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Rhino is an open-source implementation of JavaScript written entirely in Java.
It is typically embedded into Java applications to provide scripting to end users.
/* -*- 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/. */
// API class
package org.mozilla.javascript;
/**
* Class ImporterTopLevel
*
* This class defines a ScriptableObject that can be instantiated as a top-level ("global")
* object to provide functionality similar to Java's "import" statement.
*
*
This class can be used to create a top-level scope using the following code:
*
*
* Scriptable scope = new ImporterTopLevel(cx);
*
*
* Then JavaScript code will have access to the following methods:
*
*
* - importClass - will "import" a class by making its unqualified name available as a property
* of the top-level scope
*
- importPackage - will "import" all the classes of the package by searching for unqualified
* names as classes qualified by the given package.
*
*
* The following code from the shell illustrates this use:
*
*
* js> importClass(java.io.File)
* js> f = new File('help.txt')
* help.txt
* js> importPackage(java.util)
* js> v = new Vector()
* []
*
*
* @author Norris Boyd
*/
public class ImporterTopLevel extends TopLevel {
private static final long serialVersionUID = -9095380847465315412L;
private static final Object IMPORTER_TAG = "Importer";
public ImporterTopLevel() {}
public ImporterTopLevel(Context cx) {
this(cx, false);
}
public ImporterTopLevel(Context cx, boolean sealed) {
initStandardObjects(cx, sealed);
}
@Override
public String getClassName() {
return (topScopeFlag) ? "global" : "JavaImporter";
}
public static void init(Context cx, Scriptable scope, boolean sealed) {
ImporterTopLevel obj = new ImporterTopLevel();
obj.exportAsJSClass(MAX_PROTOTYPE_ID, scope, sealed);
}
public void initStandardObjects(Context cx, boolean sealed) {
// Assume that Context.initStandardObjects initialize JavaImporter
// property lazily so the above init call is not yet called
cx.initStandardObjects(this, sealed);
topScopeFlag = true;
// If seal is true then exportAsJSClass(cx, seal) would seal
// this obj. Since this is scope as well, it would not allow
// to add variables.
IdFunctionObject ctor = exportAsJSClass(MAX_PROTOTYPE_ID, this, false);
if (sealed) {
ctor.sealObject();
}
// delete "constructor" defined by exportAsJSClass so "constructor"
// name would refer to Object.constructor
// and not to JavaImporter.prototype.constructor.
delete("constructor");
}
@Override
public boolean has(String name, Scriptable start) {
return super.has(name, start) || getPackageProperty(name, start) != NOT_FOUND;
}
@Override
public Object get(String name, Scriptable start) {
Object result = super.get(name, start);
if (result != NOT_FOUND) return result;
result = getPackageProperty(name, start);
return result;
}
private Object getPackageProperty(String name, Scriptable start) {
Object result = NOT_FOUND;
Scriptable scope = start;
if (topScopeFlag) {
scope = ScriptableObject.getTopLevelScope(scope);
}
Object[] elements = getNativeJavaPackages(scope);
if (elements == null) {
return result;
}
for (int i = 0; i < elements.length; i++) {
NativeJavaPackage p = (NativeJavaPackage) elements[i];
Object v = p.getPkgProperty(name, start, false);
if (v != null && !(v instanceof NativeJavaPackage)) {
if (result == NOT_FOUND) {
result = v;
} else {
throw Context.reportRuntimeErrorById(
"msg.ambig.import", result.toString(), v.toString());
}
}
}
return result;
}
private static Object[] getNativeJavaPackages(Scriptable scope) {
// retrive the native java packages stored in top scope.
synchronized (scope) {
if (scope instanceof ScriptableObject) {
ScriptableObject so = (ScriptableObject) scope;
ObjArray importedPackages = (ObjArray) so.getAssociatedValue(AKEY);
if (importedPackages != null) {
return importedPackages.toArray();
}
}
}
return null;
}
/** @deprecated Kept only for compatibility. */
@Deprecated
public void importPackage(Context cx, Scriptable thisObj, Object[] args, Function funObj) {
js_importPackage(this, args);
}
private Object js_construct(Scriptable scope, Object[] args) {
ImporterTopLevel result = new ImporterTopLevel();
for (int i = 0; i != args.length; ++i) {
Object arg = args[i];
if (arg instanceof NativeJavaClass) {
ImporterTopLevel.importClass(result, (NativeJavaClass) arg);
} else if (arg instanceof NativeJavaPackage) {
ImporterTopLevel.importPackage(result, (NativeJavaPackage) arg);
} else {
throw Context.reportRuntimeErrorById(
"msg.not.class.not.pkg", Context.toString(arg));
}
}
// set explicitly prototype and scope
// as otherwise in top scope mode BaseFunction.construct
// would keep them set to null. It also allow to use
// JavaImporter without new and still get properly
// initialized object.
result.setParentScope(scope);
result.setPrototype(this);
return result;
}
private static Object js_importClass(Scriptable scope, Object[] args) {
for (int i = 0; i != args.length; i++) {
Object arg = args[i];
if (!(arg instanceof NativeJavaClass)) {
throw Context.reportRuntimeErrorById("msg.not.class", Context.toString(arg));
}
importClass(scope, (NativeJavaClass) arg);
}
return Undefined.instance;
}
private static Object js_importPackage(ScriptableObject scope, Object[] args) {
for (int i = 0; i != args.length; i++) {
Object arg = args[i];
if (!(arg instanceof NativeJavaPackage)) {
throw Context.reportRuntimeErrorById("msg.not.pkg", Context.toString(arg));
}
importPackage(scope, (NativeJavaPackage) arg);
}
return Undefined.instance;
}
private static void importPackage(ScriptableObject scope, NativeJavaPackage pkg) {
if (pkg == null) {
return;
}
synchronized (scope) {
ObjArray importedPackages = (ObjArray) scope.getAssociatedValue(AKEY);
if (importedPackages == null) {
importedPackages = new ObjArray();
scope.associateValue(AKEY, importedPackages);
}
for (int j = 0; j != importedPackages.size(); j++) {
if (pkg.equals(importedPackages.get(j))) {
return;
}
}
importedPackages.add(pkg);
}
}
private static void importClass(Scriptable scope, NativeJavaClass cl) {
String s = cl.getClassObject().getName();
String n = s.substring(s.lastIndexOf('.') + 1);
Object val = scope.get(n, scope);
if (val != NOT_FOUND && val != cl) {
throw Context.reportRuntimeErrorById("msg.prop.defined", n);
}
// defineProperty(n, cl, DONTENUM);
scope.put(n, scope, cl);
}
@Override
protected void initPrototypeId(int id) {
String s;
int arity;
switch (id) {
case Id_constructor:
arity = 0;
s = "constructor";
break;
case Id_importClass:
arity = 1;
s = "importClass";
break;
case Id_importPackage:
arity = 1;
s = "importPackage";
break;
default:
throw new IllegalArgumentException(String.valueOf(id));
}
initPrototypeMethod(IMPORTER_TAG, id, s, arity);
}
@Override
public Object execIdCall(
IdFunctionObject f, Context cx, Scriptable scope, Scriptable thisObj, Object[] args) {
if (!f.hasTag(IMPORTER_TAG)) {
return super.execIdCall(f, cx, scope, thisObj, args);
}
int id = f.methodId();
switch (id) {
case Id_constructor:
return js_construct(scope, args);
case Id_importClass:
return js_importClass(realScope(scope, thisObj, f), args);
case Id_importPackage:
return js_importPackage(realScope(scope, thisObj, f), args);
}
throw new IllegalArgumentException(String.valueOf(id));
}
private ScriptableObject realScope(Scriptable scope, Scriptable thisObj, IdFunctionObject f) {
if (topScopeFlag) {
// when used as top scope importPackage and importClass are global
// function that ignore thisObj. We use the the top level scope
// which might not be the same as 'this' when used shared scopes
thisObj = ScriptableObject.getTopLevelScope(scope);
}
return ensureType(thisObj, ScriptableObject.class, f);
}
@Override
protected int findPrototypeId(String s) {
int id;
switch (s) {
case "constructor":
id = Id_constructor;
break;
case "importClass":
id = Id_importClass;
break;
case "importPackage":
id = Id_importPackage;
break;
default:
id = 0;
break;
}
return id;
}
private static final int Id_constructor = 1,
Id_importClass = 2,
Id_importPackage = 3,
MAX_PROTOTYPE_ID = 3;
private static final String AKEY = "importedPackages";
private boolean topScopeFlag;
}
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