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
Related
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 am using this Spring AOP code in my Spring Boot starter project in STS. After debugging this for some time I don't see any problem with the AspectJ syntax. The Maven dependencies are generated by STS for a AOP starter project. Is there a glaring omission in this code like an annotation ? The other problem could be with the AOP starter project or with the way I try to test the code in a #PostConstruct method.
I installed AJDT but it appears STS should show AspectJ markers in the IDE on its own. Right ? I don't see the markers. What other AspectJ debugging options are included in STS ? -Xlint is what I used in Eclipse/AJDT.
StateHandler.java
public class StateHandler<EVENTTYPE extends EventType> {
private State<EVENTTYPE> state;
private Event<EVENTTYPE> event;
public StateHandler(State<EVENTTYPE> state, Event<EVENTTYPE> event) {
this.state = state;
this.event = event;
}
public void handle( Event<EVENTTYPE> event ){
state = state.handle( event );
}
public State<EVENTTYPE> getState() {
return state;
}
}
DeviceLogger .java
#Aspect
#Component
public class DeviceLogger {
private static Logger logger = Logger.getLogger("Device");
#Around("execution(* com.devicemachine.StateHandler.*(..))")
public void log() {
logger.info( "Logger" );
}
}
LoggerApplication.java
#SpringBootApplication
public class LoggerApplication {
private static Logger logger = Logger.getLogger("Device");
public static void main(String[] args) {
SpringApplication.run(LoggerApplication.class, args);
}
#PostConstruct
public void log(){
DeviceState s = DeviceState.BLOCKED;
StateHandler<DeviceEvent> sh = new StateHandler<DeviceEvent>( s,
Event.block(DeviceEvent.BLOCKED, "AuditMessage") );
sh.handle(Event.block(DeviceEvent.UNBLOCKED, "AuditMessage"));
}
}
There are 3 obvious things wrong and 1 not so obvious wrong.
Your aspect is wrong and breaks proper method execution. When using an around aspect you must always return Object and use a ProceedingJoinPoint and call proceed() on that.
You are creating new instances of classes yourself, Spring, by default, uses proxy based AOP and will only proxy beans it knows.
In a #PostConstruct method it might be that proxies aren't created yet and that nothing is being intercepted
You need to use class based proxies for that to be enabled add spring.aop.proxy-target-class=true to your application.properties. By default JDK Dynamic Proxies are used which are interface based.
Fix Aspect
Your current aspect doesn't use a ProceedingJoinPoint and as such never does the actual method call. Next to that if you now would have a method that returns a value it would all of a sudden return null. As you aren't calling proceed on the ProceedingJoinPoint.
#Around("execution(* com.devicemachine.StateHandler.*(..))")
public Object log(ProceedingJoinPoint pjp) throws Throwable {
logger.info( "Logger" );
return pjp.proceed();
}
Create a bean to fix proxying and #PostConstruct
#SpringBootApplication
public class LoggerApplication {
private static Logger logger = Logger.getLogger("Device");
public static void main(String[] args) {
ApplicationContext context = SpringApplication.run(LoggerApplication.class, args);
StateHandler<DeviceEvent> sh = context.getBean(StateHandler<DeviceEvent>.class);
sh.handle(Event.block(DeviceEvent.UNBLOCKED, "AuditMessage"));
}
#Bean
public StateHandler<DeviceEvent> auditMessageStateHandler() {
return new StateHandler<DeviceEvent>(DeviceState.BLOCKED, Event.block(DeviceEvent.BLOCKED, "AuditMessage") );
}
}
Add property to enable class proxies
In your application.properties in src\main\resources add the following property with a value of true
spring.aop.proxy-target-class=true
Well I really don't know why this does not work:
Every jar needed is in the place. Including aspectjrt.
Basically I start with configuration class:
#Configuration
#ComponentScan(basePackages = { "some.path" })
#EnableAspectJAutoProxy
public class SomeConf { ... }
Then I have my Aspect:
#Component
#Aspect
public class ControllerLoggerAspect {
#Pointcut("execution(* some.path.ATest.*(..))")
private void aspectTest() {
System.out.println("\n\n ASPECT WORKING \n\n");
}
}
Under some.path I have Atest class:
package some.path;
public class ATest {
public void dummyMethod(){
System.out.println("\n\n\nDummy static executed\n\n\n");
}
}
Imagine now that I have controller:
#Controller
#RequestMapping(value = "/mapping")
public class SomeController {
#RequestMapping(value = "/something")
public ResponseEntity<String> publish(#RequestParam("Id") Long[] ids) {
//aspect should be invoked here
new ATest().dummyMethod();
return new ResponseEntity<>("{ \"status\": \"stubbed\"}", HttpStatus.OK);
}
}
Everything is invoked properly except aspect method. No errors, no exceptions, nothing. Any ideas?
Spring AOP only works on Spring beans, i.e. if you want to intercept one of its methods, class ATest needs to be a #Component.
You need to configure the advice you want execute. The pointcut only helps in determining the join points. The advice will be executed, not the pointcut.
You could write a Advice like this using your pointcut "aspectTest()":
#Before("aspectTest()")
public void beforeAdvice(){
System.out.println("\n\n ASPECT WORKING \n\n");
}
Or you could just replace your Pointcut annotation in the example with an advice annotation like this:
#Before("execution(* some.path.ATest.*(..))")
public void aspectTest() {
System.out.println("\n\n ASPECT WORKING \n\n");
}
Here you have a list of all adivces:
#Before("aspectTest()")
#After("aspectTest()")
#AfterReturning(pointcut = "aspectTest()", returning="retVal")
#AfterThrowing(pointcut = "aspectTest()", throwing="ex")
#Around("aspectTest()")