What is the best way to know if all the variables in a Class are null?

Question

This would mean that the class was initialized, but the variables were not set.

A sample Class:

public class User {      String id = null;     String name = null;      public String getId() {         return id;     }     public void setId(String id) {         this.id = id;     }      public String getName() {         return name;     }     public void setName(String name) {         this.name = name;     } } 

The actual class is huge that I prefer not to check if(xyz == null) for each of the variables.

Answer 1

Another non-reflective solution for Java 8, in the line of paxdiabo's answer but without using a series of if's, would be to stream all fields and check for nullness:

return Stream.of(id, name)         .allMatch(Objects::isNull); 

This remains quite easy to maintain while avoiding the reflection hammer.

Answer 2

Try something like this:

public boolean checkNull() throws IllegalAccessException {     for (Field f : getClass().getDeclaredFields())         if (f.get(this) != null)             return false;     return true;             } 

Although it would probably be better to check each variable if at all feasible.