![]() ![]() Using reflection,it can quickly dynamically initialize the classes required.įor example ,Spring uses bean configuration such as (Here is a set of examples of how to use JUnit.)įor web frameworks, product developers define their own implementation of interfaces and classes and put is in the configuration files. Change accessibility flag of Constructor, Method,Fieldįor example, JUnit use reflection to look through methods tagged with the annotation, and then call those methods when running the unit test.Invoke any method of an object at runtime.Examine a class’s field adn method at runtime.Construct an object for a class at runtime.Relection is the ability of a program to examine and modify the structure and behavior of an object at runtime.Introspection is the ability of a program to examine the type or properties of an object at runtime.If(types != null & types.“Reflection is commonly used by programs which require the ability to examine or modify the runtime behavior of applications running in Java Virtual machine.” The concept is ofen mixed with introspecion.The following are their definitions from Wiki: Type types = superclass.getActualTypeArguments() ParameterizedType superclass = (ParameterizedType) clazz.getGenericSuperclass() Maybe there are some magic with "Field", I cannot get it working for a local variable (or parameter). interfaces now contains all common interfacesOf course you can get multiple results, so you would have to take a pick. Set set = getInterfaces(o.getClass()) // assumption: no element is null Set interfaces = getInterfaces(first.getClass()) // assumption: no element is null Do this for all elements, each time using Collection.retainAll. You need to collect all interfaces a class implements using Class.getInterfaces() (don't forget the super classes!). otherwise it's the common super class of X.getSuperclass() and Y.getSuperclass()įor interfaces it's also not that hard. if Y is a direct or indirect super class of X then it's Y if X is a direct or indirect super class of Y then it's X The common super class for any two classes X and Y is easy: You loop through all the elements and find out a common super class (worst case this will be ) or a number of common interfaces (0 or more). ![]() ![]() In Java 1.4 all you can do is make a guess. again, please let me know if this should be posted as a new topic.am posting here for some inquisitive minds who may be looking out for this solution in java 1.4 i wish to find out their type (of B,C,etc.) (similar to OwnerType here) at runtime.ĭo we have any way to make that possible in java 1.4?.to add to this, i can't use instanceOf test as the component in which this utility goes has no other knowledge than the Object being passed to it. Now the question, i've an object of type A that has a List.the List contains objects of type B, C.etc. Public static void main(String args) throws Exception whose criteria has to be created. But only generics-related info is only available for the class in general - not for specific instances of the class. That info is also accessible via reflection. The class file contains info about the generic types of its member variables - that info is necessary if/when you try to compile another class using classes in a jar file, for example. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |