jdk.nashorn.internal.runtime.Undefined Java Examples

/**
 * Given a JS script object, retrieves a function from it by name, binds it to the script object as its "this", and
 * adapts its parameter types, return types, and arity to the specified type and arity. This method is public mainly
 * for implementation reasons, so the adapter classes can invoke it from their constructors that take a Object
 * in its first argument to obtain the method handles for their method implementations.
 * @param obj the script obj
 * @param name the name of the property that contains the function
 * @param type the method type it has to conform to
 * @return the appropriately adapted method handle for invoking the script function, or null if the value of the
 * property is either null or undefined, or "toString" was requested as the name, but the object doesn't directly
 * define it but just inherits it through prototype.
 */
public static MethodHandle getHandle(final Object obj, final String name, final MethodType type) {
    if (! (obj instanceof ScriptObject)) {
        throw typeError("not.an.object", ScriptRuntime.safeToString(obj));
    }

    final ScriptObject sobj = (ScriptObject)obj;
    // Since every JS Object has a toString, we only override "String toString()" it if it's explicitly specified
    if ("toString".equals(name) && !sobj.hasOwnProperty("toString")) {
        return null;
    }

    final Object fnObj = sobj.get(name);
    if (fnObj instanceof ScriptFunction) {
        return bindAndAdaptHandle((ScriptFunction)fnObj, sobj, type);
    } else if(fnObj == null || fnObj instanceof Undefined) {
        return null;
    } else {
        throw typeError("not.a.function", name);
    }
}
 

@Override
public Type ldc(final MethodVisitor method, final Object c) {
    if (c == null) {
        method.visitInsn(ACONST_NULL);
    } else if (c instanceof Undefined) {
        return loadUndefined(method);
    } else if (c instanceof String) {
        method.visitLdcInsn(c);
        return STRING;
    } else if (c instanceof Handle) {
        method.visitLdcInsn(c);
        return Type.typeFor(MethodHandle.class);
    } else {
        throw new UnsupportedOperationException("implementation missing for class " + c.getClass() + " value=" + c);
    }

    return Type.OBJECT;
}
 

/**
 * Given a JS script object, retrieves a function from it by name, binds it to the script object as its "this", and
 * adapts its parameter types, return types, and arity to the specified type and arity. This method is public mainly
 * for implementation reasons, so the adapter classes can invoke it from their constructors that take a Object
 * in its first argument to obtain the method handles for their method implementations.
 * @param obj the script obj
 * @param name the name of the property that contains the function
 * @param type the method type it has to conform to
 * @return the appropriately adapted method handle for invoking the script function, or null if the value of the
 * property is either null or undefined, or "toString" was requested as the name, but the object doesn't directly
 * define it but just inherits it through prototype.
 */
public static MethodHandle getHandle(final Object obj, final String name, final MethodType type) {
    if (! (obj instanceof ScriptObject)) {
        throw typeError("not.an.object", ScriptRuntime.safeToString(obj));
    }

    final ScriptObject sobj = (ScriptObject)obj;
    // Since every JS Object has a toString, we only override "String toString()" it if it's explicitly specified
    if ("toString".equals(name) && !sobj.hasOwnProperty("toString")) {
        return null;
    }

    final Object fnObj = sobj.get(name);
    if (fnObj instanceof ScriptFunction) {
        return adaptHandle(((ScriptFunction)fnObj).getBoundInvokeHandle(sobj), type);
    } else if(fnObj == null || fnObj instanceof Undefined) {
        return null;
    } else {
        throw typeError("not.a.function", name);
    }
}
 

/**
 * Given a JS script object, retrieves a function from it by name, binds it to the script object as its "this", and
 * adapts its parameter types, return types, and arity to the specified type and arity. This method is public mainly
 * for implementation reasons, so the adapter classes can invoke it from their constructors that take a Object
 * in its first argument to obtain the method handles for their method implementations.
 * @param obj the script obj
 * @param name the name of the property that contains the function
 * @param type the method type it has to conform to
 * @return the appropriately adapted method handle for invoking the script function, or null if the value of the
 * property is either null or undefined, or "toString" was requested as the name, but the object doesn't directly
 * define it but just inherits it through prototype.
 */
public static MethodHandle getHandle(final Object obj, final String name, final MethodType type) {
    if (! (obj instanceof ScriptObject)) {
        throw typeError("not.an.object", ScriptRuntime.safeToString(obj));
    }

    final ScriptObject sobj = (ScriptObject)obj;
    // Since every JS Object has a toString, we only override "String toString()" it if it's explicitly specified
    if ("toString".equals(name) && !sobj.hasOwnProperty("toString")) {
        return null;
    }

    final Object fnObj = sobj.get(name);
    if (fnObj instanceof ScriptFunction) {
        return bindAndAdaptHandle((ScriptFunction)fnObj, sobj, type);
    } else if(fnObj == null || fnObj instanceof Undefined) {
        return null;
    } else {
        throw typeError("not.a.function", name);
    }
}
 

/**
 * Given a JS script object, retrieves a function from it by name, binds it to the script object as its "this", and
 * adapts its parameter types, return types, and arity to the specified type and arity. This method is public mainly
 * for implementation reasons, so the adapter classes can invoke it from their constructors that take a Object
 * in its first argument to obtain the method handles for their method implementations.
 * @param obj the script obj
 * @param name the name of the property that contains the function
 * @param type the method type it has to conform to
 * @return the appropriately adapted method handle for invoking the script function, or null if the value of the
 * property is either null or undefined, or "toString" was requested as the name, but the object doesn't directly
 * define it but just inherits it through prototype.
 */
public static MethodHandle getHandle(final Object obj, final String name, final MethodType type) {
    if (! (obj instanceof ScriptObject)) {
        throw typeError("not.an.object", ScriptRuntime.safeToString(obj));
    }

    final ScriptObject sobj = (ScriptObject)obj;
    // Since every JS Object has a toString, we only override "String toString()" it if it's explicitly specified
    if ("toString".equals(name) && !sobj.hasOwnProperty("toString")) {
        return null;
    }

    final Object fnObj = sobj.get(name);
    if (fnObj instanceof ScriptFunction) {
        return bindAndAdaptHandle((ScriptFunction)fnObj, sobj, type);
    } else if(fnObj == null || fnObj instanceof Undefined) {
        return null;
    } else {
        throw typeError("not.a.function", name);
    }
}
 

/**
 * Given a JS script object, retrieves a function from it by name, binds it to the script object as its "this", and
 * adapts its parameter types, return types, and arity to the specified type and arity. This method is public mainly
 * for implementation reasons, so the adapter classes can invoke it from their constructors that take a Object
 * in its first argument to obtain the method handles for their method implementations.
 * @param obj the script obj
 * @param name the name of the property that contains the function
 * @param type the method type it has to conform to
 * @return the appropriately adapted method handle for invoking the script function, or null if the value of the
 * property is either null or undefined, or "toString" was requested as the name, but the object doesn't directly
 * define it but just inherits it through prototype.
 */
public static MethodHandle getHandle(final Object obj, final String name, final MethodType type) {
    if (! (obj instanceof ScriptObject)) {
        throw typeError("not.an.object", ScriptRuntime.safeToString(obj));
    }

    final ScriptObject sobj = (ScriptObject)obj;
    // Since every JS Object has a toString, we only override "String toString()" it if it's explicitly specified
    if ("toString".equals(name) && !sobj.hasOwnProperty("toString")) {
        return null;
    }

    final Object fnObj = sobj.get(name);
    if (fnObj instanceof ScriptFunction) {
        return bindAndAdaptHandle((ScriptFunction)fnObj, sobj, type);
    } else if(fnObj == null || fnObj instanceof Undefined) {
        return null;
    } else {
        throw typeError("not.a.function", name);
    }
}
 

@Override
public Type ldc(final MethodVisitor method, final Object c) {
    if (c == null) {
        method.visitInsn(ACONST_NULL);
    } else if (c instanceof Undefined) {
        return loadUndefined(method);
    } else if (c instanceof String) {
        method.visitLdcInsn(c);
        return STRING;
    } else if (c instanceof Handle) {
        method.visitLdcInsn(c);
        return Type.typeFor(MethodHandle.class);
    } else {
        throw new UnsupportedOperationException("implementation missing for class " + c.getClass() + " value=" + c);
    }

    return Type.OBJECT;
}
 

@Override
protected IteratorResult next(final Object arg) {
    final int index = nextIndex;
    final String string = iteratedString;

    if (string == null || index >= string.length()) {
        // ES6 21.1.5.2.1 step 8
        iteratedString = null;
        return makeResult(Undefined.getUndefined(), Boolean.TRUE, global);
    }

    final char first = string.charAt(index);
    if (first >= 0xd800 && first <= 0xdbff && index < string.length() - 1) {
        final char second = string.charAt(index + 1);
        if (second >= 0xdc00 && second <= 0xdfff) {
            nextIndex += 2;
            return makeResult(String.valueOf(new char[] {first, second}), Boolean.FALSE, global);
        }
    }

    nextIndex++;
    return makeResult(String.valueOf(first), Boolean.FALSE, global);
}
 

@Override
public Type ldc(final MethodVisitor method, final Object c) {
    if (c == null) {
        method.visitInsn(ACONST_NULL);
    } else if (c instanceof Undefined) {
        return loadUndefined(method);
    } else if (c instanceof String) {
        method.visitLdcInsn(c);
        return STRING;
    } else if (c instanceof Handle) {
        method.visitLdcInsn(c);
        return Type.typeFor(MethodHandle.class);
    } else {
        throw new UnsupportedOperationException("implementation missing for class " + c.getClass() + " value=" + c);
    }

    return Type.OBJECT;
}
 

@Override
protected  IteratorResult next(final Object arg) {
    if (iterator == null) {
        return makeResult(Undefined.getUndefined(), Boolean.TRUE, global);
    }

    final LinkedMap.Node node = iterator.next();

    if (node == null) {
        iterator = null;
        return makeResult(Undefined.getUndefined(), Boolean.TRUE, global);
    }

    if (iterationKind == IterationKind.KEY_VALUE) {
        final NativeArray array = new NativeArray(new Object[] {node.getKey(), node.getKey()});
        return makeResult(array, Boolean.FALSE, global);
    }

    return makeResult(node.getKey(), Boolean.FALSE, global);
}
 

@Override
protected  IteratorResult next(final Object arg) {
    if (iterator == null) {
        return makeResult(Undefined.getUndefined(), Boolean.TRUE, global);
    }

    final LinkedMap.Node node = iterator.next();

    if (node == null) {
        iterator = null;
        return makeResult(Undefined.getUndefined(), Boolean.TRUE, global);
    }

    if (iterationKind == IterationKind.KEY_VALUE) {
        final NativeArray array = new NativeArray(new Object[] {node.getKey(), node.getValue()});
        return makeResult(array, Boolean.FALSE, global);
    }

    return makeResult(iterationKind == IterationKind.KEY ? node.getKey() : node.getValue(), Boolean.FALSE, global);
}
 

@Override
public Type ldc(final MethodVisitor method, final Object c) {
    if (c == null) {
        method.visitInsn(ACONST_NULL);
    } else if (c instanceof Undefined) {
        return loadUndefined(method);
    } else if (c instanceof String) {
        method.visitLdcInsn(c);
        return STRING;
    } else if (c instanceof Handle) {
        method.visitLdcInsn(c);
        return Type.typeFor(MethodHandle.class);
    } else {
        throw new UnsupportedOperationException("implementation missing for class " + c.getClass() + " value=" + c);
    }

    return Type.OBJECT;
}
 

@Override
public GuardedInvocation getGuardedInvocation(final LinkRequest request, final LinkerServices linkerServices) throws Exception {
    final LinkRequest requestWithoutContext = request.withoutRuntimeContext(); // Nashorn has no runtime context
    final Object self = requestWithoutContext.getReceiver();
    final CallSiteDescriptor desc = requestWithoutContext.getCallSiteDescriptor();

    if (desc.getNameTokenCount() < 2 || !"dyn".equals(desc.getNameToken(CallSiteDescriptor.SCHEME))) {
        // We only support standard "dyn:*[:*]" operations
        return null;
    }

    final GuardedInvocation inv;
    if (self instanceof ScriptObject) {
        inv = ((ScriptObject)self).lookup(desc, request);
    } else if (self instanceof Undefined) {
        inv = Undefined.lookup(desc);
    } else {
        throw new AssertionError(); // Should never reach here.
    }

    return Bootstrap.asType(inv, linkerServices, desc);
}
 

static void populateMap(final Map<Object, Object> map, final Object arg, final Global global) {
    // This method is similar to NativeMap.populateMap, but it uses a different
    // map implementation and the checking/conversion of keys differs as well.
    if (arg != null && arg != Undefined.getUndefined()) {
        AbstractIterator.iterate(arg, global, value -> {
            if (isPrimitive(value)) {
                throw typeError(global, "not.an.object", ScriptRuntime.safeToString(value));
            }
            if (value instanceof ScriptObject) {
                final ScriptObject sobj = (ScriptObject) value;
                map.put(checkKey(sobj.get(0)), sobj.get(1));
            }
        });
    }
}
 

/**
 * ECMA6 23.3.3.3 WeakMap.prototype.get ( key )
 *
 * @param self the self reference
 * @param key the key
 * @return the associated value or undefined
 */
@Function(attributes = Attribute.NOT_ENUMERABLE)
public static Object get(final Object self, final Object key) {
    final NativeWeakMap map = getMap(self);
    if (isPrimitive(key)) {
        return Undefined.getUndefined();
    }
    return map.jmap.get(key);
}
 

private static GuardedInvocation getGuardedInvocation(final Object self, final LinkRequest request, final CallSiteDescriptor desc) {
    final GuardedInvocation inv;
    if (self instanceof ScriptObject) {
        inv = ((ScriptObject)self).lookup(desc, request);
    } else if (self instanceof Undefined) {
        inv = Undefined.lookup(desc);
    } else {
        throw new AssertionError(self.getClass().getName()); // Should never reach here.
    }

    return inv;
}
 

private static MethodHandle getREDUCE_CALLBACK_INVOKER() {
    return Global.instance().getDynamicInvoker(REDUCE_CALLBACK_INVOKER,
            new Callable<MethodHandle>() {
                @Override
                public MethodHandle call() {
                    return Bootstrap.createDynamicInvoker("dyn:call", Object.class, Object.class,
                         Undefined.class, Object.class, Object.class, long.class, Object.class);
                }
            });
}
 

private static MethodHandle getREDUCE_CALLBACK_INVOKER() {
    return Global.instance().getDynamicInvoker(REDUCE_CALLBACK_INVOKER,
            new Callable<MethodHandle>() {
                @Override
                public MethodHandle call() {
                    return Bootstrap.createDynamicInvoker("dyn:call", Object.class, Object.class,
                         Undefined.class, Object.class, Object.class, double.class, Object.class);
                }
            });
}
 

private static GuardedInvocation getGuardedInvocation(final Object self, final LinkRequest request, final CallSiteDescriptor desc) {
    final GuardedInvocation inv;
    if (self instanceof ScriptObject) {
        inv = ((ScriptObject)self).lookup(desc, request);
    } else if (self instanceof Undefined) {
        inv = Undefined.lookup(desc);
    } else {
        throw new AssertionError(self.getClass().getName()); // Should never reach here.
    }

    return inv;
}
 

private static MethodHandle getREDUCE_CALLBACK_INVOKER() {
    return Global.instance().getDynamicInvoker(REDUCE_CALLBACK_INVOKER,
            new Callable<MethodHandle>() {
                @Override
                public MethodHandle call() {
                    return Bootstrap.createDynamicInvoker("dyn:call", Object.class, Object.class,
                         Undefined.class, Object.class, Object.class, double.class, Object.class);
                }
            });
}
 

private static MethodHandle getREDUCE_CALLBACK_INVOKER() {
    return Global.instance().getDynamicInvoker(REDUCE_CALLBACK_INVOKER,
            new Callable<MethodHandle>() {
                @Override
                public MethodHandle call() {
                    return Bootstrap.createDynamicInvoker("dyn:call", Object.class, Object.class,
                         Undefined.class, Object.class, Object.class, double.class, Object.class);
                }
            });
}
 

static void populateWeakSet(final Map<Object, Boolean> set, final Object arg, final Global global) {
    if (arg != null && arg != Undefined.getUndefined()) {
        AbstractIterator.iterate(arg, global, value -> {
                set.put(checkKey(value), Boolean.TRUE);
        });
    }
}
 

/**
 * ECMA 6 19.4.1.1 Symbol ( [ description ] )
 *
 * @param newObj is this function invoked with the new operator
 * @param self   self reference
 * @param args   arguments
 * @return new symbol value
 */
@Constructor(arity = 1)
public static Object constructor(final boolean newObj, final Object self, final Object... args) {
    if (newObj) {
        throw typeError("symbol.as.constructor");
    }
    final String description = args.length > 0 && args[0] != Undefined.getUndefined() ?
            JSType.toString(args[0]) : "";
    return new Symbol(description);
}
 

/**
 * ES6 19.4.2.5 Symbol.keyFor ( sym )
 *
 * @param self self reference
 * @param arg the argument
 * @return the symbol name
 */
@Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)
public synchronized static Object keyFor(final Object self, final Object arg) {
    if (!(arg instanceof Symbol)) {
        throw typeError("not.a.symbol", ScriptRuntime.safeToString(arg));
    }
    final String name = ((Symbol) arg).getName();
    return globalSymbolRegistry.get(name) == arg ? name : Undefined.getUndefined();
}
 

@RequestMapping("onResolve")
public FullHttpResponse onResolve(Channel channel, FullHttpRequest request) throws Exception {
  HttpRequestForm taskRequest = getJSONParams(request, HttpRequestForm.class);
  //遍历扩展模块是否有对应的处理
  List<ExtensionInfo> extensionInfos = ExtensionContent.get();
  for (ExtensionInfo extensionInfo : extensionInfos) {
    if (extensionInfo.getMeta().isEnabled()) {
      if (extensionInfo.getHookScript() != null
          && !StringUtils.isEmpty(extensionInfo.getHookScript().getScript())) {
        Event event = extensionInfo.getHookScript().hasEvent(HookScript.EVENT_RESOLVE, taskRequest.getUrl());
        if (event != null) {
          try {
            //执行resolve方法
            Object result = ExtensionUtil.invoke(extensionInfo, event, taskRequest, false);
            if (result != null && !(result instanceof Undefined)) {
              ObjectMapper objectMapper = new ObjectMapper();
              String temp = objectMapper.writeValueAsString(result);
              TaskForm taskForm = objectMapper.readValue(temp, TaskForm.class);
              //有一个扩展解析成功的话直接返回
              return HttpHandlerUtil.buildJson(taskForm, Include.NON_DEFAULT);
            }
          } catch (Exception e) {
            LOGGER.error("An exception occurred while resolve()", e);
          }
        }
      }
    }
  }
  return new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK);
}
 

public static String inspect(final Undefined x, final String w) {
    return w + ": undefined";
}
 

@SuppressWarnings("unused")
private static boolean isNashornTypeOrUndefined(final Object obj) {
    return obj instanceof ScriptObject || obj instanceof Undefined;
}
 

static Object convertUndefinedValue(final Class<?> targetType) {
    return invoke(Bootstrap.getLinkerServices().getTypeConverter(Undefined.class, targetType),
            ScriptRuntime.UNDEFINED);
}
 

static Object convertUndefinedValue(final Class<?> targetType) {
    return invoke(Bootstrap.getLinkerServices().getTypeConverter(Undefined.class, targetType),
            ScriptRuntime.UNDEFINED);
}
 

@Override
public Type loadUndefined(final MethodVisitor method) {
    method.visitFieldInsn(GETSTATIC, className(ScriptRuntime.class), "UNDEFINED", typeDescriptor(Undefined.class));
    return UNDEFINED;
}