I have the following interface:
public interface Performance {
public void perform();
}
Implemented by the following class:
#Component
public class Woodstock implements Performance {
public void perform() {
System.out.println("Woodstock.perform()");
}
}
The aspect I want to apply is this one:
#Aspect
public class Audience {
#Pointcut("execution(* concert.Performance.perform(..)) "
+ "&& bean('woodstock')"
)
public void performance() {}
#Around("performance()")
public void watchPerformance(ProceedingJoinPoint jp) {
try {
System.out.println("Taking seats");
jp.proceed();
System.out.println("CLAP CLAP CLAP!!!");
} catch (Throwable e) {
System.out.println("Demanding a refund");
}
}
}
The configuration file for the program is declaring the following beans:
#Bean
public Audience audience(){
return new Audience();
}
#Bean
public Performance woodstock(){
return new Woodstock();
}
And the test I'm running is this:
#Autowired
ApplicationContext context;
#Autowired
#Qualifier("woodstock")
Performance performance;
#Test
public void test(){
printBeanNames();
performance.perform();
}
Now, in the Audience class I specified in the annotation that I want to apply the aspect for the perform() method from the interface concert.Performance (execution(* concert.Performance.perform(..))) and I am explicitly limiting the application of the aspect to the bean whose name is "woodstock" (&& bean('woodstock')).
But when I run it I see that the aspect is not applied to the woodstock bean, although that bean is the one being used (it prints Woodstock.perform())
If instead of bean() I use !bean() then it does work, so it seems that it cannot consider that bean as the one named "woodstock".
Is there something wrong in the code above?
The special Spring AOP bean() pointcut works like bean(myBean) or bean(*Bean), there are no inline single or double quotes around the bean name according to the Spring AOP documentation (scroll down a little bit in this chapter).
Related
I'm trying to get some advice to execute.
When I use annotation without parameters its do execute but when the annotation includes parameters it's not.
#Aspect
class a{
#Pointcut("execution(#com.annotations.AnnotationName* *(..))")
void someMethod() {}
#Around("someMethod()")
public Object aroundSomeMethod(ProceedingJoinPoint pjp) throws Throwable
{
// some code
}
}
Annotation:
#Target(ElementType.METHOD)
#Retention(RetentionPolicy.RUNTIME)
public #interface AnnotationName
{
public String someString();
public boolean someBoolean();
}
The use of the annotation:
#AnnotationName(
someString= "string",
someBoolean = false
)
private void mycode()
{//code }
Following aspect code would advice a target method annotated with #AnnotationName
#Component
#Aspect
public class SomeMethodAspect {
#Pointcut("#annotation(annotationName) && within(so.qn69016852..*)")
private void someMethod(AnnotationName annotationName) {}
#Around("someMethod(annotationName)")
public Object aroundSomeMethod(ProceedingJoinPoint pjp,AnnotationName annotationName) throws Throwable
{
System.out.println(annotationName.someString());
System.out.println(annotationName.someBoolean());
return pjp.proceed();
}
}
Couple of corrections/observations .
Spring AOP cannot advice a private method of a Spring bean. The mycode() method should be in a bean and ideally public. ( Refer )
The Aspect should also be a spring bean. This can be achieved by annotating the aspect with #Component
Remember to limit the scope : https://docs.spring.io/spring-framework/docs/current/reference/html/core.html#writing-good-pointcuts
You may also go through this answer from #kriegaex to understand why an #annotation has a global scope.
Update :
The code shared by OP also works with modifying a typo ( a space between the AnnotationName and * in the pointcut expression ) . The observations shared earlier holds good here as well.
#Component
#Aspect
public class SomeMethodAspect {
#Pointcut("execution(#so.qn69016852.anno.AnnotationName * so.qn69016852..*.*(..))")
private void someMethod() {}
#Around("someMethod() && #annotation(annotationName)")
public Object aroundSomeMethod(ProceedingJoinPoint pjp,AnnotationName annotationName) throws Throwable
{
System.out.println(annotationName.someBoolean());
System.out.println(annotationName.someString());
return pjp.proceed();
}
}
I am working on one component to achieve audit using Spring AOP. I could use it for most of the service's methods. But found that with Mybatis mappers AOP point-cuts don't work.
Basically, Spring AOP only works with Spring-managed beans. But these mapper beans have been scanned using mybatis.spring.*.MapperScan and can be autowired in other Spring components.
Why can these beans not be scanned for Spring AOP? Any idea?
I can use AspectJ but was keen to find out how mybatis.spring.*.MapperScan works.
for example -
I have these configurations one for Mybatis mapper scan and other config for application specific configurations.
#Configuration
#MapperScan("com.test.mapper")
public class ProviderConfiguration {
#Bean
public SqlSessionFactory sqlSessionFactory(final DataSource src) throws Exception {
...
}
}
#Configuration
#EnableAspectJAutoProxy
public class MainConfiguration {
}
My Dao logic where i call mapper method -
#Component
public class TestDao {
//injecting mybatis mapper here
#Inject
private SaveTableData saveTableData;
public TableData save(TableData tableData) {
saveTableData.updateTableData(tableData);
}
}
I have registered my pointcuts as below
#Component
#Aspect
public class TestAdvices {
#Pointcut("execution(* com.test.mapper.SaveTableData.updateTableData(*))")
public void commonSaveTableData(TableData tableData) {
}
#Pointcut("execution(* com.test.service.CreateTableData.createTableData(*))")
public void commonCreateTableData(TableData tableData) {
}
//advices
#After("commonSaveTableData(tableData)")
public void addHistoryWhenSaveTableData(TableData tableData) throws Throwable {
//do stuff
}
//advices
#After("commonCreateTableData(tableData)")
public void addHistoryWhenCreateTableData(TableData tableData) throws Throwable {
//do stuff
}
}
Issue is commonCreateTableData which is on service method works as expected. But commonSaveTableData which is on Mybatis mapper method does't get invoke.
Question is if i can autowire these Mappers in any Spring bean why can't Spring AOP intercept method call using these pointcuts?
I think your pointcut expression is not correct, try this
#Component
#Aspect
public class TestAdvices {
#Pointcut("execution(* com.test.mapper.SaveTableData.updateTableData(*)) && args(tableData)", argNames="tableData")
public void commonSaveTableData(TableData tableData) {
}
//advices
#After("commonSaveTableData(tableData)", argNames="tableData")
public void addHistoryWhenSaveTableData(TableData tableData) throws Throwable {
//do stuff
}
//...
}
The reason you can't cut into the mapper like this is that when mapper is scanned by mybatis, it's bean definition has bean changed in a way that its interface is still the mapper interface but its class has been changed to MapperFactoryBean
Im studying for the Spring Core cert exam, and i'm doing some testing of the framework.
I'd like to know if there is a way to know if a Bean was proxied by CGLIB or the JDK library.
I already know the basic concepts like if you declare a Bean using the interface Spring will use the JDK to proxy it (unless you tell it otherwise). And if you declare a bean directly on a class it will proxy it by inheritance using CGLIB.
What I would like to know is what should I look for while debugging to check which library was used.
Given the following code, when I debug it, I dont see any difference in the instances of the beans created. I was expecting to see something like ConcreteBean$CGLIB in the bean that has no interface...
EDIT: i now understand that proxies are only created by spring when functionality needs to be added by a PostProcessor, but still, i'd like to know what to look for in the debugger to find if CGLIB was applied or not.
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(classes = MainConfig.class)
public class ProxiesTest {
#Autowired
RandomBean randomBean;
#Autowired
ConcreteBean concreteBean;
public void setUp() {
}
#Test
public void randomBeanTest() {
randomBean.doSomething();
}
#Test
public void concreteBeanTest() {
concreteBean.doSomething();
}
}
public class ConcreteBean {
public void doSomething() {
String concreteBean = "hello";
}
#PreDestroy
public void destroy() {
System.out.print("ConcreteBean Destroy");
}
}
public interface RandomBean {
public void doSomething();
public void destroy();
}
public class RandomBeanImpl implements RandomBean {
#Autowired
ApplicationContext context;
public void doSomething() {
context.getParentBeanFactory();
}
public void destroy() {
System.out.print("RandomBean destroyed");
}
}
#Configuration
#ComponentScan(basePackages = "com.certification.postprocessors")
public class MainConfig {
#Bean
public ConcreteBean concreteBean(){
return new ConcreteBean();
}
#Bean
public RandomBean randomBean() {
return new RandomBeanImpl();
}
}
When a bean is wrapped by a Spring CGLIB proxy it states $$EnhancerBySpringCGLIB.
A JDK proxy is shown as $Proxy
It looks like this in the debugging console
There have been several arguments around not using ApplicationContext.getBean() to get a bean reference, of which most are based on logic that it violates the principles of Inversion of control.
Is there a way to get reference to prototype scoped bean without calling context.getBean() ?
Consider to use Spring Boot!
Than you can do something like this...
Runner:
#SpringBootApplication
public class Runner{
public static void main(String[] args) {
SpringApplication.run(Runner.class, args);
}
}
Some Controller:
#Controller
public class MyController {
// Spring Boot injecting beans through #Autowired annotation
#Autowired
#Qualifier("CoolFeature") // Use Qualifier annotation to mark a class, if for example
// you have more than one concreate class with differant implementations of some interface.
private CoolFeature myFeature;
public void testFeature(){
myFeature.doStuff();
}
}
Some cool feature:
#Component("CoolFeature") // To identify with Qualifier
public class CoolFeature{
#Autowired
private SomeOtherBean utilityBean;
public void doStuff(){
// use utilityBean in some way
}
}
No XML files to handle.
We can still access context for manual configurations if needed.
Suggested reading:
Spring Boot Reference
Pro Spring Boot
This type of problem can be solved using method injection, which is described in more detail here: https://docs.spring.io/spring/docs/current/spring-framework-reference/html/beans.html#beans-factory-method-injection
This is the most common approach to create prototype bean:
abstract class MyService {
void doSome() {
OtherService otherService = getOtherService();
}
abstract OtherService getOtherService();
}
#Configuration
class Config {
#Bean
public MyService myService() {
return new MyService() {
OtherService getOtherService() {
return otherService();
}
}
}
#Bean
#Scope("prototype")
public OtherService otherService() {
return new OtherService();
}
}
I struggle to use aspect in Spring MVC project.
Method that is a pointcut is running fine, but without advise.
Here is class, that starts whole spring boot and that is root of spring context:
#Lazy
#SpringBootApplication
#EnableAspectJAutoProxy(proxyTargetClass=true)
#Configuration
public class MainSpringBootClass{
public static void main(String[] args)
{
SpringApplication.run(MainSpringBootClass.class, args);
}
}
Here is class with method, that is pointcut.
#Component
#Log
#Aspect
#EnableAspectJAutoProxy(proxyTargetClass=true)
public class MyExampleClass
{
public void example()
{
System.out.println("example");
}
}
And here is my aspect:
#Aspect
#Component
#EnableAspectJAutoProxy(proxyTargetClass=true)
public class MyAspect implements MethodBeforeAdvice
{
#Pointcut("execution(* com.example.MyExampleClass.example())")
public void asd()
{
// pointcut
}
#Before("asd()")
public void login()
{
System.out.println("im am logging in");
}
#Before("execution(* com.example.MyExampleClass.example())")
public void login2()
{
System.out.println("im am logging in2");
}
#Override
public void before(Method method, Object[] args, Object target) throws Throwable
{
System.out.println("aop before");
}
}
And here is my controller:
#RestController
#EnableAspectJAutoProxy(proxyTargetClass=true)
public class MyExampleController
{
private final MyExampleClass myExampleClass;
#Inject
public AdController(MyExampleClass myExampleClass)
{
this.myExampleClass = myExampleClass;
}
#RequestMapping("/")
public String index()
{
myExampleClass.example();
return "x";
}
}
As You can see, I have been trying to bruteforce correct result with annotations.
I have also seen on some website, that I need specific dependencies, so here are mine (pasting only those, related to aspects):
compile 'org.springframework:spring-aop:+'
compile 'org.aspectj:aspectjrt:+'
compile 'org.aspectj:aspectjweaver:+'
compile 'cglib:cglib:+'
compile 'cglib:cglib-nodep:+'
All dependencies have been successfully downloaded, project compiles and runs fine.
When I hit localhost:8080 then I see returned value "x", and inside logs I see "example".
However, I do not see any advices from spring aop nor aspectj - what am I doing wrong?
I am just using this project as sandbox to learn aspects, so I would be eager to learn, how to do it with each of Spring AOP and AspectJ.
The most important thing for me is to do it all without XML.
EDIT:
I have added simple constructor to MyAspect with println to check, if it is created (as it is normal spring bean with #Component after all) and it does - it is correctly created by spring.
EDIT 2:
IntelliJ IDEA tells me about methods login and login2: "This advice advices no method", but at the same time, I am able to jump (with control-click) from string, that is value in annotations to correct implementations.
All you should need is something like this:
#Aspect
#Component
public class MyAspect {
#Before("execution(* com.example.MyExampleClass.example(..))")
public void logBefore(JoinPoint pjp) throws Throwable {
System.out.println("before...");
}
}
You might have to replace all of the aspectJ dependencies with spring-boot-starter-aop .
Here's an example project that works (see RestControllerAspect.java):
https://github.com/khoubyari/spring-boot-rest-example