Java/Spring/Log

Spring Aspect Logging

File: IBusinessLogic.java

public interface IBusinessLogic
{
   public void foo();
   
   public void bar() throws BusinessLogicException;
}

File: LoggingThrowsAdvice.java
import org.springframework.aop.ThrowsAdvice;
import java.lang.reflect.Method;
public class LoggingThrowsAdvice implements ThrowsAdvice
{
   public void afterThrowing(Method method, Object[] args, Object target, Throwable subclass)
   {
      System.out.println("Logging that a " + subclass + "Exception was thrown.");
   }
}

File: MainApplication.java

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.FileSystemXmlApplicationContext;
public class MainApplication
{
   public static void main(String [] args)
   {
      // Read the configuration file
      ApplicationContext ctx
          = new FileSystemXmlApplicationContext("build/springconfig.xml");
      //Instantiate an object
      IBusinessLogic testObject = (IBusinessLogic) ctx.getBean("businesslogicbean");
      //Execute the public methods of the bean
      testObject.foo();
      
      try
      {
         testObject.bar();
      }
      catch(BusinessLogicException ble)
      {
         System.out.println("Caught BusinessLogicException");
      }
   }
}

File: springconfig.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC  "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
  <!--CONFIG-->
  <bean id="businesslogicbean"
  class="org.springframework.aop.framework.ProxyFactoryBean">
    <property name="proxyInterfaces">
      <value>IBusinessLogic</value>
    </property>
    <property name="target">
      <ref local="beanTarget"/>
    </property>
    <property name="interceptorNames">
      <list>
        <value>tracingBeforeAdvisor</value>
        <value>tracingAfterAdvisor</value>
        <value>loggingThrowsAdvisor</value>
      </list>
    </property>
  </bean>
  <!--CLASS-->
  <bean id="beanTarget"
  class="BusinessLogic"/>
  <!-- Advisor pointcut definition for before advice -->
  <bean id="tracingBeforeAdvisor"
  class="org.springframework.aop.support.RegexpMethodPointcutAdvisor">
    <property name="advice">
      <ref local="theTracingBeforeAdvice"/>
    </property>
    <property name="pattern">
      <value>.*</value>
    </property>
  </bean>
  
  <!-- Advisor pointcut definition for after advice -->
  <bean id="tracingAfterAdvisor"
  class="org.springframework.aop.support.RegexpMethodPointcutAdvisor">
    <property name="advice">
      <ref local="theTracingAfterAdvice"/>
    </property>
    <property name="pattern">
      <value>.*</value>
    </property>
  </bean>
  
  <!-- Advisor pointcut definition for throws advice -->
  <bean id="loggingThrowsAdvisor"
  class="org.springframework.aop.support.RegexpMethodPointcutAdvisor">
    <property name="advice">
      <ref local="theLoggingThrowsAdvice"/>
    </property>
    <property name="pattern">
      <value>.*</value>
    </property>
  </bean>
  <!--ADVICE-->
  <bean id="theTracingBeforeAdvice"
  class="TracingBeforeAdvice"/>
  <bean id="theTracingAfterAdvice"
  class="TracingAfterAdvice"/>
  <bean id="theLoggingThrowsAdvice"
  class="LoggingThrowsAdvice"/>
</beans>

File: TracingAfterAdvice.java
import java.lang.reflect.Method;
import org.springframework.aop.AfterReturningAdvice;
public class TracingAfterAdvice implements AfterReturningAdvice
{
   public void afterReturning(Object object, Method m, Object[] args, Object target) throws Throwable
   {
       System.out.println("Hello world! (by " + this.getClass().getName() + ")");
   }
}

File: TracingBeforeAdvice.java
import java.lang.reflect.Method;
import org.springframework.aop.MethodBeforeAdvice;
public class TracingBeforeAdvice implements MethodBeforeAdvice
{
   public void before(Method m, Object[] args, Object target) throws Throwable
   {
      System.out.println("Hello world! (by " + this.getClass().getName() + ")");
   }
}

File: BusinessLogic.java

public class BusinessLogic implements IBusinessLogic
{
     public void foo() 
     {
       System.out.println("Inside BusinessLogic.foo()");
     }
     
     public void bar() throws BusinessLogicException
     {
        System.out.println("Inside BusinessLogic.bar()");
        throw new BusinessLogicException();
     }
}

File: BusinessLogicException.java

public class BusinessLogicException extends Exception
{
}