Class EventExample

java.lang.Object

org.slf4j.helpers.MarkerIgnoringBase

org.apache.velocity.example.EventExample

All Implemented Interfaces:

Serializable, org.apache.velocity.app.event.EventHandler, org.apache.velocity.app.event.InvalidReferenceEventHandler, org.apache.velocity.app.event.MethodExceptionEventHandler, org.apache.velocity.app.event.ReferenceInsertionEventHandler, org.slf4j.Logger

public class EventExample
extends org.slf4j.helpers.MarkerIgnoringBase
implements org.apache.velocity.app.event.ReferenceInsertionEventHandler, org.apache.velocity.app.event.MethodExceptionEventHandler, org.apache.velocity.app.event.InvalidReferenceEventHandler

This class is a simple demonstration of how the event handling features of the Velocity Servlet Engine are used. It uses a custom logger as well to check the log message stream when testing the InvalidReferenceEventHandler.

Version:

$Id$

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
private boolean	exceptionSwitch
static final int	LOG_LEVEL_DEBUG
static final int	LOG_LEVEL_ERROR
static final int	LOG_LEVEL_INFO
static final int	LOG_LEVEL_TRACE
static final int	LOG_LEVEL_WARN
private boolean	logOutput
protected String	name

Fields inherited from interface org.slf4j.Logger

ROOT_LOGGER_NAME

Constructor Summary

Constructors

Constructor	Description
EventExample()

Method Summary

Modifier and Type	Method	Description
void	debug(String msg)
void	debug(String format, Object param1)
void	debug(String format, Object... argArray)
void	debug(String format, Object param1, Object param2)
void	debug(String msg, Throwable t)
void	error(String msg)
void	error(String format, Object arg)
void	error(String format, Object... argArray)
void	error(String format, Object arg1, Object arg2)
void	error(String msg, Throwable t)
void	formatAndLog(int level, String format, Object... arguments)	This prints the level and formatted message to System.out.
String	getName()	Required init methods for Logger interface
void	info(String msg)
void	info(String format, Object arg)
void	info(String format, Object... argArray)
void	info(String format, Object arg1, Object arg2)
void	info(String msg, Throwable t)
Object	invalidGetMethod(org.apache.velocity.context.Context context, String reference, Object object, String property, org.apache.velocity.util.introspection.Info info)
Object	invalidMethod(org.apache.velocity.context.Context context, String reference, Object object, String method, org.apache.velocity.util.introspection.Info info)
boolean	invalidSetMethod(org.apache.velocity.context.Context context, String leftreference, String rightreference, org.apache.velocity.util.introspection.Info info)	Event handler for when the right hand side of a #set() directive is null, which results in a log message.
boolean	isDebugEnabled()
boolean	isErrorEnabled()
boolean	isInfoEnabled()
boolean	isLevelEnabled(int level)	This always returns true because logging levels can't be disabled in this impl.
boolean	isTraceEnabled()
boolean	isWarnEnabled()
void	log(int level, String message)	This just prints the message and level to System.out.
void	log(int level, String message, Throwable t)	This prints the level, message, and the Throwable's message to System.out.
static void	main(String[] args)
Object	methodException(org.apache.velocity.context.Context context, Class claz, String method, Exception e, org.apache.velocity.util.introspection.Info info)
protected Object	readResolve()
Object	referenceInsert(org.apache.velocity.context.Context context, String reference, Object value)	Event handler for when a reference is inserted into the output stream.
void	throwException()	silly method to throw an exception to demonstrate the method invocation exception event handling
void	trace(String msg)
void	trace(String format, Object param1)
void	trace(String format, Object... argArray)
void	trace(String format, Object param1, Object param2)
void	trace(String msg, Throwable t)
void	warn(String msg)
void	warn(String format, Object arg)
void	warn(String format, Object... argArray)
void	warn(String format, Object arg1, Object arg2)
void	warn(String msg, Throwable t)

Methods inherited from class org.slf4j.helpers.MarkerIgnoringBase

debug, debug, debug, debug, debug, error, error, error, error, error, info, info, info, info, info, isDebugEnabled, isErrorEnabled, isInfoEnabled, isTraceEnabled, isWarnEnabled, toString, trace, trace, trace, trace, trace, warn, warn, warn, warn, warn

Methods inherited from class Object

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

Field Details

logOutput

private boolean logOutput

exceptionSwitch

private boolean exceptionSwitch

LOG_LEVEL_TRACE

public static final int LOG_LEVEL_TRACE

See Also:

• Constant Field Values

LOG_LEVEL_DEBUG

public static final int LOG_LEVEL_DEBUG

See Also:

• Constant Field Values

LOG_LEVEL_INFO

public static final int LOG_LEVEL_INFO

See Also:

• Constant Field Values

LOG_LEVEL_WARN

public static final int LOG_LEVEL_WARN

See Also:

• Constant Field Values

LOG_LEVEL_ERROR

public static final int LOG_LEVEL_ERROR

See Also:

• Constant Field Values

name

protected String name

Constructor Details

EventExample

public EventExample()

Method Details

main

public static void main(String[] args)

throwException

public void throwException()
                    throws Exception

silly method to throw an exception to demonstrate the method invocation exception event handling

Throws:

Exception

referenceInsert

public Object referenceInsert(org.apache.velocity.context.Context context,
 String reference,
 Object value)

Event handler for when a reference is inserted into the output stream.

Specified by:

referenceInsert in interface org.apache.velocity.app.event.ReferenceInsertionEventHandler

invalidGetMethod

public Object invalidGetMethod(org.apache.velocity.context.Context context,
 String reference,
 Object object,
 String property,
 org.apache.velocity.util.introspection.Info info)

Specified by:

invalidGetMethod in interface org.apache.velocity.app.event.InvalidReferenceEventHandler

invalidMethod

public Object invalidMethod(org.apache.velocity.context.Context context,
 String reference,
 Object object,
 String method,
 org.apache.velocity.util.introspection.Info info)

Specified by:

invalidMethod in interface org.apache.velocity.app.event.InvalidReferenceEventHandler

invalidSetMethod

public boolean invalidSetMethod(org.apache.velocity.context.Context context,
 String leftreference,
 String rightreference,
 org.apache.velocity.util.introspection.Info info)

Event handler for when the right hand side of a #set() directive is null, which results in a log message. This method gives the application a chance to 'vote' on msg generation

Specified by:

invalidSetMethod in interface org.apache.velocity.app.event.InvalidReferenceEventHandler

methodException

public Object methodException(org.apache.velocity.context.Context context,
 Class claz,
 String method,
 Exception e,
 org.apache.velocity.util.introspection.Info info)

Specified by:

methodException in interface org.apache.velocity.app.event.MethodExceptionEventHandler

log

public void log(int level,
 String message)

This just prints the message and level to System.out.

log

public void log(int level,
 String message,
 Throwable t)

This prints the level, message, and the Throwable's message to System.out.

formatAndLog

public void formatAndLog(int level,
 String format,
 Object... arguments)

This prints the level and formatted message to System.out.

isLevelEnabled

public boolean isLevelEnabled(int level)

This always returns true because logging levels can't be disabled in this impl.

getName

public String getName()

Required init methods for Logger interface

Specified by:

getName in interface org.slf4j.Logger

isTraceEnabled

public boolean isTraceEnabled()

Specified by:

isTraceEnabled in interface org.slf4j.Logger

trace

public void trace(String msg)

Specified by:

trace in interface org.slf4j.Logger

trace

public void trace(String format,
 Object param1)

Specified by:

trace in interface org.slf4j.Logger

trace

public void trace(String format,
 Object param1,
 Object param2)

Specified by:

trace in interface org.slf4j.Logger

trace

public void trace(String format,
 Object... argArray)

Specified by:

trace in interface org.slf4j.Logger

trace

public void trace(String msg,
 Throwable t)

Specified by:

trace in interface org.slf4j.Logger

isDebugEnabled

public boolean isDebugEnabled()

Specified by:

isDebugEnabled in interface org.slf4j.Logger

debug

public void debug(String msg)

Specified by:

debug in interface org.slf4j.Logger

debug

public void debug(String format,
 Object param1)

Specified by:

debug in interface org.slf4j.Logger

debug

public void debug(String format,
 Object param1,
 Object param2)

Specified by:

debug in interface org.slf4j.Logger

debug

public void debug(String format,
 Object... argArray)

Specified by:

debug in interface org.slf4j.Logger

debug

public void debug(String msg,
 Throwable t)

Specified by:

debug in interface org.slf4j.Logger

isInfoEnabled

public boolean isInfoEnabled()

Specified by:

isInfoEnabled in interface org.slf4j.Logger

info

public void info(String msg)

Specified by:

info in interface org.slf4j.Logger

info

public void info(String format,
 Object arg)

Specified by:

info in interface org.slf4j.Logger

info

public void info(String format,
 Object arg1,
 Object arg2)

Specified by:

info in interface org.slf4j.Logger

info

public void info(String format,
 Object... argArray)

Specified by:

info in interface org.slf4j.Logger

info

public void info(String msg,
 Throwable t)

Specified by:

info in interface org.slf4j.Logger

isWarnEnabled

public boolean isWarnEnabled()

Specified by:

isWarnEnabled in interface org.slf4j.Logger

warn

public void warn(String msg)

Specified by:

warn in interface org.slf4j.Logger

warn

public void warn(String format,
 Object arg)

Specified by:

warn in interface org.slf4j.Logger

warn

public void warn(String format,
 Object arg1,
 Object arg2)

Specified by:

warn in interface org.slf4j.Logger

warn

public void warn(String format,
 Object... argArray)

Specified by:

warn in interface org.slf4j.Logger

warn

public void warn(String msg,
 Throwable t)

Specified by:

warn in interface org.slf4j.Logger

isErrorEnabled

public boolean isErrorEnabled()

Specified by:

isErrorEnabled in interface org.slf4j.Logger

error

public void error(String msg)

Specified by:

error in interface org.slf4j.Logger

error

public void error(String format,
 Object arg)

Specified by:

error in interface org.slf4j.Logger

error

public void error(String format,
 Object arg1,
 Object arg2)

Specified by:

error in interface org.slf4j.Logger

error

public void error(String format,
 Object... argArray)

Specified by:

error in interface org.slf4j.Logger

error

public void error(String msg,
 Throwable t)

Specified by:

error in interface org.slf4j.Logger

readResolve

protected Object readResolve()
                      throws ObjectStreamException

Throws:

ObjectStreamException