Package it.unimi.dsi.io

Class FileLinesMutableStringIterable

java.lang.Object

it.unimi.dsi.io.FileLinesMutableStringIterable

All Implemented Interfaces:

Size64, Iterable<MutableString>

public class FileLinesMutableStringIterable
extends Object
implements Iterable<MutableString>, Size64

A wrapper exhibiting the lines of a file as an Iterable of mutable strings.

Warning: the lines returned by iterators generated by instances of this class are not cacheable. The returned value is a MutableString instance that is reused at each call, and that is modified by a call to hasNext(). Thus, for instance,

 ObjectIterators.unwrap(fileLinesMutableStringIterable.iterator());
 

will not give the expected results. Use allLines() or allLinesBig() for that purpose.

The result of a call to iterator() can be used to scan the file; each call will open an independent input stream. The returned iterator type (FileLinesIterator) is Closeable, and should be closed after usage. Exhausted iterators, however, will be closed automagically.

Using a suitable constructor it is possible to specify a decompression class, which must extend InputStream and provide a constructor accepting an InputStream (e.g., GZIPInputStream if the file is compressed in gzip format).

Convenience static methods makes it possible to build on the fly an iterator over an input stream using the same conventions.

This class implements size64(), which will return the number of lines of the file, computed with a full scan at the first invocation. However, it is also possible to specify at construction time the number of lines in the file to skip the first scan. It is responsibility of the caller that the specified size and the actual number of lines in the file do match.

Since:

2.6.17

Author:

Sebastiano Vigna

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final class	FileLinesMutableStringIterable.FileLinesIterator	An iterator over the lines of a FileLinesMutableStringIterable.

Constructor Summary

Constructors

Constructor	Description
FileLinesMutableStringIterable(String filename)	Creates a file-lines iterable for the specified filename using the platform encoding.
FileLinesMutableStringIterable(String filename, long size)	Creates a file-lines iterable for the specified filename and size using the platform encoding.
FileLinesMutableStringIterable(String filename, long size, Class<? extends InputStream> decompressor)	Creates a file-lines iterable for the specified filename and size using the platform encoding, optionally assuming that the file is compressed.
FileLinesMutableStringIterable(String filename, long size, String encoding)	Creates a file-lines iterable for the specified filename and size using the specified encoding.
FileLinesMutableStringIterable(String filename, long size, Charset encoding)	Creates a file-lines iterable for the specified filename and size using the specified encoding.
FileLinesMutableStringIterable(String filename, long size, Charset encoding, Class<? extends InputStream> decompressor)	Creates a file-lines iterable for the specified filename and size with the specified encoding, optionally assuming that the file is compressed.
FileLinesMutableStringIterable(String filename, Class<? extends InputStream> decompressor)	Creates a file-lines iterable for the specified filename using the platform encoding, optionally assuming that the file is compressed.
FileLinesMutableStringIterable(String filename, String encoding)	Creates a file-lines iterable for the specified filename using the specified encoding.
FileLinesMutableStringIterable(String filename, String encoding, Class<? extends InputStream> decompressor)	Creates a file-lines iterable for the specified filename with the specified encoding, optionally assuming that the file is compressed.
FileLinesMutableStringIterable(String filename, Charset encoding)	Creates a file-lines iterable for the specified filename using the specified encoding.
FileLinesMutableStringIterable(String filename, Charset encoding, Class<? extends InputStream> decompressor)	Creates a file-lines iterable for the specified filename with the specified encoding, optionally assuming that the file is compressed.

Method Summary

Modifier and Type	Method	Description
ObjectList<String>	allLines()	Returns all lines as a list.
ObjectBigList<String>	allLinesBig()	Returns all lines as a big list.
FileLinesMutableStringIterable.FileLinesIterator	iterator()
static FileLinesMutableStringIterable.FileLinesIterator	iterator(InputStream inputStream, Charset encoding)	A convenience method returning a one-off FileLinesMutableStringIterable.FileLinesIterator reading from an input stream.
static FileLinesMutableStringIterable.FileLinesIterator	iterator(InputStream inputStream, Charset encoding, Class<? extends InputStream> decompressor)	A convenience method returning a one-off FileLinesMutableStringIterable.FileLinesIterator reading from an input stream.
long	size64()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Methods inherited from interface it.unimi.dsi.fastutil.Size64

size

Constructor Details

FileLinesMutableStringIterable

public FileLinesMutableStringIterable(String filename)

Creates a file-lines iterable for the specified filename using the platform encoding.

Parameters:

filename - a filename.

FileLinesMutableStringIterable

public FileLinesMutableStringIterable(String filename,
 long size)

Creates a file-lines iterable for the specified filename and size using the platform encoding.

Parameters:

filename - a filename.

size - the number of lines in the file.

FileLinesMutableStringIterable

public FileLinesMutableStringIterable(String filename,
 Charset encoding)

Creates a file-lines iterable for the specified filename using the specified encoding.

Parameters:

filename - a filename.

encoding - an encoding.

FileLinesMutableStringIterable

public FileLinesMutableStringIterable(String filename,
 long size,
 Charset encoding)

Creates a file-lines iterable for the specified filename and size using the specified encoding.

Parameters:

filename - a filename.

size - the number of lines in the file.

encoding - an encoding.

FileLinesMutableStringIterable

public FileLinesMutableStringIterable(String filename,
 String encoding)

Creates a file-lines iterable for the specified filename using the specified encoding.

Parameters:

filename - a filename.

encoding - an encoding.

FileLinesMutableStringIterable

public FileLinesMutableStringIterable(String filename,
 long size,
 String encoding)

Creates a file-lines iterable for the specified filename and size using the specified encoding.

Parameters:

filename - a filename.

size - the number of lines in the file.

encoding - an encoding.

FileLinesMutableStringIterable

public FileLinesMutableStringIterable(String filename,
 Class<? extends InputStream> decompressor)
                               throws NoSuchMethodException,
SecurityException

Creates a file-lines iterable for the specified filename using the platform encoding, optionally assuming that the file is compressed.

Parameters:

filename - a filename.

decompressor - a class extending InputStream that will be used as a decompressor, or null for no decompression.

Throws:

NoSuchMethodException

SecurityException

FileLinesMutableStringIterable

public FileLinesMutableStringIterable(String filename,
 long size,
 Class<? extends InputStream> decompressor)
                               throws NoSuchMethodException,
SecurityException

Creates a file-lines iterable for the specified filename and size using the platform encoding, optionally assuming that the file is compressed.

Parameters:

filename - a filename.

size - the number of lines in the file.

decompressor - a class extending InputStream that will be used as a decompressor, or null for no decompression.

Throws:

NoSuchMethodException

SecurityException

FileLinesMutableStringIterable

public FileLinesMutableStringIterable(String filename,
 Charset encoding,
 Class<? extends InputStream> decompressor)
                               throws NoSuchMethodException,
SecurityException

Creates a file-lines iterable for the specified filename with the specified encoding, optionally assuming that the file is compressed.

Parameters:

filename - a filename.

encoding - an encoding.

decompressor - a class extending InputStream that will be used as a decompressor, or null for no decompression.

Throws:

NoSuchMethodException

SecurityException

FileLinesMutableStringIterable

public FileLinesMutableStringIterable(String filename,
 String encoding,
 Class<? extends InputStream> decompressor)
                               throws NoSuchMethodException,
SecurityException

Creates a file-lines iterable for the specified filename with the specified encoding, optionally assuming that the file is compressed.

Parameters:

filename - a filename.

encoding - an encoding.

decompressor - a class extending InputStream that will be used as a decompressor, or null for no decompression.

Throws:

NoSuchMethodException

SecurityException

FileLinesMutableStringIterable

public FileLinesMutableStringIterable(String filename,
 long size,
 Charset encoding,
 Class<? extends InputStream> decompressor)
                               throws NoSuchMethodException,
SecurityException

Creates a file-lines iterable for the specified filename and size with the specified encoding, optionally assuming that the file is compressed.

Parameters:

filename - a filename.

size - the number of lines in the file.

encoding - an encoding.

decompressor - a class extending InputStream that will be used as a decompressor, or null for no decompression.

Throws:

NoSuchMethodException

SecurityException

Method Details

iterator

public FileLinesMutableStringIterable.FileLinesIterator iterator()

Specified by:

iterator in interface Iterable<MutableString>

iterator

public static FileLinesMutableStringIterable.FileLinesIterator iterator(InputStream inputStream,
 Charset encoding)

A convenience method returning a one-off FileLinesMutableStringIterable.FileLinesIterator reading from an input stream.

Parameters:

inputStream - an input stream.

encoding - an encoding.

Returns:

an iterator returning the lines contained in the provided input stream.

iterator

public static FileLinesMutableStringIterable.FileLinesIterator iterator(InputStream inputStream,
 Charset encoding,
 Class<? extends InputStream> decompressor)

A convenience method returning a one-off FileLinesMutableStringIterable.FileLinesIterator reading from an input stream.

Parameters:

inputStream - an input stream.

encoding - an encoding.

decompressor - a class extending InputStream that will be used as a decompressor, or null for no decompression.

Returns:

an iterator returning the lines contained in the provided input stream.

size64

public long size64()

Specified by:

size64 in interface Size64

allLines

public ObjectList<String> allLines()

Returns all lines as a list.

Returns:

all lines of the file wrapped by this file-lines collection.

See Also:

• allLinesBig()

Implementation Specification:

This method iterates over the lines of the file and accumulates the resulting strings in a standard list. Thus, it will throw an exception on files with more than Integer.MAX_VALUE lines.

allLinesBig

public ObjectBigList<String> allLinesBig()

Returns all lines as a big list.

Returns:

all lines of the file wrapped by this file-lines collection.

See Also:

• allLines()

Implementation Specification:

This method iterates over the lines of the file and accumulates the resulting strings in a big list. Thus, it supports files with more than Integer.MAX_VALUE lines.