org.apache.tools.ant.filters

Class HeadFilter

public final class HeadFilter extends BaseParamFilterReader implements ChainableReader

Reads the first n lines of a stream. (Default is first 10 lines.)

Example:

<headfilter lines="3"/>
Or:
<filterreader classname="org.apache.tools.ant.filters.HeadFilter">
    <param name="lines" value="3"/>
 </filterreader>
Constructor Summary
HeadFilter()
Constructor for "dummy" instances.
HeadFilter(Reader in)
Creates a new filtered reader.
Method Summary
Readerchain(Reader rdr)
Creates a new HeadFilter 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

HeadFilter

public HeadFilter()
Constructor for "dummy" instances.

See Also: BaseFilterReader

HeadFilter

public HeadFilter(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 HeadFilter 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 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.

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 B) 2000-2007 Apache Software Foundation. All Rights Reserved.