Package org.apache.tools.ant.filters

Class TailFilter

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.TailFilter

All Implemented Interfaces:

Closeable, AutoCloseable, Readable, ChainableReader, Parameterizable

public final class TailFilter
extends BaseParamFilterReader
implements ChainableReader

Reads the last n lines of a stream. (Default is last10 lines.) Example:

<tailfilter lines="3"/>

Or:

<filterreader classname="org.apache.tools.ant.filters.TailFilter">
   <param name="lines" value="3"/>
 </filterreader>

Field Summary

Fields inherited from class java.io.FilterReader

in

Fields inherited from class java.io.Reader

lock

Constructor Summary

Constructors

Constructor	Description
TailFilter()	Constructor for "dummy" instances.
TailFilter(Reader in)	Creates a new filtered reader.

Method Summary

Modifier and Type	Method	Description
Reader	chain(Reader rdr)	Creates a new TailFilter using the passed in Reader for instantiation.
int	read()	Returns the next character in the filtered stream.
void	setLines(long lines)	Sets the number of lines to be returned in the filtered stream.
void	setSkip(long skip)	Sets the number of lines to be skipped in the filtered stream.

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

nullReader, read, read, transferTo

Methods inherited from class java.lang.Object

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

Constructor Details

TailFilter

public TailFilter()

Constructor for "dummy" instances.

See Also:

• BaseFilterReader()

TailFilter

public TailFilter(Reader in)

Creates a new filtered reader.

Parameters:

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

Method Details

read

public int read()
         throws IOException

Returns the next character in the filtered stream. If the read-ahead has been completed, the next character in the buffer is returned. Otherwise, the stream is read to the end and buffered (with the buffer growing as necessary), then the appropriate position in the buffer is set to read from.

Overrides:

read in class FilterReader

Returns:

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

Throws:

IOException - if the underlying stream throws an IOException during reading

setLines

public void setLines(long lines)

Sets the number of lines to be returned in the filtered stream.

Parameters:

lines - the number of lines to be returned in the filtered stream

setSkip

public void setSkip(long skip)

Sets the number of lines to be skipped in the filtered stream.

Parameters:

skip - the number of lines to be skipped in the filtered stream

chain

public Reader chain(Reader rdr)

Creates a new TailFilter 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