/*
* 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.optional;
import org.apache.tools.ant.BuildException;
import java.util.Iterator;
import org.apache.tools.ant.util.ScriptRunnerBase;
import org.apache.tools.ant.util.ReflectWrapper;
/**
* This class is used to run scripts using JSR 223.
* @since Ant 1.7.0
*/
public class JavaxScriptRunner extends ScriptRunnerBase {
private ReflectWrapper engine;
/**
* Get the name of the manager prefix.
* @return "javax"
*/
public String getManagerName() {
return "javax";
}
/** {@inheritDoc}. */
public boolean supportsLanguage() {
if (engine != null) {
return true;
}
checkLanguage();
ClassLoader origLoader = replaceContextLoader();
try {
return createEngine() != null;
} catch (Exception ex) {
return false;
} finally {
restoreContextLoader(origLoader);
}
}
/**
* Do the work to run the script.
*
* @param execName the name that will be passed to the
* scripting engine for this script execution.
*
* @exception BuildException if something goes wrong executing the script.
*/
public void executeScript(String execName) throws BuildException {
evaluateScript(execName);
}
/**
* Do the work to eval the script.
*
* @param execName the name that will be passed to the
* scripting engine for this script execution.
* @return the result of the evaluation
* @exception BuildException if something goes wrong executing the script.
*/
public Object evaluateScript(String execName) throws BuildException {
checkLanguage();
ClassLoader origLoader = replaceContextLoader();
try {
ReflectWrapper engine = createEngine();
if (engine == null) {
throw new BuildException(
"Unable to create javax script engine for "
+ getLanguage());
}
for (Iterator i = getBeans().keySet().iterator(); i.hasNext();) {
String key = (String) i.next();
Object value = getBeans().get(key);
if ("FX".equalsIgnoreCase(getLanguage())) {
engine.invoke(
"put", String.class, key
+ ":" + value.getClass().getName(),
Object.class, value);
} else {
engine.invoke(
"put", String.class, key,
Object.class, value);
}
}
// execute the script
return engine.invoke("eval", String.class, getScript());
} catch (BuildException be) {
//catch and rethrow build exceptions
// this may be a BuildException wrapping a ScriptException
// deeply wrapping yet another BuildException - for
// example because of self.fail() - see
// https://issues.apache.org/bugzilla/show_bug.cgi?id=47509
throw unwrap(be);
} catch (Exception be) {
//any other exception? Get its cause
Throwable t = be;
Throwable te = be.getCause();
if (te != null) {
if (te instanceof BuildException) {
throw (BuildException) te;
} else {
t = te;
}
}
throw new BuildException(t);
} finally {
restoreContextLoader(origLoader);
}
}
private ReflectWrapper createEngine() throws Exception {
if (engine != null) {
return engine;
}
ReflectWrapper manager = new ReflectWrapper(
getClass().getClassLoader(), "javax.script.ScriptEngineManager");
Object e = manager.invoke(
"getEngineByName", String.class, getLanguage());
if (e == null) {
return null;
}
ReflectWrapper ret = new ReflectWrapper(e);
if (getKeepEngine()) {
this.engine = ret;
}
return ret;
}
/**
* Traverse a Throwable's cause(s) and return the BuildException
* most deeply nested into it - if any.
*/
private static BuildException unwrap(Throwable t) {
BuildException deepest =
t instanceof BuildException ? (BuildException) t : null;
Throwable current = t;
while (current.getCause() != null) {
current = current.getCause();
if (current instanceof BuildException) {
deepest = (BuildException) current;
}
}
return deepest;
}
}