Package com.google.common.io

Class CharStreams

com.google.common.io.CharStreams

@GwtIncompatible
public final class CharStreams
extends 

Provides utility methods for working with character streams.

All method parameters must be non-null unless documented otherwise.

Some of the methods in this class take arguments with a generic type of Readable & Closeable. A implements both of those interfaces. Similarly for Appendable & Closeable and .

Since:

1.0

Author:

Chris Nokleberg, Bin Zhu, Colin Decker

Method Summary

Modifier and Type	Method	Description
static	target)	Returns a Writer that sends all output to the given target.
static long	from, to)	Copies all characters between the and objects.
static long	readable)	Reads and discards data from the given Readable until the end of the stream is reached.
static	nullWriter()	Returns a that simply discards written chars.
static <>	r)	Reads all of the lines from a object.
static <T> T	readable, LineProcessor<T> processor)	Streams lines from a object, stopping when the processor returns false or all lines have been read and returning the result produced by the processor.
static void	reader, long n)	Discards n characters of data from the reader.
static	r)	Reads all characters from a object into a .

Methods inherited from class java.lang.

, , , , , , , , , ,

Method Detail

copy

public static long  from,
                         to)
                 throws 

Copies all characters between the and objects. Does not close or flush either object.

Parameters:

from - the object to read from

to - the object to write to

Returns:

the number of characters copied

Throws:

- if an I/O error occurs

toString

public static   r)
                       throws 

Reads all characters from a object into a . Does not close the Readable.

Parameters:

r - the object to read from

Returns:

a string containing all the characters

Throws:

- if an I/O error occurs

readLines

@Beta
public static <>  r)
                              throws 

Reads all of the lines from a object. The lines do not include line-termination characters, but do include other leading and trailing whitespace.

Does not close the Readable. If reading files or resources you should use the Files.readLines(java.io.File, java.nio.charset.Charset) and Resources.readLines(java.net.URL, java.nio.charset.Charset, com.google.common.io.LineProcessor<T>) methods.

Parameters:

r - the object to read from

Returns:

a mutable containing all the lines

Throws:

- if an I/O error occurs

readLines

@Beta

public static <T> T  readable,
                              LineProcessor<T> processor)
                       throws 

Streams lines from a object, stopping when the processor returns false or all lines have been read and returning the result produced by the processor. Does not close readable. Note that this method may not fully consume the contents of readable if the processor stops processing early.

Throws:

- if an I/O error occurs

Since:

14.0

exhaust

@Beta

public static long  readable)
                    throws 

Reads and discards data from the given Readable until the end of the stream is reached. Returns the total number of chars read. Does not close the stream.

Throws:

Since:

20.0

skipFully

@Beta
public static void  reader,
                             long n)
                      throws 

Discards n characters of data from the reader. This method will block until the full amount has been skipped. Does not close the reader.

Parameters:

reader - the reader to read from

n - the number of characters to skip

Throws:

- if this stream reaches the end before skipping all the characters

- if an I/O error occurs

nullWriter

@Beta
public static  nullWriter()

Returns a that simply discards written chars.

Since:

15.0

asWriter

@Beta
public static   target)

Returns a Writer that sends all output to the given target. Closing the writer will close the target if it is , and flushing the writer will flush the target if it is .

Parameters:

target - the object to which output will be sent

Returns:

a new Writer object, unless target is a Writer, in which case the target is returned