ix.util
Class PropertyLogger

java.lang.Object
  ix.util.PropertyLogger

public class PropertyLogger
extends java.lang.Object

Automatically log property values to a file. The property, object, and property-value must all be strings.

Nested Class Summary

class

PropertyLogger.LoggingMap A Map-like object that records any property value that is given to its 'put' method.

Constructor Summary

PropertyLogger(java.lang.String logFileName)
Make a logger for the named file.

Method Summary

PropertyLogger.LoggingMap	ensureMap(java.lang.String propName) Returns this logger's LoggingMap for the named property, creating it if it does not already exist.
java.lang.String	get(java.lang.String propName, java.lang.String objectName) Returns the object's value of the named property, or else else if no such value has been assigned.
PropertyLogger.LoggingMap	getMap(java.lang.String propName) Returns this logger's LoggingMap for the named property, or else null of no such map yet exists.
static void	main(java.lang.String[] argv) Simple main program for testing.
void	put(java.lang.String propName, java.lang.String objectName, java.lang.String propValue) Records a value for the named object and property.
boolean	putIfNew(java.lang.String propName, java.lang.String objectName, java.lang.String propValue) Records a value for the named object and property, but only if the value is new.
void	readLogIfExists() Reads and remembers property values from this logger's log file if the file exists.

Methods inherited from class java.lang.Object

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

Constructor Detail

PropertyLogger

public PropertyLogger(java.lang.String logFileName)

Make a logger for the named file.

Method Detail

getMap

public PropertyLogger.LoggingMap getMap(java.lang.String propName)

Returns this logger's LoggingMap for the named property, or else null of no such map yet exists.

ensureMap

public PropertyLogger.LoggingMap ensureMap(java.lang.String propName)

Returns this logger's LoggingMap for the named property, creating it if it does not already exist.

get

public java.lang.String get(java.lang.String propName,
                            java.lang.String objectName)

Returns the object's value of the named property, or else else if no such value has been assigned.

put

public void put(java.lang.String propName,
                java.lang.String objectName,
                java.lang.String propValue)

Records a value for the named object and property. The first time this method is called, this logger's log file will be renamed, if it exists, and a new log file will be created. Any values that had been read by calling readLogIfExists() will be recorded in the new file, followed by the new property value.

putIfNew

public boolean putIfNew(java.lang.String propName,
                        java.lang.String objectName,
                        java.lang.String propValue)

Records a value for the named object and property, but only if the value is new. "New" means either that no value had been recorded for that object and property combination before, or that a different value had been recorded. "Different" is determined by calling 'equals'. Recording a value affacts the log file in the same way as put(String,String,String).

Returns:

true if the information was new and false otherwise.

readLogIfExists

public void readLogIfExists()

Reads and remembers property values from this logger's log file if the file exists. This method does not change the file.

When the first new property value is assigned, the file will be renamed (if it exists), and a new file will be created. The old property values (if any), plus the new value, will then be written to the new file.

main

public static void main(java.lang.String[] argv)

Simple main program for testing. Takes one command-line argument which should be the name of the log file.