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 javax.script.ScriptEngine;
  32 import javax.script.ScriptEngineFactory;
  33 import jdk.nashorn.internal.runtime.Context;
  34 import jdk.nashorn.internal.runtime.Version;
  35 
  36 /**
  37  * JSR-223 compliant script engine factory for Nashorn. The engine answers for:
  38  * <ul>
  39  * <li>names {@code "nashorn"}, {@code "Nashorn"}, {@code "js"}, {@code "JS"}, {@code "JavaScript"},
  40  * {@code "javascript"}, {@code "ECMAScript"}, and {@code "ecmascript"};</li>
  41  * <li>MIME types {@code "application/javascript"}, {@code "application/ecmascript"}, {@code "text/javascript"}, and
  42  * {@code "text/ecmascript"};</li>
  43  * <li>as well as for the extension {@code "js"}.</li>
  44  * </ul>
  45  * Programs executing in engines created using {@link #getScriptEngine(String[])} will have the passed arguments
  46  * accessible as a global variable named {@code "arguments"}.
  47  *
  48  * @since 1.8u40
  49  */
  50 @jdk.Exported
  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             throw new IllegalArgumentException("Invalid key");
 127         }
 128     }
 129 
 130     @Override
 131     public String getProgram(final String... statements) {
 132         final StringBuilder sb = new StringBuilder();
 133 
 134         for (final String statement : statements) {
 135             sb.append(statement).append(';');
 136         }
 137 
 138         return sb.toString();
 139     }
 140 
 141     // default options passed to Nashorn script engine
 142     private static final String[] DEFAULT_OPTIONS = new String[] { "-doe" };
 143 
 144     @Override
 145     public ScriptEngine getScriptEngine() {
 146         try {
 147             return new NashornScriptEngine(this, DEFAULT_OPTIONS, getAppClassLoader(), null);
 148         } catch (final RuntimeException e) {
 149             if (Context.DEBUG) {
 150                 e.printStackTrace();
 151             }
 152             throw e;
 153         }
 154     }
 155 
 156     /**
 157      * Create a new Script engine initialized by given class loader.
 158      *
 159      * @param appLoader class loader to be used as script "app" class loader.
 160      * @return newly created script engine.
 161      * @throws SecurityException
 162      *         if the security manager's {@code checkPermission}
 163      *         denies {@code RuntimePermission("nashorn.setConfig")}
 164      */
 165     public ScriptEngine getScriptEngine(final ClassLoader appLoader) {
 166         return newEngine(DEFAULT_OPTIONS, appLoader, null);
 167     }
 168 
 169     /**
 170      * Create a new Script engine initialized by given class filter.
 171      *
 172      * @param classFilter class filter to use.
 173      * @return newly created script engine.
 174      * @throws NullPointerException if {@code classFilter} is {@code null}
 175      * @throws SecurityException
 176      *         if the security manager's {@code checkPermission}
 177      *         denies {@code RuntimePermission("nashorn.setConfig")}
 178      */
 179     public ScriptEngine getScriptEngine(final ClassFilter classFilter) {
 180         classFilter.getClass(); // null check
 181         return newEngine(DEFAULT_OPTIONS, getAppClassLoader(), classFilter);
 182     }
 183 
 184     /**
 185      * Create a new Script engine initialized by 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         args.getClass(); // null check
 196         return newEngine(args, getAppClassLoader(), null);
 197     }
 198 
 199     /**
 200      * Create a new Script engine initialized by given arguments.
 201      *
 202      * @param args arguments array passed to script engine.
 203      * @param appLoader class loader to be used as script "app" class loader.
 204      * @return newly created script engine.
 205      * @throws NullPointerException if {@code args} is {@code null}
 206      * @throws SecurityException
 207      *         if the security manager's {@code checkPermission}
 208      *         denies {@code RuntimePermission("nashorn.setConfig")}
 209      */
 210     public ScriptEngine getScriptEngine(final String[] args, final ClassLoader appLoader) {
 211         args.getClass(); // null check
 212         return newEngine(args, appLoader, null);
 213     }
 214 
 215     /**
 216      * Create a new Script engine initialized by given arguments.
 217      *
 218      * @param args arguments array passed to script engine.
 219      * @param appLoader class loader to be used as script "app" class loader.
 220      * @param classFilter class filter to use.
 221      * @return newly created script engine.
 222      * @throws NullPointerException if {@code args} or {@code classFilter} is {@code null}
 223      * @throws SecurityException
 224      *         if the security manager's {@code checkPermission}
 225      *         denies {@code RuntimePermission("nashorn.setConfig")}
 226      */
 227     public ScriptEngine getScriptEngine(final String[] args, final ClassLoader appLoader, final ClassFilter classFilter) {
 228         args.getClass(); // null check
 229         classFilter.getClass(); // null check
 230         return newEngine(args, appLoader, classFilter);
 231     }
 232 
 233     private ScriptEngine newEngine(final String[] args, final ClassLoader appLoader, final ClassFilter classFilter) {
 234         checkConfigPermission();
 235         try {
 236             return new NashornScriptEngine(this, args, appLoader, classFilter);
 237         } catch (final RuntimeException e) {
 238             if (Context.DEBUG) {
 239                 e.printStackTrace();
 240             }
 241             throw e;
 242         }
 243     }
 244 
 245     // -- Internals only below this point
 246 
 247     private static void checkConfigPermission() {
 248         final SecurityManager sm = System.getSecurityManager();
 249         if (sm != null) {
 250             sm.checkPermission(new RuntimePermission(Context.NASHORN_SET_CONFIG));
 251         }
 252     }
 253 
 254     private static final List<String> names;
 255     private static final List<String> mimeTypes;
 256     private static final List<String> extensions;
 257 
 258     static {
 259         names = immutableList(
 260                     "nashorn", "Nashorn",
 261                     "js", "JS",
 262                     "JavaScript", "javascript",
 263                     "ECMAScript", "ecmascript"
 264                 );
 265 
 266         mimeTypes = immutableList(
 267                         "application/javascript",
 268                         "application/ecmascript",
 269                         "text/javascript",
 270                         "text/ecmascript"
 271                     );
 272 
 273         extensions = immutableList("js");
 274     }
 275 
 276     private static List<String> immutableList(final String... elements) {
 277         return Collections.unmodifiableList(Arrays.asList(elements));
 278     }
 279 
 280     private static ClassLoader getAppClassLoader() {
 281         // Revisit: script engine implementation needs the capability to
 282         // find the class loader of the context in which the script engine
 283         // is running so that classes will be found and loaded properly
 284         final ClassLoader ccl = Thread.currentThread().getContextClassLoader();
 285         return (ccl == null)? NashornScriptEngineFactory.class.getClassLoader() : ccl;
 286     }
 287 }