Spring Framework

org.springframework.aop.interceptor
Class AbstractTraceInterceptor

java.lang.Object
  extended by org.springframework.aop.interceptor.AbstractTraceInterceptor
All Implemented Interfaces:
java.io.Serializable, org.aopalliance.aop.Advice, org.aopalliance.intercept.Interceptor, org.aopalliance.intercept.MethodInterceptor
Direct Known Subclasses:
AbstractMonitoringInterceptor, CustomizableTraceInterceptor, SimpleTraceInterceptor

public abstract class AbstractTraceInterceptor
extends java.lang.Object
implements org.aopalliance.intercept.MethodInterceptor, java.io.Serializable

Base MethodInterceptor implementation for tracing.

By default, log messages are written to the log for the interceptor class, not the class which is being intercepted. Setting the useDynamicLogger bean property to true causes all log messages to be written to the Log for the target class being intercepted.

Subclasses must implement the invokeUnderTrace method, which is invoked by this class ONLY when a particular invocation SHOULD be traced. Subclasses should write to the Log instance provided.

Since:
1.2
Author:
Rob Harrop, Juergen Hoeller
See Also:
setUseDynamicLogger(boolean), invokeUnderTrace(org.aopalliance.intercept.MethodInvocation, org.apache.commons.logging.Log), Serialized Form

Field Summary
protected  org.apache.commons.logging.Log defaultLogger
          The default Log instance used to write trace messages.
 
Constructor Summary
AbstractTraceInterceptor()
           
 
Method Summary
protected  java.lang.Class getClassForLogging(java.lang.Object target)
          Determine the class to use for logging purposes.
protected  org.apache.commons.logging.Log getLoggerForInvocation(org.aopalliance.intercept.MethodInvocation invocation)
          Return the appropriate Log instance to use for the given MethodInvocation.
 java.lang.Object invoke(org.aopalliance.intercept.MethodInvocation invocation)
          Determines whether or not logging is enabled for the particular MethodInvocation.
protected abstract  java.lang.Object invokeUnderTrace(org.aopalliance.intercept.MethodInvocation invocation, org.apache.commons.logging.Log logger)
          Subclasses must override this method to perform any tracing around the supplied MethodInvocation.
protected  boolean isInterceptorEnabled(org.aopalliance.intercept.MethodInvocation invocation, org.apache.commons.logging.Log logger)
          Determine whether the interceptor should kick in, that is, whether the invokeUnderTrace method should be called.
protected  boolean isLogEnabled(org.apache.commons.logging.Log logger)
          Determine whether the given Log instance is enabled.
 void setHideProxyClassNames(boolean hideProxyClassNames)
          Set to "true" to have dynamic loggers hide proxy class names wherever possible.
 void setLoggerName(java.lang.String loggerName)
          Set the name of the logger to use.
 void setUseDynamicLogger(boolean useDynamicLogger)
          Set whether to use a dynamic logger or a static logger.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

defaultLogger

protected transient org.apache.commons.logging.Log defaultLogger
The default Log instance used to write trace messages. This instance is mapped to the implementing Class.

Constructor Detail

AbstractTraceInterceptor

public AbstractTraceInterceptor()
Method Detail

setUseDynamicLogger

public void setUseDynamicLogger(boolean useDynamicLogger)
Set whether to use a dynamic logger or a static logger. Default is a static logger for this trace interceptor.

Used to determine which Log instance should be used to write log messages for a particular method invocation: a dynamic one for the Class getting called, or a static one for the Class of the trace interceptor.

NOTE: Specify either this property or "loggerName", not both.

See Also:
getLoggerForInvocation(org.aopalliance.intercept.MethodInvocation)

setLoggerName

public void setLoggerName(java.lang.String loggerName)
Set the name of the logger to use. The name will be passed to the underlying logger implementation through Commons Logging, getting interpreted as log category according to the logger's configuration.

This can be specified to not log into the category of a class (whether this interceptor's class or the class getting called) but rather into a specific named category.

NOTE: Specify either this property or "useDynamicLogger", not both.

See Also:
LogFactory.getLog(String), Logger.getLogger(String), Logger.getLogger(String)

setHideProxyClassNames

public void setHideProxyClassNames(boolean hideProxyClassNames)
Set to "true" to have dynamic loggers hide proxy class names wherever possible. Default is "false".


invoke

public java.lang.Object invoke(org.aopalliance.intercept.MethodInvocation invocation)
                        throws java.lang.Throwable
Determines whether or not logging is enabled for the particular MethodInvocation. If not, the method invocation proceeds as normal, otherwise the method invocation is passed to the invokeUnderTrace method for handling.

Specified by:
invoke in interface org.aopalliance.intercept.MethodInterceptor
Throws:
java.lang.Throwable
See Also:
invokeUnderTrace(org.aopalliance.intercept.MethodInvocation, org.apache.commons.logging.Log)

getLoggerForInvocation

protected org.apache.commons.logging.Log getLoggerForInvocation(org.aopalliance.intercept.MethodInvocation invocation)
Return the appropriate Log instance to use for the given MethodInvocation. If the useDynamicLogger flag is set, the Log instance will be for the target class of the MethodInvocation, otherwise the Log will be the default static logger.

Parameters:
invocation - the MethodInvocation being traced
Returns:
the Log instance to use
See Also:
setUseDynamicLogger(boolean)

getClassForLogging

protected java.lang.Class getClassForLogging(java.lang.Object target)
Determine the class to use for logging purposes.

Parameters:
target - the target object to introspect
Returns:
the target class for the given object
See Also:
setHideProxyClassNames(boolean)

isInterceptorEnabled

protected boolean isInterceptorEnabled(org.aopalliance.intercept.MethodInvocation invocation,
                                       org.apache.commons.logging.Log logger)
Determine whether the interceptor should kick in, that is, whether the invokeUnderTrace method should be called.

Default behavior is to check whether the given Log instance is enabled. Subclasses can override this to apply the interceptor in other cases as well.

Parameters:
invocation - the MethodInvocation being traced
logger - the Log instance to check
See Also:
invokeUnderTrace(org.aopalliance.intercept.MethodInvocation, org.apache.commons.logging.Log), isLogEnabled(org.apache.commons.logging.Log)

isLogEnabled

protected boolean isLogEnabled(org.apache.commons.logging.Log logger)
Determine whether the given Log instance is enabled.

Default is true when the "trace" level is enabled. Subclasses can override this to change the level under which 'tracing' occurs.

Parameters:
logger - the Log instance to check

invokeUnderTrace

protected abstract java.lang.Object invokeUnderTrace(org.aopalliance.intercept.MethodInvocation invocation,
                                                     org.apache.commons.logging.Log logger)
                                              throws java.lang.Throwable
Subclasses must override this method to perform any tracing around the supplied MethodInvocation. Subclasses are responsible for ensuring that the MethodInvocation actually executes by calling MethodInvocation.proceed().

By default, the passed-in Log instance will have log level "trace" enabled. Subclasses do not have to check for this again, unless they overwrite the isInterceptorEnabled method to modify the default behavior.

Parameters:
logger - the Log to write trace messages to
Returns:
the result of the call to MethodInvocation.proceed()
Throws:
java.lang.Throwable - if the call to MethodInvocation.proceed() encountered any errors
See Also:
isInterceptorEnabled(org.aopalliance.intercept.MethodInvocation, org.apache.commons.logging.Log), isLogEnabled(org.apache.commons.logging.Log)

Spring Framework