info.monitorenter.reflection
Class ObjectRecorder

java.lang.Object
  java.lang.Thread
      info.monitorenter.reflection.ObjectRecorder

All Implemented Interfaces:

Runnable

public class ObjectRecorder
extends Thread

The ObjectRecorder takes records(inspections) of an objects state using reflection and accessibility- framework.

It's strategy is to:

  - try to set any field accessible.
  - try to get the value of the field.
  - if not suceed: try to invoke a bean- conform getter.
  - if NoSuchMethod, it's useless (no implementation of MagicClazz here).
  

Furthermore the ObjectRecorder has a history - size (buffer) and an adjustable distance between each inspection.

Version:

$Revision: 1.5 $

Author:

Achim Westermann

Nested Class Summary

class

ObjectRecorder.ObjectInspection Data container for the inspection of the internal intance.

Nested classes/interfaces inherited from class java.lang.Thread

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

protected IRingBuffer	m_buffer Fast buffer to store recorded fiels.
protected EventListenerList	m_changeListeners The listeners on this recorder.
protected Field[]	m_fields The fields to inspect on the instance.
protected long	m_interval The time - interval between to inspections of the Object.
protected Object	m_toinspect The instance to instpec.
protected static boolean	VERBOSE Verbosity constant.

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

ObjectRecorder(Object toinspect, long interval)
Creates an instance that will inspect the given Object in the given time interval.

Method Summary

void	addChangeListener(ChangeListener x) Adds a change listener that will be informed about new recordings of the inpected instances.
protected void	fireChange() Informs the listeners about a change of this instance.
TimeStampedValue[]	getAttributeHistory(String attributeName) The History returned by this Method represents the past of the field specified by attributeName.
String[]	getAttributeNames() Returns the names of the fields to inspect.
Object	getInspected() Returns the inspected instance.
TimeStampedValue	getLastValue(String fieldname) Returns the last recoreded value taken from the given field along with the timestamp identifying the time this value was recored.
IRingBuffer	getRingBuffer() Returns the internal fifo buffer that stores the ObjectRecorder.ObjectInspection instances that have been done.
void	inspect() Makes a record of the state of the object specified in the constructor.
void	removeChangeListener(ChangeListener x) Removes the given listener for changes of the inpsected instance.
void	run()
void	setHistoryLength(int length) Define the amount of recorded states of the Object to inspect that remain in memory.
void	setInterval(long sleeptime) Sets the interval for inpection of the instance to inspect in ms.
String	toString()

Methods inherited from class java.lang.Thread

activeCount, checkAccess, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, yield

Methods inherited from class java.lang.Object

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

Field Detail

VERBOSE

protected static final boolean VERBOSE

Verbosity constant.

See Also:

Constant Field Values

m_buffer

protected IRingBuffer m_buffer

Fast buffer to store recorded fiels.

m_changeListeners

protected EventListenerList m_changeListeners

The listeners on this recorder.

m_fields

protected Field[] m_fields

The fields to inspect on the instance.

m_interval

protected long m_interval

The time - interval between to inspections of the Object.

m_toinspect

protected Object m_toinspect

The instance to instpec.

Constructor Detail

ObjectRecorder

public ObjectRecorder(Object toinspect,
                      long interval)

Creates an instance that will inspect the given Object in the given time interval.

Parameters:

toinspect - the instance to inspect.

interval - the interval of inspection in ms.

Method Detail

addChangeListener

public void addChangeListener(ChangeListener x)

Adds a change listener that will be informed about new recordings of the inpected instances.

Parameters:

x - the change listener that will be informed about new recordings of the inpected instances.

fireChange

protected void fireChange()

Informs the listeners about a change of this instance.

getAttributeHistory

public TimeStampedValue[] getAttributeHistory(String attributeName)
                                       throws NoSuchAttributeException

The History returned by this Method represents the past of the field specified by attributeName. It starts from low index with the newest values taken from the inspected Object and ends with the oldest.

Parameters:

attributeName - field name of the internal instance to inspect.

Returns:

An array filled with TimeStampedValues that represent the past of the last inspections of the field with attributeName.

Throws:

NoSuchAttributeException - if the attribute / field described by the given argument does not exist on the internal Object to instpect.

See Also:

getInspected()

getAttributeNames

public String[] getAttributeNames()

Returns the names of the fields to inspect.

Returns:

the names of the fields to inspect.

getInspected

public Object getInspected()

Returns the inspected instance.

Returns:

the inspected instance.

getLastValue

public TimeStampedValue getLastValue(String fieldname)
                              throws NoSuchAttributeException

Returns the last recoreded value taken from the given field along with the timestamp identifying the time this value was recored.

Parameters:

fieldname - the field whose value was recorded.

Returns:

the last recoreded value taken from the given field along with the timestamp identifying the time this value was recored.

Throws:

NoSuchAttributeException - if no such field exists on the Object to inspect.

getRingBuffer

public IRingBuffer getRingBuffer()

Returns the internal fifo buffer that stores the ObjectRecorder.ObjectInspection instances that have been done.

Returns:

the internal fifo buffer that stores the ObjectRecorder.ObjectInspection instances that have been done.

inspect

public void inspect()

Makes a record of the state of the object specified in the constructor. The new record is stored in a RingBuffer and contains all retrieveable values of the Object specified in the constructor. Reflection is used to get the values. If a field is private it's value is tried to be taken from the Object by invoking a getter - method conform with the bean - specification: The name of the method has to be "get" followed by the name of the field with first letter uppercase.

removeChangeListener

public void removeChangeListener(ChangeListener x)

Removes the given listener for changes of the inpsected instance.

Parameters:

x - the listener to remove.

run

public void run()

Specified by:

run in interface Runnable

Overrides:

run in class Thread

See Also:

Runnable.run()

setHistoryLength

public void setHistoryLength(int length)

Define the amount of recorded states of the Object to inspect that remain in memory.

Default value is 100.

Parameters:

length - the amount of recorded states of the Object to inspect that remain in memory.

setInterval

public void setInterval(long sleeptime)

Sets the interval for inpection of the instance to inspect in ms.

Parameters:

sleeptime - the interval for inpection of the instance to inspect in ms.

See Also:

ObjectRecorder(Object, long)

toString

public String toString()

Overrides:

toString in class Thread

See Also:

Object.toString()