Class ModifiedSelector
- All Implemented Interfaces:
- Cloneable,- EventListener,- BuildListener,- Parameterizable,- ResourceSelector,- ExtendFileSelector,- FileSelector
Selector class that uses Algorithm, Cache and Comparator for its work. The Algorithm is used for computing a hashvalue for a file. The Comparator decides whether to select or not. The Cache stores the other value for comparison by the Comparator in a persistent manner.
The ModifiedSelector is implemented as a CoreSelector and uses default values for all its attributes therefore the simplest example is
   <copy todir="dest">
       <fileset dir="src">
           <modified/>
       </fileset>
   </copy>
 
 The same example rewritten as CoreSelector with setting the all values (same as defaults are) would be
   <copy todir="dest">
       <fileset dir="src">
           <modified update="true"
                     cache="propertyfile"
                     algorithm="digest"
                     comparator="equal">
               <param name="cache.cachefile"     value="cache.properties"/>
               <param name="algorithm.algorithm" value="MD5"/>
           </modified>
       </fileset>
   </copy>
 
 And the same rewritten as CustomSelector would be
   <copy todir="dest">
       <fileset dir="src">
           <custom class="org.apache.tools.ant.type.selectors.ModifiedSelector">
               <param name="update"     value="true"/>
               <param name="cache"      value="propertyfile"/>
               <param name="algorithm"  value="digest"/>
               <param name="comparator" value="equal"/>
               <param name="cache.cachefile"     value="cache.properties"/>
               <param name="algorithm.algorithm" value="MD5"/>
           </custom>
       </fileset>
   </copy>
 
 If you want to provide your own interface implementation you can do that via the *classname attributes. If the classes are not on Ant's core classpath, you will have to provide the path via nested <classpath> element, so that the selector can find the classes.
   <modified cacheclassname="com.mycompany.MyCache">
       <classpath>
           <pathelement location="lib/mycompany-antutil.jar"/>
       </classpath>
   </modified>
 
 All these three examples copy the files from src to dest using the ModifiedSelector. The ModifiedSelector uses the PropertyfileCache , the DigestAlgorithm and the EqualComparator for its work. The PropertyfileCache stores key-value-pairs in a simple java properties file. The filename is cache.properties. The update flag lets the selector update the values in the cache (and on first call creates the cache). The DigestAlgorithm computes a hashvalue using the java.security.MessageDigest class with its MD5-Algorithm and its standard provider. The new computed hashvalue and the stored one are compared by the EqualComparator which returns 'true' (more correct a value not equals zero (1)) if the values are not the same using simple String comparison.
A useful scenario for this selector is inside a build environment for homepage generation (e.g. with Apache Forrest).
 <target name="generate-and-upload-site">
     <echo> generate the site using forrest </echo>
     <antcall target="site"/>
     <echo> upload the changed files </echo>
     <ftp server="${ftp.server}" userid="${ftp.user}" password="${ftp.pwd}">
         <fileset dir="htdocs/manual">
             <modified/>
         </fileset>
     </ftp>
 </target>
 Here all changed files are uploaded to the server. The ModifiedSelector saves therefore much upload time.
This selector uses reflection for setting the values of its three interfaces (using org.apache.tools.ant.IntrospectionHelper) therefore no special 'configuration interfaces' has to be implemented by new caches, algorithms or comparators. All present setXX methods can be used. E.g. the DigestAlgorithm can use a specified provider for computing its value. For selecting this there is a setProvider(String providername) method. So you can use a nested <param name="algorithm.provider" value="MyProvider"/>.
- Since:
- Ant 1.6
- 
Nested Class SummaryNested ClassesModifier and TypeClassDescriptionstatic classThe enumerated type for algorithm.static classThe enumerated type for cache.static classThe enumerated type for algorithm.
- 
Field SummaryFields inherited from class org.apache.tools.ant.types.selectors.BaseExtendSelectorparametersFields inherited from class org.apache.tools.ant.ProjectComponentdescription, location, project
- 
Constructor SummaryConstructors
- 
Method SummaryModifier and TypeMethodDescriptionvoidaddClasspath(Path path) Add the classpath.voidSupport for nested <param> tags.voidSupport for nested <param> tags.voidbuildFinished(BuildEvent event) Signals that the last target has finished.voidbuildStarted(BuildEvent event) Signals that a build has started.voidConfigures this Selector.Get the algorithm type to use.getCache()Get the cache type to use.Returns and initializes the classloader for this class.Comparator<? super String> Get the comparator type to use.booleanGetter for the delay updateintGetter for the modified countbooleanisSelected(File basedir, String filename, File file) Implementation of BaseExtendSelector.isSelected().booleanisSelected(Resource resource) Implementation of ResourceSelector.isSelected().protected <T> TLoads the specified class and initializes an object of that class.voidmessageLogged(BuildEvent event) Signals a message logging event.protected voidsave the cache filevoidSet the algorithm type to use.voidsetAlgorithmClass(String classname) Setter for algorithmClass.voidSet the cache type to use.voidsetCacheClass(String classname) Setter for cacheClass.voidsetClassLoader(ClassLoader loader) Set the used ClassLoader.voidSet the comparator type to use.voidsetComparatorClass(String classname) Setter for comparatorClass.voidsetDelayUpdate(boolean delayUpdate) Setter for the delay updatevoidsetModified(int modified) Setter for the modified countvoidsetParameters(Parameter... parameters) Defined in org.apache.tools.ant.types.Parameterizable.voidsetSeldirs(boolean seldirs) Support for seldirs attribute.voidsetSelres(boolean newValue) Support for selres attribute.voidsetUpdate(boolean update) Support for update attribute.voidtargetFinished(BuildEvent event) Signals that a target has finished.voidtargetStarted(BuildEvent event) Signals that a target is starting.voidtaskFinished(BuildEvent event) Signals that a task has finished.voidtaskStarted(BuildEvent event) Signals that a task is starting.toString()Override Object.toString().protected voidtryToSetAParameter(Object obj, String name, String value) Try to set a value on an object using reflection.voiduseParameter(Parameter parameter) Support for nested<param name="" value=""/>tags.voidOverrides BaseSelector.verifySettings().Methods inherited from class org.apache.tools.ant.types.selectors.BaseExtendSelectorgetParametersMethods inherited from class org.apache.tools.ant.types.selectors.BaseSelectorgetError, setError, setError, validateMethods inherited from class org.apache.tools.ant.types.DataTypecheckAttributesAllowed, checkChildrenAllowed, circularReference, clone, dieOnCircularReference, dieOnCircularReference, dieOnCircularReference, getCheckedRef, getCheckedRef, getCheckedRef, getCheckedRef, getCheckedRef, getDataTypeName, getRefid, invokeCircularReferenceCheck, isChecked, isReference, noChildrenAllowed, pushAndInvokeCircularReferenceCheck, setChecked, setRefid, tooManyAttributesMethods inherited from class org.apache.tools.ant.ProjectComponentgetDescription, getLocation, getProject, log, log, setDescription, setLocation, setProject
- 
Constructor Details- 
ModifiedSelectorpublic ModifiedSelector()Bean-Constructor.
 
- 
- 
Method Details- 
verifySettingspublic void verifySettings()Overrides BaseSelector.verifySettings().- Overrides:
- verifySettingsin class- BaseSelector
 
- 
configurepublic void configure()Configures this Selector. Does this work only once per Selector object.Because some problems while configuring from <custom>Selector the configuration is done in the following order: - collect the configuration data
- wait for the first isSelected() call
- set the default values
- set values for name pattern '*': update, cache, algorithm, comparator
- set values for name pattern '*.*: cache.cachefile, ...
 This configuration algorithm is needed because you don't know the order of arriving config-data. E.g. if you first set the cache.cachefilename and after that the cache itself, the default value for cachefilename is used, because setting the cache implies creating a new Cache instance - with its defaults. 
- 
loadClassLoads the specified class and initializes an object of that class. Throws a BuildException using the given message if an error occurs during loading/instantiation or if the object is not from the given type.- Type Parameters:
- T- desired type
- Parameters:
- classname- the classname
- msg- the message-part for the BuildException
- type- the type to check against
- Returns:
- a castable object
 
- 
isSelectedImplementation of ResourceSelector.isSelected().- Specified by:
- isSelectedin interface- FileSelector
- Specified by:
- isSelectedin interface- ResourceSelector
- Parameters:
- resource- The resource to check
- Returns:
- whether the resource is selected
- See Also:
 
- 
isSelectedImplementation of BaseExtendSelector.isSelected().- Specified by:
- isSelectedin interface- FileSelector
- Specified by:
- isSelectedin class- BaseExtendSelector
- Parameters:
- basedir- as described in BaseExtendSelector
- filename- as described in BaseExtendSelector
- file- as described in BaseExtendSelector
- Returns:
- as described in BaseExtendSelector
 
- 
saveCacheprotected void saveCache()save the cache file
- 
setAlgorithmClassSetter for algorithmClass.- Parameters:
- classname- new value
 
- 
setComparatorClassSetter for comparatorClass.- Parameters:
- classname- new value
 
- 
setCacheClassSetter for cacheClass.- Parameters:
- classname- new value
 
- 
setUpdatepublic void setUpdate(boolean update) Support for update attribute.- Parameters:
- update- new value
 
- 
setSeldirspublic void setSeldirs(boolean seldirs) Support for seldirs attribute.- Parameters:
- seldirs- new value
 
- 
setSelrespublic void setSelres(boolean newValue) Support for selres attribute.- Parameters:
- newValue- the new value
 
- 
getModifiedpublic int getModified()Getter for the modified count- Returns:
- modified count
 
- 
setModifiedpublic void setModified(int modified) Setter for the modified count- Parameters:
- modified- count
 
- 
getDelayUpdatepublic boolean getDelayUpdate()Getter for the delay update- Returns:
- true if we should delay for performance
 
- 
setDelayUpdatepublic void setDelayUpdate(boolean delayUpdate) Setter for the delay update- Parameters:
- delayUpdate- true if we should delay for performance
 
- 
addClasspath
- 
getClassLoaderReturns and initializes the classloader for this class.- Returns:
- the classloader
 
- 
setClassLoaderSet the used ClassLoader. If you invoke this selector by API (e.g. inside some testcases) the selector will use a different classloader for loading the interface implementations than the caller. Therefore you will get a ClassCastException if you get the implementations from the selector and cast them.- Parameters:
- loader- the ClassLoader to use
 
- 
addParam
- 
addParamSupport for nested <param> tags.- Parameters:
- parameter- the parameter object
 
- 
setParametersDefined in org.apache.tools.ant.types.Parameterizable. Overwrite implementation in superclass because only special parameters are valid.- Specified by:
- setParametersin interface- Parameterizable
- Overrides:
- setParametersin class- BaseExtendSelector
- Parameters:
- parameters- the parameters to set.
- See Also:
 
- 
useParameterSupport for nested<param name="" value=""/>tags. Parameter named cache, algorithm, comparator or update are mapped to the respective set-Method. Parameter which names starts with cache. or algorithm. or comparator. are tried to set on the appropriate object via its set-methods. Other parameters are invalid and an BuildException will be thrown.- Parameters:
- parameter- Key and value as parameter object
 
- 
tryToSetAParameterTry to set a value on an object using reflection. Helper method for easier access to IntrospectionHelper.setAttribute().- Parameters:
- obj- the object on which the attribute should be set
- name- the attributename
- value- the new value
 
- 
toString
- 
buildFinishedSignals that the last target has finished.- Specified by:
- buildFinishedin interface- BuildListener
- Parameters:
- event- received BuildEvent
- See Also:
 
- 
targetFinishedSignals that a target has finished.- Specified by:
- targetFinishedin interface- BuildListener
- Parameters:
- event- received BuildEvent
- See Also:
 
- 
taskFinishedSignals that a task has finished.- Specified by:
- taskFinishedin interface- BuildListener
- Parameters:
- event- received BuildEvent
- See Also:
 
- 
buildStartedSignals that a build has started.- Specified by:
- buildStartedin interface- BuildListener
- Parameters:
- event- received BuildEvent
 
- 
targetStartedSignals that a target is starting.- Specified by:
- targetStartedin interface- BuildListener
- Parameters:
- event- received BuildEvent
- See Also:
 
- 
taskStartedSignals that a task is starting.- Specified by:
- taskStartedin interface- BuildListener
- Parameters:
- event- received BuildEvent
- See Also:
 
- 
messageLoggedSignals a message logging event.- Specified by:
- messageLoggedin interface- BuildListener
- Parameters:
- event- received BuildEvent
- See Also:
 
- 
getCache
- 
setCacheSet the cache type to use.- Parameters:
- name- an enumerated cache type.
 
- 
getAlgorithmGet the algorithm type to use.- Returns:
- the enumerated algorithm type
 
- 
setAlgorithmSet the algorithm type to use.- Parameters:
- name- an enumerated algorithm type.
 
- 
getComparatorGet the comparator type to use.- Returns:
- the enumerated comparator type
 
- 
setComparatorSet the comparator type to use.- Parameters:
- name- an enumerated comparator type.
 
 
-