org.apache.tools.ant.filters

Class TailFilter

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>
Constructor Summary
TailFilter()
Constructor for "dummy" instances.
TailFilter(Reader in)
Creates a new filtered reader.
Method Summary
Readerchain(Reader rdr)
Creates a new TailFilter using the passed in Reader for instantiation.
intread()
Returns the next character in the filtered stream.
voidsetLines(long lines)
Sets the number of lines to be returned in the filtered stream.
voidsetSkip(long skip)
Sets the number of lines to be skipped in the filtered stream.

Constructor Detail

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 Detail

chain

public final Reader chain(Reader rdr)
Creates a new TailFilter using the passed in Reader for instantiation.

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

read

public final int read()
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.

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 final 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 final 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

Copyright