RhinoScriptEngine.java
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
package org.mozilla.javascript.engine;
import java.io.IOException;
import java.io.Reader;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
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.ScriptEngine;
import javax.script.ScriptEngineFactory;
import javax.script.ScriptException;
import javax.script.SimpleBindings;
import org.mozilla.javascript.Callable;
import org.mozilla.javascript.Context;
import org.mozilla.javascript.ContextFactory;
import org.mozilla.javascript.RhinoException;
import org.mozilla.javascript.Script;
import org.mozilla.javascript.Scriptable;
import org.mozilla.javascript.ScriptableObject;
/**
* This is the implementation of the standard ScriptEngine interface for Rhino.
*
* <p>An instance of the Rhino ScriptEngine is fully self-contained. Bindings at the GLOBAL_SCOPE
* may be set, but there is nothing special about them -- if both global and ENGINE_SCOPE bindings
* are set then the "engine" bindings override the global ones.
*
* <p>The Rhino engine is not thread safe. Rhino does no synchronization of ScriptEngine instances
* and no synchronization of Bindings instances. It is up to the caller to ensure that the
* ScriptEngine and all its Bindings are used by a single thread at a time.
*
* <p>The Rhino script engine includes some top-level built-in functions. See the Builtins class for
* more documentation.
*
* <p>The engine supports a few configuration parameters that may be set at the "engine scope". Both
* are numbers that may be set to a String or Number object.
*
* <ul>
* <li>javax.script.language_version: The version of the JavaScript language supported, which is
* an integer defined in the Context class. The default is the latest "ES6" version, defined
* as 200.
* <li>org.mozilla.javascript.optimization_level: The level of optimization Rhino performs on the
* generated bytecode. Default is 9, which is the most. Set to -1 to use interpreted mode.
* </ul>
*/
public class RhinoScriptEngine extends AbstractScriptEngine implements Compilable, Invocable {
/**
* Reserved key for the Rhino optimization level. This is supported for backward compatibility
* -- any value less than zero results in using interpreted mode.
*
* @deprecated Replaced in 1.8.0; use {@link #INTERPRETED_MODE} instead.
*/
@Deprecated
public static final String OPTIMIZATION_LEVEL = "org.mozilla.javascript.optimization_level";
/**
* Reserved key for interpreted mode, which is much slower than the default compiled mode but
* necessary on Android where Rhino can't generate class files.
*/
public static final String INTERPRETED_MODE = "org.mozilla.javascript.interpreted_mode";
static final int DEFAULT_LANGUAGE_VERSION = Context.VERSION_ES6;
private static final boolean DEFAULT_DEBUG = true;
private static final String DEFAULT_FILENAME = "eval";
private static final CtxFactory ctxFactory = new CtxFactory();
private final RhinoScriptEngineFactory factory;
private final Builtins builtins;
private ScriptableObject topLevelScope = null;
RhinoScriptEngine(RhinoScriptEngineFactory factory) {
this.factory = factory;
this.builtins = new Builtins();
}
private Scriptable initScope(Context cx, ScriptContext sc) throws ScriptException {
configureContext(cx);
if (topLevelScope == null) {
topLevelScope = cx.initStandardObjects();
// We need to stash this away so that the built in functions can find
// this engine's specific stuff that they need to work.
topLevelScope.associateValue(Builtins.BUILTIN_KEY, builtins);
builtins.register(cx, topLevelScope, sc);
}
Scriptable engineScope = new BindingsObject(sc.getBindings(ScriptContext.ENGINE_SCOPE));
engineScope.setParentScope(null);
engineScope.setPrototype(topLevelScope);
if (sc.getBindings(ScriptContext.GLOBAL_SCOPE) != null) {
Scriptable globalScope = new BindingsObject(sc.getBindings(ScriptContext.GLOBAL_SCOPE));
globalScope.setParentScope(null);
globalScope.setPrototype(topLevelScope);
engineScope.setPrototype(globalScope);
}
return engineScope;
}
@Override
public Object eval(String script, ScriptContext context) throws ScriptException {
try (Context cx = ctxFactory.enterContext()) {
Scriptable scope = initScope(cx, context);
Object ret = cx.evaluateString(scope, script, getFilename(), 0, null);
return Context.jsToJava(ret, Object.class);
} catch (RhinoException re) {
throw new ScriptException(
re.getMessage(), re.sourceName(), re.lineNumber(), re.columnNumber());
}
}
@Override
public Object eval(Reader reader, ScriptContext context) throws ScriptException {
try (Context cx = ctxFactory.enterContext()) {
Scriptable scope = initScope(cx, context);
Object ret = cx.evaluateReader(scope, reader, getFilename(), 0, null);
return Context.jsToJava(ret, Object.class);
} catch (RhinoException re) {
throw new ScriptException(
re.getMessage(), re.sourceName(), re.lineNumber(), re.columnNumber());
} catch (IOException ioe) {
throw new ScriptException(ioe);
}
}
@Override
public CompiledScript compile(String script) throws ScriptException {
try (Context cx = ctxFactory.enterContext()) {
configureContext(cx);
Script s = cx.compileString(script, getFilename(), 1, null);
return new RhinoCompiledScript(this, s);
} catch (RhinoException re) {
throw new ScriptException(
re.getMessage(), re.sourceName(), re.lineNumber(), re.columnNumber());
}
}
@Override
public CompiledScript compile(Reader script) throws ScriptException {
try (Context cx = ctxFactory.enterContext()) {
configureContext(cx);
Script s = cx.compileReader(script, getFilename(), 1, null);
return new RhinoCompiledScript(this, s);
} catch (RhinoException re) {
throw new ScriptException(
re.getMessage(), re.sourceName(), re.lineNumber(), re.columnNumber());
} catch (IOException ioe) {
throw new ScriptException(ioe);
}
}
Object eval(Script script, ScriptContext sc) throws ScriptException {
try (Context cx = ctxFactory.enterContext()) {
Scriptable scope = initScope(cx, sc);
Object ret = script.exec(cx, scope, scope);
return Context.jsToJava(ret, Object.class);
} catch (RhinoException re) {
throw new ScriptException(
re.getMessage(), re.sourceName(), re.lineNumber(), re.columnNumber());
}
}
@Override
public Object invokeFunction(String name, Object... args)
throws ScriptException, NoSuchMethodException {
return invokeMethod(null, name, args);
}
@Override
public Object invokeMethod(Object thiz, String name, Object... args)
throws ScriptException, NoSuchMethodException {
return invokeMethodRaw(thiz, name, Object.class, args);
}
Object invokeMethodRaw(Object thiz, String name, Class<?> returnType, Object... args)
throws ScriptException, NoSuchMethodException {
try (Context cx = ctxFactory.enterContext()) {
Scriptable scope = initScope(cx, context);
Scriptable localThis;
if (thiz == null) {
localThis = scope;
} else {
localThis = Context.toObject(thiz, scope);
}
Object f = ScriptableObject.getProperty(localThis, name);
if (f == Scriptable.NOT_FOUND) {
throw new NoSuchMethodException(name);
}
if (!(f instanceof Callable)) {
throw new ScriptException("\"" + name + "\" is not a function");
}
Callable func = (Callable) f;
if (args != null) {
for (int i = 0; i < args.length; i++) {
args[i] = Context.javaToJS(args[i], scope);
}
}
Object ret = func.call(cx, scope, localThis, args);
if (returnType == Void.TYPE) {
return null;
}
return Context.jsToJava(ret, returnType);
} catch (RhinoException re) {
throw new ScriptException(
re.getMessage(), re.sourceName(), re.lineNumber(), re.columnNumber());
}
}
@SuppressWarnings("unchecked")
@Override
public <T> T getInterface(Class<T> clasz) {
if ((clasz == null) || !clasz.isInterface()) {
throw new IllegalArgumentException("Not an interface");
}
try (Context cx = ctxFactory.enterContext()) {
Scriptable scope = initScope(cx, context);
if (methodsMissing(scope, clasz)) {
return null;
}
} catch (ScriptException se) {
return null;
}
return (T)
Proxy.newProxyInstance(
Thread.currentThread().getContextClassLoader(),
new Class<?>[] {clasz},
new RhinoInvocationHandler(this, null));
}
@SuppressWarnings("unchecked")
@Override
public <T> T getInterface(Object thiz, Class<T> clasz) {
if ((clasz == null) || !clasz.isInterface()) {
throw new IllegalArgumentException("Not an interface");
}
try (Context cx = ctxFactory.enterContext()) {
Scriptable scope = initScope(cx, context);
Scriptable thisObj = Context.toObject(thiz, scope);
if (methodsMissing(thisObj, clasz)) {
return null;
}
} catch (ScriptException se) {
return null;
}
return (T)
Proxy.newProxyInstance(
Thread.currentThread().getContextClassLoader(),
new Class<?>[] {clasz},
new RhinoInvocationHandler(this, thiz));
}
@Override
public Bindings createBindings() {
return new SimpleBindings();
}
@Override
public ScriptEngineFactory getFactory() {
return factory;
}
@SuppressWarnings("deprecation")
private void configureContext(Context cx) throws ScriptException {
Object lv = get(ScriptEngine.LANGUAGE_VERSION);
if (lv != null) {
cx.setLanguageVersion(parseInteger(lv));
}
Object ol = get(OPTIMIZATION_LEVEL);
if (ol != null) {
// Handle backwardly-compatible "optimization level".
cx.setOptimizationLevel(parseInteger(ol));
}
Object interpreted = get(INTERPRETED_MODE);
if (interpreted != null) {
cx.setInterpretedMode(parseBoolean(interpreted));
}
}
private static int parseInteger(Object v) throws ScriptException {
if (v instanceof String) {
try {
return Integer.parseInt((String) v);
} catch (NumberFormatException nfe) {
throw new ScriptException("Invalid number " + v);
}
}
if (v instanceof Integer) {
return (Integer) v;
}
throw new ScriptException("Value must be a string or number");
}
private static boolean parseBoolean(Object v) throws ScriptException {
if (v instanceof String) {
return Boolean.parseBoolean((String) v);
}
if (v instanceof Boolean) {
return (Boolean) v;
}
throw new ScriptException("Value must be a string or boolean");
}
private String getFilename() {
Object fn = get(ScriptEngine.FILENAME);
if (fn instanceof String) {
return (String) fn;
}
return DEFAULT_FILENAME;
}
private static boolean methodsMissing(Scriptable scope, Class<?> clasz) {
for (Method m : clasz.getMethods()) {
if (m.getDeclaringClass() == Object.class) {
continue;
}
Object methodObj = ScriptableObject.getProperty(scope, m.getName());
if (!(methodObj instanceof Callable)) {
return true;
}
}
return false;
}
private static final class CtxFactory extends ContextFactory {
@Override
protected boolean hasFeature(Context cx, int featureIndex) {
if (featureIndex == Context.FEATURE_INTEGER_WITHOUT_DECIMAL_PLACE) {
return true;
}
return super.hasFeature(cx, featureIndex);
}
@Override
protected void onContextCreated(Context cx) {
cx.setLanguageVersion(Context.VERSION_ES6);
cx.setGeneratingDebug(DEFAULT_DEBUG);
}
}
}