How to get an existing Join in a JPA criteria query

QueryJoinHelper.java

import com.emdeon.claimmaster.entities.Ubhcdata;
import com.emdeon.claimmaster.entities.Ubupload;
import com.emdeon.claimmaster.entities.Ubuploadclaimrelation;

import javax.persistence.criteria.Join;
import javax.persistence.criteria.JoinType;
import javax.persistence.criteria.Root;
import javax.persistence.metamodel.CollectionAttribute;
import javax.persistence.metamodel.ListAttribute;
import javax.persistence.metamodel.SingularAttribute;
import java.util.Iterator;
import java.util.Set;

/**
 * Created by qlehenaff on 12/10/15.
 *
 * Find and return a join between R and J
 *
 */
public class QueryJoinHelper<R, J> {
    /**
     * Find and return a join between R and J on attribute
     * @param root root entity
     * @param attribute join attribute between R and J
     * @param joinedEntity Class instance of the joined entity
     * @return
     */
    public Join<R, J> getExistingJoin(Root<R> root, SingularAttribute<R, J> attribute, Class<J> joinedEntity) {
        Join<R, J> ubhcdataRoot = null;
        final Set<Join<R, ?>> joins = root.getJoins();
        if (!joins.isEmpty()) {
            final Iterator<Join<R, ?>> iterator = joins.iterator();
            while (iterator.hasNext()) {
                final Join<R, ?> next = iterator.next();
                if (next.getModel().getBindableJavaType().getSimpleName().equals(joinedEntity.getSimpleName())) {
                    ubhcdataRoot = (Join<R, J>) next;
                    break;
                }
            }
            if (ubhcdataRoot == null) {
                ubhcdataRoot = root.join(attribute);
            }
        } else {
            ubhcdataRoot = root.join(attribute);
        }
        return ubhcdataRoot;
    }
    /**
     * Find and return a join between R and J on attribute
     * @param root root entity
     * @param attribute join attribute between R and J
     * @param joinedEntity Class instance of the joined entity
     * @return
     */
    public Join<R, J> getExistingJoin(Root<R> root, CollectionAttribute<R, J> attribute, Class<J> joinedEntity) {
        Join<R, J> ubhcdataRoot = null;
        final Set<Join<R, ?>> joins = root.getJoins();
        if (!joins.isEmpty()) {
            final Iterator<Join<R, ?>> iterator = joins.iterator();
            while (iterator.hasNext()) {
                final Join<R, ?> next = iterator.next();
                if (next.getModel().getBindableJavaType().getSimpleName().equals(joinedEntity.getSimpleName())) {
                    ubhcdataRoot = (Join<R, J>) next;
                    break;
                }
            }
            if (ubhcdataRoot == null) {
                ubhcdataRoot = root.join(attribute, JoinType.INNER);
            }
        } else {
            ubhcdataRoot = root.join(attribute);
        }
        return ubhcdataRoot;
    }

    public Join<R, J> getExistingJoin(Join<?, R> rJoin, SingularAttribute<R, J> attribute, Class<J> joinedEntity) {
        Join<R, J> ubhcdataRoot = null;
        final Set<Join<R, ?>> joins = rJoin.getJoins();
        if (!joins.isEmpty()) {
            final Iterator<Join<R, ?>> iterator = joins.iterator();
            while (iterator.hasNext()) {
                final Join<R, ?> next = iterator.next();
                if (next.getModel().getBindableJavaType().getSimpleName().equals(joinedEntity.getSimpleName())) {
                    ubhcdataRoot = (Join<R, J>) next;
                    break;
                }
            }
            if (ubhcdataRoot == null) {
                ubhcdataRoot = rJoin.join(attribute);
            }
        } else {
            ubhcdataRoot = rJoin.join(attribute);
        }
        return ubhcdataRoot;
    }

    public Join<R, J> getExistingJoin(Root<R> root, ListAttribute<R, J> attribute, Class<J> joinedEntity) {{
        Join<R, J> ubhcdataRoot = null;
        final Set<Join<R, ?>> joins = root.getJoins();
        if (!joins.isEmpty()) {
            final Iterator<Join<R, ?>> iterator = joins.iterator();
            while (iterator.hasNext()) {
                final Join<R, ?> next = iterator.next();
                if (next.getModel().getBindableJavaType().getSimpleName().equals(joinedEntity.getSimpleName())) {
                    ubhcdataRoot = (Join<R, J>) next;
                    break;
                }
            }
            if (ubhcdataRoot == null) {
                ubhcdataRoot = root.join(attribute);
            }
        } else {
            ubhcdataRoot = root.join(attribute);
        }
        return ubhcdataRoot;
    }
    }
}