org.apache.tools.ant.util.ScriptRunnerCreator Maven / Gradle / Ivy
/*
* 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.tools.ant.util;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Project;
/**
* This is a helper class used by ScriptRunnerHelper to
* create a ScriptRunner based on a classloader and on a language.
*/
public class ScriptRunnerCreator {
private static final String AUTO = "auto";
private static final String OATAU = "org.apache.tools.ant.util";
private static final String UTIL_OPT = OATAU + ".optional";
private static final String BSF = "bsf";
private static final String BSF_PACK = "org.apache.bsf";
private static final String BSF_MANAGER = BSF_PACK + ".BSFManager";
private static final String BSF_RUNNER = UTIL_OPT + ".ScriptRunner";
private static final String JAVAX = "javax";
private static final String JAVAX_MANAGER = "javax.script.ScriptEngineManager";
private static final String JAVAX_RUNNER = UTIL_OPT + ".JavaxScriptRunner";
private Project project;
private String manager;
private String language;
private ClassLoader scriptLoader = null;
/**
* Constructor for creator.
* @param project the current project.
*/
public ScriptRunnerCreator(Project project) {
this.project = project;
}
/**
* Create a ScriptRunner.
* @param manager the script manager ("auto" | "bsf" | "javax")
* @param language the language.
* @param classLoader the classloader to use
* @return the created script runner.
* @throws BuildException if unable to create the ScriptRunner.
*/
public synchronized ScriptRunnerBase createRunner(
String manager, String language, ClassLoader classLoader) {
this.manager = manager;
this.language = language;
this.scriptLoader = classLoader;
if (language == null) {
throw new BuildException("script language must be specified");
}
if (!manager.equals(AUTO) && !manager.equals(JAVAX) && !manager.equals(BSF)) {
throw new BuildException("Unsupported language prefix " + manager);
}
// Check for bsf first then javax
// This version does not check if the scriptManager
// supports the language.
ScriptRunnerBase ret = null;
ret = createRunner(BSF, BSF_MANAGER, BSF_RUNNER);
if (ret == null) {
ret = createRunner(JAVAX, JAVAX_MANAGER, JAVAX_RUNNER);
}
if (ret != null) {
return ret;
}
if (JAVAX.equals(manager)) {
throw new BuildException(
"Unable to load the script engine manager " + "(" + JAVAX_MANAGER + ")");
}
if (BSF.equals(manager)) {
throw new BuildException(
"Unable to load the BSF script engine manager " + "(" + BSF_MANAGER + ")");
}
throw new BuildException("Unable to load a script engine manager "
+ "(" + BSF_MANAGER + " or " + JAVAX_MANAGER + ")");
}
/**
* Create a script runner if the scriptManager matches the passed
* in manager.
* This checks if the script manager exists in the scriptLoader
* classloader and if so it creates and returns the script runner.
* @param checkManager check if the manager matches this value.
* @param managerClass the name of the script manager class.
* @param runnerClass the name of ant's script runner for this manager.
* @return the script runner class.
* @throws BuildException if there is a problem creating the runner class.
*/
private ScriptRunnerBase createRunner(
String checkManager, String managerClass, String runnerClass) {
ScriptRunnerBase runner = null;
if (!manager.equals(AUTO) && !manager.equals(checkManager)) {
return null;
}
if (managerClass.equals(BSF_MANAGER)) {
if (scriptLoader.getResource(LoaderUtils.classNameToResource(managerClass)) == null) {
return null;
}
new ScriptFixBSFPath().fixClassLoader(scriptLoader, language);
} else {
try {
Class.forName(managerClass, true, scriptLoader);
} catch (Exception ex) {
return null;
}
}
try {
runner = (ScriptRunnerBase) Class.forName(
runnerClass, true, scriptLoader).newInstance();
runner.setProject(project);
} catch (Exception ex) {
throw ReflectUtil.toBuildException(ex);
}
runner.setLanguage(language);
runner.setScriptClassLoader(scriptLoader);
return runner;
}
}