org.springframework.aop.interceptor

Class AbstractTraceInterceptor

java.lang.Object

org.springframework.aop.interceptor.AbstractTraceInterceptor

All Implemented Interfaces:

Serializable, Advice, Interceptor, MethodInterceptor

Direct Known Subclasses:

AbstractMonitoringInterceptor, CustomizableTraceInterceptor, SimpleTraceInterceptor

public abstract class AbstractTraceInterceptor
extends Object
implements MethodInterceptor, 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

Fields

Modifier and Type	Field and Description
protected Log	defaultLogger The default Log instance used to write trace messages.

Constructor Summary

Constructors

Constructor and Description
AbstractTraceInterceptor()

Method Summary

Modifier and Type	Method and Description
protected Class<?>	getClassForLogging(Object target) Determine the class to use for logging purposes.
protected Log	getLoggerForInvocation(MethodInvocation invocation) Return the appropriate Log instance to use for the given MethodInvocation.
Object	invoke(MethodInvocation invocation) Determines whether or not logging is enabled for the particular MethodInvocation.
protected abstract Object	invokeUnderTrace(MethodInvocation invocation, Log logger) Subclasses must override this method to perform any tracing around the supplied MethodInvocation.
protected boolean	isInterceptorEnabled(MethodInvocation invocation, Log logger) Determine whether the interceptor should kick in, that is, whether the invokeUnderTrace method should be called.
protected boolean	isLogEnabled(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	setLogExceptionStackTrace(boolean logExceptionStackTrace) Set whether to pass an exception to the logger, suggesting inclusion of its stack trace into the log.
void	setLoggerName(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.
protected void	writeToLog(Log logger, String message) Write the supplied trace message to the supplied Log instance.
protected void	writeToLog(Log logger, String message, Throwable ex) Write the supplied trace message and Throwable to the supplied Log instance.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

defaultLogger

protected transient 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(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".

setLogExceptionStackTrace

public void setLogExceptionStackTrace(boolean logExceptionStackTrace)

Set whether to pass an exception to the logger, suggesting inclusion of its stack trace into the log. Default is "true"; set this to "false" in order to reduce the log output to just the trace message (which may include the exception class name and exception message, if applicable).

Since:

4.3.10

invoke

public Object invoke(MethodInvocation invocation)
              throws 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 MethodInterceptor

Parameters:

invocation - the method invocation joinpoint

Returns:

the result of the call to Joinpoint.proceed(); might be intercepted by the interceptor

Throws:

Throwable - if the interceptors or the target object throws an exception

See Also:

invokeUnderTrace(org.aopalliance.intercept.MethodInvocation, org.apache.commons.logging.Log)

getLoggerForInvocation

protected Log getLoggerForInvocation(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 Class<?> getClassForLogging(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(MethodInvocation invocation,
                                       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(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

writeToLog

protected void writeToLog(Log logger,
                          String message)

Write the supplied trace message to the supplied Log instance.

To be called by invokeUnderTrace(org.aopalliance.intercept.MethodInvocation, org.apache.commons.logging.Log) for enter/exit messages.

Delegates to writeToLog(Log, String, Throwable) as the ultimate delegate that controls the underlying logger invocation.

Since:

4.3.10

See Also:

writeToLog(Log, String, Throwable)

writeToLog

protected void writeToLog(Log logger,
                          String message,
                          Throwable ex)

Write the supplied trace message and Throwable to the supplied Log instance.

To be called by invokeUnderTrace(org.aopalliance.intercept.MethodInvocation, org.apache.commons.logging.Log) for enter/exit outcomes, potentially including an exception. Note that an exception's stack trace won't get logged when setLogExceptionStackTrace(boolean) is "false".

By default messages are written at TRACE level. Subclasses can override this method to control which level the message is written at, typically also overriding isLogEnabled(org.apache.commons.logging.Log) accordingly.

Since:

4.3.10

See Also:

setLogExceptionStackTrace(boolean), isLogEnabled(org.apache.commons.logging.Log)

invokeUnderTrace

protected abstract Object invokeUnderTrace(MethodInvocation invocation,
                                           Log logger)
                                    throws 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, and may delegate to writeToLog for actual messages to be written.

Parameters:

logger - the Log to write trace messages to

Returns:

the result of the call to MethodInvocation.proceed()

Throws:

Throwable - if the call to MethodInvocation.proceed() encountered any errors

See Also:

isLogEnabled(org.apache.commons.logging.Log), writeToLog(Log, String), writeToLog(Log, String, Throwable)