java - Does a class without fields have a special name? -

what class without fields called? i'm beginner in programming java , i'm trying understand , learn classes, have following class "daluser" doesn't have fields, methods, validatesession in folder called dal:

import com.app.be.beuser;  public class daluser{       public beuser validatesession(string user, string password)     {      ...     } 

i have class beuser has fields user , password , located in folder or package called be. particular type of class or common class despite not having fields?

what class without fields called?

there no universally applicable name this:

• classes no fields have no explicit state, strictly speaking, every java object has state associated mutex. hence calling them "stateless classes" bit of stretch.

• classes no fields may be "helper classes", absence of fields neither necessary or sufficient precondition.

• an instance has no state immutable, call classes no fields "immutable classes" ... though locking use-case applies here too.

another distinction between helper classes , stateless classes whether class designed instantiated. helper class (in normal usage) consists of static methods, , not instantiated. (an instance serves no purpose). stateless class designed instantiated, , passed around other classes make method calls on instance; e.g. "policy object".

then there sub-case of "base class" use-case there no fields in base class. (in case, calling class "stateless" misleading, since there typically state in child classes.)

in short, need examine class , how being used determine label (or labels) best apply it.

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in specific example, code best described stateless class. because designed instantiated , passed around in different contexts, functionality not depend on state of object itself.

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here other examples illustrate why there no simple answer this.

1) helper class, has (static) field.

 public class plumbing {      private static nostapsfixed;      private plumbing() { }      public class fixtap(tap t) {          // fix 't'      }  } 

2) base class. has no fields, not intended helper class.

 public abstract class tradesman {      // no fields      public abstract invoice issueinvoice();  } 

3) here use of class no fields (java.lang.object) in way not "helper".

 final object mylock = new object();  ...  synchronized (mylock) {      ...  } 

4) , here example of class has no fields , not helper.

 public enum agreement {      yes, no  }