content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.apache.ambari.server.orm.dao;
  
  import java.util.Collections;
  import java.util.List;
  
  import jakarta.persistence.EntityManager;
  import jakarta.persistence.NoResultException;
  import jakarta.persistence.Query;
  import jakarta.persistence.TypedQuery;
  import jakarta.persistence.criteria.CriteriaBuilder;
  import jakarta.persistence.criteria.CriteriaQuery;
  import jakarta.persistence.criteria.Root;
  
  import com.google.inject.Singleton;
  
  @Singleton
  public class DaoUtils {
  
    public <T> List<T> selectAll(EntityManager entityManager, Class<T> entityClass) {
      CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
      CriteriaQuery<T> query = criteriaBuilder.createQuery(entityClass);
      Root<T> root = query.from(entityClass);
      query.select(root);
      TypedQuery<T> typedQuery = entityManager.createQuery(query);
      try {
        return typedQuery.getResultList();
      } catch (NoResultException ignored) {
        return Collections.emptyList();
      }
    }
  
    public <T> List<T> selectList(TypedQuery<T> query, Object... parameters) {
      setParameters(query, parameters);
      try {
        return query.getResultList();
      } catch (NoResultException ignored) {
        return Collections.emptyList();
      }
    }
  
    public <T> T selectSingle(TypedQuery<T> query, Object... parameters) {
      setParameters(query, parameters);
      try {
        return query.getSingleResult();
      } catch (NoResultException ignored) {
        return null;
      }
    }
  
    public <T> T selectOne(TypedQuery<T> query, Object... parameters) {
      setParameters(query, parameters);
      try {
        return query.setMaxResults(1).getSingleResult();
      } catch (NoResultException ignored) {
        return null;
      }
    }
  
    public int executeUpdate(Query query, Object... parameters) {
      setParameters(query, parameters);
      return query.executeUpdate();
    }
  
    public void setParameters(Query query, Object... parameters) {
      for (int i = 0; i < parameters.length; i++) {
        query.setParameter(i + 1, parameters[i]);
      }
    }
  }
  