1 /*
2 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package jdk.nashorn.internal.runtime;
27
28 import java.lang.invoke.MethodHandle;
29 import java.lang.invoke.MethodHandles;
30 import java.lang.invoke.MethodType;
31 import jdk.internal.dynalink.CallSiteDescriptor;
32 import jdk.internal.dynalink.beans.StaticClass;
33 import jdk.internal.dynalink.linker.GuardedInvocation;
34 import jdk.internal.dynalink.linker.LinkRequest;
35 import jdk.internal.dynalink.support.Guards;
36 import jdk.nashorn.internal.lookup.MethodHandleFactory;
37 import jdk.nashorn.internal.lookup.MethodHandleFunctionality;
38 import jdk.nashorn.internal.objects.NativeJava;
39 import jdk.nashorn.internal.objects.annotations.Attribute;
40 import jdk.nashorn.internal.objects.annotations.Function;
41
42 /**
43 * An object that exposes Java packages and classes as its properties. Packages are exposed as objects that have further
44 * sub-packages and classes as their properties. Normally, three instances of this class are exposed as built-in objects
45 * in Nashorn: {@code "Packages"}, {@code "java"}, and {@code "javax"}. Typical usages are:
46 * <pre>
47 * var list = new java.util.ArrayList()
48 * var sprocket = new Packages.com.acme.Sprocket()
49 * </pre>
50 * or you can store the type objects in a variable for later reuse:
51 * <pre>
52 * var ArrayList = java.util.ArrayList
53 * var list = new ArrayList
54 * </pre>
55 * You can also use {@link NativeJava#type(Object, Object)} to access Java classes. These two statements are mostly
56 * equivalent:
57 * <pre>
58 * var listType1 = java.util.ArrayList
59 * var listType2 = Java.type("java.util.ArrayList")
60 * </pre>
61 * The difference is that {@code Java.type()} will throw an error if the class does not exist, while the first
62 * expression will return an empty object, as it must treat all non-existent classes as potentially being further
63 * subpackages. As such, {@code Java.type()} has the potential to catch typos earlier. A further difference is that
64 * {@code Java.type()} doesn't recognize {@code .} (dot) as the separator between outer class name and inner class name,
65 * it only recognizes the dollar sign. These are equivalent:
66 * <pre>
67 * var ftype1 = java.awt.geom.Arc2D$Float
68 * var ftype2 = java.awt.geom.Arc2D.Float
69 * var ftype3 = Java.asType("java.awt.geom.Arc2D$Float")
70 * var ftype4 = Java.asType("java.awt.geom.Arc2D").Float
71 * </pre>
72 */
73 public final class NativeJavaPackage extends ScriptObject {
74 private static final MethodHandleFunctionality MH = MethodHandleFactory.getFunctionality();
75 private static final MethodHandle CLASS_NOT_FOUND = findOwnMH("classNotFound", Void.TYPE, NativeJavaPackage.class);
76 private static final MethodHandle TYPE_GUARD = Guards.getClassGuard(NativeJavaPackage.class);
77
78 /** Full name of package (includes path.) */
79 private final String name;
80
81 /**
82 * Public constructor to be accessible from {@link jdk.nashorn.internal.objects.Global}
83 * @param name package name
84 * @param proto proto
85 */
86 public NativeJavaPackage(final String name, final ScriptObject proto) {
87 super(proto, null);
88 this.name = name;
89 }
90
91 @Override
92 public String getClassName() {
93 return "JavaPackage";
94 }
95
96 @Override
97 public boolean equals(final Object other) {
98 if (other instanceof NativeJavaPackage) {
99 return name.equals(((NativeJavaPackage)other).name);
100 }
101 return false;
102 }
103
104 @Override
105 public int hashCode() {
106 return name == null ? 0 : name.hashCode();
107 }
108
109 /**
110 * Get the full name of the package
111 * @return the name
112 */
113 public String getName() {
114 return name;
115 }
116
117 @Override
118 public String safeToString() {
119 return toString();
120 }
121
122 @Override
123 public String toString() {
124 return "[JavaPackage " + name + "]";
125 }
126
127 @Override
128 public Object getDefaultValue(final Class<?> hint) {
129 if (hint == String.class) {
130 return toString();
131 }
132
133 return super.getDefaultValue(hint);
134 }
135
136 @Override
137 protected GuardedInvocation findNewMethod(CallSiteDescriptor desc) {
138 return createClassNotFoundInvocation(desc);
139 }
140
141 @Override
142 protected GuardedInvocation findCallMethod(CallSiteDescriptor desc, LinkRequest request) {
143 return createClassNotFoundInvocation(desc);
144 }
145
146 private static GuardedInvocation createClassNotFoundInvocation(final CallSiteDescriptor desc) {
147 // If NativeJavaPackage is invoked either as a constructor or as a function, throw a ClassNotFoundException as
148 // we can assume the user attempted to instantiate a non-existent class.
149 final MethodType type = desc.getMethodType();
150 return new GuardedInvocation(
151 MH.dropArguments(CLASS_NOT_FOUND, 1, type.parameterList().subList(1, type.parameterCount())),
152 type.parameterType(0) == NativeJavaPackage.class ? null : TYPE_GUARD);
153 }
154
155 @SuppressWarnings("unused")
156 private static void classNotFound(final NativeJavaPackage pkg) throws ClassNotFoundException {
157 throw new ClassNotFoundException(pkg.name);
158 }
159
160 /**
161 * "No such property" call placeholder.
162 *
163 * This can never be called as we override {@link ScriptObject#noSuchProperty}. We do declare it here as it's a signal
164 * to {@link WithObject} that it's worth trying doing a {@code noSuchProperty} on this object.
165 *
166 * @param self self reference
167 * @param name property name
168 * @return never returns
169 */
170 @Function(attributes = Attribute.NOT_ENUMERABLE)
171 public static Object __noSuchProperty__(final Object self, final Object name) {
172 throw new AssertionError("__noSuchProperty__ placeholder called");
173 }
174
175 /**
176 * "No such method call" placeholder
177 *
178 * This can never be called as we override {@link ScriptObject#noSuchMethod}. We do declare it here as it's a signal
179 * to {@link WithObject} that it's worth trying doing a noSuchProperty on this object.
180 *
181 * @param self self reference
182 * @param args arguments to method
183 * @return never returns
184 */
185 @Function(attributes = Attribute.NOT_ENUMERABLE)
186 public static Object __noSuchMethod__(final Object self, final Object... args) {
187 throw new AssertionError("__noSuchMethod__ placeholder called");
188 }
189
190 /**
191 * Handle creation of new attribute.
192 * @param desc the call site descriptor
193 * @param request the link request
194 * @return Link to be invoked at call site.
195 */
196 @Override
197 public GuardedInvocation noSuchProperty(final CallSiteDescriptor desc, final LinkRequest request) {
198 final String propertyName = desc.getNameToken(2);
199 final String fullName = name.isEmpty() ? propertyName : name + "." + propertyName;
200
201 final Context context = getContext();
202
203 Class<?> javaClass = null;
204 try {
205 javaClass = context.findClass(fullName);
206 } catch (final NoClassDefFoundError | ClassNotFoundException e) {
207 //ignored
208 }
209
210 if (javaClass == null) {
211 set(propertyName, new NativeJavaPackage(fullName, getProto()), false);
212 } else {
213 set(propertyName, StaticClass.forClass(javaClass), false);
214 }
215
216 return super.lookup(desc, request);
217 }
218
219 @Override
220 public GuardedInvocation noSuchMethod(final CallSiteDescriptor desc, final LinkRequest request) {
221 return noSuchProperty(desc, request);
222 }
223
224 private static MethodHandle findOwnMH(final String name, final Class<?> rtype, final Class<?>... types) {
225 return MH.findStatic(MethodHandles.lookup(), NativeJavaPackage.class, name, MH.type(rtype, types));
226 }
227 }
--- EOF ---