I want to write my own Secure module library for web but i not solution somethings. Example; I have a class and have a method. Method have my custom annotation.
class example{
#Admin
public void go(){
syso("working");
}
}
When This method called , how can i trigger my annotation.
(Example; Hibernate Validators. We write hibernate annotation on method , it working only method called)
by the way my english is bad :)
Annotations are not "triggered"... you have to write code that looks for their presence and takes action.
The "code" can either be executed at runtime, but is more commonly executed at compile time using the Annotation Processing Tool to alter the source to inject extra, typically cross-cutting, code appropriate for the annotation.
Related
I'd like to learn if there are some rules / conditions that a Spring component is wrapped (proxied) by CGLIB. For example, take this case:
#Component
public class TestComponent {
}
#Service
//#Transactional(rollbackFor = Throwable.class)
public class ProcessComponent {
#Autowired
private TestComponent testComponent;
public void doSomething(int key) {
// try to debug "testComponent" instance here ...
}
}
If we let it like this and debug the testComponent field inside the method, then we'll see that it's not wrapped by CGLIB.
Now if we uncomment the #Transactional annotation and debug, we'll find that the instance is wrapped: it's of type ProcessComponent$$EnhancerByCGLIB$$14456 or something like that. It's clearly because Spring needs to create a proxy class to handle the transaction support.
But I'm wondering, is there any way that we can detect how and when does this wrapping happen ? For example, some specific locations in Spring's source code to debug into to find more information; or some documentations on the rules of how they decide to create a proxy.
For your information, I need to know about this because I'm facing a situation where some component (not #Transactional, above example is just for demonstrating purpose) in my application suddenly becomes proxied (I found a revision a bit in the past where it is not). The most important issue is that this'll affect such components that also contain public final methods and another issue (also of importance) is that there must have been some unexpected changes in the design / structure of classes. For these kind of issues, of course we must try to find out what happened / who did the change that led to this etc...
One note is that we have just upgraded our application from Spring Boot 2.1.0RELEASE to 2.1.10RELEASE. And checking the code revision by revision up till now is not feasible, because there have been quite a lot of commits.
Any kind of help would be appreciated, thanks in advance.
You could debug into org.springframework.aop.framework.autoproxy.AbstractAdvisorAutoProxyCreator.getAdvicesAndAdvisorsForBean(Class, String, TargetSource).
If any advisor is found, the bean will be proxied.
If you use a #Lookup method injection it will also proxy the component class.
In a Play (now 2.6) project, both annotation based validation (for example, #Constraints.Required) as well as validation via the Validatable (plus #Validate) are used. This worked fine until now, but as of play 2.6 both are now executed simultaneously per default.
This leads to the unfortunate effect, that the validate method (from Validatable) can now no longer be sure that all the other validations have already finished successfully, so we must add various null-checks, etc. in validate on fields that are already marked not-null per annotation.
Is there a way in Play 2.6 to get the behavior, that validate() is only called after all annotation based validation rules have finished successfully?
From https://www.playframework.com/documentation/2.6.x/Migration26#form-changes:
Be aware: The “old” validate method was invoked only after all other constraints were successful before. By default class-level constraints however are called simultaneously with any other constraint annotations - no matter if they passed or failed. To (also) define an order between the constraints you can now use constraint groups.
This is how that looks:
import javax.validation.GroupSequence;
import javax.validation.groups.Default;
#GroupSequence({ Default.class, SignUpCheck.class, LoginCheck.class })
public interface OrderedChecks { }
See https://www.playframework.com/documentation/2.6.x/JavaForms#advanced-validation for details.
Hi i try to create new annotation with action:
My annotation
#Retention(RetentionPolicy.RUNTIME)
public #interface myCustomAnnotations{
String errorMessage();
}
My fucntion
#myCustomAnnotations(errorMessage = "error message")
public void sendIssue() {
}
now i want to log the error message if someone call this method
I search for ever for solution, so if you can help me, it will be awesome!!!
If you don't want to use any existed solutions for logging you can take a look at AspectJ.
With AspectJ you will be able to write an aspect which will be called after, before or around methods specified by your annotation. There are a lot of details, so it's better to see here for example http://www.yegor256.com/2014/06/01/aop-aspectj-java-method-logging.html
This won't be done simply by declaring custom annotation on methods. Annotations won't trigger automatically. If it were normal annotations then it could be triggered/executed by Annotation Processor at compile time. In your case, as you're using #Retention(RetentionPolicy.RUNTIME) that means annotation needs to be parsed at runtime manually. Have a good read on this answer. Using the reflection, this is the way you can log your message.
My advice is not getting called for method getPOInvoice method from this method, but if I call it separately then advice is getting called and getPOInvoice and getPOInvoice is declared in same class.
public StreamingOutput getPDFStream(String invoiceId, String versionNumber) throws TugnavException {
final POInvoice poInv = getPOInvoice(invoiceId, versionNumber);
...
}
My advice is:
#AfterReturning(value="execution(* com.tugnav.service.facade.*.get*(..))", returning="doc")
public TugnavBaseDocument setupTimeCreatedString(TugnavBaseDocument doc){
...
}
If I call this method from another class then advice is getting called.
Why is it not getting called internally?
You need to read the documentation about proxies here.
Basically, because of the way proxies are generated, a instance method call within another instance method will not trigger an aspect (or proxy behavior).
Given:
class FooBar {
// advised method
public void foo() {
bar();
}
// would've been advised
public void bar() {
// ... do something
}
}
Say an instance of FooBar was proxied, a call to foo() will trigger the aspect because from outside you have a reference to the proxy object. When you call bar() internally, you have access to this (equivalent to this.bar()) which is a reference to the target instance, the actual object, so there is no added behavior.
There are a few ways to solve this problem, but probably not the way you want. See the answer to this question.
AOP would not normally work this way.
AOP is added as an aspect through Proxies, to compiled class, so it does not have any effect on the internal class invocations.
When it's an outer cal, you are actually referring to some Proxy which intercepts your call and triggers appropriate AOP calls.
When it's internal cal, inside the class, it is a direct call, without any Proxy involved.
As a solution you can do following:
Refactore service you are using, to exclude internal calls
Alter bytecode on Class loading, with your AOP functionality :)
If you want that your advice is called for getPOInvoice method when you are invoking from method getPDFStream(..), both in the same bean, you can't use a proxy-based AOP, like Spring use by default. Instead you should use load time weaving(LTW) with AspectJ.
http://static.springsource.org/spring/docs/3.2.2.RELEASE/spring-framework-reference/html/aop.html#aop-aj-ltw
I am working on webservices with spring DI. I am using the Eclipse IDE and have written a validator. I am testing the code in SoapUI. The question is I have a validator class UpdateRequestValidator which is extending another interface IValidator which has a method validate() and therefore the UpdateRequestValidator class is implementing the validate() method. This method is being called from an endpoint adadpter class. I am using an annotation #Override before validate() method in UpdateRequestValidator class. The validator is working fine with or without the #Override annotation.
Now the question is that what role is this annotation playing here, and is there any side-effect if i remove it because the code and validator is working perfectly well after removing it.
The #Override is just a "tag" telling the compiler that that metode overrides another methode.
Removing #Override would not change anything but if you remove the validate() methode in the parent class and still have the override notation you'll get a compile time error