I have a remove() in my DAO class and sometimes I got error because
FOREING KEY violation
. I.E: When user try to remove a Product that is used by a Customer.
This is my remove() method:
public void delete(AbstractEntity entidade) throws DAOException {
try {
entidade = getEm().merge(entidade);
getEm().remove(entidade);
} catch (Exception e) {
logger.error(e);
throw new DAOException(e.getMessage());
}
}
The problem is that error just appear when database touched. I need to validate some exceptions in this point to send a right Exception to USER, like: "You can delete this because other information is using it."
Related
I have a unique constraint on one of my entities and whenever I get a PSQLException which occurs whenever that constraint is violated, I want to respond with a bad request.
This is my exception handler which I tried to implement:
#ControllerAdvice
public class DatabaseExceptionHandler {
#ExceptionHandler(value = PSQLException.class)
#ResponseStatus(HttpStatus.BAD_REQUEST)
public void handleDatabaseExceptions(PSQLException e) {
// i want to respond with a bad request only when this condition is satisfied
//
// if (e.getSQLState().equals("23505")) {
//
// }
}
}
And this is where the model is saved in db:
public DepartmentForHoliday setDepartment(DepartmentForHoliday department) {
if (department.getDepartmentId() == null) {
Department savedDepartment = new Department();
savedDepartment.setName(department.getName());
try {
departmentRepository.save(savedDepartment);
} catch (PSQLException e) {
/*here i have a compiler error which says that this exception is never thrown in the corresponding try block, but where ?*/
}
}
This is the exception that is thrown when I add a duplicate entry:
org.postgresql.util.PSQLException: ERROR: duplicate key value violates unique constraint "uk_1t68827l97cwyxo9r1u6t4p7d"
Detail: Key (name)=(Tech) already exists.
at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2458) ~[postgresql-9.4.1211.jre7.jar:9.4.1211.jre7]
How to handle PSQLExceptions ? Should I make my own exception as a wrapper or how to solve this problem ?
Key problem is that PSQLException is wrapped into some Spring exception (which I assume from your code); you have to unwrap it (for example using guava's Throwables):
public DepartmentForHoliday setDepartment(DepartmentForHoliday department) {
if (department.getDepartmentId() == null) {
Department savedDepartment = new Department();
savedDepartment.setName(department.getName());
try {
departmentRepository.save(savedDepartment);
} catch (RuntimeException e) {
Throwable rootCause = com.google.common.base.Throwables.getRootCause(e);
if (rootCause instanceof SQLException) {
if ("23505".equals(((SQLException) rootCause).getSQLState())) {
// do smth interesting :)
}
}
}
}
}
Once you do that you can throw your custom exception and handle it in DatabaseExceptionHandler
You are catching PSQLException. Instead of that, please catch SQLException. With SQLException you will can handle all this SQL exceptions.
You can check the SQLException knowledge at this link
Then in your code just treat the SQLException as you want. The most generic catch clause is the following one:
catch (SQLException e)
{
System.out.println("ERROR: Fetch statement failed: " +
e.getMessage());
}
With this code you are printing the exception. If you want more information, check this
This is quite late, but building on previous responses I was able to solve it as so:
try {
return this.projectRepository.saveAndFlush(patchedProjectEntity);
} catch (DataIntegrityViolationException e) {
if (e.getMostSpecificCause().getClass().getName().equals("org.postgresql.util.PSQLException") && ((SQLException) e.getMostSpecificCause()).getSQLState().equals("23505"))
throw new UniqueConstraintViolationException("", e.getMostSpecificCause());
throw e;
}
Where UniqueConstraintViolationException is a custom exception and handled with a spring controller advice.
You might as well register an exception handler for that wrapped exception (that #radek mentioned) directly.
In your case that's:
#ExceptionHandler(DataIntegrityViolationException::class)
protected fun handleDataIntegrityException(ex: DataIntegrityViolationException, request: WebRequest) : ResponseEntity<SomeBody>{
return ResponseEntity.badRequest().body(someBodyHere)
}
The error is converted within convertHibernateAccessException in org.springframework.orm.jpa.vendorHibernateJpaDialect, which has already processed away from PSQL. You can add a breakpoint there and follow the stacktrace.
There is a lot of proxy'ing happening under the hood, but the takeaway is that there is always a readable, expressive Exception to use directly.
This is my Exception:
public class MyException extends Exception {
private String errorCode="Unknown_Exception";
public MyException(String message, String errorCode){
super(message);
this.errorCode=errorCode;
}
public String getErrorCode(){
return this.errorCode;
}
}
Now immagine the next scenario, the code is way too long to paste here:
1 I got a Presentation class made in Swing in Presentation package
2 In package calculations I made simple operations with few numbers from received database fields
3 In package connections I got the database connections
Trouble comes here:
-In presentation layer I catch all errors, like this:
try {
//here is a method called updateCombo() wich throws:
//throw new MyException(e.getMessage(),"ERROR_UPDATING_COMBO_BOX");
} catch (MyException ex) {
try {
//Here we process error code, if error is not defined, uses default errors.
processCode(ex);
} catch (MyException ex1) {
Logger.getLogger(Presentacion.class.getName()).log(Level.SEVERE, null, ex1);
}
}
processCode is a simple list with cases, like this:
private void processCode(MyException e) throws MyException {
switch (e.getErrorCode()) {
case "ERROR_UPDATING_COMBO_BOX":
lblErrorText.setText("Error updating combo.");
throw e;
case "ERROR_SELECTING_PRIMARY_KEY":
lblErrorText.setText("Error selecting PK");
throw e;
case "ERROR_OPENING_CONNECTION":
lblErrorText.setText("Error opening connection.");
throw e;
default:
lblErrorText.setText("Excepcion not defined: "+ e.getMessage());
e.printStackTrace();
}
This is the scenario, the connection fails in 3rd package and leads to this:
throw new MyException(e.getMessage(),"ERROR_OPENING_CONNECTION");
As I said, the error is thrown to the upper layer with throws clause in method header, this beeing 2nd package.
2nd package also throws a new exception to Presentation, because of failing connection:
throw new MyException(e.getMessage(),"ERROR_SELECTING_PRIMARY_KEY");
Presentation methods also throw this exception becase 2nd layer failed:
throw new MyException(e.getMessage(),"ERROR_UPDATING_COMBO_BOX");
The main problem:
Using debug i found out that the program does what it has to do. It gets to the connection layer and does this successfully:
throw new MyException(e.getMessage(),"ERROR_OPENING_CONNECTION");
But, in 2nd layer, calculations, if connection fails it throws a new exception:
throw new MyException(e.getMessage(),"ERROR_SELECTING_PRIMARY_KEY");
This is the problem:
throw new
throwing new exception overrides ERROR_OPENING_CONNECTION with ERROR_SELECTING_PRIMARY_KEY. When it gets to presentation due to its "throw new" overrides ERROR_SELECTING_PRIMARY_KEY with ERROR_UPDATING_COMBO_BOX, resulting in the final error shown in the screen:
lblErrorText.setText("Error updating combo.");
Is there any way to return to presentation once first error is caught without overriding by next errors?
Maybe I misunderstood the concept but I want to catch all possible errors because:
-If connection is OK but method in 2nd layer fails it should throw ERROR_SELECTING_PRIMARY_KEY.
-If 2nd layer (calculations) does it OK but there is error in presentation it should lead to ERROR_UPDATING_COMBO_BOX.
You can use e.getCause() which will return a Throwable and check if this cause belongs to MyException. In case it is, you can check the e.getCause() again recursively until you obtain the deepest error code in the stacktrace and perform the validation for this exception.
Here's an example:
public MyException getDeepestException(MyException e) {
Throwable t = e.getCause();
if (t instanceof MyException) {
return getDeepestException((MyException)t);
}
return e;
}
As pointed out by #RealSkeptic, in order to use this approach, you will need to add an additional constructor to your custom exception:
public MyException(String message, Throwable cause, String errorCode){
super(message, cause);
this.errorCode = errorCode;
}
And when throwing your exception, call the proper constructor:
try {
//...
} catch (SomeException e) {
throw new MyException(<a proper message should be here>, e, "ERROR_SELECTING_PRIMARY_KEY");
}
If I understand you correctly, if the exception caught by one package happens to be a MyException, you want the original MyException to be passed up, otherwise (if the exception is some other type of Exception) you want to create a new MyException.
In this case, you should have two catch clauses.
try {
// Whatever you do in the try clause
} catch ( MyException myEx ) {
throw myEx;
} catch ( Exception e ) {
throw new MyException(e.getMessage(),"ERROR_SELECTING_PRIMARY_KEY");
}
Suppose i have two triggers and both raise two different errors in the database.
When i try to insert a new entity and catch the persistance exception, how can i discriminate between those two errors? I mean something like this:
try {
entityManager.getTransaction().begin();
entityManager.persist(entity);
entityManager.getTransaction().commit();
} catch (EntityExistsException exception) {
//...
} catch (PersistenceException exception) {
if(ERROR_FROM_TRIGGER_ONE) {
//do something about it
} else if(ERROR_FROM_TRIGGER_TWO) {
//do something about it
}
}
JPA uses JDBC API as low level and from side of jdbc driver there is no difference between error in incorrect query syntax or broken trigger. So generally you cant implement such check.
But some database vendors (Oracle for example) provide unique error number in message when exception occurs, which can be used to identify real problem such as broken trigger.
Isn't the first error thrown a EJBTransactionRollBack? If not just catch a general error, siphon down to the root cause and then handle it appropriately
catch (Exception e) {
while(e.getCause() != null) {
e = e.getCause();
}
if(e instanceof PersistenceException) {
//do something
} else if (e instanceof EntityExistsException) {
//do something else
}
}
I have a managed stateless session bean with injected EntityManager em.
What I am trying to do is to have a database table with unique column. Then I run some algorithm which is trying to insert an entity. If entity exists however it will update it or skip it.
I would like to have something like this:
try {
em.persist(cd);
em.flush();
} catch (PersistenceException e) {
// Check if the exception is DatabaseException and ConstraintViolation
// Update instead or skip it
}
Problem is that I am able to catch only PersistenceException. DatabaseException is not catched. It is sad because only DatabaseException has method called getDatabaseErrorCode() I would like to use to check duplicate entry. I dont understand it because PersistenceException.getCause() returns DatabaseException.
So my question is: How do I catch DatabaseException and check the MySQL error code?
Thank you for any ideas and experiences with this.
I have a suggestion which is I use in my application. We can retrieve the SQLException from PersistenceException. After that, try to get sql error code for SQLException. If your requirement is to get the sql error code, your can follow my example;
public void insert(Group group) throws DAOException {
try {
//your operation
em.flush();
logger.debug("insert() method has been successfully finisehd.");
} catch (PersistenceException pe) {
String sqlErroCode = getErrorCode(pe);
// do your operation based on sql errocode
}
}
protected String getErrorCode(RuntimeException e) {
Throwable throwable = e;
while (throwable != null && !(throwable instanceof SQLException)) {
throwable = throwable.getCause();
}
if (throwable instanceof SQLException) {
Properties properties = --> load sql error code form configuration file.
SQLException sqlex = (SQLException) throwable;
String errorCode = properties.getProperty(sqlex.getErrorCode() + "");
return errorCode;
}
return "NONE";
}
Example error code configuration of mysql
mysql_error_code.properties
#MySQL Database
1062=DUPLICATE_KEY_FOUND
1216=CHILD_RECORD_FOUND
1217=PARENT_RECORD_NOT_FOUND
1048=NULL_VALUE_FOUND
1205=RECORD_HAS_BEEN_LOCKED
I need to extract data from a DB2 table, run some processing on each returned row and output to a flat file. I'm using iBatis but found that using the queryForList I started getting out of memory errors, I'll be looking at 100k+ rows of data increasing.
I've looked at using queryWithRowHandler instead but the iBatis RowHandler interface doesn't throw an exception from its handleRow function so if it gets an error I can't properly report it back and stop iterating the rest of the data. It looks like I can throw a RuntimeException but that doesn't strike me as a neat way of doing things.
I'd like to be able to stop processing while throwing a meaningful Exception indicating whether the error occurred on the data manipulation, the file access or whatever.
Has anyone had experience with this approach or have an alternative solution using iBatis. I know I could look to do this without iBatis, just using JDBC, but as iBatis is used for all other DB access in my app I'd like to avail of this architecture if possible.
1) Create your own RowHandler interface with checked Exceptions in signature:
public interface MySpecialRowHandler {
public void handleRow(Object row)
throws DataException, FileException, WhateverException;
}
2) Inherit (or even better, delegate ) from SqlMapDaoTemplate to add a new method that will manage your own handler with the same Exceptions in signature:
public class MySpecialTemplate extends SqlMapDaoTemplate {
...
public void queryWithRowHandler(String id,
final MySpecialRowHandler myRowHandler
) throws DataException, FileException, WhateverException {
// "holder" will hold the exception thrown by your special rowHandler
// both "holder" and "myRowHandler" need to be declared as "final"
final Set<Exception> holder = new HashSet<Exception>();
this.queryWithRowHandler(id,new RowHandler() {
public void handleRow(Object row) {
try {
// your own row handler is executed in IBatis row handler
myRowHandler.handleRow(row);
} catch (Exception e) {
holder.add(e);
}
}
});
// if an exception was thrown, rethrow it.
if (!holder.isEmpty()) {
Exception e = holder.iterator().next();
if (e instanceof DataException) throw (DataException)e;
if (e instanceof FileException) throw (FileException)e;
if (e instanceof WhateverException) throw (WhateverException)e;
// You'll need this, in case none of the above works
throw (RuntimeException)e;
}
}
}
3) Your business code will look like this:
// create your rowHandler
public class Db2RowHandler implements MySpecialRowHandler {
void handleRow(Object row) throws DataException, FileException, WhateverException {
// what you would have done in ibatis RowHandler, with your own exceptions
}
}
// use it.
MySpecialTemplate template = new MySpecialTemplate(daoManager);
try {
template.queryWithRowHandler("selectAllDb2", new Db2RowHandler());
} catch (DataException e) {
// ...
} catch (FileException e) {
...