org.apache.tools.ant.filters
Class SortFilter

java.lang.Object
  java.io.Reader
      java.io.FilterReader
          org.apache.tools.ant.filters.BaseFilterReader
              org.apache.tools.ant.filters.BaseParamFilterReader
                  org.apache.tools.ant.filters.SortFilter

All Implemented Interfaces:

java.io.Closeable, java.lang.Readable, ChainableReader, Parameterizable

public final class SortFilter
extends BaseParamFilterReader
implements ChainableReader

Sort a file before and/or after the file.

Examples:

   <copy todir="build">
       <fileset dir="input" includes="*.txt"/>
       <filterchain>
           <sortfilter/>
       </filterchain>
   </copy>
 

Sort all files *.txt from src location and copy them into build location. The lines of each file are sorted in ascendant order comparing the lines via the String.compareTo(Object o) method.

   <copy todir="build">
       <fileset dir="input" includes="*.txt"/>
       <filterchain>
           <sortfilter reverse="true"/>
       </filterchain>
   </copy>
 

Sort all files *.txt from src location into reverse order and copy them into build location. If reverse parameter has value true (default value), then the output line of the files will be in ascendant order.

   <copy todir="build">
       <fileset dir="input" includes="*.txt"/>
       <filterchain>
           <filterreader classname="org.apache.tools.ant.filters.SortFilter">
             <param name="comparator" value="org.apache.tools.ant.filters.EvenFirstCmp"/>
           </filterreader>
       </filterchain>
   </copy>
 

Sort all files *.txt from src location using as sorting criterium EvenFirstCmp class, that sorts the file lines putting even lines first then odd lines for example. The modified files are copied into build location. The EvenFirstCmp, has to an instanciable class via Class.newInstance(), therefore in case of inner class has to be static. It also has to implement java.util.Comparator interface, for example:

         package org.apache.tools.ant.filters;
         ...(omitted)
           public final class EvenFirstCmp implements <b>Comparator</b> {
             public int compare(Object o1, Object o2) {
             ...(omitted)
             }
           }
 

The example above is equivalent to:

   <componentdef name="evenfirst"
                 classname="org.apache.tools.ant.filters.EvenFirstCmp"/>
   <copy todir="build">
       <fileset dir="input" includes="*.txt"/>
       <filterchain>
           <sortfilter>
               <evenfirst/>
           </sortfilter>
       </filterchain>
   </copy>
 

If parameter comparator is present, then reverse parameter will not be taken into account.

Since:

Ant 1.8.0

Field Summary

Fields inherited from class java.io.FilterReader

in

Fields inherited from class java.io.Reader

lock

Constructor Summary

SortFilter()
Constructor for "dummy" instances.

SortFilter(java.io.Reader in)
Creates a new filtered reader.

Method Summary

void	add(java.util.Comparator<? super java.lang.String> comparator) Set the comparator to be used as sorting criterion as nested element.
java.io.Reader	chain(java.io.Reader rdr) Creates a new SortReader using the passed in Reader for instantiation.
java.util.Comparator<? super java.lang.String>	getComparator() Returns the comparator to be used for sorting.
boolean	isReverse() Returns true if the sorting process will be in reverse order, otherwise the sorting process will be in ascendant order.
int	read() Returns the next character in the filtered stream.
void	setComparator(java.util.Comparator<? super java.lang.String> comparator) Set the comparator to be used as sorting criterium.
void	setReverse(boolean reverse) Sets the sorting process will be in ascendant (reverse=false) or to descendant (reverse=true).

Methods inherited from class org.apache.tools.ant.filters.BaseParamFilterReader

getParameters, setParameters

Methods inherited from class org.apache.tools.ant.filters.BaseFilterReader

getInitialized, getProject, read, readFully, readLine, setInitialized, setProject, skip

Methods inherited from class java.io.FilterReader

close, mark, markSupported, ready, reset

Methods inherited from class java.io.Reader

read, read

Methods inherited from class java.lang.Object

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

Constructor Detail

SortFilter

public SortFilter()

Constructor for "dummy" instances.

See Also:

BaseFilterReader.BaseFilterReader()

SortFilter

public SortFilter(java.io.Reader in)

Creates a new filtered reader.

Parameters:

in - A Reader object providing the underlying stream. Must not be null.

Method Detail

read

public int read()
         throws java.io.IOException

Returns the next character in the filtered stream. If the desired number of lines have already been read, the resulting stream is effectively at an end. Otherwise, the next character from the underlying stream is read and returned.

Overrides:

read in class java.io.FilterReader

Returns:

the next character in the resulting stream, or -1 if the end of the resulting stream has been reached

Throws:

java.io.IOException - if the underlying stream throws an IOException during reading

chain

public java.io.Reader chain(java.io.Reader rdr)

Creates a new SortReader using the passed in Reader for instantiation.

Specified by:

chain in interface ChainableReader

Parameters:

rdr - A Reader object providing the underlying stream. Must not be null.

Returns:

a new filter based on this configuration, but filtering the specified reader

isReverse

public boolean isReverse()

Returns true if the sorting process will be in reverse order, otherwise the sorting process will be in ascendant order.

Returns:

true if the sorting process will be in reverse order, otherwise the sorting process will be in ascendant order.

setReverse

public void setReverse(boolean reverse)

Sets the sorting process will be in ascendant (reverse=false) or to descendant (reverse=true).

Parameters:

reverse - Boolean representing reverse ordering process.

getComparator

public java.util.Comparator<? super java.lang.String> getComparator()

Returns the comparator to be used for sorting.

Returns:

the comparator

setComparator

public void setComparator(java.util.Comparator<? super java.lang.String> comparator)

Set the comparator to be used as sorting criterium.

Parameters:

comparator - the comparator to set

add

public void add(java.util.Comparator<? super java.lang.String> comparator)

Set the comparator to be used as sorting criterion as nested element.

Parameters:

comparator - the comparator to set