Package 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:
Closeable,AutoCloseable,Readable,ChainableReader,Parameterizable
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>-
Field Summary
Fields inherited from class java.io.FilterReader
in -
Constructor Summary
ConstructorsConstructorDescriptionConstructor for "dummy" instances.HeadFilter(Reader in) Creates a new filtered reader. -
Method Summary
Modifier and TypeMethodDescriptionCreates 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.Methods inherited from class org.apache.tools.ant.filters.BaseParamFilterReader
getParameters, setParametersMethods inherited from class org.apache.tools.ant.filters.BaseFilterReader
getInitialized, getProject, read, readFully, readLine, setInitialized, setProject, skipMethods inherited from class java.io.FilterReader
close, mark, markSupported, ready, resetMethods inherited from class java.io.Reader
nullReader, read, read, transferTo
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Constructor Details
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HeadFilter
public HeadFilter()Constructor for "dummy" instances.- See Also:
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HeadFilter
Creates a new filtered reader.- Parameters:
in- A Reader object providing the underlying stream. Must not benull.
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Method Details
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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.- Overrides:
readin classFilterReader- 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
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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
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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
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chain
Creates a new HeadFilter using the passed in Reader for instantiation.- Specified by:
chainin interfaceChainableReader- Parameters:
rdr- A Reader object providing the underlying stream. Must not benull.- Returns:
- a new filter based on this configuration, but filtering the specified reader
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