org.apache.tools.ant.filters
Class HeadFilter
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.HeadFilter
- All Implemented Interfaces:
- ChainableReader, Parameterizable
- 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>
- Author:
- Magesh Umasankar
Fields inherited from class java.io.FilterReader |
in |
Fields inherited from class java.io.Reader |
lock |
Constructor Summary |
HeadFilter()
Constructor for "dummy" instances. |
HeadFilter(java.io.Reader in)
Creates a new filtered reader. |
Method Summary |
java.io.Reader |
chain(java.io.Reader rdr)
Creates a new HeadFilter 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. |
Methods inherited from class java.io.FilterReader |
close, mark, markSupported, ready, reset |
Methods inherited from class java.io.Reader |
read |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
HeadFilter
public HeadFilter()
- Constructor for "dummy" instances.
- See Also:
BaseFilterReader.BaseFilterReader()
HeadFilter
public HeadFilter(java.io.Reader in)
- Creates a new filtered reader.
- Parameters:
in
- A Reader object providing the underlying stream.
Must not be null
.
read
public final 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.
- 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
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
chain
public final java.io.Reader chain(java.io.Reader rdr)
- Creates a new HeadFilter 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
Copyright © 2000-2003 Apache Software Foundation. All Rights Reserved.