How to get class level annotation from ProceedingJoinPoint - java

I am trying to implement an interceptor with #Aspect. I need to get class level annotation
Here is my interceptor
#Aspect
public class MyInterceptor {
#Around("execution(* com.test.example..*(..))")
public Object intercept(ProceedingJoinPoint pjp) throws Throwable {
Object result;
try {
result = pjp.proceed();
} catch (Throwable e) {
throw e;
}
return result;
}
}
and here is my annotation
#Retention(RetentionPolicy.RUNTIME)
public #interface MyAnnotation {
String reason();
}
and here is the class
#MyAnnotation(reason="yes")
public class SomeClassImpl implements SomeClass {
}
In interceptor I need to get the annotation and the value assigned to reason attribute.

Interceptor class to get value of the annotation marked at class level
#Aspect
#Component
public class MyInterceptor {
#Around("#target(annotation)")
public Object intercept(ProceedingJoinPoint joinPoint, MyAnnotation annotation) throws Throwable {
System.out.println(" called with '" + annotation.reason() + "'");
return joinPoint.proceed();
}
}

Related

Custom annotation does not work in method

I created annotation to check permissions on the APIs. Annotation worked when placed in class or method. But when I use it for both class and method at the same time, the annotation placed on the method is ignored
Here is an example:
#RestController
#RequestMapping("/user")
#CustomAnnotation(permission="manageUser")
public class UserController {
#CustomAnnotation(permission="updateUser")
#PutMapping("/{id}")
public UserDto getUser(HttpServletRequest request) {
...
}
}
Now #CustomAnnotation(permission="updateUser") in the getUser() method will be ignored and only execute annation in class UserController
My custom code
#Target(value = {ElementType.METHOD, ElementType.TYPE})
#Retention(value = RetentionPolicy.RUNTIME)
#Inherited
#Documented
public #interface CustomAuthorize {
public String permission() default "";
public String attribute() default "";
}
#Aspect
#Component
public class CustomAnnotationAspect {
#Autowired
CustomAuthorizationImpl authBean;
#Pointcut("#annotation(customAuthorize) || #within(customAuthorize)")
public void pointcutForCustomAnnotation(CustomAuthorize customAuthorize) {
// Do nothing.
}
#Around("pointcutForCustomAnnotation(customAuthorize)")
public Object customAspect(ProceedingJoinPoint pjp, CustomAuthorize customAuthorize) throws Throwable {
if (Objects.isNull(customAuthorize)) {
System.out.println("Call from method");
// Check permission
return pjp.proceed();
}
System.out.println("Call from class");
ExpressionParser elParser = new SpelExpressionParser();
if (!customAuthorize.permission().isBlank()) {
// check permission
}
return pjp.proceed();
}
}

How to Intercept #transactional arguments if #transactional applied at class level

I want to capture the argument of #transactional if it is applied at class level.
for e.g. if #transactional applied at method level like :-
class A {
#transactional(readOnly= true)
public void someMethod(){
// some code...
}
}
then I am able to Intercept and capture the formal argument i.e. readOnly with this code like :-
#Aspect
#Component
#Order(0)
public class ReadOnlyRouteInterceptor {
private static final Logger logger = LoggerFactory.getLogger(ReadOnlyRouteInterceptor.class);
#Around("#annotation(transactional)")
public Object proceed(ProceedingJoinPoint proceedingJoinPoint, Transactional transactional) {
if (transactional.readOnly())
//do something
}
However the above code will not work if #transactional applied at class level as :-
#transactional(readOnly= true)
class A {
public void someMethod(){
// some code...
}
}
Now in order to Intercept the #transactional annotation which is applied at class level I have following code :-
#Pointcut("#within(org.springframework.transaction.annotation.Transactional *)")
public void beanAnnotatedWithTransactional() {}
#Pointcut("execution(public * *(..))")
public void publicMethod() {}
#Pointcut("publicMethod() && beanAnnotatedWithTransactional()")
public void publicMethodInsideAClassMarkedWithATransactional() {}
My actual problem here is I am unable to check the value of readOnly flag if #transactional is applied at class level.
For type level annotation :
#Around("#within(transactional)")
public Object myMethod(ProceedingJoinPoint pjp, Transactional transactional) throws Throwable {
boolean readOnly = transactional.readOnly();
...
return pjp.proceed();
}
For method level annotation:
#Around("execution(public * *(..)) && #annotation(org.springframework.transaction.annotation.Transactional)")
public Object myMethod(ProceedingJoinPoint pjp) throws Throwable {
MethodSignature signature = (MethodSignature) pjp.getSignature();
Method method = signature.getMethod();
Transactional annotation = method.getAnnotation(org.springframework.transaction.annotation.Transactional.class);
boolean value = annotation. readOnly();
...
return pjp.proceed();
}
Another (cleaner) option for method level :
#Around("#annotation(transactional)")
public Object myMethod(ProceedingJoinPoint pjp, Transactional transactional) throws Throwable {
}
or
With more control over tager :
#Around("execution(#org.springframework.transaction.annotation.Transactional public * *(..)) && #annotation("transactional")
public Object myMethod(ProceedingJoinPoint pjp, Transactional transactional) throws Throwable {
}
You may use the TransactionSynchronizationManager to get reference to the transaction details.
Following code provides the readonly details of the current active transaction.
import org.springframework.transaction.support.TransactionSynchronizationManager;
#Component
#Aspect
public class TestTransactionalAspect {
#Pointcut("#within(org.springframework.transaction.annotation.Transactional)")
public void beanAnnotatedWithTransactional() {}
#Pointcut("execution(public * *(..))")
public void publicMethod() {}
#Around("publicMethod() && beanAnnotatedWithTransactional()")
public void publicMethodInsideAClassMarkedWithATransactional(ProceedingJoinPoint pjp) {
try {
System.out.println("Intercepted "+pjp.toShortString());
if (TransactionSynchronizationManager.isActualTransactionActive()) {
System.out.println("Is transaction readonly : "+TransactionSynchronizationManager.isCurrentTransactionReadOnly());
}
pjp.proceed();
} catch (Throwable e) {
e.printStackTrace();
}
}
}
Update:
Assuming this is not a Spring Boot project , #EnableTransactionManagement is mandatory for your spring application to work with transactions. Data will get persisted to database without transactions as well.
#EnableTransactionManagement annotation has to be used on
#Configuration classes.
Following is a sample code to enable transaction management in spring
#Configuration
#EnableTransactionManagement
public class AppConfig {
#Bean
public FooRepository fooRepository() {
// configure and return a class having #Transactional methods
return new JdbcFooRepository(dataSource());
}
#Bean
public DataSource dataSource() {
// configure and return the necessary JDBC DataSource
}
#Bean
public PlatformTransactionManager txManager() {
return new DataSourceTransactionManager(dataSource());
}
}
Based on the answers above I tried with the following code it is very simple.
/**
* This Aspect advice will be called only if transactional applied at method level
*/
#Around("#annotation(transactional)")
public Object proceedWithMethodLevelAnnotation(ProceedingJoinPoint proceedingJoinPoint,
Transactional transactional) {
if( transactional.readOnly() ) {
//do something
}
/**
* This Aspect advice will be called only if transactional annotation applied at class level
*/
#Around("#within(transactional)")
public Object proceedWithClassLevelAnnotation(ProceedingJoinPoint proceedingJoinPoint,
Transactional transactional)
if( transactional.readOnly() ) {
//do something
}
}

#AroundInvoke does not work when attribute supplied

I have following classes.
#Inherited
#InterceptorBinding
#Retention(RUNTIME)
#Target({ TYPE, METHOD })
public #interface MyLogger {
public boolean skipParams() default true;
}
#MyLogger
#Interceptor
public class MyInterceptor {
#AroundInvoke
public Object logMethod(InvocationContext joinPoint) throws Exception {
// Some log statements here
}
}
public class MyClass {
#MyLogger()
void test1(){
// some code
}
#MyLogger(skipParams = true)
void test2(){
// some code
}
#MyLogger(skipParams = false)
void test3(){
// some code
}
}
#AroundInvoke does not work when attribute supplied.
logMethod() gets called for test1(), but not for test2() and test3().

pass result of annotation work to annotated method

Annotation:
#Target(ElementType.METHOD)
#Retention(RetentionPolicy.RUNTIME)
public #interface Multipart {
Class acceptClass();
}
Annotated method:
#Multipart (acceptClass = SomeClass.class)
public void someMethod(SomeClass a){
//do stuff..
}
MultipartAspect:
#Aspect
public class MultipartAspect {
#Autowired(required=true)
private HttpServletRequest request;
#Pointcut(value = "#annotation(Multipart)", argNames = "multipart")
public void before(JoinPoint jp, Multipart multipart) {}
#Before("before()")
public SomeClass doStuffBeforeThing() {
SomeClass sc = new SomeClass(); //object of passed class
//do something..
return sc; //return this to annotated method(somemethod)
}
}
I want before method works execute annotation, create object of passed class(SomeClass) and the pass object of this class to annotated method. Could I do this?
You should use #Around advice instead of #Before.

CDI-Interceptor: Get param from intercepted Method

I have a interface
#InterceptorBinding
#Retention(RetentionPolicy.RUNTIME)
#Target({ ElementType.METHOD, ElementType.TYPE })
public #interface LoggingInterceptorBinding {
}
and a class:
#LoggingInterceptorBinding
#Interceptor
public class LoggingInterceptor implements Serializable {
#AroundInvoke
public Object onMethodCall(InvocationContext context) throws Exception {
try {
System.out.println("Log before Method");
return context.proceed();
} finally {
System.out.println("Log after Method");
}
}
and a annotated method:
#LoggingInterceptorBinding
public void sayHello(String name)
Is it possible to get the parameter "name" from sayHello in the interceptors "onMethodCalls"-method?
The InvocationContext interface has a getParameters() method that
Returns the parameter values that will be passed to the method of the
target class. If setParameters() has been called, getParameters()
returns the values to which the parameters have been set.

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