java - if (specialmarkId != null) {.....} got ignored -

i using auto generated jpacontroller of netbeans 8 using java 1.8.

public void create(physical physical) {         if (physical.gettalentcollection() == null) {             physical.settalentcollection(new arraylist<talent>());         }         entitymanager em = null;         try {             em = getentitymanager();             em.gettransaction().begin();             specialmark specialmarkid = physical.getspecialmarkid();             system.out.println(specialmarkid+ "...nullvalue");            if (specialmarkid != null) {                 system.out.println(specialmarkid+ "...ain't right");                 specialmarkid = em.getreference(specialmarkid.getclass(), specialmarkid.getid());                 physical.setspecialmarkid(specialmarkid);             } ..... } 

during physical object creation, specialmark (part of physical object) optional.

it can have value or null.

specialmark in table physical allows have null values.

when specialmark null, if (specialmarkid != null) {...} should skipped. instead, got ignored , proceed.

the error message is

"... instance of null pk has been incorrectly provided find operation. @ db.jpa.physicaljpacontroller.create(physicaljpacontroller.java:57)"   system.out.println(specialmarkid+ "...nullvalue"); output "null...nullvalue" shows specialmarkid value null  system.out.println(specialmarkid+ "...ain't right"); 

output "null...ain't right" shows if (specialmarkid != null) {...} has been ignored specialmarkid null.

why (specialmarkid != null) {...} not work?

i guess specialmarkid not null, specialmarkid.tostring() overwriten return string "null".

instead of

system.out.println(specialmarkid+ "...nullvalue"); 

try like

system.out.println((specialmarkid != null?         specialmarkid.tostring() + "(not  null)": "(this null)")         + "...nullvalue");