introspection

I have a Java object obj that has attributes obj.attr1 , obj.attr2 etc. The attributes are possibly accessed through an extra level of indirection: obj.getAttr1() , obj.getAttr2() , if not public. The challenge : I want a function that takes an object, and returns a Map<String, Object> , where the keys are strings "attr1" , "attr2" etc. and values are the corresponding objects obj.attr1 , obj.attr2 . I imagine the function would be invoked with something like toMap(obj) , or toMap(obj, "attr1", "attr3") (where attr1 and attr3 are a subset of obj 's attributes), or perhaps toMap(obj, "getAttr1"

This question already has an answer here: How to quickly determine if a method is overridden in Java 8 answers How to find out if a method is overridden by child classes? For example, public class Test { static public class B { public String m() {return "From B";}; } static public class B1 extends B { } static public class B2 extends B { public String m() {return "from B2";}; } /** * @param args * @throws FileNotFoundException */ public static void main(String[] args) { B b1 = new B1(); System.out.println("b1 = " + b1.m()); B b2 = new B2(); System.out.println("b1 = " + b2.m()); } } Given an

I'm fairly new to JavaScript and am not sure this is possible to do but basically I would like to take an object and convert it into an array of strings in the format; array[0] = 'prop1=value1' The reasoning behind this is that I'm having a user enter a list of k=v pairs into a form, later it's written as an object within a json blob. Going from the key value csl to the json object was simple, now I need to go back the other way (I've received the JSON via an ajax call and want to populate a blank form). Is this possible in JavaScript? If not please offer a reasonable work around. Sample code;

If I have a class, how can I list all its instance variable names? eg: @interface MyClass : NSObject { int myInt; NSString* myString; NSMutableArray* myArray; } I would like to get "myInt", "myString", and "myArray". Is there some way to perhaps get an array of names that I can iterate over? I've tried searching the Objective-C documentation but couldn't find anything (and I'm not sure what this is called either). As mentioned, you can use the Objective-C runtime API to retrieve the instance variable names: unsigned int varCount; Ivar *vars = class_copyIvarList([MyClass class], &varCount); for

Two stackoverflow answers suggest the approach using fusion adapt_struct to iterate over struct fields. The approach looks nice. However, how do you iterate into a field which itself is a struct? Following the previous answers, I come up with the code below. The problem is at the "#if 0" clause the code does not compile. As an alternative solution I created "decode()" function to take a void pointer to the target argument. That works, but loses the type information at compile time. Is there a better solution? struct Foo_s { int i; }; BOOST_FUSION_ADAPT_STRUCT( Foo_s, (int, i) ) struct Bar_s {

I need a way to inspect a class so I can safely identify which attributes are user-defined class attributes. The problem is that functions like dir(), inspect.getmembers() and friends return all class attributes including the pre-defined ones like: __class__ , __doc__ , __dict__ , __hash__ . This is of course understandable, and one could argue that I could just make a list of named members to ignore, but unfortunately these pre-defined attributes are bound to change with different versions of Python therefore making my project volnerable to changed in the python project - and I don't like

Can any one explain the use of Java reflection and introspection? When we need to use both? Anthony Forloney Reflection (taken from oracle java tutorial ) Reflection is commonly used by programs which require the ability to examine or modify the runtime behavior of applications running in the Java virtual machine. This is a relatively advanced feature and should be used only by developers who have a strong grasp of the fundamentals of the language. With that caveat in mind, reflection is a powerful technique and can enable applications to perform operations which would otherwise be impossible.