Java instance method different call ways

There is no difference from doing:

//...
public void otherMethod(){
  someMethod();
}
//...

to doing

//...
public void otherMethod(){
  this.someMethod(); // `this` in this case refers to the class instance 
}
//...

Now if you would have

class SomeClass {
   public static void someMethod(){}

   public void otherMethod(){
      //Calling someMethod()
   }
}

you could do:

//...
public void otherMethod(){
  SomeClass.someMethod(); // as the method is static you don't need to call it from an instance using `this` or omitting the class 
}
//...

And lastly this syntax SomeClass.this.someMethod(); would not be correct in all scenarios. An example of where this could be used (correct) is as follow:

class SomeClass {
   public void someMethod(){}

   public void otherMethod(){
      //Calling someMethod()
   }

    class OtherClass {

        public OtherClass() {
            // OtherClass#someMethod hides SomeClass#someMethod so in order to call it it must be done like this
            SomeClass.this.someMethod();
        }

        public void someMethod(){}
    }
}