Dynamic JPQL query qith JOIN - jpa

Question

Had to write a jpql query, based on the input need to add and condition and for some input had to need JOIN queries.
#Override
public List<IncidentHdr> fetchIncidents(IncidentHdrDto incidentHdrDto) {
StringBuilder query = new StringBuilder();
query.append(ReposJPQL.GET_INCIDENT_DETAILS);
Map<String, Object> parameters = new HashMap<String, Object>();
List<String> criteria = new ArrayList<String>();
if(incidentHdrDto.getIncidentId() > 0) {
criteria.add("inc.incidentId = :incidentId");
parameters.put("incidentId", incidentHdrDto.getIncidentId());
}
if(incidentHdrDto.getCatCode() > 0) {
criteria.add("inc.catCode = :catCode");
parameters.put("catCode", incidentHdrDto.getCatCode());
}
if(incidentHdrDto.getType != null) {
//here i need to generate a join query
//SELECT * FROM INCIDENT JOIN CATEGORY_MAST ON(INCIDENT.CAT_CODE = CATEGORY_MAST.CAT_CODE) WHERE CATEGORY_MAST.TYPE_CODE = 16
}
Query q = em.createQuery(query.toString());
logger.info("Get Incidents Query : "+query.toString());
for (Entry<String, Object> entry : parameters.entrySet()) {
q.setParameter(entry.getKey(), entry.getValue());
}
List<IncidentHdr> incidentHdrs = q.getResultList();
return incidentHdrs;
}
where as ReposJPQL is the base query which had a where condition.
public interface ReposJPQL {
public String GET_INCIDENT_DETAILS = "SELECT inc FROM IncidentHdr inc WHERE 1 = 1" ;
}