| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 org.apache.openjpa.jdbc.meta.strats; |
| |
| import java.sql.Connection; |
| import java.sql.PreparedStatement; |
| import java.sql.ResultSet; |
| import java.sql.SQLException; |
| |
| import org.apache.commons.lang.StringUtils; |
| import org.apache.openjpa.jdbc.kernel.JDBCStore; |
| import org.apache.openjpa.jdbc.meta.ClassMapping; |
| import org.apache.openjpa.jdbc.schema.Column; |
| import org.apache.openjpa.jdbc.sql.DBDictionary; |
| import org.apache.openjpa.jdbc.sql.SQLBuffer; |
| import org.apache.openjpa.lib.log.Log; |
| import org.apache.openjpa.lib.util.Localizer; |
| import org.apache.openjpa.meta.JavaTypes; |
| |
| /** |
| * Stores the class name along with each database object record. |
| * |
| * @author Abe White |
| */ |
| public class ClassNameDiscriminatorStrategy |
| extends InValueDiscriminatorStrategy { |
| |
| private static final Localizer _loc = Localizer.forPackage |
| (ClassNameDiscriminatorStrategy.class); |
| |
| public static final String ALIAS = "class-name"; |
| |
| public String getAlias() { |
| return ALIAS; |
| } |
| |
| protected int getJavaType() { |
| return JavaTypes.STRING; |
| } |
| |
| protected Object getDiscriminatorValue(ClassMapping cls) { |
| return cls.getDescribedType().getName(); |
| } |
| |
| protected Class getClass(Object val, JDBCStore store) |
| throws ClassNotFoundException { |
| ClassLoader loader = getClassLoader(store); |
| return Class.forName((String) val, true, loader); |
| } |
| |
| public void loadSubclasses(JDBCStore store) |
| throws SQLException, ClassNotFoundException { |
| if (isFinal) { |
| disc.setSubclassesLoaded(true); |
| return; |
| } |
| |
| Column col = disc.getColumns()[0]; |
| DBDictionary dict = store.getDBDictionary(); |
| SQLBuffer select = dict.toSelect(new SQLBuffer(dict).append(col), |
| store.getFetchConfiguration(), |
| new SQLBuffer(dict).append(col.getTable()), null, null, |
| null, null, true, false, 0, Long.MAX_VALUE); |
| |
| Log log = disc.getMappingRepository().getLog(); |
| if (log.isTraceEnabled()) |
| log.trace(_loc.get("load-subs", col.getTable().getFullName())); |
| |
| ClassLoader loader = getClassLoader(store); |
| Connection conn = store.getConnection(); |
| PreparedStatement stmnt = null; |
| ResultSet rs = null; |
| try { |
| stmnt = select.prepareStatement(conn); |
| rs = stmnt.executeQuery(); |
| String className; |
| while (rs.next()) { |
| className = dict.getString(rs, 1); |
| if (StringUtils.isEmpty(className)) |
| throw new ClassNotFoundException(_loc.get("no-class-name", |
| disc.getClassMapping(), col).getMessage()); |
| Class.forName(className, true, loader); |
| } |
| disc.setSubclassesLoaded(true); |
| } finally { |
| if (rs != null) |
| try { |
| rs.close(); |
| } catch (SQLException se) { |
| } |
| if (stmnt != null) |
| try { |
| stmnt.close(); |
| } catch (SQLException se) { |
| } |
| try { |
| conn.close(); |
| } catch (SQLException se) { |
| } |
| } |
| } |
| |
| /** |
| * Return the class loader to use for loading class names. |
| */ |
| private ClassLoader getClassLoader(JDBCStore store) { |
| return store.getConfiguration().getClassResolverInstance(). |
| getClassLoader(disc.getClassMapping().getDescribedType(), |
| store.getContext().getClassLoader()); |
| } |
| } |