Package com.inductiveautomation.ignition.common

Class PersistentProperties

java.lang.Object

java.util.Dictionary<K,V>

java.util.Hashtable<Object,Object>

java.util.Properties

com.inductiveautomation.ignition.common.PersistentProperties

All Implemented Interfaces:

Serializable, Cloneable, Map<Object,Object>

public class PersistentProperties
extends Properties

A simple extension of properties that is meant to represent a file based property file. The entire property file will be written eventually after a call to setProperty(), according to the max storage frequency.

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected boolean	_savePaused
protected int	maxStorageFrequencyMS
protected boolean	writeQueued
protected Thread	writeThread

Fields inherited from class java.util.Properties

defaults

Constructor Summary

Constructors

Constructor	Description
PersistentProperties()
PersistentProperties(File file, String comments)
PersistentProperties(File file, String comments, boolean requireInitial)	Creates a new PersistentProperties object.

Method Summary

Modifier and Type	Method	Description
protected void	copyFile(File source, File dest)
File	getFile()
int	getMaxStorageFrequencyMS()	Returns the maximum rate at which the file will be written.
File	getTempFile()
boolean	isNew()
Set<Object>	keySet()
protected void	potentiallyExecuteWrite()
Object	remove(Object key)
Object	removeIntermediate(Object key)
void	setMaxStorageFrequencyMS(int maxStorageFrequencyMS)	Sets the maximum rate at which the file will be written.
Object	setProperty(String key, String value)
Object	setPropertyIntermediate(String key, String value)	Sets a property without pesisting the change.
void	storeChanges()	Do the following to ensure there is always a well-formed file on the HD Write file to temp file Copy temp file to main file
protected void	tryLoad(File file)	Tries to call super.loadFromXML with an input stream from this file.

Methods inherited from class java.util.Properties

clear, clone, compute, computeIfAbsent, computeIfPresent, contains, containsKey, containsValue, elements, entrySet, equals, forEach, get, getOrDefault, getProperty, getProperty, hashCode, isEmpty, keys, list, list, load, load, loadFromXML, merge, propertyNames, put, putAll, putIfAbsent, rehash, remove, replace, replace, replaceAll, save, size, store, store, storeToXML, storeToXML, storeToXML, stringPropertyNames, toString, values

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

_savePaused

protected transient boolean _savePaused

maxStorageFrequencyMS

protected int maxStorageFrequencyMS

writeThread

protected transient Thread writeThread

writeQueued

protected transient boolean writeQueued

Constructor Details

PersistentProperties

public PersistentProperties(File file,
 String comments)
                     throws IOException

Throws:

IOException

PersistentProperties

public PersistentProperties(File file,
 String comments,
 boolean requireInitial)
                     throws IOException

Creates a new PersistentProperties object. The backup file will be "."+filename+".bak" and the clean file will be filename+"_clean".

Parameters:

requireInitial - Whether or not a valid file or _clean file is required. If false, the constructor will accept the situation where none of the 3 files exist.

Throws:

IOException

PersistentProperties

public PersistentProperties()

Method Details

getMaxStorageFrequencyMS

public int getMaxStorageFrequencyMS()

Returns the maximum rate at which the file will be written. After a property is set, the file is written immediately, unless the specified time has not passed, in which case the file will be marked as "dirty" and written when the delay expires.

Defaults to 500ms.

setMaxStorageFrequencyMS

public void setMaxStorageFrequencyMS(int maxStorageFrequencyMS)

Sets the maximum rate at which the file will be written. If 0, writes will occur immediately, and in the same thread, instead of asynchronously.

isNew

public boolean isNew()

getFile

public File getFile()

getTempFile

public File getTempFile()

tryLoad

protected void tryLoad(File file)
                throws IOException

Tries to call super.loadFromXML with an input stream from this file.

Throws:

IOException - if anything goes wrong with the load.

removeIntermediate

public Object removeIntermediate(Object key)

remove

public Object remove(Object key)

Specified by:

remove in interface Map<Object,Object>

Overrides:

remove in class Properties

setProperty

public Object setProperty(String key,
 String value)

Overrides:

setProperty in class Properties

setPropertyIntermediate

public Object setPropertyIntermediate(String key,
 String value)

Sets a property without pesisting the change.

keySet

public Set<Object> keySet()

Specified by:

keySet in interface Map<Object,Object>

Overrides:

keySet in class Properties

storeChanges

public void storeChanges()

Do the following to ensure there is always a well-formed file on the HD

1. Write file to temp file
2. Copy temp file to main file

potentiallyExecuteWrite

protected void potentiallyExecuteWrite()

copyFile

protected void copyFile(File source,
 File dest)
                 throws IOException

Throws:

IOException