Spring ..Can 1 interceptor intercept all calls to all objects within a clas

Question

My Building implementation contains Floor objects, which in turn contain Door objects. These floor objects are driven by the parent Building that contains them. If a Floor makes a call to a Door class this call can't be intercepted by the first buildingBean below. I had to create another one "floorBean" as listed below to catch these.
Can the buildingBean be modified to catch all calls made by objects within them?
<!-- Bean configuration -->
     <bean id="buildingBean" class="org.springframework.aop.framework.ProxyFactoryBean">
          <property name="proxyInterfaces">
               <list>
                    <value>src.Building</value>
               </list>
          </property>
          <property name="target">
               <ref local="myBuilding"/>
          </property>
          <property name="interceptorNames">
               <list>
                    <value>theTracingBeforeAdvisor</value>
                    <value>theTracingAfterAdvisor</value>
               </list>
          </property>
     </bean>
     <!-- -->
     <!-- Bean Classes -->
     <!-- -->
     <!-- -->
          <bean id="floorBean" class="org.springframework.aop.framework.ProxyFactoryBean">
          <property name="proxyInterfaces">
               <list>
                    <value>src.Floor</value>
               </list>
          </property>
          <property name="target">
               <ref local="myFloor1"/>
          </property>
          <property name="interceptorNames">
               <list>
                    <value>theTracingBeforeAdvisor</value>
                    <value>theTracingAfterAdvisor</value>
               </list>
          </property>
     </bean>
     

Answer 1

Threads are part of code that allows you to run multiple operations "simultaneously". "Simultaneously", because threads are not run actually simultaneously in any one-CPU machine. Since you most propably have only one CPU in your system, you can only execute one CPU instruction at time. Basically this means that your CPU can handle only one java-operation at time. It does not matter if you put some code in thread and start it, it will still take up all CPU time as long as the thread runs.
So you would need a way to let other threads run also, for that purpose thread contains a yield feature that allows you to give time for other threads to run.
http://java.sun.com/j2se/1.4.1/docs/api/java/lang/Thread.html#yield()
You need to use thread's yield() method in your thread code, in a place you want to give other threads time to run. Also bear in mind that if you yield your first thread run to allow second thread to run, you also need to add yield to the second thread also. If you don't, after yielding the first thread, the second thread will eat up all CPU time until it finishes, thus meaning the rest of your first thread will be run after second thread is done.
One good place to execute yield() is usually at the end of a loop, for example 'for' or 'while' loop. This way you prevent for example while-deadlocks.
Here is a java thread tutorial, worthy reading:
http://java.sun.com/docs/books/tutorial/essential/threads/