コード例 #1
0
  /** Type-munging for field setting and method invocation. Conforms to LC3 specification */
  static Object coerceTypeImpl(Class<?> type, Object value) {
    if (value != null && value.getClass() == type) {
      return value;
    }

    switch (getJSTypeCode(value)) {
      case JSTYPE_NULL:
        // raise error if type.isPrimitive()
        if (type.isPrimitive()) {
          reportConversionError(value, type);
        }
        return null;

      case JSTYPE_UNDEFINED:
        if (type == ScriptRuntime.StringClass || type == ScriptRuntime.ObjectClass) {
          return "undefined";
        } else {
          reportConversionError("undefined", type);
        }
        break;

      case JSTYPE_BOOLEAN:
        // Under LC3, only JS Booleans can be coerced into a Boolean value
        if (type == Boolean.TYPE
            || type == ScriptRuntime.BooleanClass
            || type == ScriptRuntime.ObjectClass) {
          return value;
        } else if (type == ScriptRuntime.StringClass) {
          return value.toString();
        } else {
          reportConversionError(value, type);
        }
        break;

      case JSTYPE_NUMBER:
        if (type == ScriptRuntime.StringClass) {
          return ScriptRuntime.toString(value);
        } else if (type == ScriptRuntime.ObjectClass) {
          return coerceToNumber(Double.TYPE, value);
        } else if ((type.isPrimitive() && type != Boolean.TYPE)
            || ScriptRuntime.NumberClass.isAssignableFrom(type)) {
          return coerceToNumber(type, value);
        } else {
          reportConversionError(value, type);
        }
        break;

      case JSTYPE_STRING:
        if (type == ScriptRuntime.StringClass || type.isInstance(value)) {
          return value;
        } else if (type == Character.TYPE || type == ScriptRuntime.CharacterClass) {
          // Special case for converting a single char string to a
          // character
          // Placed here because it applies *only* to JS strings,
          // not other JS objects converted to strings
          if (((String) value).length() == 1) {
            return new Character(((String) value).charAt(0));
          } else {
            return coerceToNumber(type, value);
          }
        } else if ((type.isPrimitive() && type != Boolean.TYPE)
            || ScriptRuntime.NumberClass.isAssignableFrom(type)) {
          return coerceToNumber(type, value);
        } else {
          reportConversionError(value, type);
        }
        break;

      case JSTYPE_JAVA_CLASS:
        if (value instanceof Wrapper) {
          value = ((Wrapper) value).unwrap();
        }

        if (type == ScriptRuntime.ClassClass || type == ScriptRuntime.ObjectClass) {
          return value;
        } else if (type == ScriptRuntime.StringClass) {
          return value.toString();
        } else {
          reportConversionError(value, type);
        }
        break;

      case JSTYPE_JAVA_OBJECT:
      case JSTYPE_JAVA_ARRAY:
        if (value instanceof Wrapper) {
          value = ((Wrapper) value).unwrap();
        }
        if (type.isPrimitive()) {
          if (type == Boolean.TYPE) {
            reportConversionError(value, type);
          }
          return coerceToNumber(type, value);
        } else {
          if (type == ScriptRuntime.StringClass) {
            return value.toString();
          } else {
            if (type.isInstance(value)) {
              return value;
            } else {
              reportConversionError(value, type);
            }
          }
        }
        break;

      case JSTYPE_OBJECT:
        if (type == ScriptRuntime.StringClass) {
          return ScriptRuntime.toString(value);
        } else if (type.isPrimitive()) {
          if (type == Boolean.TYPE) {
            reportConversionError(value, type);
          }
          return coerceToNumber(type, value);
        } else if (type.isInstance(value)) {
          return value;
        } else if (type == ScriptRuntime.DateClass && value instanceof NativeDate) {
          double time = ((NativeDate) value).getJSTimeValue();
          // XXX: This will replace NaN by 0
          return new Date((long) time);
        } else if (type.isArray() && value instanceof NativeArray) {
          // Make a new java array, and coerce the JS array components
          // to the target (component) type.
          NativeArray array = (NativeArray) value;
          long length = array.getLength();
          Class<?> arrayType = type.getComponentType();
          Object Result = Array.newInstance(arrayType, (int) length);
          for (int i = 0; i < length; ++i) {
            try {
              Array.set(Result, i, coerceType(arrayType, array.get(i, array)));
            } catch (EvaluatorException ee) {
              reportConversionError(value, type);
            }
          }

          return Result;
        } else if (value instanceof Wrapper) {
          value = ((Wrapper) value).unwrap();
          if (type.isInstance(value)) return value;
          reportConversionError(value, type);
        } else if (type.isInterface() && value instanceof Callable) {
          // Try to use function as implementation of Java interface.
          //
          // XXX: Currently only instances of ScriptableObject are
          // supported since the resulting interface proxies should
          // be reused next time conversion is made and generic
          // Callable has no storage for it. Weak references can
          // address it but for now use this restriction.
          if (value instanceof ScriptableObject) {
            ScriptableObject so = (ScriptableObject) value;
            Object key = Kit.makeHashKeyFromPair(COERCED_INTERFACE_KEY, type);
            Object old = so.getAssociatedValue(key);
            if (old != null) {
              // Function was already wrapped
              return old;
            }
            Context cx = Context.getContext();
            Object glue = InterfaceAdapter.create(cx, type, (Callable) value);
            // Store for later retrival
            glue = so.associateValue(key, glue);
            return glue;
          }
          reportConversionError(value, type);
        } else {
          reportConversionError(value, type);
        }
        break;
    }

    return value;
  }