org.mozilla.javascript.MemberBox Maven / Gradle / Ivy
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/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* 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;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Member;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
/**
* Wrapper class for Method and Constructor instances to cache getParameterTypes() results, recover
* from IllegalAccessException in some cases and provide serialization support.
*
* @author Igor Bukanov
*/
final class MemberBox implements Serializable {
private static final long serialVersionUID = 6358550398665688245L;
private transient Member memberObject;
transient Class[] argTypes;
transient boolean vararg;
transient Function asGetterFunction;
transient Function asSetterFunction;
transient Object delegateTo;
MemberBox(Method method) {
init(method);
}
MemberBox(Constructor constructor) {
init(constructor);
}
private void init(Method method) {
this.memberObject = method;
this.argTypes = method.getParameterTypes();
this.vararg = method.isVarArgs();
}
private void init(Constructor constructor) {
this.memberObject = constructor;
this.argTypes = constructor.getParameterTypes();
this.vararg = constructor.isVarArgs();
}
Method method() {
return (Method) memberObject;
}
Constructor ctor() {
return (Constructor) memberObject;
}
Member member() {
return memberObject;
}
boolean isMethod() {
return memberObject instanceof Method;
}
boolean isCtor() {
return memberObject instanceof Constructor;
}
boolean isStatic() {
return Modifier.isStatic(memberObject.getModifiers());
}
boolean isPublic() {
return Modifier.isPublic(memberObject.getModifiers());
}
String getName() {
return memberObject.getName();
}
Class getDeclaringClass() {
return memberObject.getDeclaringClass();
}
String toJavaDeclaration() {
StringBuilder sb = new StringBuilder();
if (isMethod()) {
Method method = method();
sb.append(method.getReturnType());
sb.append(' ');
sb.append(method.getName());
} else {
Constructor ctor = ctor();
String name = ctor.getDeclaringClass().getName();
int lastDot = name.lastIndexOf('.');
if (lastDot >= 0) {
name = name.substring(lastDot + 1);
}
sb.append(name);
}
sb.append(JavaMembers.liveConnectSignature(argTypes));
return sb.toString();
}
@Override
public String toString() {
return memberObject.toString();
}
/** Function returned by calls to __lookupGetter__ */
Function asGetterFunction(final String name, final Scriptable scope) {
// Note: scope is the scriptable this function is related to; therefore this function
// is constant for this member box.
// Because of this we can cache the function in the attribute
if (asGetterFunction == null) {
asGetterFunction =
new BaseFunction(scope, ScriptableObject.getFunctionPrototype(scope)) {
@Override
public Object call(
Context cx,
Scriptable callScope,
Scriptable thisObj,
Object[] originalArgs) {
MemberBox nativeGetter = MemberBox.this;
Object getterThis;
Object[] args;
if (nativeGetter.delegateTo == null) {
getterThis = thisObj;
args = ScriptRuntime.emptyArgs;
} else {
getterThis = nativeGetter.delegateTo;
args = new Object[] {thisObj};
}
return nativeGetter.invoke(getterThis, args);
}
@Override
public String getFunctionName() {
return name;
}
};
}
return asGetterFunction;
}
/** Function returned by calls to __lookupSetter__ */
Function asSetterFunction(final String name, final Scriptable scope) {
// Note: scope is the scriptable this function is related to; therefore this function
// is constant for this member box.
// Because of this we can cache the function in the attribute
if (asSetterFunction == null) {
asSetterFunction =
new BaseFunction(scope, ScriptableObject.getFunctionPrototype(scope)) {
@Override
public Object call(
Context cx,
Scriptable callScope,
Scriptable thisObj,
Object[] originalArgs) {
MemberBox nativeSetter = MemberBox.this;
Object setterThis;
Object[] args;
Object value =
originalArgs.length > 0
? FunctionObject.convertArg(
cx,
thisObj,
originalArgs[0],
FunctionObject.getTypeTag(
nativeSetter.argTypes[0]))
: Undefined.instance;
if (nativeSetter.delegateTo == null) {
setterThis = thisObj;
args = new Object[] {value};
} else {
setterThis = nativeSetter.delegateTo;
args = new Object[] {thisObj, value};
}
return nativeSetter.invoke(setterThis, args);
}
@Override
public String getFunctionName() {
return name;
}
};
}
return asSetterFunction;
}
Object invoke(Object target, Object[] args) {
Method method = method();
// handle delegators
if (target instanceof Delegator) {
target = ((Delegator) target).getDelegee();
}
for (int i = 0; i < args.length; ++i) {
if (args[i] instanceof Delegator) {
args[i] = ((Delegator) args[i]).getDelegee();
}
}
try {
try {
return method.invoke(target, args);
} catch (IllegalAccessException ex) {
Method accessible = searchAccessibleMethod(method, argTypes);
if (accessible != null) {
memberObject = accessible;
method = accessible;
} else {
if (!VMBridge.instance.tryToMakeAccessible(method)) {
throw Context.throwAsScriptRuntimeEx(ex);
}
}
// Retry after recovery
return method.invoke(target, args);
}
} catch (InvocationTargetException ite) {
// Must allow ContinuationPending exceptions to propagate unhindered
Throwable e = ite;
do {
e = ((InvocationTargetException) e).getTargetException();
} while ((e instanceof InvocationTargetException));
if (e instanceof ContinuationPending) throw (ContinuationPending) e;
throw Context.throwAsScriptRuntimeEx(e);
} catch (Exception ex) {
throw Context.throwAsScriptRuntimeEx(ex);
}
}
Object newInstance(Object[] args) {
Constructor ctor = ctor();
try {
try {
return ctor.newInstance(args);
} catch (IllegalAccessException ex) {
if (!VMBridge.instance.tryToMakeAccessible(ctor)) {
throw Context.throwAsScriptRuntimeEx(ex);
}
}
return ctor.newInstance(args);
} catch (Exception ex) {
throw Context.throwAsScriptRuntimeEx(ex);
}
}
private static Method searchAccessibleMethod(Method method, Class[] params) {
int modifiers = method.getModifiers();
if (Modifier.isPublic(modifiers) && !Modifier.isStatic(modifiers)) {
Class c = method.getDeclaringClass();
if (!Modifier.isPublic(c.getModifiers())) {
String name = method.getName();
Class[] intfs = c.getInterfaces();
for (int i = 0, N = intfs.length; i != N; ++i) {
Class intf = intfs[i];
if (Modifier.isPublic(intf.getModifiers())) {
try {
return intf.getMethod(name, params);
} catch (NoSuchMethodException ex) {
} catch (SecurityException ex) {
}
}
}
for (; ; ) {
c = c.getSuperclass();
if (c == null) {
break;
}
if (Modifier.isPublic(c.getModifiers())) {
try {
Method m = c.getMethod(name, params);
int mModifiers = m.getModifiers();
if (Modifier.isPublic(mModifiers) && !Modifier.isStatic(mModifiers)) {
return m;
}
} catch (NoSuchMethodException ex) {
} catch (SecurityException ex) {
}
}
}
}
}
return null;
}
private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
in.defaultReadObject();
Member member = readMember(in);
if (member instanceof Method) {
init((Method) member);
} else {
init((Constructor) member);
}
}
private void writeObject(ObjectOutputStream out) throws IOException {
out.defaultWriteObject();
writeMember(out, memberObject);
}
/**
* Writes a Constructor or Method object.
*
* Methods and Constructors are not serializable, so we must serialize information about the
* class, the name, and the parameters and recreate upon deserialization.
*/
private static void writeMember(ObjectOutputStream out, Member member) throws IOException {
if (member == null) {
out.writeBoolean(false);
return;
}
out.writeBoolean(true);
if (!(member instanceof Method || member instanceof Constructor))
throw new IllegalArgumentException("not Method or Constructor");
out.writeBoolean(member instanceof Method);
out.writeObject(member.getName());
out.writeObject(member.getDeclaringClass());
if (member instanceof Method) {
writeParameters(out, ((Method) member).getParameterTypes());
} else {
writeParameters(out, ((Constructor) member).getParameterTypes());
}
}
/** Reads a Method or a Constructor from the stream. */
private static Member readMember(ObjectInputStream in)
throws IOException, ClassNotFoundException {
if (!in.readBoolean()) return null;
boolean isMethod = in.readBoolean();
String name = (String) in.readObject();
Class declaring = (Class) in.readObject();
Class[] parms = readParameters(in);
try {
if (isMethod) {
return declaring.getMethod(name, parms);
}
return declaring.getConstructor(parms);
} catch (NoSuchMethodException e) {
throw new IOException("Cannot find member: " + e);
}
}
private static final Class[] primitives = {
Boolean.TYPE,
Byte.TYPE,
Character.TYPE,
Double.TYPE,
Float.TYPE,
Integer.TYPE,
Long.TYPE,
Short.TYPE,
Void.TYPE
};
/**
* Writes an array of parameter types to the stream.
*
*
Requires special handling because primitive types cannot be found upon deserialization by
* the default Java implementation.
*/
private static void writeParameters(ObjectOutputStream out, Class[] parms)
throws IOException {
out.writeShort(parms.length);
outer:
for (Class parm : parms) {
boolean primitive = parm.isPrimitive();
out.writeBoolean(primitive);
if (!primitive) {
out.writeObject(parm);
continue;
}
for (int j = 0; j < primitives.length; j++) {
if (parm.equals(primitives[j])) {
out.writeByte(j);
continue outer;
}
}
throw new IllegalArgumentException("Primitive " + parm + " not found");
}
}
/** Reads an array of parameter types from the stream. */
private static Class[] readParameters(ObjectInputStream in)
throws IOException, ClassNotFoundException {
Class[] result = new Class[in.readShort()];
for (int i = 0; i < result.length; i++) {
if (!in.readBoolean()) {
result[i] = (Class) in.readObject();
continue;
}
result[i] = primitives[in.readByte()];
}
return result;
}
}