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.api.scripting;
  27 
  28 import java.util.Arrays;
  29 import java.util.Collections;
  30 import java.util.List;
  31 import java.util.Objects;
  32 import javax.script.ScriptEngine;
  33 import javax.script.ScriptEngineFactory;
  34 import jdk.nashorn.internal.runtime.Context;
  35 import jdk.nashorn.internal.runtime.Version;
  36 
  37 /**
  38  * JSR-223 compliant script engine factory for Nashorn. The engine answers for:
  39  * <ul>
  40  * <li>names {@code "nashorn"}, {@code "Nashorn"}, {@code "js"}, {@code "JS"}, {@code "JavaScript"},
  41  * {@code "javascript"}, {@code "ECMAScript"}, and {@code "ecmascript"};</li>
  42  * <li>MIME types {@code "application/javascript"}, {@code "application/ecmascript"}, {@code "text/javascript"}, and
  43  * {@code "text/ecmascript"};</li>
  44  * <li>as well as for the extension {@code "js"}.</li>
  45  * </ul>
  46  * Programs executing in engines created using {@link #getScriptEngine(String[])} will have the passed arguments
  47  * accessible as a global variable named {@code "arguments"}.
  48  *
  49  * @since 1.8u40
  50  */
  51 public final class NashornScriptEngineFactory implements ScriptEngineFactory {
  52     @Override
  53     public String getEngineName() {
  54         return (String) getParameter(ScriptEngine.ENGINE);
  55     }
  56 
  57     @Override
  58     public String getEngineVersion() {
  59         return (String) getParameter(ScriptEngine.ENGINE_VERSION);
  60     }
  61 
  62     @Override
  63     public List<String> getExtensions() {
  64         return Collections.unmodifiableList(extensions);
  65     }
  66 
  67     @Override
  68     public String getLanguageName() {
  69         return (String) getParameter(ScriptEngine.LANGUAGE);
  70     }
  71 
  72     @Override
  73     public String getLanguageVersion() {
  74         return (String) getParameter(ScriptEngine.LANGUAGE_VERSION);
  75     }
  76 
  77     @Override
  78     public String getMethodCallSyntax(final String obj, final String method, final String... args) {
  79         final StringBuilder sb = new StringBuilder().append(obj).append('.').append(method).append('(');
  80         final int len = args.length;
  81 
  82         if (len > 0) {
  83             sb.append(args[0]);
  84         }
  85         for (int i = 1; i < len; i++) {
  86             sb.append(',').append(args[i]);
  87         }
  88         sb.append(')');
  89 
  90         return sb.toString();
  91     }
  92 
  93     @Override
  94     public List<String> getMimeTypes() {
  95         return Collections.unmodifiableList(mimeTypes);
  96     }
  97 
  98     @Override
  99     public List<String> getNames() {
 100         return Collections.unmodifiableList(names);
 101     }
 102 
 103     @Override
 104     public String getOutputStatement(final String toDisplay) {
 105         return "print(" + toDisplay + ")";
 106     }
 107 
 108     @Override
 109     public Object getParameter(final String key) {
 110         switch (key) {
 111         case ScriptEngine.NAME:
 112             return "javascript";
 113         case ScriptEngine.ENGINE:
 114             return "Oracle Nashorn";
 115         case ScriptEngine.ENGINE_VERSION:
 116             return Version.version();
 117         case ScriptEngine.LANGUAGE:
 118             return "ECMAScript";
 119         case ScriptEngine.LANGUAGE_VERSION:
 120             return "ECMA - 262 Edition 5.1";
 121         case "THREADING":
 122             // The engine implementation is not thread-safe. Can't be
 123             // used to execute scripts concurrently on multiple threads.
 124             return null;
 125         default:
 126             return null;
 127         }
 128     }
 129 
 130     @Override
 131     public String getProgram(final String... statements) {
 132         Objects.requireNonNull(statements);
 133         final StringBuilder sb = new StringBuilder();
 134 
 135         for (final String statement : statements) {
 136             sb.append(Objects.requireNonNull(statement)).append(';');
 137         }
 138 
 139         return sb.toString();
 140     }
 141 
 142     // default options passed to Nashorn script engine
 143     private static final String[] DEFAULT_OPTIONS = new String[] { "-doe" };
 144 
 145     @Override
 146     public ScriptEngine getScriptEngine() {
 147         try {
 148             return new NashornScriptEngine(this, DEFAULT_OPTIONS, getAppClassLoader(), null);
 149         } catch (final RuntimeException e) {
 150             if (Context.DEBUG) {
 151                 e.printStackTrace();
 152             }
 153             throw e;
 154         }
 155     }
 156 
 157     /**
 158      * Create a new Script engine initialized with the given class loader.
 159      *
 160      * @param appLoader class loader to be used as script "app" class loader.
 161      * @return newly created script engine.
 162      * @throws SecurityException
 163      *         if the security manager's {@code checkPermission}
 164      *         denies {@code RuntimePermission("nashorn.setConfig")}
 165      */
 166     public ScriptEngine getScriptEngine(final ClassLoader appLoader) {
 167         return newEngine(DEFAULT_OPTIONS, appLoader, null);
 168     }
 169 
 170     /**
 171      * Create a new Script engine initialized with the given class filter.
 172      *
 173      * @param classFilter class filter to use.
 174      * @return newly created script engine.
 175      * @throws NullPointerException if {@code classFilter} is {@code null}
 176      * @throws SecurityException
 177      *         if the security manager's {@code checkPermission}
 178      *         denies {@code RuntimePermission("nashorn.setConfig")}
 179      */
 180     public ScriptEngine getScriptEngine(final ClassFilter classFilter) {
 181         return newEngine(DEFAULT_OPTIONS, getAppClassLoader(), Objects.requireNonNull(classFilter));
 182     }
 183 
 184     /**
 185      * Create a new Script engine initialized with the given arguments.
 186      *
 187      * @param args arguments array passed to script engine.
 188      * @return newly created script engine.
 189      * @throws NullPointerException if {@code args} is {@code null}
 190      * @throws SecurityException
 191      *         if the security manager's {@code checkPermission}
 192      *         denies {@code RuntimePermission("nashorn.setConfig")}
 193      */
 194     public ScriptEngine getScriptEngine(final String... args) {
 195         return newEngine(Objects.requireNonNull(args), getAppClassLoader(), null);
 196     }
 197 
 198     /**
 199      * Create a new Script engine initialized with the given arguments and the given class loader.
 200      *
 201      * @param args arguments array passed to script engine.
 202      * @param appLoader class loader to be used as script "app" class loader.
 203      * @return newly created script engine.
 204      * @throws NullPointerException if {@code args} is {@code null}
 205      * @throws SecurityException
 206      *         if the security manager's {@code checkPermission}
 207      *         denies {@code RuntimePermission("nashorn.setConfig")}
 208      */
 209     public ScriptEngine getScriptEngine(final String[] args, final ClassLoader appLoader) {
 210         return newEngine(Objects.requireNonNull(args), appLoader, null);
 211     }
 212 
 213     /**
 214      * Create a new Script engine initialized with the given arguments, class loader and class filter.
 215      *
 216      * @param args arguments array passed to script engine.
 217      * @param appLoader class loader to be used as script "app" class loader.
 218      * @param classFilter class filter to use.
 219      * @return newly created script engine.
 220      * @throws NullPointerException if {@code args} or {@code classFilter} is {@code null}
 221      * @throws SecurityException
 222      *         if the security manager's {@code checkPermission}
 223      *         denies {@code RuntimePermission("nashorn.setConfig")}
 224      */
 225     public ScriptEngine getScriptEngine(final String[] args, final ClassLoader appLoader, final ClassFilter classFilter) {
 226         return newEngine(Objects.requireNonNull(args), appLoader, Objects.requireNonNull(classFilter));
 227     }
 228 
 229     private ScriptEngine newEngine(final String[] args, final ClassLoader appLoader, final ClassFilter classFilter) {
 230         checkConfigPermission();
 231         try {
 232             return new NashornScriptEngine(this, args, appLoader, classFilter);
 233         } catch (final RuntimeException e) {
 234             if (Context.DEBUG) {
 235                 e.printStackTrace();
 236             }
 237             throw e;
 238         }
 239     }
 240 
 241     // -- Internals only below this point
 242 
 243     private static void checkConfigPermission() {
 244         final SecurityManager sm = System.getSecurityManager();
 245         if (sm != null) {
 246             sm.checkPermission(new RuntimePermission(Context.NASHORN_SET_CONFIG));
 247         }
 248     }
 249 
 250     private static final List<String> names;
 251     private static final List<String> mimeTypes;
 252     private static final List<String> extensions;
 253 
 254     static {
 255         names = immutableList(
 256                     "nashorn", "Nashorn",
 257                     "js", "JS",
 258                     "JavaScript", "javascript",
 259                     "ECMAScript", "ecmascript"
 260                 );
 261 
 262         mimeTypes = immutableList(
 263                         "application/javascript",
 264                         "application/ecmascript",
 265                         "text/javascript",
 266                         "text/ecmascript"
 267                     );
 268 
 269         extensions = immutableList("js");
 270     }
 271 
 272     private static List<String> immutableList(final String... elements) {
 273         return Collections.unmodifiableList(Arrays.asList(elements));
 274     }
 275 
 276     private static ClassLoader getAppClassLoader() {
 277         // Revisit: script engine implementation needs the capability to
 278         // find the class loader of the context in which the script engine
 279         // is running so that classes will be found and loaded properly
 280         final ClassLoader ccl = Thread.currentThread().getContextClassLoader();
 281         return (ccl == null)? NashornScriptEngineFactory.class.getClassLoader() : ccl;
 282     }
 283 }