struts 2+jpa+spring 的,如果用上范型的话,还是能省不少事的哦.把以前的小结之.
首先搞个DAO的基础接口
import java.io.Serializable;
import java.util.List;
import javax.persistence.Query;
public interface IBaseDAO<T> {
public T find(Class<T> clazz, Serializable id);
public void persist(T t);
public void save(T t);
public void delete(T t);
public Query createQuery(String jpql);
public int getTotalCount(String jpql);
public List<T> find(String jpql);
public List<T> find(String jpql, Object param);
public List<T> find(String jpql, Object... param);
public void saveOrUpdate(T t);
}
dao层实现:
public class BaseDAOImpl<T extends BaseBean> implements IBaseDAO<T> {
@PersistenceContext
protected EntityManager em;
public Query createQuery(String jpql) {
return em.createQuery(jpql);
}
public void delete(T t) {
em.remove(t);
}
public T find(Class<T> clazz, Serializable id) {
return em.getReference(clazz, id);
}
@SuppressWarnings("unchecked")
public List<T> find(String jpql, Object param) {
return em.createQuery(jpql).setParameter(1, param).getResultList();
}
@SuppressWarnings("unchecked")
public List<T> find(String jpql, Object[] param) {
Query query = em.createQuery(jpql);
for (int i = 1; i <= param.length; i++) {
query.setParameter(i, param[i - 1]);
}
return query.getResultList();
}
@SuppressWarnings("unchecked")
public List<T> find(String jpql) {
return em.createQuery(jpql).getResultList();
}
@SuppressWarnings("unchecked")
public int getTotalCount(String jpql) {
return ((Long) em.createQuery(jpql).getSingleResult()).intValue();
}
public void persist(T t) {
em.persist(t);
}
public void save(T t) {
em.merge(t);
}
public void saveOrUpdate(T t) {
em.merge(t);
}
public EntityManager getEntityManager() {
return em;
}
@PersistenceContext
public void setEntityManager(EntityManager entityManager) {
this.em = entityManager;
}
同样地,将CRUD的基本服务搞成一个baseservice
import java.io.Serializable;
import java.util.List;
import com.fengmanfei.blog.exception.BusinessException;
public interface IBaseService<T> {
public void create(T t) throws BusinessException;
public void save(T t) throws BusinessException;
public void delete(T t) throws BusinessException;
public T find(Class<T> clazz, Serializable id);
public int getTotalCount(String jpql);
public List<T> find(String jpql);
public List<T> find(String jpql, Object param);
public List<T> find(String jpql, Object... param);
}
公共service的实现
@Transactional
public class BaseServiceImpl<T extends BaseBean> implements IBaseService<T> {
protected Log log = LogFactory.getLog(this.getClass());
protected IBaseDAO<T> baseDAO;
public void create(T t) throws BusinessException {
baseDAO.persist(t);
}
public void delete(T t) throws BusinessException {
t.setDeleted(true);
baseDAO.save(t);
}
public void save(T t) throws BusinessException {
baseDAO.save(t);
}
public T find(Class<T> clazz, Serializable id) {
T t = baseDAO.find(clazz, id);
if (t.isDeleted()) {
return null;
}
return t;
}
public List<T> find(String jpql, Object param) {
return baseDAO.find(jpql, param);
}
public List<T> find(String jpql, Object... param) {
return baseDAO.find(jpql, param);
}
public List<T> find(String jpql) {
return baseDAO.find(jpql);
}
public int getTotalCount(String jpql) {
return (Integer) baseDAO.createQuery(jpql).getSingleResult();
}
public IBaseDAO<T> getBaseDAO() {
return baseDAO;
}
public void setBaseDAO(IBaseDAO<T> baseDAO) {
this.baseDAO = baseDAO;
}
}
再来看具体的功能,比如person的部分,
首先是person的接口:
import com.fengmanfei.blog.entity.Person;
public interface IPersonService<T extends Person> extends IBaseService<T> {
public T findPersonByAccount(String login);
public T findPersonByAccountAndPassword(String login, String password);
}
person的实现:
public class PersonServiceImpl<T extends Person> extends BaseServiceImpl<T>
implements IPersonService<T> {
public void create(T person) throws BusinessException {
log.info("");
if (findPersonByAccount(person.getAccount()) != null) {
throw new BusinessException("帐号 \"" + person.getAccount()
+ "\" 已经存在. ");
}
this.baseDAO.persist(person);
}
@SuppressWarnings("unchecked")
public T findPersonByAccount(String account) {
log.info("");
List<T> personList = this.baseDAO.find(" SELECT p FROM Person p "
+ " WHERE p.account = lower(?) AND p.deleted = false ", account
.toLowerCase().trim());
if (personList.size() > 0) {
return personList.get(0);
}
return null;
}
@SuppressWarnings("unchecked")
public T findPersonByAccountAndPassword(String login, String password) {
log.info("");
List<T> personList = this.baseDAO.find(" SELECT p FROM Person p "
+ " WHERE p.account = lower(?) "
+ " AND p.password = ? and p.deleted = false ", new String[] {
login.toLowerCase().trim(), password });
if (personList.size() > 0) {
return personList.get(0);
}
return null;
}