Creating EJB query with Criteria Builder


Just documenting it for future purposes or any one in need of help

import javax.persistence.EntityManager;
import javax.persistence.TemporalType;
import javax.persistence.TypedQuery;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Join;
import javax.persistence.criteria.JoinType;
import javax.persistence.criteria.ParameterExpression;
import javax.persistence.criteria.Path;
import javax.persistence.criteria.Predicate;
import javax.persistence.criteria.Root;

public class SampleCriteriaBuilder {

EntityManager entityManager = null;
CriteriaBuilder criteriaBuilder;
List<Predicate> andPredicates = new ArrayList<Predicate>();
TypedQuery<YourDTOObjectRoot> query;

    public SampleCriteriaBuilder(EntityManager entityManager) {
        super();

        this.entityManager = entityManager;

        criteriaBuilder = this.entityManager.getCriteriaBuilder();
        criteriaQuery = criteriaBuilder.createQuery(YourDTOObject.class);

        yourDTOObjectRoot = criteriaQuery.from(yourDTOObject.class);

        childTable1Root = yourDTOObjectRoot.join("childTable1", JoinType.LEFT);
        childTable2Root = yourDTOObjectRoot.join("childTable2", JoinType.LEFT);
                           
    }
    // Like clause
       
         Predicate likePredicate =
          criteriaBuilder.like(childTable1Root.get("someAttribute"),
 "%" + value + "%");
         andPredicates.add(likePredicate);
       
        // In clause

           String commaSepValue = "one,two,three,four";
            javax.persistence.criteria.CriteriaBuilder.In<String> inClause =
                criteriaBuilder.in(yourDTOObjectRoot.<String>get("someAttribute"));

           List commaSepValueList = commaSepValue.split(",");
            for (String valueTaken : commaSepValueList) {
                inClause.value(valueTaken);
            }

            andPredicates.add(inClause);
        // Or Clause
       
            Predicate orClause =
                criteriaBuilder.or(criteriaBuilder.equal(childTable1Root.get("someProperty"), "someValue"), criteriaBuilder.like(childTable1Root.get("someProperty"),"otherValue"));           
               
            andPredicates.add(orClause);
           
        //Comparision between two dates
       
        Path timeStampPath = yourDTOObjectRoot.<Date>get("timestamp");

        ParameterExpression<Date> dateFromExp = criteriaBuilder.parameter(Date.class);
        ParameterExpression<Date> dateToExp = criteriaBuilder.parameter(Date.class);

        Predicate predicate_date = criteriaBuilder.between(timeStampPath, dateFromExp, dateToExp);
        andPredicates.add(predicate_date);
                Predicate[] predicates = (Predicate[])andPredicates.toArray(new Predicate[andPredicates.size()]);

        criteriaQuery.where(predicates);

        query = entityManager.createQuery(criteriaQuery);

        query.setParameter(dateFromExp, dateFrom, TemporalType.DATE);
        query.setParameter(dateToExp, dateTo, TemporalType.DATE);
}