001 /*
002 * Copyright (C) 2012 eXo Platform SAS.
003 *
004 * This is free software; you can redistribute it and/or modify it
005 * under the terms of the GNU Lesser General Public License as
006 * published by the Free Software Foundation; either version 2.1 of
007 * the License, or (at your option) any later version.
008 *
009 * This software is distributed in the hope that it will be useful,
010 * but WITHOUT ANY WARRANTY; without even the implied warranty of
011 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012 * Lesser General Public License for more details.
013 *
014 * You should have received a copy of the GNU Lesser General Public
015 * License along with this software; if not, write to the Free
016 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
017 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
018 */
019
020 package org.crsh.shell.impl.command;
021
022 import groovy.lang.GroovyClassLoader;
023 import groovy.lang.GroovyCodeSource;
024 import groovy.lang.Script;
025 import org.codehaus.groovy.control.CompilationFailedException;
026 import org.codehaus.groovy.control.CompilerConfiguration;
027 import org.crsh.command.CommandInvoker;
028 import org.crsh.command.NoSuchCommandException;
029 import org.crsh.plugin.PluginContext;
030 import org.crsh.shell.ErrorType;
031 import org.crsh.util.TimestampedObject;
032 import org.crsh.vfs.Resource;
033
034 import java.io.UnsupportedEncodingException;
035
036 public abstract class AbstractClassManager<T> {
037
038 /** . */
039 private final PluginContext context;
040
041 /** . */
042 private final CompilerConfiguration config;
043
044 /** . */
045 private final Class<T> baseClass;
046
047 protected AbstractClassManager(PluginContext context, Class<T> baseClass, Class<? extends Script> baseScriptClass) {
048 CompilerConfiguration config = new CompilerConfiguration();
049 config.setRecompileGroovySource(true);
050 config.setScriptBaseClass(baseScriptClass.getName());
051
052 //
053 this.context = context;
054 this.config = config;
055 this.baseClass = baseClass;
056 }
057
058 protected abstract TimestampedObject<Class<? extends T>> loadClass(String name);
059
060 protected abstract void saveClass(String name, TimestampedObject<Class<? extends T>> clazz);
061
062 protected abstract Resource getResource(String name);
063
064 Class<? extends T> getClass(String name) throws NoSuchCommandException, NullPointerException {
065 if (name == null) {
066 throw new NullPointerException("No null argument allowed");
067 }
068
069 TimestampedObject<Class<? extends T>> providerRef = loadClass(name);
070
071 //
072 Resource script = getResource(name);
073
074 //
075 if (script != null) {
076 if (providerRef != null) {
077 if (script.getTimestamp() != providerRef.getTimestamp()) {
078 providerRef = null;
079 }
080 }
081
082 //
083 if (providerRef == null) {
084
085 //
086 String source;
087 try {
088 source = new String(script.getContent(), "UTF-8");
089 }
090 catch (UnsupportedEncodingException e) {
091 throw new NoSuchCommandException(name, ErrorType.INTERNAL, "Could not compile command script " + name, e);
092 }
093
094 //
095 Class<?> clazz;
096 try {
097 GroovyCodeSource gcs = new GroovyCodeSource(source, name, "/groovy/shell");
098 GroovyClassLoader gcl = new GroovyClassLoader(context.getLoader(), config);
099 clazz = gcl.parseClass(gcs, false);
100 }
101 catch (NoClassDefFoundError e) {
102 throw new NoSuchCommandException(name, ErrorType.INTERNAL, "Could not compile command script " + name, e);
103 }
104 catch (CompilationFailedException e) {
105 throw new NoSuchCommandException(name, ErrorType.INTERNAL, "Could not compile command script " + name, e);
106 }
107
108 //
109 if (baseClass.isAssignableFrom(clazz)) {
110 Class<? extends T> providerClass = clazz.asSubclass(baseClass);
111 providerRef = new TimestampedObject<Class<? extends T>>(script.getTimestamp(), providerClass);
112 saveClass(name, providerRef);
113 } else {
114 throw new NoSuchCommandException(name, ErrorType.INTERNAL, "Parsed script " + clazz.getName() +
115 " does not implements " + CommandInvoker.class.getName());
116 }
117 }
118 }
119
120 //
121 if (providerRef == null) {
122 return null;
123 }
124
125 //
126 return providerRef.getObject();
127 }
128
129 T getInstance(String name) throws NoSuchCommandException, NullPointerException {
130 Class<? extends T> clazz = getClass(name);
131 if (clazz == null) {
132 return null;
133 }
134
135 //
136 try {
137 return clazz.newInstance();
138 }
139 catch (Exception e) {
140 throw new NoSuchCommandException(name, ErrorType.INTERNAL, "Could not create command " + name + " instance", e);
141 }
142 }
143 }