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.lang.invoke.MethodHandle;

    29 import jdk.dynalink.beans.StaticClass;

    30 import jdk.dynalink.linker.LinkerServices;

    31 import jdk.nashorn.internal.runtime.Context;

    32 import jdk.nashorn.internal.runtime.ScriptFunction;

    33 import jdk.nashorn.internal.runtime.ScriptObject;

    34 import jdk.nashorn.internal.runtime.ScriptRuntime;

    35 import jdk.nashorn.internal.runtime.linker.Bootstrap;

    36 

    37 /**

    38  * Utilities that are to be called from script code.

    39  *

    40  * @since 1.8u40

    41  */

    42 public final class ScriptUtils {

    43     private ScriptUtils() {}

    44 

    45     /**

    46      * Returns AST as JSON compatible string. This is used to

    47      * implement "parse" function in resources/parse.js script.

    48      *

    49      * @param code code to be parsed

    50      * @param name name of the code source (used for location)

    51      * @param includeLoc tells whether to include location information for nodes or not

    52      * @return JSON string representation of AST of the supplied code

    53      */

    54     public static String parse(final String code, final String name, final boolean includeLoc) {

    55         return ScriptRuntime.parse(code, name, includeLoc);

    56     }

    57 

    58     /**

    59      * Method which converts javascript types to java types for the

    60      * String.format method (jrunscript function sprintf).

    61      *

    62      * @param format a format string

    63      * @param args arguments referenced by the format specifiers in format

    64      * @return a formatted string

    65      */

    66     public static String format(final String format, final Object[] args) {

    67         return Formatter.format(format, args);

    68     }

    69 

    70     /**

    71      * Create a wrapper function that calls {@code func} synchronized on {@code sync} or, if that is undefined,

    72      * {@code self}. Used to implement "sync" function in resources/mozilla_compat.js.

    73      *

    74      * @param func the function to wrap

    75      * @param sync the object to synchronize on

    76      * @return a synchronizing wrapper function

    77      * @throws IllegalArgumentException if func does not represent a script function

    78      */

    79     public static Object makeSynchronizedFunction(final Object func, final Object sync) {

    80         final Object unwrapped = unwrap(func);

    81         if (unwrapped instanceof ScriptFunction) {

    82             return ((ScriptFunction)unwrapped).createSynchronized(unwrap(sync));

    83         }

    84 

    85         throw new IllegalArgumentException();

    86     }

    87 

    88     /**

    89      * Make a script object mirror on given object if needed.

    90      *

    91      * @param obj object to be wrapped

    92      * @return wrapped object

    93      * @throws IllegalArgumentException if obj cannot be wrapped

    94      */

    95     public static ScriptObjectMirror wrap(final Object obj) {

    96         if (obj instanceof ScriptObjectMirror) {

    97             return (ScriptObjectMirror)obj;

    98         }

    99 

   100         if (obj instanceof ScriptObject) {

   101             final ScriptObject sobj = (ScriptObject)obj;

   102             return (ScriptObjectMirror) ScriptObjectMirror.wrap(sobj, Context.getGlobal());

   103         }

   104 

   105         throw new IllegalArgumentException();

   106     }

   107 

   108     /**

   109      * Unwrap a script object mirror if needed.

   110      *

   111      * @param obj object to be unwrapped

   112      * @return unwrapped object

   113      */

   114     public static Object unwrap(final Object obj) {

   115         if (obj instanceof ScriptObjectMirror) {

   116             return ScriptObjectMirror.unwrap(obj, Context.getGlobal());

   117         }

   118 

   119         return obj;

   120     }

   121 

   122     /**

   123      * Wrap an array of object to script object mirrors if needed.

   124      *

   125      * @param args array to be unwrapped

   126      * @return wrapped array

   127      */

   128     public static Object[] wrapArray(final Object[] args) {

   129         if (args == null || args.length == 0) {

   130             return args;

   131         }

   132 

   133         return ScriptObjectMirror.wrapArray(args, Context.getGlobal());

   134     }

   135 

   136     /**

   137      * Unwrap an array of script object mirrors if needed.

   138      *

   139      * @param args array to be unwrapped

   140      * @return unwrapped array

   141      */

   142     public static Object[] unwrapArray(final Object[] args) {

   143         if (args == null || args.length == 0) {

   144             return args;

   145         }

   146 

   147         return ScriptObjectMirror.unwrapArray(args, Context.getGlobal());

   148     }

   149 

   150     /**

   151      * Convert the given object to the given type.

   152      *

   153      * @param obj object to be converted

   154      * @param type destination type to convert to. type is either a Class

   155      * or nashorn representation of a Java type returned by Java.type() call in script.

   156      * @return converted object

   157      */

   158     public static Object convert(final Object obj, final Object type) {

   159         if (obj == null) {

   160             return null;

   161         }

   162 

   163         final Class<?> clazz;

   164         if (type instanceof Class) {

   165             clazz = (Class<?>)type;

   166         } else if (type instanceof StaticClass) {

   167             clazz = ((StaticClass)type).getRepresentedClass();

   168         } else {

   169             throw new IllegalArgumentException("type expected");

   170         }

   171 

   172         final LinkerServices linker = Bootstrap.getLinkerServices();

   173         final Object objToConvert = unwrap(obj);

   174         final MethodHandle converter = linker.getTypeConverter(objToConvert.getClass(), clazz);

   175         if (converter == null) {

   176             // no supported conversion!

   177             throw new UnsupportedOperationException("conversion not supported");

   178         }

   179 

   180         try {

   181             return converter.invoke(objToConvert);

   182         } catch (final RuntimeException | Error e) {

   183             throw e;

   184         } catch (final Throwable t) {

   185             throw new RuntimeException(t);

   186         }

   187     }

   188 }