ScriptLoader.java revision 1894:48d8835e3aaa 
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
26package jdk.nashorn.internal.runtime;
27
28import java.lang.module.ModuleDescriptor;
29import java.lang.module.ModuleDescriptor.Modifier;
30import java.security.CodeSource;
31import java.util.Objects;
32import java.util.Set;
33
34/**
35 * Responsible for loading script generated classes.
36 *
37 */
38final class ScriptLoader extends NashornLoader {
39    private static final String NASHORN_PKG_PREFIX = "jdk.nashorn.internal.";
40
41    private volatile boolean structureAccessAdded;
42    private final Context context;
43    private final Module scriptModule;
44
45    /*package-private*/ Context getContext() {
46        return context;
47    }
48
49    /**
50     * Constructor.
51     */
52    ScriptLoader(final Context context) {
53        super(context.getStructLoader());
54        this.context = context;
55
56        // new scripts module, it's specific exports and read-edges
57        scriptModule = createModule("jdk.scripting.nashorn.scripts");
58
59        // specific exports from nashorn to new scripts module
60        NASHORN_MODULE.addExports(OBJECTS_PKG, scriptModule);
61        NASHORN_MODULE.addExports(RUNTIME_PKG, scriptModule);
62        NASHORN_MODULE.addExports(RUNTIME_ARRAYS_PKG, scriptModule);
63        NASHORN_MODULE.addExports(RUNTIME_LINKER_PKG, scriptModule);
64        NASHORN_MODULE.addExports(SCRIPTS_PKG, scriptModule);
65
66        // nashorn needs to read scripts module methods,fields
67        NASHORN_MODULE.addReads(scriptModule);
68    }
69
70    private Module createModule(final String moduleName) {
71        final Module structMod = context.getStructLoader().getModule();
72        final ModuleDescriptor.Builder builder =
73            ModuleDescriptor.newModule(moduleName, Set.of(Modifier.SYNTHETIC))
74                    .requires("java.logging")
75                    .requires(NASHORN_MODULE.getName())
76                    .requires(structMod.getName())
77                    .packages(Set.of(SCRIPTS_PKG));
78
79        if (Context.javaSqlFound) {
80            builder.requires("java.sql");
81        }
82
83        if (Context.javaSqlRowsetFound) {
84            builder.requires("java.sql.rowset");
85        }
86
87        final ModuleDescriptor descriptor = builder.build();
88
89        final Module mod = Context.createModuleTrusted(structMod.getLayer(), descriptor, this);
90        loadModuleManipulator();
91        return mod;
92    }
93
94    @Override
95    protected Class<?> loadClass(final String name, final boolean resolve) throws ClassNotFoundException {
96        checkPackageAccess(name);
97        final Class<?> cl = super.loadClass(name, resolve);
98        if (!structureAccessAdded) {
99            final StructureLoader structLoader = context.getStructLoader();
100            if (cl.getClassLoader() == structLoader) {
101                structureAccessAdded = true;
102                structLoader.addModuleExport(scriptModule);
103            }
104        }
105        return cl;
106    }
107
108    @Override
109    protected Class<?> findClass(final String name) throws ClassNotFoundException {
110        final ClassLoader appLoader = context.getAppLoader();
111
112        /*
113         * If the appLoader is null, don't bother side-delegating to it!
114         * Bootloader has been already attempted via parent loader
115         * delegation from the "loadClass" method.
116         *
117         * Also, make sure that we don't delegate to the app loader
118         * for nashorn's own classes or nashorn generated classes!
119         */
120        if (appLoader == null || name.startsWith(NASHORN_PKG_PREFIX)) {
121            throw new ClassNotFoundException(name);
122        }
123
124        /*
125         * This split-delegation is used so that caller loader
126         * based resolutions of classes would work. For example,
127         * java.sql.DriverManager uses caller's class loader to
128         * get Driver instances. Without this split-delegation
129         * a script class evaluating DriverManager.getDrivers()
130         * will not get back any JDBC driver!
131         */
132        return appLoader.loadClass(name);
133    }
134
135    // package-private and private stuff below this point
136
137    /**
138     * Install a class for use by the Nashorn runtime
139     *
140     * @param name Binary name of class.
141     * @param data Class data bytes.
142     * @param cs CodeSource code source of the class bytes.
143     *
144     * @return Installed class.
145     */
146    synchronized Class<?> installClass(final String name, final byte[] data, final CodeSource cs) {
147        return defineClass(name, data, 0, data.length, Objects.requireNonNull(cs));
148    }
149}
150