My project use struts2 and spring, I have some service method to deal with business logic.
e.g
public void aMethod(){
if(!validate()) return;
process();
}
private boolean validate() {
return validateA()&&validateB()&&validateB();
}
But when I call in action (Controller) layer, I found that no error message show in page.
So I change my method to blow:
public String validate() {
if (!validateA()) {
return "error.msg.A";
} else if (!validateB()) {
return "error.msg.B";
}
return null;
}
Action layer call validate method directly and get the error message to process i18n related work.
My question is that:
Any best practices for i18n in service layer?
My validate method is very strange in service layer after my change. Any good way to show i18n error message and also keep service layer clear?
What I usually do is to have custom exceptions that have a key and message attributes.
The key is the i18n key for that error, and the message is a default message.
So in the service:
try{
some code
}
catch(SomeException e){
handleAppropriatly;
throw new MyCustomException("error.foo","Some default message",e);
}
The action catches the message and adds it to the correct place appropriately (addActionError/addFieldError) using the key, allowing you to take advantage of any internationalisation you have.
Related
I am implementing payments for my website using the API of an external service (ie. the service of the payment provider).
Let's say the user clicks 'BUY', and then we go to my controller which says something along the lines of:
public function buyFunction() {
$result = $this->ExternalService->pay();
if ($result->success == true) {
return 'We are happy';
}
}
I have also created the aforementioned externalService which has the pay() method:
class ExternalService {
public function pay() {
response = //Do stuff with Guzzle to call the API to make the payment
return response;
}
}
Now, sometimes things go wrong.
Let's say the API returns an error - which means that it throws a GuzzleException - how do I handle that?
Ideally, if there is an error, I would like to log it and redirect the user to a page and tell him that something went wrong.
What I've tried
I have tried using a try/catch statement within the pay() function and using abort(500) but this doesn't allow me to redirect to the page I want to.
I have tried using a try/catch statement within the pay() function and using return redirect('/mypage') but this just returns a Redirect object to the controller, which then fails when it tries to call result->success
I have tried using number 2 but also adding a try/catch block to the controller method, but nothing changed.
In the end, I have found two solutions. In both, I use a try/catch block inside the pay() method. Then I either return 0; and check in the controller if (result == 0) or I use abort( redirect('/mypage') ); inside the try/catch block of the pay() method.
What is the right way to handle this?
How to use the try/catch blocks?
In my experience, avoid handling exceptions let them pass through and handle them accordingly with try catches. This is the most pragmatic approach. Alternatively you will end up checking result is correct in weird places, eg. if ($result) {...}. Just assume it went good, except if the exception is thrown. Bonus: never do Pokemon catches with Exception $e unless you specifically needs it!
class ExternalService {
public function pay() {
try {
response = $client->get(...);
} catch (BadResponseException $exception) {
Log::warning('This should not happen check payment api: ' . $exception->getMessage());
throw new PaymentException('Payment did not go through');
}
return response;
}
}
Assuming you have your own Exception.
class PaymentException extends HttpException
{
public function __construct(?\Exception $previous = null)
{
parent::__construct(Response::HTTP_BAD_REQUEST, 'Unexpected error processing the payment', $previous);
}
}
This enables you to handle the flow in a controller, where it would make sense to handle the redirect. Sometimes if the exception is very integral or common to the web app, it can also be handled by the exception handler instead.
class PaymentController {
public function pay(PaymentService $service) {
try {
$payment = $service->buyFunction();
} catch (PaymentException $exception) {
return redirect()->route('app.payment.error');
}
return view('app.payment.success', compact('payment'));
}
}
I want to use spring aspect for my crosscutting process like a before or after handler in my process execution lifetime.
For example
What I want before a method I want to execute my handler and due to its response I want to finialize myprocess and return custom response.
In example in stop condition should I throw custom exception to stop process that time how can I handle my return response ,I want to give meaningfull object at the client.What is the best way to do that?
#Before
MyHandler()
{
bool stop=checkvalue();
if(stop==false)
continue...
else
{
//break all process
and return custom response to client
//throw exception but meaningfullresponse??
}
}
Instead of using Before advice, I would use Around advice to wrap the method invocation and call checkValue() on beforehand:
#Around("someJoinpoint")
public Object MyHandler(ProceedingJoinPoint pjp) {
if (!checkvalue()) {
return pjp.proceed();
} else {
return someCustomResponseToClient();
}
}
More info on Around advice can be found in the Spring documentation.
I have got a domain class with some custom validators like the following:
class Domain {
String attribute1
OtherDomain attribute2
static constraints = {
attribute2 nullable: true, validator: {OtherDomain od, Domain d ->
if (od) {
log.debug "entering validation"
// certain validation here
}
}
}
For updating I have got a simple action in the corresponding DomainController:
#Transactional
def update(Domain domainInstance) {
log.debug "entering update()"
// rest of update
}
I'm wondering why in my debuglog I get the debug messages in the following order:
entering validation
entering update()
The problem is that the validation fails at this point (StackOverflowError). I know the reason for this error and I know what to do to circumvent this error (doing so within update action). However, I don't know why there is a validation before the programme even gets into the update() action. And I don't know how to prevent a validation at this point.
Do you have any suggestions?
The reason you see the "entering validation" message before "entering update()" is because you have declared a command object of type Domain. This means that Grails will bind any request parameters to domainInstance and then call validate() on it, before the action is executed. This allows you to write code like this:
#Transactional
def update(Domain domainInstance) {
// at this point request params have been bound and validate() has
// been executed, so any validation errors will be available in
// domainInstance.errors
if (domainInstance.hasErrors() {
// do something
}
log.debug "entering update()"
}
I have a CRM plugin registered on Create (synchronous, post-operation) of a custom entity that performs some actions, and I want the Create operation to succeed in spite of errors in the plugin. For performance reasons, I also want the plugin to fire immediately when a record is created, so making the plugin asynchronous is undesirable. I've implemented this by doing something like the following:
public class FooPlugin : IPlugin
{
public FooPlugin(string unsecureInfo, string secureInfo) { }
public void Execute(IServiceProvider serviceProvider)
{
try
{
// Boilerplate
var context = (IPluginExecutionContext) serviceProvider.GetService(typeof (IPluginExecutionContext));
var serviceFactory = (IOrganizationServiceFactory) serviceProvider.GetService(typeof (IOrganizationServiceFactory));
IOrganizationService service = serviceFactory.CreateOrganizationService(context.UserId);
// Additional validation omitted
var targetEntity = (Entity) context.InputParameters["Target"];
UpdateFrobber(service, (EntityReference)targetEntity["new_frobberid"]);
CreateFollowUpFlibber(service, targetEntity);
CloseTheEntity(service, targetEntity);
}
catch (Exception ex)
{
// Send an email but do not re-throw the exception
// because we don't want a failure to roll-back the transaction.
try
{
SendEmailForException(ex, context);
}
catch { }
}
}
}
However, when an error occurs (e.g. in UpdateFrobber(...)), the service client receives this exception:
System.ServiceModel.FaultException`1[Microsoft.Xrm.Sdk.OrganizationServiceFault]:
There is no active transaction. This error is usually caused by custom plug-ins
that ignore errors from service calls and continue processing.
Server stack trace:
at System.ServiceModel.Channels.ServiceChannel.HandleReply(ProxyOperationRuntime operation, ref ProxyRpc rpc)
at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)
Exception rethrown at [0]:
at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(ref MessageData msgData, Int32 type)
at Microsoft.Xrm.Sdk.IOrganizationService.Create(Entity entity)
at Microsoft.Xrm.Sdk.Client.OrganizationServiceProxy.CreateCore(Entity entity)
at Microsoft.Xrm.Sdk.Client.OrganizationServiceProxy.Create(Entity entity)
at Microsoft.Xrm.Client.Services.OrganizationService.<>c__DisplayClassd.<Create>b__c(IOrganizationService s)
at Microsoft.Xrm.Client.Services.OrganizationService.InnerOrganizationService.UsingService(Func`2 action)
at Microsoft.Xrm.Client.Services.OrganizationService.Create(Entity entity)
at MyClientCode() in MyClientCode.cs: line 100
My guess is that this happens because UpdateFrobber(...) uses the IOrganizationService instance derived from the plugin, so any CRM service calls that it makes participate in the same transaction as the plugin, and if those "child" operations fail, it causes the entire transaction to rollback. Is this correct? Is there a "safe" way to ignore an error from a "child" operation in a synchronous plugin? Perhaps a way of instantiating an IOrganizationService instance that doesn't re-use the plugin's context?
In case it's relevant, we're running CRM 2013, on-premises.
You cannot ignore unhandled exceptions from child plugins when your plugin is participating in a database transaction.
However, when your plugin is operating On Premise in partial trusted mode, you can actually create a OrganizationServiceProxy instance of your own and use that to access CRM. Be sure you reference the server your plugin is executing on to avoid "double hop" problems.
If really needed, I would create an ExecuteMultipleRequest with ContinueOnError = true, for your email you could just check the ExecuteMultipleResponse...
But it looks a bit overkill.
You can catch exceptions if running in async mode. Be sure to verify your mode when catching the exception.
Sample Code:
try
{
ExecuteTransactionResponse response =
(ExecuteTransactionResponse)service.Execute(exMultReq);
}
catch (Exception ex)
{
errored = true;
if (context.Mode == 0) //0 sync, 1 Async.
throw new InvalidPluginExecutionException(
$"Execute Multiple Transaction
Failed.\n{ex.Message}\n{innermessage}", ex);
}
if(errored == true)
{
//Do more stuff to handle it, such as Log the failure.
}
It is not possible to do so for a synchronous plugin.
A more detailed summary, explaining the execution mode and use case can be found on my blog: https://helpfulbit.com/handling-exceptions-in-plugins/
Cheers.
Can someone give me a working example of an ExceptionHandler which extends ExceptionHandlerWrapper for both normal and ajax request. I don't want to use a filter. I want all my exception handling to be in one entry place for logging purpose.
In Omnifaces we have the FullAjaxExceptionHandler but only for ajax request. How can I refactor this class in order to take into account both types of request?
In order to render the error page inside my CustomExceptionHandler, I use inside a utility method such a statement which identify the type of request (normal or ajax)
if (context.getPartialViewContext().isAjaxRequest()) {
ViewHandler viewHandler = context.getApplication().getViewHandler();
UIViewRoot viewRoot = viewHandler.createView(context, errorPageLocation);
context.setViewRoot(viewRoot);
context.getPartialViewContext().setRenderAll(true);
context.renderResponse();
} else {
NavigationHandler nav = context.getApplication().getNavigationHandler();
nav.handleNavigation(context, null, errorPageLocation);
context.renderResponse();
}
By this way I can handle both request effectively in my CustomExceptionHandler
In the Wrapper you can use, if you want to detect the type of request:
context == null || !context.getPartialViewContext().isAjaxRequest()
Also recommend you to integrate the WrapperHandler with Deltaspike Exception Control
And finally a common way to redirect (working for both types of requests):
public static void redirect(FacesContext fc, String view) {
ExternalContext ec = fc.getExternalContext();
String path = ec.encodeResourceURL(fc.getApplication().getViewHandler().getActionURL(fc, view));
try {
ec.redirect(path);
} catch(Exception e) {
throw new RuntimeException();
}
}