I'm new to Spring Framework so I decided to buy a book ("Spring in action" 3rd edition). Currently I'm at first chapter which covers basics - Dependency Injection (DI) and Aspect oriented programming (AOP).
I managed to run this code which showed DI.
1#Interface implemented by knight
package com.springinaction.knights;
public interface Knight {
void embarkOnQuest() throws QuestException;
}
1#Knight class
package com.springinaction.knights;
public class BraveKnight implements Knight {
private Quest quest;
public BraveKnight(Quest quest) {
this.quest = quest; //<co id="co_injectedQuest"/>
}
public void embarkOnQuest() throws QuestException {
quest.embark();
}
}
#2Quest interface
package com.springinaction.knights;
public interface Quest {
void embark() throws QuestException;
}
#2Quest Exception
package com.springinaction.knights;
public class QuestException extends RuntimeException {
private static final long serialVersionUID = 1L;
}
#2Quest type class implementation
package com.springinaction.knights;
public class SlayDragonQuest implements Quest {
public void embark() throws QuestException {
System.out.println("Slaying Dragon!");
}
}
#3Testing brave knight DI
package com.springinaction.knights;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class KnightMain {
public static void main(String[] args) {
ApplicationContext context =
new ClassPathXmlApplicationContext("knights.xml"); //<co id="co_loadKnightContext"/>
Knight knight = (Knight) context.getBean("knight"); //<co id="co_getBeanKnight"/>
knight.embarkOnQuest();//<co id="co_useKnight"/>
}
}
This is XML application context which injects quest into knight
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.2.xsd">
<bean id="quest" class="com.springinaction.knights.SlayDragonQuest" /><!--<co
id="co_quest_bean"/> -->
<bean id="knight" class="com.springinaction.knights.BraveKnight">
<constructor-arg ref="quest" /> <!--<co id="co_inject_quest_bean"/> -->
</bean>
</beans>
To this moment everything works, but when author wants to show AOP then something is wrong in XML file. The idea is that minstrel sings (logs) before knight goes on a quest and sings (logs off) when knight comes back from a quest.
Minstrel class
package com.springinaction.knights;
public class Minstrel {
public void singBeforeQuest() { //<co id="co_singBefore"/>
System.out.println("Fa la la; The knight is so brave!");
}
public void singAfterQuest() { //<co id="co_singAfter"/>
System.out.println(
"Tee hee he; The brave knight did embark on a quest!");
}
}
XML AOP file, I guess there is some kind of error here, but I don't know what...
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-3.2.xsd">
<bean id="knight" class="com.springinaction.knights.BraveKnight">
<constructor-arg ref="quest" />
</bean>
<bean id="quest"
class="com.springinaction.knights.SlayDragonQuest" />
<bean id="minstrel"
class="com.springinaction.knights.Minstrel" /> <!--<co id="co_minstrel_bean"/>-->
<aop:config>
<aop:aspect ref="minstrel">
<aop:pointcut id="embark"
expression="execution(* *.embarkOnQuest(..))" /> <!--<co id="co_define_pointcut"/>-->
<aop:before pointcut-ref="embark"
method="singBeforeQuest"/> <!--<co id="co_minstrel_before_advice"/>-->
<aop:after pointcut-ref="embark"
method="singAfterQuest"/> <!--<co id="co_minstrel_after_advice"/>-->
</aop:aspect>
</aop:config>
</beans>
Testing this looks exactly like in #3 Testing BraveKnight
Exception which is verry long.
sie 20, 2013 3:06:58 PM org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@14d5bc9: startup date [Tue Aug 20 15:06:58 CEST 2013]; root of context hierarchy
sie 20, 2013 3:06:58 PM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [knights-aop.xml]
sie 20, 2013 3:06:58 PM org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
INFO: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@46aa61: defining beans [knight,quest,minstrel,org.springframework.aop.config.internalAutoProxyCreator,org.springframework.aop.aspectj.AspectJPointcutAdvisor#0,org.springframework.aop.aspectj.AspectJPointcutAdvisor#1,embark]; root of factory hierarchy
sie 20, 2013 3:06:58 PM org.springframework.beans.factory.support.DefaultSingletonBeanRegistry destroySingletons
INFO: Destroying singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@46aa61: defining beans [knight,quest,minstrel,org.springframework.aop.config.internalAutoProxyCreator,org.springframework.aop.aspectj.AspectJPointcutAdvisor#0,org.springframework.aop.aspectj.AspectJPointcutAdvisor#1,embark]; root of factory hierarchy
Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'knight' defined in class path resource [knights-aop.xml]: BeanPostProcessor before instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.aop.aspectj.AspectJPointcutAdvisor#0': Cannot create inner bean '(inner bean)' of type [org.springframework.aop.aspectj.AspectJMethodBeforeAdvice] while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)': Cannot resolve reference to bean 'embark' while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'embark': Instantiation of bean failed; nested exception is java.lang.NoClassDefFoundError: org/aspectj/weaver/BCException
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:454)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:295)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:292)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:626)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:932)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:479)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
at com.springinaction.knights.KnightAopMain.main(KnightAopMain.java:10)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.aop.aspectj.AspectJPointcutAdvisor#0': Cannot create inner bean '(inner bean)' of type [org.springframework.aop.aspectj.AspectJMethodBeforeAdvice] while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)': Cannot resolve reference to bean 'embark' while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'embark': Instantiation of bean failed; nested exception is java.lang.NoClassDefFoundError: org/aspectj/weaver/BCException
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:282)
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:126)
at org.springframework.beans.factory.support.ConstructorResolver.resolveConstructorArguments(ConstructorResolver.java:629)
at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:148)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1045)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:949)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:487)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:295)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:292)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:198)
at org.springframework.aop.framework.autoproxy.BeanFactoryAdvisorRetrievalHelper.findAdvisorBeans(BeanFactoryAdvisorRetrievalHelper.java:86)
at org.springframework.aop.framework.autoproxy.AbstractAdvisorAutoProxyCreator.findCandidateAdvisors(AbstractAdvisorAutoProxyCreator.java:101)
at org.springframework.aop.aspectj.autoproxy.AspectJAwareAdvisorAutoProxyCreator.shouldSkip(AspectJAwareAdvisorAutoProxyCreator.java:103)
at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.postProcessBeforeInstantiation(AbstractAutoProxyCreator.java:276)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInstantiation(AbstractAutowireCapableBeanFactory.java:890)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.resolveBeforeInstantiation(AbstractAutowireCapableBeanFactory.java:862)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:448)
... 10 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)': Cannot resolve reference to bean 'embark' while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'embark': Instantiation of bean failed; nested exception is java.lang.NoClassDefFoundError: org/aspectj/weaver/BCException
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:329)
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:107)
at org.springframework.beans.factory.support.ConstructorResolver.resolveConstructorArguments(ConstructorResolver.java:615)
at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:148)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1045)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:949)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:487)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458)
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:271)
... 28 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'embark': Instantiation of bean failed; nested exception is java.lang.NoClassDefFoundError: org/aspectj/weaver/BCException
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1007)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:953)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:487)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:314)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:323)
... 36 more
Caused by: java.lang.NoClassDefFoundError: org/aspectj/weaver/BCException
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Unknown Source)
at java.lang.Class.getConstructor0(Unknown Source)
at java.lang.Class.getDeclaredConstructor(Unknown Source)
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:78)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1000)
... 42 more
Caused by: java.lang.ClassNotFoundException: org.aspectj.weaver.BCException
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 48 more
Download AspectJ and add aspectjrt.jar
& aspectjweaver.jar
to your classpath. Spring's aop config with the aop namespace is based on AspectJ, which is no more shipped bundled with org.springframework.aop jar.
Following is maven dependency in case its a maven based project
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>${org.springframework.version}</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.6.1</version>
</dependency>