Exception handling
Hello experts,
could you please take a look at my code. I am really not sure if my exception handling is correct or maybe completely wrong.
As you can see I catch every exception log what happened and throw a new RuntimeException!
Could you give me a hand how I should implement exception handling in my DAO beans?
@Stateless
public class CustomerServiceBean implements CustomerService, CustomerServiceRemote
{
private @PersistenceContext(unitName = "order") EntityManager em;
private static Logger logger = Logger.getLogger(Customer.class);
/**
* Persist customer object
* @param customer the customer to persist
* @return the persisted customer object
* @throws GenericServiceException
*/
@PermitAll
public Customer persistCustomer(Customer customer) throws GenericServiceException
{
if(customer == null)
{
String errorMessage = "Can not persist empty object!";
logger.warn(errorMessage);
throw new GenericServiceException(errorMessage);
}
try
{
if(logger.isDebugEnabled())
logger.debug("Persist customer " + customer.toString() + ".");
em.persist(customer);
if(logger.isDebugEnabled())
logger.debug("Customer " + customer.toString() + " with id " + customer.getId() + " persisted!");
return customer;
}
catch(Throwable e)
{
logger.error("Could not persist customer " + customer.toString(),e);
throw new GenericServiceException(e.getMessage(),e.getCause());
}
}
/**
* Merge customer object
* @param customer the customer to persist
* @return the merged customer object
* @throws GenericServiceException
*/
@PermitAll
public Customer mergeCustomer(Customer customer) throws GenericServiceException
{
if(customer == null)
{
String errorMessage = "Can not merge empty object!";
logger.warn(errorMessage);
throw new GenericServiceException(errorMessage);
}
try
{
if(logger.isDebugEnabled())
logger.debug("Merge customer " + customer.toString() + ".");
return em.merge(customer);
}
catch(Throwable e)
{
logger.error("Could not merge customer " + customer.toString(),e);
throw new GenericServiceException(e.getMessage(),e.getCause());
}
}
/**
* Find customer
* @param id
* @return the customer object
* @throws GenericServiceException
*/
@PermitAll
public Customer findCustomerById(int id) throws GenericServiceException
{
try
{
if(logger.isDebugEnabled())
logger.debug("Find customer " + id);
return em.find(Customer.class, id);
}
catch(Throwable e)
{
logger.error("Could not find customer " + id,e);
throw new GenericServiceException(e.getMessage(),e.getCause());
}
}
/**
* Find customer
* @param id
* @param mustExist if true an exception will be thrown if the object does not exist.
* @return a customer object.
* @throws GenericServiceException
*/
@PermitAll
public Customer findCustomerById(int id, boolean mustExist) throws GenericServiceException
{
try
{
if(logger.isDebugEnabled())
logger.debug("Find customer " + id);
if(mustExist)
{
Customer customer = new Customer(id);
em.refresh(customer);
return customer;
}
else
return em.find(Customer.class, id);
}
catch(Throwable e)
{
logger.error("Could not find customer " + id,e);
throw new GenericServiceException(e.getMessage(),e.getCause());
}
}
/**
* Find customer
* @param customer the customer to search for
* @return the customer object
* @throws GenericServiceException
*/
@PermitAll
public Customer findCustomerById(Customer customer) throws GenericServiceException
{
if(customer == null)
{
String errorMessage = "Can not search by using an empty object!";
logger.warn(errorMessage);
throw new GenericServiceException(errorMessage);
}
try
{
if(logger.isDebugEnabled())
logger.debug("Find customer " + customer.getId());
return em.find(Customer.class,customer.getId());
}
catch(Throwable e)
{
logger.error("Could not find customer " + customer.getId(),e);
throw new GenericServiceException(e.getMessage(),e.getCause());
}
}
/**
* Remove all customers
* @return the number of removed customer objects
* @throws GenericServiceException
*/
@PermitAll
public long removeAllCustomers() throws GenericServiceException
{
try
{
if(logger.isDebugEnabled())
logger.debug("Remove all customer objects!");
return em.createQuery("delete from Customer").executeUpdate();
}
catch(Throwable e)
{
logger.error("Could not remove all customer objects!",e);
throw new GenericServiceException(e.getMessage(),e.getCause());
}
}
/**
* Get all customers
* @return a collection of customers objects
* @throws GenericServiceException
*/
@PermitAll
public Collection<Customer> getAllCustomers() throws GenericServiceException
{
try
{
if(logger.isDebugEnabled())
logger.debug("Find all customer objects!");
return (Collection<Customer>) em.createQuery("from Customer").getResultList();
}
catch(Throwable e)
{
logger.error("Could not find customer objects!",e);
throw new GenericServiceException(e.getMessage(),e.getCause());
}
}
/**
* Get all customers
* @param noOfObjects
* @param startIndex
* @return a collection of customer objects
* @throws GenericServiceException
*/
@PermitAll
public Collection<Customer> getAllCustomers(int noOfObjects, int startIndex) throws GenericServiceException
{
try
{
if(logger.isDebugEnabled())
logger.debug("Find all customer objects with paging!");
Query query = em.createQuery("from Customer");
query.setMaxResults(noOfObjects);
query.setFirstResult(startIndex);
return (Collection<Customer>) query.getResultList();
}
catch(Throwable e)
{
logger.error("Could not find customer objects with paging!",e);
throw new GenericServiceException(e.getMessage(),e.getCause());
}
}
/**
* Remove customer
* @param id the identifier of the object to be removed
* @throws GenericServiceException
*/
@PermitAll
public void removeCustomer(int id) throws GenericServiceException
{
Customer customer;
try
{
if(logger.isDebugEnabled())
logger.debug("Remove customer " + id);
customer = em.find(Customer.class,id);
}
catch(Throwable e)
{
logger.error("Could not remove customer " + id,e);
throw new GenericServiceException(e.getMessage(),e.getCause());
}
if(customer == null)
{
String errorMessage = "Can not remove a non existing object!";
logger.warn(errorMessage);
throw new GenericServiceException(errorMessage);
}
try
{
em.remove(customer);
}
catch(Throwable e)
{
logger.error("Could not remove customer " + id,e);
throw new GenericServiceException(e.getMessage(),e.getCause());
}
}
/**
* Get customer
* @param name
* @return the customer object
* @throws GenericServiceException
*/
@PermitAll
public Customer getCustomerByName(String name) throws GenericServiceException
{
try
{
if(logger.isDebugEnabled())
logger.debug("Search for customer!");
String ejbQL = " from Customer a where a.name = :param1";
Query query = em.createQuery(ejbQL);
query.setParameter("param1",name);
return (Customer) query.getSingleResult();
}
catch(Throwable e)
{
logger.error("Could not search for customer!",e);
throw new GenericServiceException(e.getMessage(),e.getCause());
}
}
/**
* Search customer
* @param name
* @return a collection of customer objects
* @throws GenericServiceException
*/
@PermitAll
public Collection<Customer> searchCustomerByName(String name) throws GenericServiceException
{
try
{
if(logger.isDebugEnabled())
logger.debug("Search for customers!");
String ejbQL = " from Customer a where a.name like :param1";
Query query = em.createQuery(ejbQL);
query.setParameter("param1",name);
return (Collection<Customer>) query.getResultList();
}
catch(Throwable e)
{
logger.error("Could not search for customers!",e);
throw new GenericServiceException(e.getMessage(),e.getCause());
}
}
/**
* Search for customers objects via an ejb query string
* @param ejbQL the ejb query string
* @return a collection of customer objects
* @throws GenericServiceException
*/
@PermitAll
public Collection<Customer> searchCustomers(String ejbQL) throws GenericServiceException
{
if(ejbQL == null || ejbQL.equals(""))
{
String errorMessage = "Query string must not be empty!";
logger.warn(errorMessage);
throw new GenericServiceException(errorMessage);
}
try
{
if(logger.isDebugEnabled())
logger.debug("Search for customer objects!");
return (Collection<Customer>) em.createQuery(ejbQL).getResultList();
}
catch(Throwable e)
{
logger.error("Could not search for customers by using query: " + ejbQL,e);
throw new GenericServiceException(e.getMessage(),e.getCause());
}
}
/**
* Search for customers objects via an ejb query string
* @param ejbQL
* @param noOfObjects
* @param startIndex
* @return a collection of customer objects
* @throws GenericServiceException
*/
@PermitAll
public Collection<Customer> searchCustomers(String ejbQL, int noOfObjects, int startIndex) throws GenericServiceException
{
if(ejbQL == null || ejbQL.equals(""))
{
String errorMessage = "Query string must not be empty!";
logger.warn(errorMessage);
throw new GenericServiceException(errorMessage);
}
try
{
if(logger.isDebugEnabled())
logger.debug("Search for customer objects!");
Query query = em.createQuery(ejbQL);
query.setMaxResults(noOfObjects);
query.setFirstResult(startIndex);
return (Collection<Customer>) query.getResultList();
}
catch(Throwable e)
{
logger.error("Could not search for customers by using query: " + ejbQL,e);
throw new GenericServiceException(e.getMessage(),e.getCause());
}
}
/**
* Check if customer already exists
* @param id
* @return true if the customer already exists
* @throws GenericServiceException
*/
@PermitAll
public boolean checkCustomer(int id) throws GenericServiceException
{
try
{
if(logger.isDebugEnabled())
logger.debug("Check customer " + id + "!");
long counter = (Long) em.createQuery("select count(a) from Customer a where a.id = :param").setParameter("param",id).getSingleResult();
if(counter == 0)
return false;
return true;
}
catch(Throwable e)
{
logger.error("Could not check customer!",e);
throw new GenericServiceException(e.getMessage(),e.getCause());
}
}
/**
* Remove a list of customers
* @param customers a list of objects to be removed
* @throws GenericServiceException
*/
@PermitAll
public void removeCustomers(Collection<Customer> customers) throws GenericServiceException
{
try
{
if(logger.isDebugEnabled())
logger.debug("Remove a list of customers!");
for(Customer listItem : customers)
{
Customer customer = em.find(Customer.class,listItem.getId());
em.remove(customer);
}
}
catch(Throwable e)
{
logger.error("Could not remove customers!",e);
throw new GenericServiceException(e.getMessage(),e.getCause());
}
}
/**
* Persist a list of customers
* @param customers a list of objects to be persistet
* @return a list of persisted customers
* @throws GenericServiceException
*/
@PermitAll
public Collection<Customer> persistCustomers(Collection<Customer> customers) throws GenericServiceException
{
Collection<Customer> itemList = new ArrayList();
try
{
if(logger.isDebugEnabled())
logger.debug("Persist a list of customers!");
for(Customer item : customers)
{
em.persist(item);
itemList.add(item);
}
return itemList;
}
catch(Throwable e)
{
logger.error("Could not persist customers!",e);
throw new GenericServiceException(e.getMessage(),e.getCause());
}
}
/**
* Merge a list of customers
* @param customers a list of objects to be merged
* @return a list of merged customers
* @throws GenericServiceException
*/
@PermitAll
public Collection<Customer> mergeCustomers(Collection<Customer> customers) throws GenericServiceException
{
Collection<Customer> itemList = new ArrayList();
if(logger.isDebugEnabled())
logger.debug("Merge a list of customers!");
try
{
for(Customer item : customers)
{
em.merge(item);
itemList.add(item);
}
return itemList;
}
catch(Throwable e)
{
logger.error("Could not merge customers!",e);
throw new GenericServiceException(e.getMessage(),e.getCause());
}
}
/**
* Count customers
* @return the number of persistent customers
* @throws GenericServiceException
*/
@PermitAll
@TransactionAttribute(TransactionAttributeType.NOT_SUPPORTED)
public Long countCustomers() throws GenericServiceException
{
try
{
if(logger.isDebugEnabled())
logger.debug("Count customers!");
return (Long) em.createQuery("select count (a) from Customer a").getSingleResult();
}
catch(Throwable e)
{
logger.error("Could not count customers!",e);
throw new GenericServiceException(e.getMessage(),e.getCause());
}
}
/**
* Count customers
* @param criteria the query criteria(s)
* @return the number of persistent customers
* @throws GenericServiceException
*/
@PermitAll
@TransactionAttribute(TransactionAttributeType.NOT_SUPPORTED)
public Long countCustomers(String criteria) throws GenericServiceException
{
if(criteria == null)
criteria = "";
try
{
if(logger.isDebugEnabled())
logger.debug("Count customers!");
if(criteria.toLowerCase().contains("where"))
return (Long) em.createQuery("select count (a) from Customer a " + criteria).getSingleResult();
else
return (Long) em.createQuery("select count (a) from Customer a where " + criteria).getSingleResult();
}
catch(Throwable e)
{
logger.error("Could not count customers by using criteria: " + criteria,e);
throw new GenericServiceException(e.getMessage(),e.getCause());
}
}
/**
* Get country of this customer
* @param id
* @return the country of this customer
* @throws GenericServiceException
*/
@PermitAll
public Country getCountryOfCustomer(int id) throws GenericServiceException
{
try
{
if(logger.isDebugEnabled())
logger.debug("Find country of customer " + id);
return (Country) em.createQuery("select b from Customer a join a.country b where a.id =" + id).getSingleResult();
}
catch(Throwable e)
{
logger.error("Could not find country of customer " + id,e);
throw new GenericServiceException(e.getMessage(),e.getCause());
}
}
}