001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    
018    package org.apache.commons.jci.compilers;
019    
020    import java.util.HashMap;
021    import java.util.Map;
022    
023    import org.apache.commons.jci.utils.ConversionUtils;
024    
025    
026    /**
027     * Creates JavaCompilers
028     * 
029     * TODO use META-INF discovery mechanism
030     * 
031     * @author tcurdt
032     */
033    public final class JavaCompilerFactory {
034    
035        /**
036         * @deprecated will be remove after the next release, please create an instance yourself
037         */
038        @Deprecated
039        private static final JavaCompilerFactory INSTANCE = new JavaCompilerFactory();
040    
041        private final Map<String, Class<?>> classCache = new HashMap<String, Class<?>>();
042        
043        /**
044         * @deprecated will be remove after the next release, please create an instance yourself
045         */
046        @Deprecated
047        public static JavaCompilerFactory getInstance() {
048            return JavaCompilerFactory.INSTANCE;
049        }
050    
051        /**
052         * Tries to guess the class name by convention. So for compilers
053         * following the naming convention
054         * 
055         *   org.apache.commons.jci.compilers.SomeJavaCompiler
056         *   
057         * you can use the short-hands "some"/"Some"/"SOME". Otherwise
058         * you have to provide the full class name. The compiler is
059         * getting instanciated via (cached) reflection.
060         * 
061         * @param pHint
062         * @return JavaCompiler or null
063         */
064        public JavaCompiler createCompiler(final String pHint) {
065            
066            final String className;
067            if (pHint.indexOf('.') < 0) {
068                className = "org.apache.commons.jci.compilers." + ConversionUtils.toJavaCasing(pHint) + "JavaCompiler";
069            } else {
070                className = pHint;
071            }
072            
073            Class<?> clazz = classCache.get(className);
074            
075            if (clazz == null) {
076                try {
077                    clazz = Class.forName(className);
078                    classCache.put(className, clazz);
079                } catch (ClassNotFoundException e) {
080                    clazz = null;
081                }
082            }
083    
084            if (clazz == null) {
085                return null;
086            }
087            
088            try {
089                return (JavaCompiler) clazz.newInstance();
090            } catch (Throwable t) {
091                return null;
092            }
093        }
094        
095    }