I recently change to Spring-boot for development. Can anyone help me to understand better in Spring?
In laravel, there is dd() function, which is useful to dump variable value. The picture below show the result of dd(). Can I achieve same thing in Spring?
There is no such behavior, but you can make it similar.
Create an exception and include the result data you want to see.
Register the exception in the #ExceptionHandler.
If you want to be global, create an #ExceptionHandler in #ControllerAdvice.
Related
I was going through a video tutorial where the instructor focussed on handling any Runtime exceptions through the #ExceptionHandler in Spring.
What is the difference between the approach of handling it via try catch or via #ExceptionHandler?Which is the better approach and when to use either of them?
bro we use #ExceptionHandler above a method which we want to handle all the exception that occurs in your code while in case of try and catch you just handle the exception where it occurs only. But if we want that every exception that occurs in our program to be handled by one method, so that it will look clean and professional, we use #ExceptionHandler. Here is the link that might help you understand this.
https://howtodoinjava.com/spring-core/spring-exceptionhandler-annotation/
Let me know if this helps.
I am trying to define a custom renderable exception exactly as shown in the documentation example but when I throw my custom exception, the render and report functions inside the exception class are totally ignored.
I am aware that I can handle my custom exceptions inside the exception handler but this is something I would prefer to do inside the exception class.
Is it something more that I should do to register the exception in order for the render and report functions to be called? What am I missing?
Thank you!
EDIT: I'm using Lumen 5.7.
Turns out that this feature is not available in Lumen framework, only in Laravel. Lumen's documentation is very misleading as it lets one to imagine that the features concerning errors are common in Laravel and Lumen.
In any case, currently in Lumen only exception handling inside the exception handler is available.
Looks like it feature will be added in one of next 5.8.* releases.
PR: https://github.com/laravel/lumen-framework/pull/958
Hi I'm looking at a Spring Boot application and I'm trying to understand everything that it does. It uses Camel and I am not finding the documentation for Camel especially helpful. Basically I might have a fundamental misunderstanding that a Camel SME would really be able to help with. The piece of code I am looking at is ...
public class SBJobScheduler extends RouteBuilder {
from("direct:alertBatch")
.log(LoggingLevel.INFO, SB_LOGGER, "#The Scheduler is going to start ::sbJob:: batch.# ")
.to("spring-batch:sbJob")
.end();
So I am trying to find how in the heck can I know where "alertBatch" is. I don't see any beans by this name, but maybe I'm missing it. I just want to know what is this value and I'm using the debugger and it doesn't tell me.
alertBatch is the name that uniquely identifies this endpoint. From Camel documentation:
The direct: component provides direct, synchronous invocation of any consumers when a producer sends a message exchange. This endpoint can be used to connect existing routes in the same camel context.
URI format
direct:someName[?options]
Where someName can be any string that uniquely identifies the endpoint.
You can read more about this component here
I suggest that you create a public constant in the same class that creates the route, this way, when you need to call this route, you just refer the created constant. This way you turn your code clean, more readable and allows the call hierarchy functionality from IDEs.
I am creating a Spring Boot web application, but i am confused why people use Global Exception handlers(#ControllerAdvice) when there is Error Page Registrar which is neater and more explicit. Please can someone explain more and is it possible to call an Error page registrar from a global Exception Handler Class( class annoted with #ControllerAdvice, with an #Exceptionhandler method).
As Brian answer, I think you can do this. I got a sample to prove this one in here if you still need to refer: https://github.com/kennytai/SampleSpringbootExceptionHandler
At this sample, I use the #ControllerAdvice in class GlobalExceptionHandler to manage all exceptions from TestController.
Hope this help.
It's actually the opposite the error pages mechanism in Spring Boot is the global one; it's catching all exceptions unhandled by the application. Note that in a Servlet environment, it's even dispatching the request back into the container on the /error path.
You're right though, this mechanism is really powerful and you can achieve a lot with it.
The other exception handling mechanisms you're mentioning are provided by Spring MVC itself. They're executed during the handling of the request and don't require an additional dispatch to the container. In some cases, they can be more limited because they offer less features than the full ErrorController (which is an MVC Controller).
But unlike error pages, you can configure those to focus on only specific errors:
You can declare an #ExceptionHandler within a Controller and specify the type of Exception you'd like to handle
You can configure the #ControllerAdvice annotation to only apply to specific packages, Controllers extending a specific interface or annotated with a specific annotation
I'd say the latter are quite useful when you want to deal with business exceptions at the controller level. You can do that with error pages, but you might end up with a single error controller dealing with too many things.
I provide a highly customisable application to my clients which is working totally by itself. But If one my client wants to overwrite any Controller, I want to replace my implementation by theirs. However just overwriting the controller causes an ambiguous definition of mappings.
I have been using Component Scanning to load beans.
The potential solutions came to my mind are:
Using component scanner with excluding by a custom filter? (This seems not so easy)
Using a xxxxPostProcessor to remove some beans? (How?)
Any help?
If I got your Question properly,
You can differ implementation by changing URL to particular Implementation name
Say Telecom is interface and AirtelImpl and RelianceImpl are Controllers then
Your request mapping
#RequestMapping(value= "/airtel/doBilling")
#RequestMapping(value= "/reliance/doBilling")
In this way, Implementation flow will differ.
I have followed these steps:
Created a custom annotation: #Devoted
Created a custom ImportBeanDefinitionRegistrar. Iterated already registered bean definitions to find out `#Devoted #Controller's and removed them.
Based on a request I will provide implementation details.