| /* |
| * 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.kernel; |
| |
| import java.security.AccessController; |
| import java.security.PrivilegedActionException; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import org.apache.openjpa.kernel.exps.ExpressionParser; |
| import org.apache.openjpa.lib.util.J2DoPrivHelper; |
| import org.apache.openjpa.lib.util.Services; |
| import org.apache.openjpa.util.InternalException; |
| |
| /** |
| * Constants and utilities for query languages. |
| */ |
| public class QueryLanguages { |
| |
| public static final String LANG_SQL = "openjpa.SQL"; |
| public static final String LANG_STORED_PROC = "openjpa.StoredProcedure.SQL"; |
| public static final String LANG_PREPARED_SQL = "openjpa.prepared.SQL"; |
| public static final String LANG_METHODQL = "openjpa.MethodQL"; |
| |
| private static Map _expressionParsers = new HashMap(); |
| static { |
| // Load and cache all the query languages available in the system. |
| Class[] classes = Services.getImplementorClasses( |
| ExpressionParser.class, |
| AccessController.doPrivileged( |
| J2DoPrivHelper.getClassLoaderAction(ExpressionParser.class))); |
| for (Class aClass : classes) { |
| ExpressionParser ep; |
| try { |
| ep = (ExpressionParser) AccessController.doPrivileged( |
| J2DoPrivHelper.newInstanceAction(aClass)); |
| } |
| catch (PrivilegedActionException pae) { |
| throw new InternalException(pae.getException()); |
| } |
| catch (InstantiationException | IllegalAccessException e) { |
| throw new InternalException(e); |
| } |
| _expressionParsers.put(ep.getLanguage(), ep); |
| } |
| } |
| |
| /** |
| * Return the {@link ExpressionParser} for <code>language</code>, or |
| * <code>null</code> if no expression parser exists in the system for |
| * the specified language. |
| */ |
| public static ExpressionParser parserForLanguage(String language) { |
| return (ExpressionParser) _expressionParsers.get(language); |
| } |
| } |