Premise: I have had 2 classes loaded by different class loaders – one from the app classloader and the other, a custom class loader. The class loaded by the custom class loader is trying to reflectively access a private field in the class loaded via the appclass loader. In this case, I get a runtime err…
Tag: reflection
java – Set final fields with reflection in Constructor
I’m trying to make a multi-language app with messages inside multiple *.properties files. I’ve started working on something like this: Now, there’s a lot of messages, and I don’t feel like typing the same thing each time (plus there could me typos which could be an issue…). The f…
Java: make static methods of one class mirror instance methods of another class
I have a POJO like this: As an alternative to Java reflection (which is quite slow in general), I would like to define a class with static methods like this: which enforces the creation/deprecation of a static method every time the Foo class is updated. For example, if the field bar2 is deleted in FooStatic, …
Is it technically possible to derive a class that only has a private constructor in Java?
I found a lot of answers about it on this site, but most of them are based on modifying the requirements or modifying the code of the parent class to do so. Without discussing the requirements and modifying the code of the parent class, can we get its constructor and derive it through reflection and other mea…
Check if Annotation is inherited
I have an annotation and three classes like this: Is there any way I can determine if a present annotation is inherited or declared directly at the class? Something like a method public boolean isInherited(Class<?> clazz, MyAnnotation annotation) that should only be called if the annotation is present. …
Updating field using reflection from parent class
I have a Parent class that has a method that uses reflection to retrieve and update fields. This method will be called by the child class When the child class (in this case, an anonymous class) calls the method, which is inherited form the parent, the value of this is the child class. Because of that, I thoug…
Using JAVA Reflection how to create custom JSON object mapping
I have a json Object in the below format, I need to assign the values from Json to java object, But the label name in JSON and class is different. I wanted to implement the custom object mapper using Java reflection. the mapping is as below, But I am not getting idea to implement this, Any valuable suggestion…
How to scan for annotations in methods only in specific classes using reflection library java?
I have an annotation @API which I assign to all the routes i.e RequestMapping in a controller in java spring.What I want to do is,First scan all the classes in a package that are annotated with @Controller and after scanning all the controller classes,I want only to scan for Methods with annotation @API in on…
In Kotlin, how does GSON.fromJson(…) manage to mutate a read-only field of an existing object?
In Kotlin, how can an instance’s read-only val field be mutated? In the following Kotlin code, gson.fromJson(…) gets a Thing(0) from the InstanceCreator and somehow manages to mutate value from 0 to 1, then return that object. How? I verified that the object returned by gson.fromJson(…) is t…
Invoke nested deepobject method via reflection
Is it possible to invoke nested method inside nested object from real object using reflection? Something like this Real object i have is chatClient and i want to invoke method of class3, which i cannot obtain directly but via class1 path. Answer You can have a logic of fetching nested fields in a function ins…