org.codehaus.mojo.jaxb2.shared.filters

Class AbstractFilter<T>

java.lang.Object

org.codehaus.mojo.jaxb2.shared.filters.AbstractFilter<T>

All Implemented Interfaces:

Filter<T>

Direct Known Subclasses:

AbstractPatternFilter, FileFilterAdapter

public abstract class AbstractFilter<T>
extends Object
implements Filter<T>

Abstract Filter implementation which handles separating null candidate values from non-null ones, and delegates processing to concrete subclass implementations. Also, this AbstractFilter implementation provides a standard for emitting Filter debug statements (i.e. for toString() calls).

Since:

2.0

Author:

Lennart Jörelid, jGuru Europe AB

Field Summary

Fields

Modifier and Type	Field and Description
protected org.apache.maven.plugin.logging.Log	log
protected static String	TOSTRING_INDENT Initial-line indent for human-readable toString() rendering.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractFilter() Convenience constructor which creates an AbstractFilter which does not process null values.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	accept(T candidate) Method that is invoked to determine if a candidate instance should be accepted or not.
protected void	addDelayedLogMessage(String logLevel, String message) Adds a log message to be emitted when this AbstractFilter is initialized (and the Log is made available to it).
void	initialize(org.apache.maven.plugin.logging.Log log) Initializes this Filter, and assigns the supplied Log for use by this Filter.
boolean	isInitialized()
protected abstract boolean	onCandidate(T nonNullCandidate) Method that is invoked to determine if a candidate instance should be accepted or not.
protected void	onInitialize() Override this method to perform some custom action after standard initialization is complete.
protected boolean	onNullCandidate() Override this to perform an action other than debug logging whenever this AbstractFilter receives a null candidate.
protected void	setProcessNullValues(boolean processNullValues) Assigns the processNullValues property which indicates if this AbstractFilter should process null values or not.
String	toString()
protected void	validateDiSetterCalledBeforeInitialization(String setterPropertyName) Validator method which should be called in a DI setter method to ensure that this AbstractFilter has not yet been initialized.

Methods inherited from class java.lang.Object

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

Field Detail

TOSTRING_INDENT

protected static final String TOSTRING_INDENT

Initial-line indent for human-readable toString() rendering.

See Also:

Constant Field Values

log

protected org.apache.maven.plugin.logging.Log log

Constructor Detail

AbstractFilter

protected AbstractFilter()

Convenience constructor which creates an AbstractFilter which does not process null values.

Method Detail

validateDiSetterCalledBeforeInitialization

protected final void validateDiSetterCalledBeforeInitialization(String setterPropertyName)

Validator method which should be called in a DI setter method to ensure that this AbstractFilter has not yet been initialized.

Parameters:

setterPropertyName - The name of the property to inject.

addDelayedLogMessage

protected final void addDelayedLogMessage(String logLevel,
                        String message)

Adds a log message to be emitted when this AbstractFilter is initialized (and the Log is made available to it).

Parameters:

logLevel - The logLevel of the message to emit.

message - The message to emit.

setProcessNullValues

protected final void setProcessNullValues(boolean processNullValues)

Assigns the processNullValues property which indicates if this AbstractFilter should process null values or not.

Parameters:

processNullValues - true to indicate that this AbstractFilter should process null values.

initialize

public final void initialize(org.apache.maven.plugin.logging.Log log)

Initializes this Filter, and assigns the supplied Log for use by this Filter.

Specified by:

initialize in interface Filter<T>

Parameters:

log - The non-null Log which should be used by this Filter to emit log messages.

isInitialized

public boolean isInitialized()

Specified by:

isInitialized in interface Filter<T>

Returns:

true if this Filter has been properly initialized (by a call to the initialize method).

onInitialize

protected void onInitialize()

Override this method to perform some custom action after standard initialization is complete. Default implementation does nothing, but the log is non-null and ready for use.

accept

public final boolean accept(T candidate)
                     throws IllegalStateException

Method that is invoked to determine if a candidate instance should be accepted or not. Implementing classes should be prepared to handle null candidate objects.

Specified by:

accept in interface Filter<T>

Parameters:

candidate - The candidate that should be tested for acceptance by this Filter.

Returns:

true if the candidate is accepted by this Filter and false otherwise.

Throws:

IllegalStateException - if this Filter is not initialized by a call to the initialize method before calling this matchAtLeastOnce method.

onNullCandidate

protected boolean onNullCandidate()

Override this to perform an action other than debug logging whenever this AbstractFilter receives a null candidate. You also need to override this implementation if you want to return a value other than false. There is no point in calling super.onNullCandidate() whenever this method is overridden.

Returns:

false - implying that AbstractFilters will not matchAtLeastOnce nulls by default.

onCandidate

protected abstract boolean onCandidate(T nonNullCandidate)

Method that is invoked to determine if a candidate instance should be accepted or not.

Parameters:

nonNullCandidate - The candidate that should be tested for acceptance by this Filter. Never null.

Returns:

true if the candidate is accepted by this Filter and false otherwise.

toString

public String toString()

Overrides:

toString in class Object