public abstract aspect AbstractOperationMonitor extends AbstractRequestMonitor {  
      
  protected abstract class OperationRequestContext extends RequestContext {
      /**
       * Find the appropriate statistics collector object for this
       * operation.
       * @param operation an instance of the operation being 
       *         monitored
       */
      public PerfStats lookupStats() {                
          if (getParent() != null) {
              // nested operation
              OperationStats parentStats =
                      (OperationStats)getParent().getStats();
              return parentStats.getOperationStats(getKey());
          }
          return getTopLevelStats(getKey());
      }
        
      /**
       * Determine the top-level statistics for a given operation 
       * key. This also looks up the context name for the
       * application from the operation monitor: 
       * @see AbstractOperationMonitor#getContextName(Object)
       * For a Web application, top-level statistics are normally
       * all Servlets, and the key is the Servlet name. 
       * @param key An object to uniquely identify the 
       *         operation being performed.
       */
      protected OperationStats getTopLevelStats(Object key) {
          OperationStats stats;
          synchronized(topLevelOperations) {
              stats = (OperationStats)topLevelOperations.get(key);
              if (stats == null) {                
                  stats =
                    perfStatsFactory.createTopLevelOperationStats(key,
                            getContextName(controller));
                  topLevelOperations.put(key, stats);
              }
          }
          return stats;        
      }
        
      /** 
       * @return An object that uniquely identifies the operation
       *          being performed. 
       */
      protected abstract Object getKey();     
        
      /** The current controller object executing, if any. */
      protected Object controller;
  };

  /** 
   * This advice stores the controller object whenever we construct a
   * request context. 
   */
  after(Object controller) returning (OperationRequestContext ctxt) : 
    cflow(adviceexecution() && args(controller, ..) &&
    this(AbstractOperationMonitor)) &&
    call(OperationRequestContext+.new(..)) {
      ctxt.controller = controller;
  }    

...

  /** 
   * This defaults to no join points. If a concrete aspect overrides
   * classControllerExec with a concrete definition,
   * then the monitor will track operations at matching join points
   * based on the class of the controller object.
   */ 
  protected pointcut classControllerExec(Object controller);
    
  Object around(final Object controller) :
    classControllerExec(controller) {
      RequestContext rc = new OperationRequestContext() {
          public Object doExecute() {
              return proceed(controller);
          }
                       
          protected Object getKey() {
              return controller.getClass();
          }                        
      };
      return rc.execute();        
  }    

  // Controller where the name of the signature at the monitored join point
  // determines what is being executed, for example, the method name
  /** 
   * This defaults to no join points. If a concrete monitor overrides
   * methodSignatureControllerExec with a concrete
   * definition, then it will track operations at matching join points
   * based on the run-time class of the executing controller instance
   * and the method signature at the join point.
   */ 
  protected pointcut methodSignatureControllerExec(Object controller);
    
  Object around(final Object controller) :
    methodSignatureControllerExec(controller) {
      RequestContext rc = new OperationRequestContext() {
          public Object doExecute() {
              return proceed(controller);
          }
                       
          protected Object getKey() {
              return concatenatedKey(controller.getClass(),
                thisJoinPointStaticPart.getSignature().getName());
          }
            
      };
      return rc.execute();        
  }   

public aspect StrutsMonitor extends AbstractOperationMonitor {
    /** 
     * Marker interface that allows explicitly _excluding_ classes
     * from this monitor: not used by default. If using Java™ 5, an 
     * annotation would be better.
     */
    public interface NotMonitoredAction {}

  /** 
   * Matches execution of any method defined on a Struts action or
   * any subclass, which has signature of an action execute (or 
   * perform) method, including methods dispatched to in a
   * DispatchAction or template methods with the same signature.
   */ 
  public pointcut actionMethodExec() : 
      execution(public ActionForward Action+.*(ActionMapping,
              ActionForm, ServletRequest+, ServletResponse+)) &&
      !within(NotMonitoredAction);

  /** 
   * Matches execution of an action execute (or perform) method for
   * a Struts action. Supports the Struts 1.0 API (using the perform
   * method) as well as the Struts 1.1 API (using the execute method).
   */ 
  public pointcut rootActionExec() : 
      actionMethodExec() && (execution(* Action.execute(..)) ||
      execution(* Action.perform(..)));
    
  /** @Override */
  protected pointcut classControllerExec(Object controller) :
      rootActionExec() && this(controller);

  protected pointcut dispatchActionMethodExec() :
      actionMethodExec() && execution(* DispatchAction+.*(..));

  protected pointcut methodSignatureControllerExec(Object controller):
      dispatchActionMethodExec() && this(controller);
}

public aspect SpringMvcMonitor extends AbstractOperationMonitor {
  /** 
   * marker interface that allows explicitly _excluding_ classes
   * from this monitor: not used by default 
   */
  public interface NotMonitoredController {}
    
  public pointcut springControllerExec() :
      execution(public ModelAndView Controller+.*(HttpServletRequest,
              HttpServletResponse)) &&
      !within(NotMonitoredController+);

  protected pointcut classControllerExec(Object controller) :
      springControllerExec() && execution(* handleRequest(..)) &&
      this(controller);

  protected pointcut methodSignatureControllerExec(Object controller):
      springControllerExec() && 
      execution(* MultiActionController+.*(..)) && this(controller);    
}

public class ClinicController extends MultiActionController 
  implements InitializingBean {
...
  public ModelAndView welcomeHandler(HttpServletRequest request, 
    HttpServletResponse response) throws ServletException {
      return new ModelAndView("welcomeView");
  }
...
  public ModelAndView ownerHandler(HttpServletRequest request, 
    HttpServletResponse response) throws ServletException {
       Owner owner = clinic.loadOwner(
         RequestUtils.getIntParameter(request, "ownerId", 0));
...
       model.put("owner", owner);
       return new ModelAndView("ownerView", "model", model);
  }
...

 
public aspect ServletMonitor extends AbstractOperationMonitor {
    
  /** 
   * Execution of any Servlet method: typically not overridden in
   * HttpServlets. 
   */
  public pointcut ServletService(Servlet Servlet) :
      execution(void Servlet.service(..)) && this(Servlet);
        
  /** Execution of any Servlet request methods. */
  public pointcut httpServletDo(HttpServlet Servlet) :
      execution(void HttpServlet.do*(..)) && this(Servlet);
    
  /** Execution of any JSP page service method. */
  public pointcut jspService(JspPage page) : 
      execution(* _jspService(..)) && this(page);
    
  protected pointcut classControllerExec(Object controller) :
      (ServletService(*) || httpServletDo(*) || jspService(*)) &&
      this(controller);

  /** 
   * Create statistics for this object: looks up Servlet context to
   * determine application name.
   */
  protected String getContextName(Object controller) {
      Servlet Servlet = (Servlet)controller;
      return Servlet.getServletConfig().getServletContext().
              getServletContextName();
  }
}

application=Spring Petclinic,operation=org.springframework.samples.
petclinic.web.ClinicController,database=jdbc:hsqldb:hsql://localhost:
9001,statement=SELECT id;name from types ORDER BY name

public aspect StatsJmxManagement {

  private String PerfStats.cachedOperationName;
    
  /** JMX operation name for this performance statistics bean. */    
  public String PerfStats.getOperationName() {
      // look up from cache
      // else 
...
      appendOperationName(buffer);
...
      return operationName;
  }
    
  /** Add bean's JMX operation name to a StringBuffer. */    
  public void PerfStats.appendOperationName(StringBuffer buffer) {
      if (cachedOperationName != null) {
          buffer.append(cachedOperationName);
      } else {
          aspectOf().nameStrategy.appendOperationName(this, buffer);
      }
  }    

  public void PerfStats.appendName(StringBuffer buffer) {
      // append the appropriate name & JMX encode
...
  }

  public StatsJmxNameStrategy getNameStrategy() {...}
 
  public void setNameStrategy(StatsJmxNameStrategy nameStrategy) { ... }
    
  private StatsJmxNameStrategy nameStrategy;
}

public interface StatsJmxNameStrategy {
  void appendOperationName(PerfStats stats, StringBuffer buffer);
}

public class GuiFriendlyStatsJmxNameStrategy extends 
  AbstractStatsJmxNameStrategy {
    
  public void appendOperationName(PerfStats stats, 
          StringBuffer buffer) {        
      PerfStats parent = stats.getParent(); 
      if (parent != null) {
          appendOperationName(parent, buffer);
          buffer.append(',');
        else {
          if (stats instanceof OperationStats) {
              OperationStats opStats = (OperationStats)stats;
              String contextName = opStats.getContextName();
              if (contextName != null) {
                  buffer.append("application=\"");
                  int pos = buffer.length();
                  buffer.append(contextName);
                  JmxManagement.jmxEncode(buffer, pos);
                  buffer.append("\",");
              }
          }
      }
      buffer.append(stats.getDescription());
      buffer.append('=');
      stats.appendName(buffer);
  }
} 

public aspect RemoteCallMonitor extends AbstractResourceMonitor {
  /** Call to remote proxy: RMI or JAX-RPC */
  public pointcut remoteProxyCall(Object recipient) : 
      call(public * Remote+.*(..) throws RemoteException) &&
      target(recipient) && !within(glassbox.inspector..*);
    
  /** Monitor remote proxy calls based on called class and method */
  Object around(final Object recipient) : 
    remoteProxyCall(recipient) {
      RequestContext requestContext = new ResourceRequestContext() {
            
          public Object doExecute() {
              return proceed(recipient);
          }
            
          public PerfStats lookupStats() {
              String key = "jaxrpc:"+recipient.getClass().getName()+
                "."+thisJoinPointStaticPart.getSignature().getName();
              key = key.intern();
                
              return lookupResourceStats(key);
          }
      };
      return requestContext.execute();
  }
}

public aspect AbstractRequestMonitor {

  /** 
   * Record an error if this request exited by throwing a 
   * Throwable.
   */
  after(RequestContext requestContext) throwing (Throwable t) : 
    requestExecution(requestContext) {
      PerfStats stats = requestContext.getStats();
      if (stats != null) {
          if (failureDetectionStrategy.isFailure(t,
                  thisJoinPointStaticPart)) {
              requestContext.recordFailure(t);
          } else {
              requestContext.recordExecution();
          }
      }
  }
  public void setFailureDetectionStrategy(...) { ... }
  public FailureDetectionStrategy getFailureDetectionStrategy() { ... }
  protected FailureDetectionStrategy failureDetectionStrategy =
      new FailureDetectionStrategy() {
        public boolean isFailure(Throwable t, StaticPart staticPart) {
            return true;
        }
      };
...
}   

public interface FailureDetectionStrategy {
  boolean isFailure(Throwable t, StaticPart staticPart);
}

/** 
 * Softens and uses Spring's exception translator to convert from
 * SQLException to unchecked, meaningful exception types 
 */
aspect DataAccessErrorHandling {
  declare soft: SQLException: jdbcCall();

  after() throwing (SQLException e) : jdbcCall() {
      throw sqlExceptionTranslator.translate("dbcall", getSql(), e);
  }

  declare precedence: ModelErrorHandling, JdbcStatementMonitor;
}

/** 
 * Conservative detection strategy: failures from SQL that often
 * indicate valid business conditions are not flagged as failures.
 */
public class DataAccessDetectionStrategy implements FailureDetectionStrategy {
  public boolean isFailure(Throwable t, StaticPart staticPart) {
      return !(t instanceof ConcurrencyFailureException) &&
         !(t instanceof DataIntegrityViolationException);
  }
}

  /** Call of send error in the Servlet API */
  public pointcut sendingErrorResponse(HttpServletResponse response,
          int sc) : 
      target(response) && call(* sendError(..)) && args(sc, ..);    
  /** Track a failure after sending an error response */
  after(HttpServletResponse response, RequestContext requestContext,
          int sc) returning : 
    sendingErrorResponse(response, sc) && inRequest(requestContext) {
      requestContext.setErrorContext(new Integer(sc));
  }

  /** Execute handle page exception in the JSP API */
  public pointcut handlePageException(PageContext pageContext,
          Throwable t) :
      call(* PageContext.handlePageException(*)) &&
      target(pageContext) && args(t);

  /** Track a failure when showing an error page */
  after(PageContext pageContext, RequestContext requestContext,
          Throwable t) returning : 
    handlePageException(pageContext, t) && inRequest(requestContext) {
      requestContext.setErrorContext(t);
  }    

public aspect ErrorHandling {
  public pointcut scope() : 
      within(glassbox.inspector..*) && !within(ErrorHandling+);

  public pointcut inMonitor() : 
      within(AbstractRequestMonitor+) || within(RequestContext+);

  public pointcut voidReturnAdviceExecution() :
      adviceexecution() &&
      if(((AdviceSignature)thisJoinPointStaticPart.getSignature()).
             getReturnType() == void.class);

  protected pointcut monitorHelperExec() : 
      inMonitor() && execution(* *(..)) && 
      !execution(* execute(..)) && !execution(* doExecute(..));
    
  protected pointcut monitorExecuteCall() : 
      (inMonitor() && withincode(* execute(..)) || 
      withincode(* doExecute(..))) && 
      (call(* *(..)) && !call(* doExecute(..)) || call(new(..)));
    
  public pointcut handlingScope() : 
       scope() && 
         voidReturnAdviceExecution() || monitorHelperExec() || monitorExecuteCall();

  /**
   * This advice ensures that errors in the monitoring code will not
   * poison the underlying application code.
   */
  Object around() : handlingScope() {
      try {
          return proceed();
      } catch (Throwable e) {
          handleError(e, thisJoinPointStaticPart);
          return null;
      }
  }

  public synchronized void handleError(Throwable t, 
          StaticPart joinPointStaticPart) {
      // log 1 in 1000 but don't rethrow
      ...
  }

  /** 
   * Count of errors: a weak map so we don't leak memory after apps
   * have been disposed of.
   */
  private Map/* <JoinPoint.StaticPart, MutableInteger> */errorCount =
      new WeakHashMap();
    
...
}

public aspect AbstractRequestMonitor {
...
    protected pointcut scope() : if(true);
    protected pointcut monitorEnabled() : isMonitorEnabled() && scope();
    protected abstract pointcut isMonitorEnabled();

    public boolean isEnabled() {
        return enabled;
    }
    public void setEnabled(boolean enabled) {
        this.enabled = enabled;
    }
    protected boolean enabled = true;
}

public aspect JdbcStatementMonitor extends AbstractResourceMonitor {
...
    /** Monitor performance for executing a JDBC statement. */
    Object around(final Statement statement) :
      statementExec(statement) && monitorEnabled() {
        ...
    }
...
    protected pointcut isMonitorEnabled() : if(aspectOf().isEnabled());
}

public aspect MonitorJmxManagement {
  /** 
   * Management interface for monitors allows enabling and disabling 
   * at runtime. 
   */
  public interface RequestMonitorMBean extends ManagedBean {
      public boolean isEnabled();
      public void setEnabled(boolean enabled);
  }

  /** 
   * Make the {@link AbstractRequestMonitor} aspect implement 
   * {@link RequestMonitorMBean}, so all instances can be managed 
   */
  declare parents: AbstractRequestMonitor implements MonitorMBean;

  public String AbstractRequestMonitor.getOperationName() {
      return "control=monitor,type="+getClass().getName();
  }
    
  public MBeanInfoAssembler AbstractRequestMonitor.getAssembler() {
      if (assembler == null) {
          initAssembler();
      }
      return assembler;
  }
...
}

<aspectj>
    <weaver>
      <exclude within="org.springframework.jmx..*"/>
      <!--  don't reweave -->
      <exclude within="glassbox.inspector..*"/>
    </weaver>
    <aspects>
      <aspect
 name="glassbox.inspector.monitor.operation.AxisOperationMonitor"/>
      <aspect
 name="glassbox.inspector.monitor.operation.SpringMvcMonitor"/>
      <aspect
...
      <aspect
 name="glassbox.inspector.monitor.resource.JdbcStatementMonitor"/>
      <concrete-aspect
 name="glassbox.inspector.monitor.operation.CustomMvcMonitor "
 extends="glassbox.inspector.monitor.operation.TemplOperationMonitor">
        <pointcut name="classControllerExecTarget"
           expression="execution(* com.ibatis.struts.BaseBean..*(..))
&& cflow(execution(* com.ibatis.struts.BeanAction.execute(..)))"/>
      </concrete-aspect>
    </aspects>
</aspectj>

 set JAVA_OPTS=-javaagent:%CATALINA_HOME%\common\lib\aspectjweaver.jar -Xmx256m 

Ron Bodkin 是 New Aspects of Software 的创始人，该公司提供应用程序开发和架构方面的咨询和培训，侧重于性能管理和有效地使用面向方面编程。Ron 以前在 Xerox PARC 为 AspectJ 小组工作，在那里他领导了第一个 AOP 实现项目并负责客户的培训，他还是 C-bridge 的创始人和 CTO，这家咨询机构采用 Java 的框架、XML 和其他互联网技术提供企业应用程序。Ron 经常为各种会议和客户进行演讲和提供教程，包括在 Software Development、The Colorado Software Summit、 TheServerSide Symposium、EclipseCon、StarWest、Software Test & Performance、OOPSLA 和 AOSD 上做报告。最近，他一直为 Glassbox 集团工作，用 AspectJ 和 JMX 开发应用程序性能管理和分析产品。可以通过 Ron 的邮箱 ron.bodkin@newaspects.com 与他联系。