srakacredits.blogg.se - Java reflection instantiate class by name

Java reflection instantiate class by name code#

Java reflection instantiate class by name code#

Please look at working code below for both options cast and reflection. In addition if you'd like to use reflection you have to declare get_is() method as public in your Target class You have to use this: Class classType = Class.forName(f.getType().getName()) Your problem is in here `Class classType = Class.forName(f.getName()) ' Declaration: Animal doggy declares a variable doggy and associates it with object type. For example, the statement Animal doggy new Animal () has three parts to it. An object instantiation java class provides the blueprint for objects, and we create an object from a class. Of course, for that you have to know your class ahead before compile. The phrase instantiating a class means to create an object.

You also can cast that newInstance to the desired class and then call method directly. UPD: Your problem is in here Class classType Class.forName (f i.

Of course, for that you have to know your class ahead before compile. You have to have instantiate your class and then you will be able to call needed method through reflection. You have to have instantiate your class and then you will be able to call needed method through reflection.

As long as your get_is() is non-static you cannot call it from class even through reflection.

You have to use reflection to call a method.

object (you get it by calling Class.forName) does not have a method get_is().

here I try to call method of the selected class The console return Unhandled exception type ClassNotFoundException import įield f = this.getClass().getDeclaredFields() įor(int i = 0 i classType = Class.forName(f.getName()) I make this code but it's a fail, when I pass the name by method forName() The class is initialized only if the initialize parameter is true and if it has not been initialized earlier.

I need to do that because all my methods is used everywhere in my code and I need to find information from those in a single place. public static Class<> forName(String name, boolean initialize, ClassLoader loader) throws ClassNotFoundException Returns the Class object associated with the class or interface with the given string name.

My first state it's find a good class, I manage that but after I find no possibility to instantiate from the class name. This can be accessed by using the:: operator from any class name or instance e.g. and the name of a Java class in the application that is to be instantiated. The Kotlin API for class details centers around the class. Also to do anything to our instantiated classes, we still will need to typecast them to the proper type which can't be done with a String, we need to know the class at compile time.I try to instantiate class from a class name but I fail, my code is in Processing / Java Library. The Java/COM bridge will identify the Java class constructor based on the. But it does demonstrate that with reflection, it is possible to create an instance if all you have is the name of the class. Now that's not groundbreaking code, for one thing the getObjectByName() method can only return an instance of a class that has a public default constructor. Return ("I am a Bar, my state is " + getState()) Return ("I am a Foo, my state is " + getState()) Object obj2 = DynamicInstantiator.getObjectByName("Bar") Object obj1 = DynamicInstantiator.getObjectByName("Foo") Throw new InstantiationException("no public default constructor") Throw new InstantiationException("no such class") If a class object is an interface or a class: 15. For the primitive tipe the interface will be an empty array: 14. Public static Object getObjectByName(String name) Some things to look for in the code below Invoke Class.forName(String className) passing the name of the class as a parameter. Getting the Superclass of a Class Object: 13. Umm, not totally clear on what you want here so I'll throw some code at you and see if I'm on the same page with you: