import jdk.nashorn.internal.runtime.ListAdapter; //导入依赖的package包/类
/**
* Given a script object and a Java type, converts the script object into the desired Java type. Currently it
* performs shallow creation of Java arrays, as well as wrapping of objects in Lists, Dequeues, Queues,
* and Collections. If conversion is not possible or fails for some reason, TypeError is thrown.
* Example:
* <pre>
* var anArray = [1, "13", false]
* var javaIntArray = Java.to(anArray, "int[]")
* print(javaIntArray[0]) // prints 1
* print(javaIntArray[1]) // prints 13, as string "13" was converted to number 13 as per ECMAScript ToNumber conversion
* print(javaIntArray[2]) // prints 0, as boolean false was converted to number 0 as per ECMAScript ToNumber conversion
* </pre>
* @param self not used
* @param obj the script object. Can be null.
* @param objType either a {@link #type(Object, Object) type object} or a String describing the type of the Java
* object to create. Can not be null. If undefined, a "default" conversion is presumed (allowing the argument to be
* omitted).
* @return a Java object whose value corresponds to the original script object's value. Specifically, for array
* target types, returns a Java array of the same type with contents converted to the array's component type.
* Converts recursively when the target type is multidimensional array. For {@link List}, {@link Deque},
* {@link Queue}, or {@link Collection}, returns a live wrapper around the object, see {@link ListAdapter} for
* details. Returns null if obj is null.
* @throws ClassNotFoundException if the class described by objType is not found
*/
@Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)
public static Object to(final Object self, final Object obj, final Object objType) throws ClassNotFoundException {
if (obj == null) {
return null;
}
if (!(obj instanceof ScriptObject) && !(obj instanceof JSObject)) {
throw typeError("not.an.object", ScriptRuntime.safeToString(obj));
}
final Class<?> targetClass;
if(objType == UNDEFINED) {
targetClass = Object[].class;
} else {
final StaticClass targetType;
if(objType instanceof StaticClass) {
targetType = (StaticClass)objType;
} else {
targetType = type(objType);
}
targetClass = targetType.getRepresentedClass();
}
if(targetClass.isArray()) {
try {
if (self instanceof SecureLookupSupplier) {
return JSType.toJavaArrayWithLookup(obj, targetClass.getComponentType(), (SecureLookupSupplier)self);
}
return JSType.toJavaArray(obj, targetClass.getComponentType());
} catch (final Exception exp) {
throw typeError(exp, "java.array.conversion.failed", targetClass.getName());
}
}
if (targetClass == List.class || targetClass == Deque.class || targetClass == Queue.class || targetClass == Collection.class) {
return ListAdapter.create(obj);
}
throw typeError("unsupported.java.to.type", targetClass.getName());
}
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