java等效于c＃typeof（）

Question

I'm very new to java. Say I've a xml parser and I'd create object from it. In c# i'd do like:

parser p = new parser(typeof(myTargetObjectType));

In my parser class I need to know which object I'm making, so that i can throw exception if parsing is not possible. How to Do the same in jave? I mean how I can take arguments like typeof(myObject)

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I understand every language has it's own way of doing something. I'm asking what's way in java

Answer 1

Java has the Class class as the entry point for any reflection operation on Java types.

Instances of the class Class represent classes and interfaces in a running Java application

To get the type of an object, represented as a Class object, you can invoke the Object#getClass() method inherited by all reference types.

Returns the runtime class of this Object .

You cannot do this (invoke getClass() ) with primitive types. However, primitive types also have an associated Class object. You can do

int.class

for instance.

Answer 2

public class Main {
  public static void main(String[] args) {
    UnsupportedClass myObject = new UnsupportedClass();
    Parser parser = new Parser(myObject.getClass());
  }
}

class Parser {
  public Parser(Class<?> objectType) {
    if (UnsupportedClass.class.isAssignableFrom(objectType)) {
          throw new UnsupportedOperationException("Objects of type UnsupportedClass are not allowed");
    }
  }
}

class UnsupportedClass {}

Or since you have the instance of the object, this is easier:

Parser parser = new Parser(myObject);

public Parser(Object object) {
    if (object instanceof UnsupportedClass) {
          throw new UnsupportedOperationException("Objects of type UnsupportedClass are not allowed");
    }
}