Empty/Null values from post request are getting assigned to 0

Question

<student>
<id>1</id>
<badge></badge>
<name>Matt</name>
</student>

This is my xml post when I observe during post.

public class Student implements Serializable{

Long id;
Integer badge;
String name;
}

My Web Service :

    @Path("add")
    @POST
    @Consumes({Mediatype.xml,Mediatype.json})
    @Produces({Mediatype.xml,Mediatype.json})
    public Response add(Student student)
    {
    }

When I debug on this add method on my service layer , variable badge gets assigned value "0", even though it is not provided by GUI.Database field for badge is also integer(postgres).

Is it something related to Integer variable, which assigns default value to 0 if not present ?

No, `Integer` is a reference type. By default, object creation will assign the variable `null`. This is behavior coming from your unmarshaller, probably JAXB. — Sotirios Delimanolis, Jul 25 '13 at 13:47
possible duplicate of [JAXB Marshalling with null fields](http://stackoverflow.com/questions/858598/jaxb-marshalling-with-null-fields) — Alex Stybaev, Jul 25 '13 at 13:55

score 0 · Answer 1 · edited May 23 '17 at 12:03

0

The type Integer is a reference type. When you create an instance of a class with a variable of a reference type, it's default value is null. So the behavior you are seeing is not Java's.

Jersey uses JAXB to marshall and unmarshall your entities. When it sees that you have a badge field that has an empty text element it must make a decision as to what the proper value to set is. It doesn't make sense to give it null since there is an element there. So it decides to initialize it to 0.

edited May 23 '17 at 12:03

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answered Jul 25 '13 at 13:52

Sotirios Delimanolis

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I am using jersey's implementation – Chetan D Jul 25 '13 at 14:06
@ChetanD Jersey's implementation of what? – Sotirios Delimanolis Jul 25 '13 at 14:09
by assigning nillable=true also it is assigning 0 to null values – Chetan D Jul 25 '13 at 14:25
@ChetanD I don't understand what you just said. Please rephrase. – Sotirios Delimanolis Jul 25 '13 at 14:26
I saw http://stackoverflow.com/questions/858598/jaxb-marshalling-with-null-fields and did nillable=false so that it should not assign null to 0 , but it didn't work as specified – Chetan D Jul 25 '13 at 14:29
You're thinking of it in reverse. What you did puts an xml element even if the field it's representing is `null`. What don't you understand about my answer. – Sotirios Delimanolis Jul 25 '13 at 14:31
I got and understood what you said , but is there any way of assigning nothing when empty string comes from gui ? – Chetan D Jul 25 '13 at 14:35
@ChetanD By _nothing_, do you mean assigning `null`? If yes, you'll need to implement some kind of adapter. Take a look at this [answer](http://stackoverflow.com/questions/5133250/jaxb-how-to-make-jaxb-not-to-unmarshal-empty-string-to-0). – Sotirios Delimanolis Jul 25 '13 at 14:37
I think in the above link you gave , he is trying to get null values from already present in database and represent them 0, Here I am trying to insert the null value in the database from my gui. – Chetan D Jul 25 '13 at 14:41
One solution would be to change the XML you send to not include the `` element. – Sotirios Delimanolis Jul 25 '13 at 14:42

Empty/Null values from post request are getting assigned to 0

1 Answers1