org.apache.tools.ant.types.selectors
Class DifferentSelector

java.lang.Object
  |
  +--org.apache.tools.ant.ProjectComponent
        |
        +--org.apache.tools.ant.types.DataType
              |
              +--org.apache.tools.ant.types.selectors.BaseSelector
                    |
                    +--org.apache.tools.ant.types.selectors.MappingSelector
                          |
                          +--org.apache.tools.ant.types.selectors.DifferentSelector
All Implemented Interfaces:
FileSelector

public class DifferentSelector
extends MappingSelector

This selector selects files against a mapped set of target files, selecting all those files which are different. Files with different lengths are deemed different automatically Files with identical timestamps are viewed as matching by default, unless you specify otherwise. Contents are compared if the lengths are the same and the timestamps are ignored or the same, except if you decide to ignore contents to gain speed.

This is a useful selector to work with programs and tasks that don't handle dependency checking properly; Even if a predecessor task always creates its output files, followup tasks can be driven off copies made with a different selector, so their dependencies are driven on the absolute state of the files, not a timestamp.

Clearly, however, bulk file comparisons is inefficient; anything that can use timestamps is to be preferred. If this selector must be used, use it over as few files as possible, perhaps following it with an <uptodate;> to keep the descendent routines conditional.


Field Summary
 
Fields inherited from class org.apache.tools.ant.types.selectors.MappingSelector
granularity, map, mapperElement, targetdir
 
Fields inherited from class org.apache.tools.ant.types.DataType
checked, description, ref
 
Fields inherited from class org.apache.tools.ant.ProjectComponent
project
 
Constructor Summary
DifferentSelector()
           
 
Method Summary
protected  boolean selectionTest(java.io.File srcfile, java.io.File destfile)
          this test is our selection test that compared the file with the destfile
 void setIgnoreContents(boolean ignoreContents)
          This flag tells the selector to ignore contents
 void setIgnoreFileTimes(boolean ignoreFileTimes)
          This flag tells the selector to ignore file times in the comparison
 
Methods inherited from class org.apache.tools.ant.types.selectors.MappingSelector
createMapper, isSelected, setGranularity, setTargetdir, verifySettings
 
Methods inherited from class org.apache.tools.ant.types.selectors.BaseSelector
getError, setError, validate
 
Methods inherited from class org.apache.tools.ant.types.DataType
checkAttributesAllowed, checkChildrenAllowed, circularReference, dieOnCircularReference, getCheckedRef, getDescription, getRefid, isChecked, isReference, noChildrenAllowed, setChecked, setDescription, setRefid, tooManyAttributes
 
Methods inherited from class org.apache.tools.ant.ProjectComponent
getProject, log, log, setProject
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

DifferentSelector

public DifferentSelector()
Method Detail

setIgnoreFileTimes

public void setIgnoreFileTimes(boolean ignoreFileTimes)
This flag tells the selector to ignore file times in the comparison

Parameters:
ignoreFileTimes - if true ignore file times

setIgnoreContents

public void setIgnoreContents(boolean ignoreContents)
This flag tells the selector to ignore contents

Parameters:
ignoreContents - if true ignore contents
Since:
ant 1.6.3

selectionTest

protected boolean selectionTest(java.io.File srcfile,
                                java.io.File destfile)
this test is our selection test that compared the file with the destfile

Specified by:
selectionTest in class MappingSelector
Parameters:
srcfile - the source file
destfile - the destination file
Returns:
true if the files are different


Copyright 2000-2005 Apache Software Foundation. All Rights Reserved.