       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 }
    --- EOF ---