In new a java object, how to control whether the programmer must implement a method

Now if I have a java class User
There is a
public void setName () {

}
Methods

as well as two of the User class constructor
public User () {

}

public User (String name) {

}

I now want other people in the new user when a User object , if
user = new User (); using a no-argument constructor, create an instance , you must override setName method
And if
user = new User (" Joe Smith " ) ; using a constructor argument to establish entities , they do not cover the setName method .
how can I do to control others such as I mean to go new a User object
------ Solution ------------------- -------------------------
add a flag, which represents a call constructor in the constructor to flag assignment . In accordance with the method set different flag to determine whether an exception is thrown .

java is not a dynamic language , want to completely let outside to see the internal methods, estimates more difficult.
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lz not the provider constructor with no arguments , ah, there is only one argument constructor , he can only use a parameter in the form of your first written unless it is an abstract class.
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  abstract class User {
  	public abstract void setName();
  }
  
  class NamedUser extends User {
  
  	public NamedUser(String userName) {
  	}
  
  	@Override
  	public void setName() {
  	}
  }
  
  

  class User {
  	 public User(String userName) {
  		}
  }
  

The first direct new user object if it must implement the set method, if new nameduser you must provide a user name

The second must provide a user name , there is no no-argument constructor
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My goal is to make other programmers in the use of new a User object is passed when the control code compilation
If
user = new User ();
Such direct new a java object can not compile the .
If you want to compile , you must follow the following two written to compile
1. either override setName method
user = new User () {
public void setName () {

}
};

2. Either use constructors with parameters
user = new User (" Joe Smith " ) ;

instead like you said during the execution of the program throwing an exception , my purpose is to control the programmer to new object


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you're right, I thought for a moment to the question I raised , or that it must implement an abstract method of problem, the problem is still not resolved, but thank you.