Hibernate criteria with variable amount of OR LIKE clauses

Question

I am fairly new to hibernate, and at the moment struggeling with firing a query with the use of criteria.

What i want to achieve is, selecting all records that contain a certain string in either the first or lastname columns.

Here is what I have. It should give a better idea.

Session session = HibernateUtil.openSession();
    Criteria criteria = session.createCriteria(Contact.class);

    if(keywords != null) {
        for(String keyword : keywords) {
            if(keyword != null && keyword.length() > 0) {
                criteria.add(Restrictions.like("firstName", keyword, MatchMode.ANYWHERE));
                criteria.add(Restrictions.or(Restrictions.like("lastName", keyword, MatchMode.ANYWHERE), null));
            }
        }
    }

    searchMatches = criteria.list();

so in the end the query should be something along the lines of:

SELECT * FROM contacts WHERE (firstname LIKE '%oe% OR lastname LIKE '%oe%'), and if multiple keywords are given, something like:

SELECT * FROM contacts WHERE (firstname LIKE '%oe% OR lastname LIKE '%oe%') OR (firstname LIKE '%roo% OR lastname LIKE '%roo%')

this would select the record containing "oe" inside either the first or lastname columns. How ever I get a crash with the code when criteria.list(); is run.

Here is the stack trace. I can not figure out what it is I am doing wrong.

Caused by: java.lang.NullPointerException
at org.hibernate.criterion.LogicalExpression.toSqlString(LogicalExpression.java:60)
at org.hibernate.loader.criteria.CriteriaQueryTranslator.getWhereCondition(CriteriaQueryTranslator.java:419)
at org.hibernate.loader.criteria.CriteriaJoinWalker.<init>(CriteriaJoinWalker.java:123)
at org.hibernate.loader.criteria.CriteriaJoinWalker.<init>(CriteriaJoinWalker.java:92)
at org.hibernate.loader.criteria.CriteriaLoader.<init>(CriteriaLoader.java:93)
at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1464)
at org.hibernate.internal.CriteriaImpl.list(CriteriaImpl.java:374)
at com.joey.wishlist.dao.impl.ContactDAOImpl.searchContacts(ContactDAOImpl.java:34)
at com.joey.wishlist.services.impl.ContactServiceImpl.searchContacts(ContactServiceImpl.java:22)
at com.joey.wishlist.presenters.ContactSearchPresenter.search(ContactSearchPresenter.java:75)

EDIT: I am one step closer.

I fixed the error. The error was caused by a malfunctioning or.

The code now looks like this:

        if(keywords != null) {
        for(String keyword : keywords) {
            if(keyword != null && keyword.length() > 0) {
                criteria.add(
                        Restrictions.or(
                            Restrictions.like("lastName", keyword, MatchMode.ANYWHERE), 
                            Restrictions.like("firstName", keyword, MatchMode.ANYWHERE)
                        ));
            }
        }
    }

Which produces this query, which is almost what i want. I just want the "AND" to be "OR". So:

Hibernate: 
/* criteria query */ select
    this_.id as id0_0_,
    this_.firstname as firstname0_0_,
    this_.lastname as lastname0_0_ 
from
    contactmanager this_ 
where
    (
        this_.lastname like ? 
        or this_.firstname like ?
    ) 
    and (
        this_.lastname like ? 
        or this_.firstname like ?
    )

I want to be:

Hibernate: 
/* criteria query */ select
    this_.id as id0_0_,
    this_.firstname as firstname0_0_,
    this_.lastname as lastname0_0_ 
from
    contactmanager this_ 
where
    (
        this_.lastname like ? 
        or this_.firstname like ?
    ) 
    or ( //Notice difference here
        this_.lastname like ? 
        or this_.firstname like ?
    )

Answer 1

Every time you call criteria.add, it adds an and to your statement. What you want to to create a disjunction:

Disjunction matchDisjunction = Restrictions.disjunction()
for(String keyword : keywords) {
            if(keyword != null && keyword.length() > 0) {
                matchDisjunction.add(
                        Restrictions.or(
                            Restrictions.like("lastName", keyword, MatchMode.ANYWHERE), 
                            Restrictions.like("firstName", keyword, MatchMode.ANYWHERE)
                        ));
            }
        }
criteria.add(matchDisjunction);

Or simply:

Disjunction matchDisjunction = Restrictions.disjunction()
for(String keyword : keywords) {
            if(keyword != null && keyword.length() > 0) {
                matchDisjunction.add( Restrictions.like("lastName", keyword, MatchMode.ANYWHERE) );
                matchDisjunction.add( Restrictions.like("firstName", keyword, MatchMode.ANYWHERE) );
            }
        }
criteria.add(matchDisjunction);