org.apache.mahout.common.iterator

Class FileLineIterator

java.lang.Object

com.google.common.collect.UnmodifiableIterator<T>

com.google.common.collect.AbstractIterator<String>

org.apache.mahout.common.iterator.FileLineIterator

All Implemented Interfaces:

Closeable, AutoCloseable, Iterator<String>, SkippingIterator<String>

public final class FileLineIterator
extends com.google.common.collect.AbstractIterator<String>
implements SkippingIterator<String>, Closeable

Iterates over the lines of a text file. This assumes the text file's lines are delimited in a manner consistent with how BufferedReader defines lines.

This class will uncompress files that end in .zip or .gz accordingly, too.

Constructor Summary

Constructors

Constructor and Description
FileLineIterator(File file) Creates a FileLineIterator over a given file, assuming a UTF-8 encoding.
FileLineIterator(File file, boolean skipFirstLine) Creates a FileLineIterator over a given file, assuming a UTF-8 encoding.
FileLineIterator(File file, Charset encoding, boolean skipFirstLine) Creates a FileLineIterator over a given file, using the given encoding.
FileLineIterator(InputStream is)
FileLineIterator(InputStream is, boolean skipFirstLine)
FileLineIterator(InputStream is, Charset encoding, boolean skipFirstLine)
FileLineIterator(InputStream is, Charset encoding, boolean skipFirstLine, String filename)

Method Summary

Methods

Modifier and Type	Method and Description
void	close()
protected String	computeNext()
void	skip(int n) Skip the next n elements supplied by this Iterator.

Methods inherited from class com.google.common.collect.AbstractIterator

endOfData, hasNext, next, peek

Methods inherited from class com.google.common.collect.UnmodifiableIterator

remove

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Iterator

hasNext, next, remove

Constructor Detail

FileLineIterator

public FileLineIterator(File file)
                 throws IOException

Creates a FileLineIterator over a given file, assuming a UTF-8 encoding.

Throws:

FileNotFoundException - if the file does not exist

IOException - if the file cannot be read

FileLineIterator

public FileLineIterator(File file,
                boolean skipFirstLine)
                 throws IOException

Creates a FileLineIterator over a given file, assuming a UTF-8 encoding.

Throws:

FileNotFoundException - if the file does not exist

IOException - if the file cannot be read

FileLineIterator

public FileLineIterator(File file,
                Charset encoding,
                boolean skipFirstLine)
                 throws IOException

Creates a FileLineIterator over a given file, using the given encoding.

Throws:

FileNotFoundException - if the file does not exist

IOException - if the file cannot be read

FileLineIterator

public FileLineIterator(InputStream is)
                 throws IOException

Throws:

IOException

FileLineIterator

public FileLineIterator(InputStream is,
                boolean skipFirstLine)
                 throws IOException

Throws:

IOException

FileLineIterator

public FileLineIterator(InputStream is,
                Charset encoding,
                boolean skipFirstLine)
                 throws IOException

Throws:

IOException

FileLineIterator

public FileLineIterator(InputStream is,
                Charset encoding,
                boolean skipFirstLine,
                String filename)
                 throws IOException

Throws:

IOException

Method Detail

computeNext

protected String computeNext()

Specified by:

computeNext in class com.google.common.collect.AbstractIterator<String>

skip

public void skip(int n)

Description copied from interface: SkippingIterator

Skip the next n elements supplied by this Iterator. If there are less than n elements remaining, this skips all remaining elements in the Iterator. This method has the same effect as calling Iterator.next() n times, except that it will never throw NoSuchElementException.

Specified by:

skip in interface SkippingIterator<String>

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException