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Groovy: A powerful, dynamic language for the JVM
/*
* The initial contribution was derived from the reference implementation
* developed by Sun in consultation with the Groovy community. The reference
* implementation had the following license header:
*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*
* Redistribution and use in source and binary forms, with or without modification, are
* permitted provided that the following conditions are met: Redistributions of source code
* must retain the above copyright notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice, this list of
* conditions and the following disclaimer in the documentation and/or other materials
* provided with the distribution. Neither the name of the Sun Microsystems nor the names of
* is contributors may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* Subsequent modifications by the Groovy community have been done under the Apache License v2:
*
* 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
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package org.codehaus.groovy.jsr223;
import groovy.lang.Binding;
import groovy.lang.Closure;
import groovy.lang.DelegatingMetaClass;
import groovy.lang.GroovyClassLoader;
import groovy.lang.MetaClass;
import groovy.lang.MissingMethodException;
import groovy.lang.MissingPropertyException;
import groovy.lang.Script;
import groovy.lang.Tuple;
import org.codehaus.groovy.control.CompilationFailedException;
import org.codehaus.groovy.control.CompilerConfiguration;
import org.codehaus.groovy.util.ManagedConcurrentValueMap;
import org.codehaus.groovy.util.ReferenceBundle;
import org.codehaus.groovy.runtime.InvokerHelper;
import org.codehaus.groovy.runtime.MetaClassHelper;
import org.codehaus.groovy.runtime.MethodClosure;
import javax.script.AbstractScriptEngine;
import javax.script.Bindings;
import javax.script.Compilable;
import javax.script.CompiledScript;
import javax.script.Invocable;
import javax.script.ScriptContext;
import javax.script.ScriptEngineFactory;
import javax.script.ScriptException;
import javax.script.SimpleBindings;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.Reader;
import java.io.Writer;
import java.lang.Class;
import java.lang.String;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
/**
* JSR-223 Engine implementation.
*
* @author Adapted from original by Mike Grogan
* @author Adapted from original by A. Sundararajan
* @author Jim White
* @author Guillaume Laforge
* @author Jochen Theodorou
*/
public class GroovyScriptEngineImpl extends AbstractScriptEngine implements Compilable, Invocable {
private static boolean debug = false;
// script-string-to-generated Class map
private ManagedConcurrentValueMap classMap = new ManagedConcurrentValueMap(ReferenceBundle.getSoftBundle());
// global closures map - this is used to simulate a single
// global functions namespace
private ManagedConcurrentValueMap globalClosures = new ManagedConcurrentValueMap(ReferenceBundle.getHardBundle());
// class loader for Groovy generated classes
private GroovyClassLoader loader;
// lazily initialized factory
private volatile GroovyScriptEngineFactory factory;
// counter used to generate unique global Script class names
private static int counter;
static {
counter = 0;
}
public GroovyScriptEngineImpl() {
this(new GroovyClassLoader(getParentLoader(), new CompilerConfiguration()));
}
public GroovyScriptEngineImpl(GroovyClassLoader classLoader) {
if (classLoader == null) throw new IllegalArgumentException("GroovyClassLoader is null");
this.loader = classLoader;
}
public Object eval(Reader reader, ScriptContext ctx)
throws ScriptException {
return eval(readFully(reader), ctx);
}
public Object eval(String script, ScriptContext ctx)
throws ScriptException {
try {
String val = (String) ctx.getAttribute("#jsr223.groovy.engine.keep.globals", ScriptContext.ENGINE_SCOPE);
ReferenceBundle bundle = ReferenceBundle.getHardBundle();
if (val != null && val.length() > 0) {
if (val.equalsIgnoreCase("soft")) {
bundle = ReferenceBundle.getSoftBundle();
} else if (val.equalsIgnoreCase("weak")) {
bundle = ReferenceBundle.getWeakBundle();
} else if (val.equalsIgnoreCase("phantom")) {
bundle = ReferenceBundle.getPhantomBundle();
}
}
globalClosures.setBundle(bundle);
} catch (ClassCastException cce) { /*ignore.*/ }
try {
Class clazz = getScriptClass(script);
if (clazz == null) throw new ScriptException("Script class is null");
return eval(clazz, ctx);
} catch (Exception e) {
if (debug) e.printStackTrace();
throw new ScriptException(e);
}
}
public Bindings createBindings() {
return new SimpleBindings();
}
public ScriptEngineFactory getFactory() {
if (factory == null) {
synchronized (this) {
if (factory == null) {
factory = new GroovyScriptEngineFactory();
}
}
}
return factory;
}
// javax.script.Compilable methods
public CompiledScript compile(String scriptSource) throws ScriptException {
try {
return new GroovyCompiledScript(this,
getScriptClass(scriptSource));
} catch (CompilationFailedException ee) {
throw new ScriptException(ee);
}
}
public CompiledScript compile(Reader reader) throws ScriptException {
return compile(readFully(reader));
}
// javax.script.Invokable methods.
public Object invokeFunction(String name, Object... args)
throws ScriptException, NoSuchMethodException {
return invokeImpl(null, name, args);
}
public Object invokeMethod(Object thiz, String name, Object... args)
throws ScriptException, NoSuchMethodException {
if (thiz == null) {
throw new IllegalArgumentException("script object is null");
}
return invokeImpl(thiz, name, args);
}
public T getInterface(Class clazz) {
return makeInterface(null, clazz);
}
public T getInterface(Object thiz, Class clazz) {
if (thiz == null) {
throw new IllegalArgumentException("script object is null");
}
return makeInterface(thiz, clazz);
}
// package-privates
Object eval(Class scriptClass, final ScriptContext ctx) throws ScriptException {
// Bindings so script has access to this environment.
// Only initialize once.
if (null == ctx.getAttribute("context", ScriptContext.ENGINE_SCOPE)) {
// add context to bindings
ctx.setAttribute("context", ctx, ScriptContext.ENGINE_SCOPE);
// direct output to ctx.getWriter
// If we're wrapping with a PrintWriter here,
// enable autoFlush because otherwise it might not get done!
final Writer writer = ctx.getWriter();
ctx.setAttribute("out", (writer instanceof PrintWriter) ?
writer :
new PrintWriter(writer, true),
ScriptContext.ENGINE_SCOPE);
// Not going to do this after all (at least for now).
// Scripts can use context.{reader, writer, errorWriter}.
// That is a modern version of System.{in, out, err} or Console.{reader, writer}().
//
// // New I/O names consistent with ScriptContext and java.io.Console.
//
// ctx.setAttribute("writer", writer, ScriptContext.ENGINE_SCOPE);
//
// // Direct errors to ctx.getErrorWriter
// final Writer errorWriter = ctx.getErrorWriter();
// ctx.setAttribute("errorWriter", (errorWriter instanceof PrintWriter) ?
// errorWriter :
// new PrintWriter(errorWriter),
// ScriptContext.ENGINE_SCOPE);
//
// // Get input from ctx.getReader
// // We don't wrap with BufferedReader here because we expect that if
// // the host wants that they do it. Either way Groovy scripts will
// // always have readLine because the GDK supplies it for Reader.
// ctx.setAttribute("reader", ctx.getReader(), ScriptContext.ENGINE_SCOPE);
}
// Fix for GROOVY-3669: Can't use several times the same JSR-223 ScriptContext for differents groovy script
if (ctx.getWriter() != null) {
ctx.setAttribute("out", new PrintWriter(ctx.getWriter(), true), ScriptContext.ENGINE_SCOPE);
}
/*
* We use the following Binding instance so that global variable lookup
* will be done in the current ScriptContext instance.
*/
Binding binding = new Binding(ctx.getBindings(ScriptContext.ENGINE_SCOPE)) {
@Override
public Object getVariable(String name) {
synchronized (ctx) {
int scope = ctx.getAttributesScope(name);
if (scope != -1) {
return ctx.getAttribute(name, scope);
}
}
throw new MissingPropertyException(name, getClass());
}
@Override
public void setVariable(String name, Object value) {
synchronized (ctx) {
int scope = ctx.getAttributesScope(name);
if (scope == -1) {
scope = ScriptContext.ENGINE_SCOPE;
}
ctx.setAttribute(name, value, scope);
}
}
};
try {
// if this class is not an instance of Script, it's a full-blown class
// then simply return that class
if (!Script.class.isAssignableFrom(scriptClass)) {
return scriptClass;
} else {
// it's a script
Script scriptObject = InvokerHelper.createScript(scriptClass, binding);
// save all current closures into global closures map
Method[] methods = scriptClass.getMethods();
for (Method m : methods) {
String name = m.getName();
globalClosures.put(name, new MethodClosure(scriptObject, name));
}
MetaClass oldMetaClass = scriptObject.getMetaClass();
/*
* We override the MetaClass of this script object so that we can
* forward calls to global closures (of previous or future "eval" calls)
* This gives the illusion of working on the same "global" scope.
*/
scriptObject.setMetaClass(new DelegatingMetaClass(oldMetaClass) {
@Override
public Object invokeMethod(Object object, String name, Object args) {
if (args == null) {
return invokeMethod(object, name, MetaClassHelper.EMPTY_ARRAY);
}
if (args instanceof Tuple) {
return invokeMethod(object, name, ((Tuple) args).toArray());
}
if (args instanceof Object[]) {
return invokeMethod(object, name, (Object[]) args);
} else {
return invokeMethod(object, name, new Object[]{args});
}
}
@Override
public Object invokeMethod(Object object, String name, Object[] args) {
try {
return super.invokeMethod(object, name, args);
} catch (MissingMethodException mme) {
return callGlobal(name, args, ctx);
}
}
@Override
public Object invokeStaticMethod(Object object, String name, Object[] args) {
try {
return super.invokeStaticMethod(object, name, args);
} catch (MissingMethodException mme) {
return callGlobal(name, args, ctx);
}
}
});
return scriptObject.run();
}
} catch (Exception e) {
throw new ScriptException(e);
} finally {
// Fix for GROOVY-3669: Can't use several times the same JSR-223 ScriptContext for different groovy script
// Groovy's scripting engine implementation adds those two variables in the binding
// but should clean up afterwards
ctx.removeAttribute("context", ScriptContext.ENGINE_SCOPE);
ctx.removeAttribute("out", ScriptContext.ENGINE_SCOPE);
}
}
Class getScriptClass(String script)
throws CompilationFailedException {
Class clazz = classMap.get(script);
if (clazz != null) {
return clazz;
}
clazz = loader.parseClass(script, generateScriptName());
classMap.put(script, clazz);
return clazz;
}
public void setClassLoader(GroovyClassLoader classLoader) {
this.loader = classLoader;
}
public GroovyClassLoader getClassLoader() {
return this.loader;
}
//-- Internals only below this point
// invokes the specified method/function on the given object.
private Object invokeImpl(Object thiz, String name, Object... args)
throws ScriptException, NoSuchMethodException {
if (name == null) {
throw new NullPointerException("method name is null");
}
try {
if (thiz != null) {
return InvokerHelper.invokeMethod(thiz, name, args);
} else {
return callGlobal(name, args);
}
} catch (MissingMethodException mme) {
throw new NoSuchMethodException(mme.getMessage());
} catch (Exception e) {
throw new ScriptException(e);
}
}
// call the script global function of the given name
private Object callGlobal(String name, Object[] args) {
return callGlobal(name, args, context);
}
private Object callGlobal(String name, Object[] args, ScriptContext ctx) {
Closure closure = globalClosures.get(name);
if (closure != null) {
return closure.call(args);
} else {
// Look for closure valued variable in the
// given ScriptContext. If available, call it.
Object value = ctx.getAttribute(name);
if (value instanceof Closure) {
return ((Closure) value).call(args);
} // else fall thru..
}
throw new MissingMethodException(name, getClass(), args);
}
// generate a unique name for top-level Script classes
private static synchronized String generateScriptName() {
return "Script" + (++counter) + ".groovy";
}
@SuppressWarnings("unchecked")
private T makeInterface(Object obj, Class clazz) {
final Object thiz = obj;
if (clazz == null || !clazz.isInterface()) {
throw new IllegalArgumentException("interface Class expected");
}
return (T) Proxy.newProxyInstance(
clazz.getClassLoader(),
new Class[]{clazz},
new InvocationHandler() {
public Object invoke(Object proxy, Method m, Object[] args)
throws Throwable {
return invokeImpl(thiz, m.getName(), args);
}
});
}
// determine appropriate class loader to serve as parent loader
// for GroovyClassLoader instance
private static ClassLoader getParentLoader() {
// check whether thread context loader can "see" Groovy Script class
ClassLoader ctxtLoader = Thread.currentThread().getContextClassLoader();
try {
Class c = ctxtLoader.loadClass(Script.class.getName());
if (c == Script.class) {
return ctxtLoader;
}
} catch (ClassNotFoundException cnfe) {
/* ignore */
}
// exception was thrown or we get wrong class
return Script.class.getClassLoader();
}
private static String readFully(Reader reader) throws ScriptException {
char[] arr = new char[8 * 1024]; // 8K at a time
StringBuilder buf = new StringBuilder();
int numChars;
try {
while ((numChars = reader.read(arr, 0, arr.length)) > 0) {
buf.append(arr, 0, numChars);
}
} catch (IOException exp) {
throw new ScriptException(exp);
}
return buf.toString();
}
}