@GwtIncompatible public final class CharStreams extends Object
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 Reader
implements both of those interfaces. Similarly for Appendable & Closeable
and Writer
.
Modifier and Type | Method and Description |
---|---|
static Writer |
asWriter(Appendable target)
Returns a Writer that sends all output to the given
Appendable target. |
static long |
copy(Readable from,
Appendable to)
Copies all characters between the
Readable and Appendable objects. |
static long |
exhaust(Readable readable)
Reads and discards data from the given
Readable until the end of the stream is reached. |
static Writer |
nullWriter()
Returns a
Writer that simply discards written chars. |
static List<String> |
readLines(Readable r)
Reads all of the lines from a
Readable object. |
static <T> T |
readLines(Readable readable,
LineProcessor<T> processor)
Streams lines from a
Readable object, stopping when the processor returns false
or all lines have been read and returning the result produced by the processor. |
static void |
skipFully(Reader reader,
long n)
Discards
n characters of data from the reader. |
static String |
toString(Readable r)
|
@CanIgnoreReturnValue public static long copy(Readable from, Appendable to) throws IOException
Readable
and Appendable
objects. Does not
close or flush either object.from
- the object to read fromto
- the object to write toIOException
- if an I/O error occurspublic static String toString(Readable r) throws IOException
r
- the object to read fromIOException
- if an I/O error occurs@Beta public static List<String> readLines(Readable r) throws IOException
Readable
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.
r
- the object to read fromList
containing all the linesIOException
- if an I/O error occurs@Beta @CanIgnoreReturnValue public static <T> T readLines(Readable readable, LineProcessor<T> processor) throws IOException
Readable
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.IOException
- if an I/O error occurs@Beta @CanIgnoreReturnValue public static long exhaust(Readable readable) throws IOException
Readable
until the end of the stream is reached.
Returns the total number of chars read. Does not close the stream.IOException
@Beta public static void skipFully(Reader reader, long n) throws IOException
n
characters of data from the reader. This method will block until the full
amount has been skipped. Does not close the reader.reader
- the reader to read fromn
- the number of characters to skipEOFException
- if this stream reaches the end before skipping all the charactersIOException
- if an I/O error occurs@Beta public static Writer nullWriter()
Writer
that simply discards written chars.@Beta public static Writer asWriter(Appendable target)
Appendable
target. Closing the
writer will close the target if it is Closeable
, and flushing the writer will flush the
target if it is Flushable
.target
- the object to which output will be sentCopyright © 2010–2019. All rights reserved.