Query is returning trailing whitespace

xaeryan · **Joined:** Fri May 04, 2007 3:43 pm **Posts:** 18

Are there any hibernate properties that control whether leading/trailing whitespace is returned from queries?
My project was working fine, but now instead of returning (for example) "Jimbo" it is returning "Jimbo _____" where the excess whitespace (I had to use underlines - spaces were just being compressed) brings the return value size to the size of the column. Not sure what was changed to cause this.
I am using Hibernate3 wired from within the Spring Framework with an Oracle9i database, in case that matters.

-TIA[/b]

cbredesen · **Posted:** Tue Jun 26, 2007 11:18 am

What is the datatype of the column? Sounds like you're using CHAR when you should use VARCHAR2.

-Chris

xaeryan · **Joined:** Fri May 04, 2007 3:43 pm **Posts:** 18

Sure enough, it is now CHAR. I'm going to guess that it was changed unbeknownst to me at some point. Since I am not able to modify types (commercial application), is there any way to still work with CHAR?

cbredesen · **Posted:** Tue Jun 26, 2007 11:51 am

You will have to trim it in you application, preferably in the DAO. If you really wanted to bury this functionality inside Hibernate, you could map the property with a custom UserType or even possibly write an Interceptor.

It would be trivial, however, to just add a line of code in your application to handle this.

HTH,

Chris

xaeryan · **Joined:** Fri May 04, 2007 3:43 pm **Posts:** 18

The only difficulty I have is that I am using the convenience methods, so for example a getRecord looks like nothing more than this:

Code:

return (MyObject) getHibernateTemplate().get( MyObject.class, thekey);

So I think making a custom type may be in order in order to continue using the convenience methods... do you have any experience with these?

cbredesen · **Posted:** Wed Jun 27, 2007 8:09 am

This forum post deals with this exact issue:
http://forum.hibernate.org/viewtopic.php?t=928294

I googled for trim string char site:hibernate.org and found it quite quickly :)

You actually may be able to extend StringType and touch only public Object get(ResultSet rs, String name), though there may be a catch here that I'm not thinking of.

To address your last post, though, you can still do:

Code:

MyObject myObject = (MyObject) getHibernateTemplate().get( MyObject.class, thekey);
if (myObject.getString() != null) {
  // trim it
}

But I like the UserType best and I think that's how most people will solve it.

-Chris

piet.t · **Joined:** Fri May 12, 2006 4:05 am **Posts:** 106

You have to take care that you don't trim() the field inside your application-code. If you do

Code:

MyObject myObject = (MyObject) getHibernateTemplate().get( MyObject.class, thekey); 
if (myObject.getString() != null) { 
  // trim it 
}

hibernate will mark the Object as dirty and issue an unneccessary update-statement.
User-type is the way to do this!

cbredesen · **Posted:** Thu Jun 28, 2007 7:30 am

Quote:

hibernate will mark the Object as dirty and issue an unneccessary update-statement. User-type is the way to do this!

Yes of course it will, thanks for pointing that out!

xaeryan · **Joined:** Fri May 04, 2007 3:43 pm **Posts:** 18

Does anyone have an example of implementing the UserType class on a recent (i.e. not 3 years ago ;-) ) version of Hibernate?
The example linked above is great, but it is missing several required function implementations - assemble, disassemble, hashcode, and replace.
The API documentation doesn't help me much on these.

rastogha · **Joined:** Fri Jun 29, 2007 9:03 am **Posts:** 12

I hope ur porblem is solved already.If not here is what i have done for same problem.
to remove the trimmed string best way is to use UserType . U need to override some methods. I have written as code for the same problem :

Code:

public class NotNullString implements UserType {
    public TrimmedString() {
        super();
    }

    public int[] sqlTypes() {
        return new int[] { Types.CHAR };
    }

    public Class returnedClass() {
        return String.class;
    }

    public boolean equals(Object x, Object y) throws HibernateException {
        return (x == y) || (x != null && y != null && (x.equals(y)));
    }

    public Object nullSafeGet(ResultSet rs, String[] names, Object owner) throws HibernateException, SQLException {
        String val = rs.getString(names[0]);
        return val != null ? val.trim() : null;
    }

    public void nullSafeSet(PreparedStatement st, Object value, int index) throws HibernateException, SQLException {
        st.setString(index, (String)value);
    }

    public Object deepCopy(Object value) throws HibernateException {
        if (value == null) return null;
        return new String((String)value);
    }

    public boolean isMutable() {
        return false;
    }

    public Object assemble(Serializable arg0, Object arg1) throws HibernateException {
        // TODO Auto-generated method stub
        return null;
    }

    public Serializable disassemble(Object arg0) throws HibernateException {
        return null;
    }

    public int hashCode(Object arg0) throws HibernateException {
        return 0;
    }

    public Object replace(Object arg0, Object arg1, Object arg2) throws HibernateException {
        return null;
    }
}

The nullSafeSet() and nullSafeGet() method is used to set and get the values from the database .

piet.t · **Joined:** Fri May 12, 2006 4:05 am **Posts:** 106

Hi,

always returning null or 0 doesn't seem like the best solution to me...
Here's what we have done concerning these methods (I don't know if we copied it from some other place, but here we are):

Code:

   public int hashCode(Object arg0) throws HibernateException {
      return arg0.hashCode();
   }

   public Serializable disassemble(Object arg0) throws HibernateException {
      return (Serializable) arg0;
   }

   public Object assemble(Serializable arg0, Object arg1)
         throws HibernateException {
      return (String) arg0;
   }

   public Object replace(Object arg0, Object arg1, Object arg2)
         throws HibernateException {
      return arg0;
   }

I don't know if this really is the way it's done, but at least it's working (as is rastogha's solution surely does too).

piet.t · **Joined:** Fri May 12, 2006 4:05 am **Posts:** 106

Hi,

always returning null or 0 doesn't seem like the best solution to me...
Here's what we have done concerning these methods (I don't know if we copied it from some other place, but here we are):

Code:

   public int hashCode(Object arg0) throws HibernateException {
      return arg0.hashCode();
   }

   public Serializable disassemble(Object arg0) throws HibernateException {
      return (Serializable) arg0;
   }

   public Object assemble(Serializable arg0, Object arg1)
         throws HibernateException {
      return (String) arg0;
   }

   public Object replace(Object arg0, Object arg1, Object arg2)
         throws HibernateException {
      return arg0;
   }

I don't know if this really is the way it's done, but at least it's working (as is rastogha's solution surely does too).

xaeryan · **Joined:** Fri May 04, 2007 3:43 pm **Posts:** 18

OK, I've got the custom UserType in place, but it doesn't seem to be working at all... I'm not sure if it is because the mapping for this table is a bit awkward with composite ID. Here is the mapping:

Code:

   <class name="login.Users" table="USERS">
        <composite-id name="id" class="login.UsersId">
            <key-property name="username" type="login.TrimmedString">
                <column name="USERNAME" sql-type="char(12)" not-null="true"/>
            </key-property>
            <key-property name="password" type="string">
                <column name="PASSWORD" length="20" />
            </key-property>
        </composite-id>
        <property name="createdtadstp" type="timestamp">
            <column name="CREATEDTADSTP" length="7" />
        </property>
        <property name="modifiedtadstp" type="timestamp">
            <column name="MODIFIEDTADSTP" length="7" />
        </property>
    </class>

Even with the trimmed string type, if I try to enter username "ryan" it fails, instead I have to enter "ryan________" (spaces). Nothing in the POJO class (login.Users) needs to be changed, right?
Not sure what I'm missing. I am using Hibernate within the Spring Framework if that has any effect... Any ideas?