectPostgreSQL; |
| import com.google.gwtorm.schema.sql.SqlDialect; |
| import com.google.gwtorm.server.StandardKeyEncoder; |
| |
| import java.sql.Connection; |
| import java.sql.SQLException; |
| import java.util.Collections; |
| import java.util.Map; |
| import java.util.WeakHashMap; |
| |
| import javax.sql.DataSource; |
| |
| /** |
| * Constructor for application {@link Schema} extensions. |
| * <p> |
| * Applications should use the Database class to create instances of their |
| * Schema extension interface, and thus open and connect to the JDBC data store. |
| * <p> |
| * Creating a new Database instance is expensive, due to the type analysis and |
| * code generation performed to implement the Schema and Access interfaces. |
| * Applications should create and cache their Database instance for the live of |
| * the application. |
| * <p> |
| * Database instances are thread-safe, but returned Schema instances are not. |
| * |
| * @param <T> |
| */ |
| public class Database<T extends Schema> implements SchemaFactory<T> { |
| private static final Map<SchemaKey, String> schemaFactoryNames = |
| Collections.synchronizedMap(new WeakHashMap<SchemaKey, String>()); |
| |
| private static class SchemaKey { |
| final Class<?> schema; |
| final SqlDialect dialect; |
| |
| SchemaKey(Class<?> s, SqlDialect d) { |
| schema = s; |
| dialect = d; |
| } |
| |
| @Override |
| public int hashCode() { |
| return schema.hashCode() * 31 + dialect.getClass().hashCode(); |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (o instanceof SchemaKey) { |
| SchemaKey a = this; |
| SchemaKey b = (SchemaKey) o; |
| |
| return a.schema == b.schema |
| && a.dialect.getClass() == b.dialect.getClass(); |
| } |
| return false; |
| } |
| } |
| |
| static { |
| KeyUtil.setEncoderImpl(new StandardKeyEncoder()); |
| } |
| |
| private final DataSource dataSource; |
| private final JavaSchemaModel schemaModel; |
| private final AbstractSchemaFactory<T> implFactory; |
| private final SqlDialect implDialect; |
| |
| /** |
| * Create a new database interface, generating the interface implementations. |
| * |
| * @param ds JDBC connection information |
| * @param schema application extension of the Schema interface to implement. |
| * @throws OrmException the schema interface is incorrectly defined, or the |
| * driver class is not available through the current class loader. |
| */ |
| public Database(final DataSource ds, final Class<T> schema) |
| throws OrmException { |
| dataSource = ds; |
| |
| SqlDialect dialect; |
| try { |
| final Connection c = ds.getConnection(); |
| try { |
| final String url = c.getMetaData().getURL(); |
| if (url.startsWith("jdbc:postgresql:")) { |
| dialect = new DialectPostgreSQL(); |
| |
| } else if (url.startsWith("jdbc:h2:")) { |
| dialect = new DialectH2(); |
| |
| } else if (url.startsWith("jdbc:mysql:")) { |
| dialect = new DialectMySQL(); |
| |
| } else { |
| throw new OrmException("No dialect known for " + url); |
| } |
| |
| dialect = dialect.refine(c); |
| } finally { |
| c.close(); |
| } |
| } catch (SQLException e) { |
| throw new OrmException("Unable to determine driver URL", e); |
| } |
| |
| schemaModel = new JavaSchemaModel(schema); |
| final GeneratedClassLoader loader = newLoader(schema); |
| final SchemaKey key = new SchemaKey(schema, dialect); |
| final String cachedName = schemaFactoryNames.get(key); |
| AbstractSchemaFactory<T> factory = null; |
| if (cachedName != null) { |
| factory = newFactory(loader, cachedName); |
| } |
| if (factory == null) { |
| final SchemaGen gen = new SchemaGen(loader, schemaModel, dialect); |
| gen.defineClass(); |
| factory = new SchemaFactoryGen<T>(loader, gen).create(); |
| schemaFactoryNames.put(key, factory.getClass().getName()); |
| } |
| implFactory = factory; |
| implDialect = dialect; |
| } |
| |
| @SuppressWarnings("unchecked") |
| private AbstractSchemaFactory<T> newFactory(final ClassLoader cl, |
| final String name) { |
| try { |
| final Class<?> ft = Class.forName(name, true, cl); |
| return (AbstractSchemaFactory<T>) ft.newInstance(); |
| } catch (InstantiationException e) { |
| return null; |
| } catch (IllegalAccessException e) { |
| return null; |
| } catch (ClassNotFoundException e) { |
| return null; |
| } |
| } |
| |
| SqlDialect getDialect() { |
| return implDialect; |
| } |
| |
| SchemaModel getSchemaModel() { |
| return schemaModel; |
| } |
| |
| /** |
| * Open a new connection to the database and get a Schema wrapper. |
| * |
| * @return a new JDBC connection, wrapped up in the application's Schema. |
| * @throws OrmException the connection could not be opened to the database. |
| * The JDBC exception detail should be examined to determine the root |
| * cause of the connection failure. |
| */ |
| public T open() throws OrmException { |
| final Connection conn; |
| try { |
| conn = dataSource.getConnection(); |
| } catch (SQLException e) { |
| throw new OrmException("Cannot open database connection", e); |
| } |
| |
| try { |
| if (!conn.getAutoCommit()) { |
| conn.setAutoCommit(true); |
| } |
| } catch (SQLException e) { |
| try { |
| conn.close(); |
| } catch (SQLException e2) { |
| } |
| throw new OrmException("Cannot force auto-commit on connection", e); |
| } |
| |
| return implFactory.create(this, conn); |
| } |
| |
| private static <T> GeneratedClassLoader newLoader(final Class<T> schema) { |
| return new GeneratedClassLoader(schema.getClassLoader()); |
| } |
| } |