Consider the flexibility of Unix pipes. If you wanted,for example, to copy just those lines that contained thestring blee from the first 10 lines of a text file 'foo'(you wouldn't want to filter a binary file)to a file 'bar', you would do something like:

cat foo|head -n10|grep blee > bar

Apache Ant was not flexible enough. There was no way for the<copy> task to do something similar. If you wantedthe <copy> task to get the first 10 lines, you would havehad to create special attributes:

<copy file="foo" tofile="bar" head="10" contains="blee"/>

The obvious problem thus surfaced: Ant tasks would not be ableto accommodate such data transformation attributes as they wouldbe endless. The task would also not know in which order theseattributes were to be interpreted. That is, must the task execute thecontains attribute first and then the head attribute or vice-versa?What Ant tasks needed was a mechanism to allow pluggable filter (datatransformer) chains. Ant would provide a few filters for which therehave been repeated requests. Users with special filtering needswould be able to easily write their own and plug them in.

The solution was to refactor data transformation orientedtasks to support FilterChains. A FilterChain is a group ofordered FilterReaders. Users can define their own FilterReadersby just extending the java.io.FilterReader class. Such customFilterReaders can be easily plugged in as nested elements of<filterchain> by using <filterreader> elements.

Example:

<copy file="${src.file}" tofile="${dest.file}">  <filterchain> <filterreader classname="your.extension.of.java.io.FilterReader">  <param name="foo" value="bar"/> </filterreader> <filterreader classname="another.extension.of.java.io.FilterReader">  <classpath> <pathelement path="${classpath}"/>  </classpath>  <param name="blah" value="blee"/>  <param type="abra" value="cadabra"/> </filterreader>  </filterchain></copy>

Ant provides some built-in filter readers. These filter readerscan also be declared using a syntax similar to the above syntax.However, they can be declared using some simpler syntax also.

Example:

<loadfile srcfile="${src.file}" property="src.file.head">  <filterchain> <headfilter lines="15"/>  </filterchain></loadfile>

is equivalent to:

<loadfile srcfile="${src.file}" property="src.file.head">  <filterchain> <filterreader classname="org.apache.tools.ant.filters.HeadFilter">  <param name="lines" value="15"/> </filterreader>  </filterchain></loadfile>

The following built-in tasks support nested <filterchain> elements.
Concat,
Copy,
LoadFile,
LoadProperties,
Move

A FilterChain is formed by defining zero or more of the followingnested elements.
FilterReader
ClassConstants
EscapeUnicode
ExpandProperties
HeadFilter
LineContains
LineContainsRegExp
PrefixLines
ReplaceTokens
StripJavaComments
StripLineBreaks
StripLineComments
SuffixLines
TabsToSpaces
TailFilter
DeleteCharacters
ConcatFilter
TokenFilter
FixCRLF
SortFilter

FilterReader

The filterreader element is the generic way todefine a filter. User defined filter elements aredefined in the build file using this. Please note thatbuilt in filter readers can also be defined using thissyntax.A FilterReader element must be supplied with a class name asan attribute value. The class resolved by this name mustextend java.io.FilterReader. If the custom filter readerneeds to be parameterized, it must implementorg.apache.tools.type.Parameterizable.

Attribute	Description	Required
classname	The class name of the filter reader.	Yes

Nested Elements:

<filterreader> supports <classpath> and <param>as nested elements. Each <param> element may take in the followingattributes - name, type and value.

The following FilterReaders are supplied with the defaultdistribution.

ClassConstants

This filters basic constants defined in a Java Class, and outputs them in lines composed of the format name=value. This filter uses the bcel library to understand the Java Class file. See Library Dependencies.

Important: This filter is different from most of the other filters. Most of the filters operate on a sequence of characters. This filter operates on the sequence of bytes that makes up a class. However the bytes arrive to the filter as a sequence of characters. This means that one must be careful on the choice of character encoding to use. Most encoding lose information on conversion from an arbitary sequence of bytes to characters and back again to bytes. In particular the usual default character encodings (CP152 and UTF-8) do. For this reason, since Ant 1.7, the character encoding ISO-8859-1 is used to convert from characters back to bytes, so one has to use this encoding for reading the java class file.

Example:

This loads the basic constants defined in a Java class as Ant properties.

<loadproperties srcfile="foo.class" encoding="ISO-8859-1">  <filterchain> <classconstants/>  </filterchain></loadproperties>

This loads the constants from a Java class file as Ant properties,prepending the names with a prefix.

<loadproperties srcfile="build/classes/org/acme/bar.class" encoding="ISO-8859-1">  <filterchain> <classconstants/> <prefixlines prefix="ini."/>  </filterchain></loadproperties>

EscapeUnicode

This filter converts its input by changing all non US-ASCII charactersinto their equivalent unicode escape backslash u plus 4 digits.

since Ant 1.6

Example:

This loads the basic constants defined in a Java class as Ant properties.

<loadproperties srcfile="non_ascii_property.properties">  <filterchain> <filterreader classname="org.apache.tools.ant.filters.EscapeUnicode"/>  </filterchain></loadproperties>

Convenience method:

<loadproperties srcfile="non_ascii_property.properties">  <filterchain> <escapeunicode/>  </filterchain></loadproperties>

ExpandProperties

If the data contains data that represents Antproperties (of the form ${...}), that is substitutedwith the property's actual value.

Example:

This results in the property modifiedmessage holding the value"All these moments will be lost in time, like teardrops in the rain"

<echo  message="All these moments will be lost in time, like teardrops in the ${weather}"  file="loadfile1.tmp"  /><property name="weather" value="rain"/><loadfile property="modifiedmessage" srcFile="loadfile1.tmp">  <filterchain> <filterreader classname="org.apache.tools.ant.filters.ExpandProperties"/>  </filterchain></loadfile>

Convenience method:

<echo  message="All these moments will be lost in time, like teardrops in the ${weather}"  file="loadfile1.tmp"  /><property name="weather" value="rain"/><loadfile property="modifiedmessage" srcFile="loadfile1.tmp">  <filterchain> <expandproperties/>  </filterchain></loadfile>

As of Ant 1.8.3, a nested PropertySet can be specified:

<property name="weather" value="rain"/><loadfile property="modifiedmessage" srcFile="loadfile1.tmp">  <filterchain> <expandproperties>  <propertyset> <propertyref name="weather" />  </propertyset> </expandproperties>  </filterchain></loadfile>

HeadFilter

This filter reads the first few lines from the data supplied to it.

Parameter Name	Parameter Value	Required
lines	Number of lines to be read. Defaults to "10" A negative value means that all lines are passed (useful with skip)	No
skip	Number of lines to be skipped (from the beginning). Defaults to "0"	No

Example:

This stores the first 15 lines of the supplied data in the property src.file.head

<loadfile srcfile="${src.file}" property="src.file.head">  <filterchain> <filterreader classname="org.apache.tools.ant.filters.HeadFilter">  <param name="lines" value="15"/> </filterreader>  </filterchain></loadfile>

Convenience method:

<loadfile srcfile="${src.file}" property="src.file.head">  <filterchain> <headfilter lines="15"/>  </filterchain></loadfile>

This stores the first 15 lines, skipping the first 2 lines, of the supplied datain the property src.file.head. (Means: lines 3-17)

<loadfile srcfile="${src.file}" property="src.file.head">  <filterchain> <headfilter lines="15" skip="2"/>  </filterchain></loadfile>

See the testcases for more examples (srcetcestcasesfiltershead-tail.xml in thesource distribution).

LineContains

This filter includes only those lines that contain all the user-specifiedstrings.

Parameter Type	Parameter Value	Required
contains	Substring to be searched for.	Yes
negate	Whether to select non-matching lines only. Since Ant 1.7	No

Example:

This will include only those lines that contain foo andbar.

<filterreader classname="org.apache.tools.ant.filters.LineContains">  <param type="contains" value="foo"/>  <param type="contains" value="bar"/></filterreader>

Convenience method:

<linecontains>  <contains value="foo"/>  <contains value="bar"/></linecontains>

Negation:

<filterreader classname="org.apache.tools.ant.filters.LineContains">  <param type="negate" value="true"/>  <param type="contains" value="foo"/>  <param type="contains" value="bar"/></filterreader>

<linecontains negate="true">  <contains value="foo"/>  <contains value="bar"/></linecontains>

LineContainsRegExp

Filter which includes only those lines that contain the user-specifiedregular expression matching strings.

Parameter Type	Parameter Value	Required
regexp	Regular expression to be searched for.	Yes
negate	Whether to select non-matching lines only. Since Ant 1.7	No
casesensitive	Perform a case sensitive match. Default is true. Since Ant 1.8.2	No

See Regexp Type for the description of the nested element regexp and ofthe choice of regular expression implementation.

Example:

This will fetch all those lines that contain the pattern foo

<filterreader classname="org.apache.tools.ant.filters.LineContainsRegExp">  <param type="regexp" value="foo*"/></filterreader>

Convenience method:

<linecontainsregexp>  <regexp pattern="foo*"/></linecontainsregexp>

Negation:

<filterreader classname="org.apache.tools.ant.filters.LineContainsRegExp">  <param type="negate" value="true"/>  <param type="regexp" value="foo*"/></filterreader>

<linecontainsregexp negate="true">  <regexp pattern="foo*"/></linecontainsregexp>

PrefixLines

Attaches a prefix to every line.

Parameter Name	Parameter Value	Required
prefix	Prefix to be attached to lines.	Yes

Example:

This will attach the prefix Foo to all lines.

<filterreader classname="org.apache.tools.ant.filters.PrefixLines">  <param name="prefix" value="Foo"/></filterreader>

Convenience method:

<prefixlines prefix="Foo"/>

SuffixLines

Attaches a suffix to every line.

since Ant 1.8.0

Parameter Name	Parameter Value	Required
suffix	Suffix to be attached to lines.	Yes

Example:

This will attach the suffix Foo to all lines.

<filterreader classname="org.apache.tools.ant.filters.SuffixLines">  <param name="suffix" value="Foo"/></filterreader>

Convenience method:

<suffixlines suffix="Foo"/>

ReplaceTokens

This filter reader replaces all strings that aresandwiched between begintoken and endtoken withuser defined values.

Parameter Type	Parameter Name	Parameter Value	Required
tokenchar	begintoken	Character marking the beginning of a token. Defaults to @	No
tokenchar	endtoken	Character marking the end of a token. Defaults to @	No
User defined String.	token	User defined search String.	Yes
Not applicable.	propertiesfile	Properties file to take tokens from.	No
User defined String.	value	Replace-value for the token	No

Example:

This replaces occurrences of the string @DATE@ in the datawith today's date and stores it in the property ${src.file.replaced}

<tstamp/><loadfile srcfile="${src.file}" property="${src.file.replaced}">  <filterchain> <filterreader classname="org.apache.tools.ant.filters.ReplaceTokens">  <param type="token" name="DATE" value="${TODAY}"/> </filterreader>  </filterchain></loadfile>

Convenience method:

<tstamp/><loadfile srcfile="${src.file}" property="${src.file.replaced}">  <filterchain> <replacetokens>  <token key="DATE" value="${TODAY}"/> </replacetokens>  </filterchain></loadfile>

This will treat each properties file entry in sample.properties as a token/key pair :

<loadfile srcfile="${src.file}" property="${src.file.replaced}">  <filterchain> <filterreader classname="org.apache.tools.ant.filters.ReplaceTokens">  <param type="propertiesfile" value="sample.properties"/> </filterreader>  </filterchain></loadfile></filterchain>

StripJavaComments

This filter reader strips away comments from the data,using Java syntax guidelines. This filter does nottake in any parameters.

Example:

<loadfile srcfile="${java.src.file}" property="${java.src.file.nocomments}">  <filterchain> <filterreader classname="org.apache.tools.ant.filters.StripJavaComments"/>  </filterchain></loadfile>

Convenience method:

<loadfile srcfile="${java.src.file}" property="${java.src.file.nocomments}">  <filterchain> <stripjavacomments/>  </filterchain></loadfile>

StripLineBreaks

This filter reader strips away specific charactersfrom the data supplied to it.

Parameter Name	Parameter Value	Required
linebreaks	Characters that are to be stripped out. Defaults to ""	No

Examples:

This strips the '' and '' characters.

<loadfile srcfile="${src.file}" property="${src.file.contents}">  <filterchain> <filterreader classname="org.apache.tools.ant.filters.StripLineBreaks"/>  </filterchain></loadfile>

Convenience method:

<loadfile srcfile="${src.file}" property="${src.file.contents}">  <filterchain> <striplinebreaks/>  </filterchain></loadfile>

This treats the '(' and ')' characters as line break characters andstrips them.

<loadfile srcfile="${src.file}" property="${src.file.contents}">  <filterchain> <filterreader classname="org.apache.tools.ant.filters.StripLineBreaks">  <param name="linebreaks" value="()"/> </filterreader>  </filterchain></loadfile>

StripLineComments

This filter removes all those lines that begin with stringsthat represent comments as specified by the user.

Parameter Type	Parameter Value	Required
comment	Strings that identify a line as a comment when they appear at the start of the line.	Yes

Examples:

This removes all lines that begin with #, --, REM, rem and //

<filterreader classname="org.apache.tools.ant.filters.StripLineComments">  <param type="comment" value="#"/>  <param type="comment" value="--"/>  <param type="comment" value="REM "/>  <param type="comment" value="rem "/>  <param type="comment" value="//"/></filterreader>

Convenience method:

<striplinecomments>  <comment value="#"/>  <comment value="--"/>  <comment value="REM "/>  <comment value="rem "/>  <comment value="//"/></striplinecomments>

TabsToSpaces

This filter replaces tabs with spaces

Parameter Name	Parameter Value	Required
tablength	Defaults to "8"	No

Examples:

This replaces tabs in ${src.file} with spaces.

<loadfile srcfile="${src.file}" property="${src.file.notab}">  <filterchain> <filterreader classname="org.apache.tools.ant.filters.TabsToSpaces"/>  </filterchain></loadfile>

Convenience method:

<loadfile srcfile="${src.file}" property="${src.file.notab}">  <filterchain> <tabstospaces/>  </filterchain></loadfile>

TailFilter

This filter reads the last few lines from the data supplied to it.

Parameter Name	Parameter Value	Required
lines	Number of lines to be read. Defaults to "10" A negative value means that all lines are passed (useful with skip)	No
skip	Number of lines to be skipped (from the end). Defaults to "0"	No

Background:

With HeadFilter and TailFilter you can extract each part of a text file you want.This graphic shows the dependencies:

Content

Filter

Line 1

	<filterchain> <headfilter lines="2"/></filterchain>
	<filterchain> <tailfilter lines="-1" skip="2"/></filterchain>
	<filterchain> <headfilter lines="-1" skip="2"/></filterchain>
	<filterchain> <headfilter lines="-1" skip="2"/> <tailfilter lines="-1" skip="2"/></filterchain>
	<filterchain> <tailfilter lines="2"/></filterchain>

Line 2

Line 3

Line 4

Line 5

Lines ...

Line 95

Line 96

Line 97

Line 98

Line 99

Examples:

This stores the last 15 lines of the supplied data in the property ${src.file.tail}

<loadfile srcfile="${src.file}" property="${src.file.tail}">  <filterchain> <filterreader classname="org.apache.tools.ant.filters.TailFilter">  <param name="lines" value="15"/> </filterreader>  </filterchain></loadfile>

Convenience method:

<loadfile srcfile="${src.file}" property="${src.file.tail}">  <filterchain> <tailfilter lines="15"/>  </filterchain></loadfile>

This stores the last 5 lines of the first 15 lines of the supplieddata in the property ${src.file.mid}

<loadfile srcfile="${src.file}" property="${src.file.mid}">  <filterchain> <filterreader classname="org.apache.tools.ant.filters.HeadFilter">  <param name="lines" value="15"/> </filterreader> <filterreader classname="org.apache.tools.ant.filters.TailFilter">  <param name="lines" value="5"/> </filterreader>  </filterchain></loadfile>

Convenience method:

<loadfile srcfile="${src.file}" property="${src.file.mid}">  <filterchain> <headfilter lines="15"/> <tailfilter lines="5"/>  </filterchain></loadfile>

This stores the last 10 lines, skipping the last 2 lines, of the supplied datain the property src.file.head. (Means: if supplied data contains 60 lines,lines 49-58 are extracted)

<loadfile srcfile="${src.file}" property="src.file.head">  <filterchain> <tailfilter lines="10" skip="2"/>  </filterchain></loadfile>

DeleteCharacters

This filter deletes specified characters.

since Ant 1.6

This filter is only available in the convenience form.

Parameter Name	Parameter Value	Required
chars	The characters to delete. This attribute is backslash enabled.	Yes

Examples:

Delete tabs and returns from the data.

<deletecharacters chars=""/>

ConcatFilter

This filter prepends or appends the content file to the filtered files.

since Ant 1.6

Parameter Name	Parameter Value	Required
prepend	The name of the file which content should be prepended to the file.	No
append	The name of the file which content should be appended to the file.	No

Examples:

Do nothing:

<filterchain> <concatfilter/></filterchain>

Adds a license text before each java source:

<filterchain> <concatfilter prepend="apache-license-java.txt"/></filterchain>

TokenFilter

This filter tokenizes the inputstream into strings and passes thesestrings to filters of strings. Unlike the other filterreaders, this doesnot support params, only convenience methods are implemented.The tokenizer and the string filters are defined by nested elements.

since Ant 1.6

Only one tokenizer element may be used, the LineTokenizer is thedefault if none are specified. A tokenizersplits the input into token strings and trailing delimiter strings.

There may be zero or more string filters. A string filter processesa token and either returns a string or a null.It the string is not null it is passed to the next filter. Thisproceeds until all the filters are called.If a string is returned after all the filters, the string isoutputs with its associated token delimitier(if one is present).The trailing delimiter may be overridden by the delimOutputattribute.

blackslash interpretationA number of attributes (including delimOutput) interpretbackslash escapes. The following are understood: , , f, and .

Attribute	Description	Required
delimOutput	This overrides the tokendelimiter returned by the tokenizer if it is not empty. This attribute is backslash enabled.	No

The following tokenizers are provided by the default distribution.

LineTokenizer
FileTokenizer
StringTokenizer

The following string filters are provided by the default distribution.

ReplaceString
ContainsString
ReplaceRegex
ContainsRegex
Trim
IgnoreBlank
DeleteCharacters
UniqFilter

The following string filters are provided by the optional distribution.

ScriptFilter

Some of the filters may be used directly within a filter chain. In thiscase a tokenfilter is created implicitly. An extra attribute "byline"is added to the filter to specify whether to use a linetokenizer(byline="true") or a filetokenizer (byline="false"). The defaultis "true".

LineTokenizer

This tokenizer splits the input into lines.The tokenizer delimits linesby "", "" or "".This is the default tokenizer.

Attribute	Description	Required
includeDelims	Include the line endings in the token. Default is false.	No

Examples:

Convert input current line endings to unix style line endings.

<tokenfilter delimoutput=""/>

Remove blank lines.

<tokenfilter> <ignoreblank/></tokenfilter>

FileTokenizer

This tokenizer treats all the input as a token. So becareful not to use this on very large input.

Examples:

Replace the first occurrence of package with //package.

<tokenfilter>  <filetokenizer/>  <replaceregex pattern="([]+[ ]*|^[ ]*)package" flags="s" replace="1//package"/></tokenfilter>

StringTokenizer

This tokenizer is based on java.util.StringTokenizer.It splits up the input into strings separated by white space, orby a specified list of delimiting characters.If the stream starts with delimiter characters, the firsttoken will be the empty string (unless the delimsaretokensattribute is used).

Attribute	Description	Required
delims	The delimiter characters. White space is used if this is not set. (White space is defined in this case by java.lang.Character.isWhitespace()).	No
delimsaretokens	If this is true, each delimiter character is returned as a token. Default is false.	No
suppressdelims	If this is true, delimiters are not returned. Default is false.	No
includeDelims	Include the delimiters in the token. Default is false.	No

Examples:

Surround each non space token with a "[]".

<tokenfilter> <stringtokenizer/> <replaceregex pattern="(.+)" replace="[1]"/></tokenfilter>

ReplaceString

This is a simple filter to replace strings.This filter may be used directly within a filterchain.

Attribute	Description	Required
from	The string that must be replaced.	Yes
to	The new value for the replaced string. When omitted an empty string is used.	No

Examples:

Replace "sun" with "moon".

<tokenfilter> <replacestring from="sun" to="moon"/></tokenfilter>

ContainsString

This is a simple filter to filter tokens that containsa specified string.

Attribute	Description	Required
contains	The string that the token must contain.	Yes

Examples:

Include only lines that contain "foo";

<tokenfilter> <containsstring contains="foo"/></tokenfilter>

ReplaceRegex

This string filter replaces regular expressions.This filter may be used directly within a filterchain.

See Regexp Typeconcerning the choice of the implementation.

Attribute	Description	Required
pattern	The regular expression pattern to match in the token.	Yes
replace	The substitution pattern to replace the matched regular expression. When omitted an empty string is used.	No
flags	SeeReplaceRegexpfor an explanation of regex flags.	No

Examples:

Replace all occurrences of "hello" with "world", ignoring case.

<tokenfilter> <replaceregex pattern="hello" replace="world" flags="gi"/></tokenfilter>

ContainsRegex

This filters strings that match regular expressions.The filter may optionally replace the matched regular expression.This filter may be used directly within a filterchain.

SeeRegexp Typeconcerning the choice of regular expression implementation.

Attribute	Description	Required
pattern	The regular expression pattern to match in the token.	Yes
replace	The substitution pattern to replace the matched regular expression. When omitted the orignal token is returned.	No
flags	SeeReplaceRegexpfor an explanation of regex flags.	No

Examples:

Filter lines that contain "hello" or "world", ignoring case.

<tokenfilter> <containsregex pattern="(hello|world)" flags="i"/></tokenfilter>

This example replaces lines like "SUITE(TestSuite, bits);" with"void register_bits();" and removes other lines.

<tokenfilter> <containsregex pattern="^ *SUITE(.*,s*(.*)s*).*" replace="void register_1();"/></tokenfilter>

Trim

This filter trims whitespace from the start and end oftokens.This filter may be used directly within a filterchain.

IgnoreBlank

This filter removes empty tokens.This filter may be used directly within a filterchain.

DeleteCharacters

This filter deletes specified characters from tokens.

Attribute	Description	Required
chars	The characters to delete. This attribute is backslash enabled.	Yes

Examples:

Delete tabs from lines, trim the lines and removes empty lines.

<tokenfilter> <deletecharacters chars=""/> <trim/> <ignoreblank/></tokenfilter>

UniqFilter

Suppresses all tokens that match their ancestor token. It is most useful if combined with a sort filter.

This filter may be used directly within a filterchain.

Example:

This suppresses duplicate lines.

<tokenfilter>  <uniqfilter/></tokenfilter>

ScriptFilter

This is an optional filter that executes a script in aApache BSF or JSR 223supported language.

See the Script task foran explanation of scripts and dependencies.

The script is provided with an object self that hasgetToken() and setToken(String) methods.The getToken() method returns the current token. The setToken(String)method replaces the current token.

This filter may be used directly within a filterchain.

Attribute	Description	Required
language	The programming language the script is written in.Must be a supported Apache BSF or JSR 223 language	Yes
manager	The script engine manager to use. See the script task for using this attribute.	No - default is "auto"
src	The location of the script as a file, if not inline	No
setbeans	whether to have all properties, references and targets as global variables in the script. since Ant 1.8.0	No, default is "true".
classpath	The classpath to pass into the script.	No
classpathref	The classpath to use, given as a reference to a path defined elsewhere.	No

This filter can take a nested <classpath> element. See the script task on how to use this element.

Examples:

Convert to uppercase:

<tokenfilter> <scriptfilter language="javascript"> self.setToken(self.getToken().toUpperCase()); </scriptfilter></tokenfilter>

Remove lines containing the string "bad" whilecopying text files:

<copy todir="dist">  <fileset dir="src" includes="**/*.txt"/>  <filterchain> <scriptfilter language="beanshell"> if (self.getToken().indexOf("bad") != -1) { self.setToken(null); } </scriptfilter>  </filterchain></copy>

Custom tokenizers and string filters

Custom string filters and tokenizers may be plugged in byextending the interfaces org.apache.tools.ant.filters.TokenFilter.Filterand org.apache.tools.ant.util.Tokenizer respectly.They are defined the build file using <typedef/>. Forexample a string filter that capitalizes words may be declared as:

package my.customant;import org.apache.tools.ant.filters.TokenFilter;public class Capitalize implements TokenFilter.Filter{ public String filter(String token) { if (token.length() == 0) return token; return token.substring(0, 1).toUpperCase() + token.substring(1);   }}

This may be used as follows:

  <typedef name="capitalize" classname="my.customant.Capitalize"   classpath="my.customant.path"/>  <copy file="input" tofile="output"> <filterchain>  <tokenfilter> <stringtokenizer/> <capitalize/>  </tokenfilter> </filterchain>  </copy>

SortFilter

since Ant 1.8.0

The sort filter reads all lines and sorts them. The sort order can be reversed and it is possible to specify a custom implementation of the java.util.Comparator interface to get even more control.

Parameter Name	Parameter Value	Required
reverse	whether to reverse the sort order, defaults to false. Note: this parameter is ignored if the comparator parameter is present as well.	No
comparator	Class name of a class that implements `java.util.Comparator` for Strings. This class will be used to determine the sort order of lines.	No

This filter is also available using the name sortfilter. The reverse parameter becomes an attribute, comparator can be specified by using a nested element.

Examples:

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

Sort all files *.txt from src locationinto build location. The lines of each file are sorted inascendant order comparing the lines via theString.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 reverseorder and copy them into build location.

  <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 assorting criterium EvenFirstCmp class, that sorts the filelines putting even lines first then odd lines for example. The modified filesare copied into build location. The EventFirstCmp,has to an instanciable class via Class.newInstance(),therefore in case of inner class has to be static. It also has toimplement 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>

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