| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
| PythonBaseFactory |
|
| 3.6666666666666665;3,667 |
| 1 | package org.apache.turbine.services.assemblerbroker.util.python; | |
| 2 | ||
| 3 | ||
| 4 | /* | |
| 5 | * Licensed to the Apache Software Foundation (ASF) under one | |
| 6 | * or more contributor license agreements. See the NOTICE file | |
| 7 | * distributed with this work for additional information | |
| 8 | * regarding copyright ownership. The ASF licenses this file | |
| 9 | * to you under the Apache License, Version 2.0 (the | |
| 10 | * "License"); you may not use this file except in compliance | |
| 11 | * with the License. You may obtain a copy of the License at | |
| 12 | * | |
| 13 | * http://www.apache.org/licenses/LICENSE-2.0 | |
| 14 | * | |
| 15 | * Unless required by applicable law or agreed to in writing, | |
| 16 | * software distributed under the License is distributed on an | |
| 17 | * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY | |
| 18 | * KIND, either express or implied. See the License for the | |
| 19 | * specific language governing permissions and limitations | |
| 20 | * under the License. | |
| 21 | */ | |
| 22 | ||
| 23 | ||
| 24 | import java.io.File; | |
| 25 | ||
| 26 | import org.apache.commons.configuration.Configuration; | |
| 27 | import org.apache.commons.lang.StringUtils; | |
| 28 | import org.apache.commons.logging.Log; | |
| 29 | import org.apache.commons.logging.LogFactory; | |
| 30 | import org.apache.turbine.modules.Assembler; | |
| 31 | import org.apache.turbine.modules.Loader; | |
| 32 | import org.apache.turbine.services.TurbineServices; | |
| 33 | import org.apache.turbine.services.assemblerbroker.AssemblerBrokerService; | |
| 34 | import org.apache.turbine.services.assemblerbroker.util.AssemblerFactory; | |
| 35 | import org.python.core.Py; | |
| 36 | import org.python.util.PythonInterpreter; | |
| 37 | ||
| 38 | /** | |
| 39 | * A factory that attempts to load a python class in the | |
| 40 | * JPython interpreter and execute it as a Turbine screen. | |
| 41 | * The JPython script should inherit from Turbine Screen or one | |
| 42 | * of its subclasses. | |
| 43 | * | |
| 44 | * @author <a href="mailto:leon@opticode.co.za">Leon Messerschmidt</a> | |
| 45 | * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a> | |
| 46 | * @param <T> the specialized assembler type | |
| 47 | */ | |
| 48 | 0 | public abstract class PythonBaseFactory<T extends Assembler> |
| 49 | implements AssemblerFactory<T> | |
| 50 | { | |
| 51 | /** Key for the python path */ | |
| 52 | public static final String PYTHON_PATH = "python.path"; | |
| 53 | ||
| 54 | /** Global config file. This is executed before every screen */ | |
| 55 | public static final String PYTHON_CONFIG_FILE = "conf.py"; | |
| 56 | ||
| 57 | /** Logging */ | |
| 58 | 0 | private static Log log = LogFactory.getLog(PythonBaseFactory.class); |
| 59 | ||
| 60 | /** Our configuration */ | |
| 61 | 0 | private final Configuration conf = TurbineServices.getInstance().getConfiguration(AssemblerBrokerService.SERVICE_NAME); |
| 62 | ||
| 63 | /** | |
| 64 | * Get an Assembler. | |
| 65 | * | |
| 66 | * @param subDirectory subdirectory within python.path | |
| 67 | * @param name name of the requested Assembler | |
| 68 | * @return an Assembler | |
| 69 | * @throws Exception generic exception | |
| 70 | */ | |
| 71 | public T getAssembler(String subDirectory, String name) | |
| 72 | throws Exception | |
| 73 | { | |
| 74 | 0 | String path = conf.getString(PYTHON_PATH); |
| 75 | ||
| 76 | 0 | if (StringUtils.isEmpty(path)) |
| 77 | { | |
| 78 | 0 | throw new Exception( |
| 79 | "Python path not found - check your Properties"); | |
| 80 | } | |
| 81 | ||
| 82 | 0 | log.debug("Screen name for JPython: " + name); |
| 83 | ||
| 84 | 0 | T assembler = null; |
| 85 | ||
| 86 | 0 | String confName = path + "/" + PYTHON_CONFIG_FILE; |
| 87 | ||
| 88 | // The filename of the Python script | |
| 89 | 0 | StringBuilder fName = new StringBuilder(); |
| 90 | ||
| 91 | 0 | fName.append(path); |
| 92 | 0 | fName.append("/"); |
| 93 | 0 | fName.append(subDirectory); |
| 94 | 0 | fName.append("/"); |
| 95 | 0 | fName.append(name.toLowerCase()); |
| 96 | 0 | fName.append(".py"); |
| 97 | ||
| 98 | 0 | File f = new File(fName.toString()); |
| 99 | ||
| 100 | 0 | if (f.exists()) |
| 101 | { | |
| 102 | 0 | PythonInterpreter interp = null; |
| 103 | ||
| 104 | try | |
| 105 | { | |
| 106 | // We try to open the Py Interpreter | |
| 107 | 0 | interp = new PythonInterpreter(); |
| 108 | ||
| 109 | // Make sure the Py Interpreter use the right classloader | |
| 110 | // This is necessary for servlet engines generally has | |
| 111 | // their own classloader implementations and servlets aren't | |
| 112 | // loaded in the system classloader. The python script will | |
| 113 | // load java package | |
| 114 | // org.apache.turbine.services.assemblerbroker.util.python; | |
| 115 | // the new classes to it as well. | |
| 116 | 0 | Py.getSystemState().setClassLoader(this.getClass().getClassLoader()); |
| 117 | ||
| 118 | // We import the Python SYS module. Now we don't need to do this | |
| 119 | // explicitly in the script. We always use the sys module to | |
| 120 | // do stuff like loading java package | |
| 121 | // org.apache.turbine.services.assemblerbroker.util.python; | |
| 122 | 0 | interp.exec("import sys"); |
| 123 | ||
| 124 | // Now we try to load the script file | |
| 125 | 0 | interp.execfile(confName); |
| 126 | 0 | interp.execfile(fName.toString()); |
| 127 | ||
| 128 | try | |
| 129 | { | |
| 130 | // We create an instance of the screen class from the | |
| 131 | // python script | |
| 132 | 0 | interp.exec("scr = " + name + "()"); |
| 133 | } | |
| 134 | 0 | catch (Throwable e) |
| 135 | { | |
| 136 | 0 | throw new Exception( |
| 137 | "\nCannot create an instance of the python class.\n" | |
| 138 | + "You probably gave your class the wrong name.\n" | |
| 139 | + "Your class should have the same name as your " | |
| 140 | + "filename.\nFilenames should be all lowercase and " | |
| 141 | + "classnames should start with a capital.\n" | |
| 142 | + "Expected class name: " + name + "\n"); | |
| 143 | 0 | } |
| 144 | ||
| 145 | // Here we convert the python screen instance to a java instance. | |
| 146 | @SuppressWarnings("unchecked") // Cast from Object necessary | |
| 147 | 0 | T t = (T) interp.get("scr", Assembler.class); |
| 148 | 0 | assembler = t; |
| 149 | } | |
| 150 | 0 | catch (Exception e) |
| 151 | { | |
| 152 | // We log the error here because this code is not widely tested | |
| 153 | // yet. After we tested the code on a range of platforms this | |
| 154 | // won't be useful anymore. | |
| 155 | 0 | log.error("PYTHON SCRIPT SCREEN LOADER ERROR:", e); |
| 156 | 0 | throw e; |
| 157 | } | |
| 158 | finally | |
| 159 | { | |
| 160 | 0 | if (interp != null) |
| 161 | { | |
| 162 | 0 | interp.close(); |
| 163 | } | |
| 164 | } | |
| 165 | } | |
| 166 | 0 | return assembler; |
| 167 | } | |
| 168 | ||
| 169 | /** | |
| 170 | * Get the loader for this type of assembler | |
| 171 | * | |
| 172 | * @return a Loader | |
| 173 | */ | |
| 174 | @Override | |
| 175 | public abstract Loader<T> getLoader(); | |
| 176 | ||
| 177 | /** | |
| 178 | * Get the size of a possibly configured cache | |
| 179 | * | |
| 180 | * @return the size of the cache in bytes | |
| 181 | */ | |
| 182 | @Override | |
| 183 | public int getCacheSize() | |
| 184 | ||
| 185 | { | |
| 186 | 0 | return getLoader().getCacheSize(); |
| 187 | } | |
| 188 | } |