org.apache.commons.digester3.plugins.strategies
Class FinderSetProperties

java.lang.Object
  org.apache.commons.digester3.plugins.RuleFinder
      org.apache.commons.digester3.plugins.strategies.FinderSetProperties

public class FinderSetProperties
extends RuleFinder

A rule-finding algorithm which expects the user to specify whether "automatic property setting" is desired. If this class discovers that this is in fact the case for a declaration, then a RuleLoader is returned which, when invoked, adds a single SetPropertiesRule instance to the digester.

This allows ordinary JavaBean classes to be used as plugins, and have xml attributes be mapped to bean properties of the same name, without any custom plugin rules being created for them.

This RuleFinder is typically used as the last RuleFinder, so that automatic property setting only occurs if there is no other source of custom rules available.

Since:

1.6

Constructor Summary

FinderSetProperties()
See findLoader(org.apache.commons.digester3.Digester, java.lang.Class, java.util.Properties).

FinderSetProperties(String propsAttr, String falseval)
Create a rule-finder which will arrange for a SetPropertiesRule to be defined for each instance of a plugin, so that xml attributes map to bean properties.

Method Summary

RuleLoader

findLoader(Digester d, Class<?> pluginClass, Properties p) Returns a RuleLoader unless the properties contain an entry with the name matching constructor param propsAttr, and the value matching what is in falseval.

Methods inherited from class java.lang.Object

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

Constructor Detail

FinderSetProperties

public FinderSetProperties()

See findLoader(org.apache.commons.digester3.Digester, java.lang.Class, java.util.Properties).

FinderSetProperties

public FinderSetProperties(String propsAttr,
                           String falseval)

Create a rule-finder which will arrange for a SetPropertiesRule to be defined for each instance of a plugin, so that xml attributes map to bean properties.

Param falseval will commonly be the string "false" for config files written in English.

Parameters:

propsAttr - must be non-null.

falseval - must be non-null.

Method Detail

findLoader

public RuleLoader findLoader(Digester d,
                             Class<?> pluginClass,
                             Properties p)
                      throws PluginException

Returns a RuleLoader unless the properties contain an entry with the name matching constructor param propsAttr, and the value matching what is in falseval.

If no custom source of rules for a plugin is found, then the user almost always wants xml attributes to map to java bean properties, so this is the default behaviour unless the user explicitly indicates that they do not want a SetPropertiesRule to be provided for the plugged-in class.

The returned object (when non-null) will add a SetPropertiesRule to the digester whenever its addRules method is invoked.

Specified by:

findLoader in class RuleFinder

Parameters:

d - The digester instance where locating plugin classes

pluginClass - The plugin Java class

p - The properties object that holds any xml attributes the user may have specified on the plugin declaration in order to indicate how to locate the plugin rules.

Returns:

a source of digester rules for the specified plugin class.

Throws:

PluginException - if the algorithm finds a source of rules, but there is something invalid about that source.