Modifier and Type	Class and Description
private static class	CharStreams.NullWriter

Modifier and Type	Field and Description
private static final int	DEFAULT_BUF_SIZE

Access	Constructor and Description
private	CharStreams()

Method Summary

Modifier and Type	Method and Description
public static Writer	Returns: a new Writer object, unless target is a Writer, in which case the target is returned asWriter(Appendable the object to which output will be sent target) Returns a Writer that sends all output to the given `Appendable` target.
public static long	Returns: the number of characters copied copy(Readable the object to read from from, Appendable the object to write to to) Copies all characters between the `Readable` and `Appendable` objects.
pack-priv static long	Returns: the number of characters copied copyReaderToBuilder(Reader the object to read from from, StringBuilder the object to write to to) Copies all characters between the `Reader` and `StringBuilder` objects.
pack-priv static long	Returns: the number of characters copied copyReaderToWriter(Reader the object to read from from, Writer the object to write to to) Copies all characters between the `Reader` and `Writer` objects.
pack-priv static CharBuffer	createBuffer() Creates a new `CharBuffer` for buffering reads or writes.
public static long	exhaust(Readable readable) Reads and discards data from the given `Readable` until the end of the stream is reached.
public static Writer	nullWriter() Returns a `Writer` that simply discards written chars.
public static List<String>	Returns: a mutable `List` containing all the lines readLines(Readable the object to read from r) Reads all of the lines from a `Readable` object.
public static <T extends @Nullable Object> 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.
public static void	skipFully(Reader the reader to read from reader, long the number of characters to skip n) Discards `n` characters of data from the reader.
public static String	Returns: a string containing all the characters toString(Readable the object to read from r) Reads all characters from a `Readable` object into a `String`.
private static StringBuilder	Returns: a `StringBuilder` containing all the characters toStringBuilder(Readable the object to read from r) Reads all characters from a `Readable` object into a new `StringBuilder` instance.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

DEFAULT_BUF_SIZE	back to summary
private static final int DEFAULT_BUF_SIZE

Constructor Detail

CharStreams	back to summary
private CharStreams()

Method Detail

asWriter back to summary

asWriter	back to summary
public static Writer asWriter(Appendable target) Returns a Writer that sends all output to the given `Appendable` target. Closing the writer will close the target if it is `Closeable`, and flushing the writer will flush the target if it is `java.io.Flushable`. Parameters target:Appendable the object to which output will be sent Returns:Writer a new Writer object, unless target is a Writer, in which case the target is returned

public static Writer asWriter(Appendable target)

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

Parameters

target:Appendable: the object to which output will be sent

Returns:Writer

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

copy back to summary

copy	back to summary
public static long copy(Readable from, Appendable to) throws IOException Copies all characters between the `Readable` and `Appendable` objects. Does not close or flush either object. Parameters from:Readable the object to read from to:Appendable the object to write to Returns:long the number of characters copied Annotations @CanIgnoreReturnValue Exceptions IOException: if an I/O error occurs

public static long copy(Readable from, Appendable to) throws IOException

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

Parameters

from:Readable: the object to read from
to:Appendable: the object to write to

Returns:long

the number of characters copied

Annotations

@CanIgnoreReturnValue

Exceptions

IOException:: if an I/O error occurs

copyReaderToBuilder back to summary

copyReaderToBuilder	back to summary
pack-priv static long copyReaderToBuilder(Reader from, StringBuilder to) throws IOException Copies all characters between the `Reader` and `StringBuilder` objects. Does not close or flush the reader. This is identical to `copy(Readable, Appendable)` but optimized for these specific types. CharBuffer has poor performance when being written into or read out of so round tripping all the bytes through the buffer takes a long time. With these specialized types we can just use a char array. Parameters from:Reader the object to read from to:StringBuilder the object to write to Returns:long the number of characters copied Annotations @CanIgnoreReturnValue Exceptions IOException: if an I/O error occurs

pack-priv static long copyReaderToBuilder(Reader from, StringBuilder to) throws IOException

Copies all characters between the Reader and StringBuilder objects. Does not close or flush the reader.

This is identical to copy(Readable, Appendable) but optimized for these specific types. CharBuffer has poor performance when being written into or read out of so round tripping all the bytes through the buffer takes a long time. With these specialized types we can just use a char array.

Parameters

from:Reader: the object to read from
to:StringBuilder: the object to write to

Returns:long

the number of characters copied

Annotations

@CanIgnoreReturnValue

Exceptions

IOException:: if an I/O error occurs

copyReaderToWriter back to summary

copyReaderToWriter	back to summary
pack-priv static long copyReaderToWriter(Reader from, Writer to) throws IOException Copies all characters between the `Reader` and `Writer` objects. Does not close or flush the reader or writer. This is identical to `copy(Readable, Appendable)` but optimized for these specific types. CharBuffer has poor performance when being written into or read out of so round tripping all the bytes through the buffer takes a long time. With these specialized types we can just use a char array. Parameters from:Reader the object to read from to:Writer the object to write to Returns:long the number of characters copied Annotations @CanIgnoreReturnValue Exceptions IOException: if an I/O error occurs

pack-priv static long copyReaderToWriter(Reader from, Writer to) throws IOException

Copies all characters between the Reader and Writer objects. Does not close or flush the reader or writer.

Parameters

from:Reader: the object to read from
to:Writer: the object to write to

Returns:long

the number of characters copied

Annotations

@CanIgnoreReturnValue

Exceptions

IOException:: if an I/O error occurs

createBuffer	back to summary
pack-priv static CharBuffer createBuffer() Creates a new `CharBuffer` for buffering reads or writes.

exhaust back to summary

exhaust	back to summary
public static long exhaust(Readable readable) throws IOException 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. Annotations @CanIgnoreReturnValue Since 20.0

public static long exhaust(Readable readable) throws IOException

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.

Annotations

@CanIgnoreReturnValue

Since

20.0

nullWriter back to summary

nullWriter	back to summary
public static Writer nullWriter() Returns a `Writer` that simply discards written chars. Since 15.0

public static Writer nullWriter()

Returns a Writer that simply discards written chars.

Since: 15.0

readLines back to summary

readLines	back to summary
public static List<String> readLines(Readable r) throws IOException Reads all of the lines from a `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` and `Resources#readLines` methods. Parameters r:Readable the object to read from Returns:List<String> a mutable `List` containing all the lines Exceptions IOException: if an I/O error occurs

public static List<String> readLines(Readable r) throws IOException

Reads all of the lines from a 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 and Resources#readLines methods.

Parameters

r:Readable: the object to read from

Returns:List<String>

a mutable List containing all the lines

Exceptions

IOException:: if an I/O error occurs

readLines back to summary

readLines	back to summary
public static <T extends @Nullable Object> T readLines(Readable readable, LineProcessor<T> processor) throws IOException 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. Does not close `readable`. Note that this method may not fully consume the contents of `readable` if the processor stops processing early. Annotations @CanIgnoreReturnValue @ParametricNullness Exceptions IOException: if an I/O error occurs Since 14.0

public static <T extends @Nullable Object> T readLines(Readable readable, LineProcessor<T> processor) throws IOException

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. Does not close readable. Note that this method may not fully consume the contents of readable if the processor stops processing early.

Annotations

@CanIgnoreReturnValue
@ParametricNullness

Exceptions

IOException:: if an I/O error occurs

Since

14.0

skipFully back to summary

skipFully	back to summary
public static void skipFully(Reader reader, long n) throws IOException 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:Reader the reader to read from n:long the number of characters to skip Exceptions IOException: if an I/O error occurs EOFException: if this stream reaches the end before skipping all the characters

public static void skipFully(Reader reader, long n) throws IOException

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:Reader: the reader to read from
n:long: the number of characters to skip

Exceptions

IOException:: if an I/O error occurs
EOFException:: if this stream reaches the end before skipping all the characters

toString back to summary

toString	back to summary
public static String toString(Readable r) throws IOException Reads all characters from a `Readable` object into a `String`. Does not close the `Readable`. Parameters r:Readable the object to read from Returns:String a string containing all the characters Exceptions IOException: if an I/O error occurs

public static String toString(Readable r) throws IOException

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

Parameters

r:Readable: the object to read from

Returns:String

a string containing all the characters

Exceptions

IOException:: if an I/O error occurs

toStringBuilder back to summary

toStringBuilder	back to summary
private static StringBuilder toStringBuilder(Readable r) throws IOException Reads all characters from a `Readable` object into a new `StringBuilder` instance. Does not close the `Readable`. Parameters r:Readable the object to read from Returns:StringBuilder a `StringBuilder` containing all the characters Exceptions IOException: if an I/O error occurs

private static StringBuilder toStringBuilder(Readable r) throws IOException

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

Parameters

r:Readable: the object to read from

Returns:StringBuilder

a StringBuilder containing all the characters

Exceptions

IOException:: if an I/O error occurs

com.google.common.io back to summary

private final Class CharStreams.NullWriter

Class Inheritance

extends Writer

java.lang.Object
java.io.Writer
com.google.common.io.CharStreams.NullWriter

Field Summary

Modifier and Type	Field and Description
private static final CharStreams.NullWriter	INSTANCE

Inherited from java.io.Writer:: lock

Constructor Summary

Access	Constructor and Description
private	NullWriter()

Method Summary

Modifier and Type	Method and Description
public Writer	append(CharSequence The character sequence to append. If `csq` is `null`, then the four characters `"null"` are appended to this writer. csq) Overrides java.io.Writer.append. Implements java.lang.Appendable.append. Appends the specified character sequence to this writer.
public Writer	append(CharSequence The character sequence from which a subsequence will be appended. If `csq` is `null`, then characters will be appended as if `csq` contained the four characters `"null"`. csq, int The index of the first character in the subsequence start, int The index of the character following the last character in the subsequence end) Overrides java.io.Writer.append. Implements java.lang.Appendable.append. Appends a subsequence of the specified character sequence to this writer.
public Writer	append(char The 16-bit character to append c) Overrides java.io.Writer.append. Implements java.lang.Appendable.append. Appends the specified character to this writer.
public void	close() Implements abstract java.io.Writer.close. Implements java.io.Closeable.close. Closes the stream, flushing it first.
public void	flush() Implements abstract java.io.Writer.flush. Implements java.io.Flushable.flush. Flushes the stream.
public String	toString() Overrides java.lang.Object.toString. Returns a string representation of the object.
public void	write(int int specifying a character to be written c) Overrides java.io.Writer.write. Writes a single character.
public void	write(char[] Array of characters to be written cbuf) Overrides java.io.Writer.write. Writes an array of characters.
public void	write(char[] Array of characters cbuf, int Offset from which to start writing characters off, int Number of characters to write len) Implements abstract java.io.Writer.write. Writes a portion of an array of characters.
public void	write(String String to be written str) Overrides java.io.Writer.write. Writes a string.
public void	write(String A String str, int Offset from which to start writing characters off, int Number of characters to write len) Overrides java.io.Writer.write. Writes a portion of a string.

Inherited from java.io.Writer:: nullWriter

Field Detail

INSTANCE	back to summary
private static final CharStreams.NullWriter INSTANCE

Constructor Detail

NullWriter	back to summary
private NullWriter()

Method Detail

append back to summary

append	back to summary
public Writer append(CharSequence csq) Overrides java.io.Writer.append. Implements java.lang.Appendable.append. Doc from java.io.Writer.append. Appends the specified character sequence to this writer. An invocation of this method of the form `out.append(csq)` behaves in exactly the same way as the invocation `out.write(csq.toString())` out.write(csq.toString()) Depending on the specification of `toString` for the character sequence `csq`, the entire sequence may not be appended. For instance, invoking the `toString` method of a character buffer will return a subsequence whose content depends upon the buffer's position and limit. Parameters csq:CharSequence The character sequence to append. If `csq` is `null`, then the four characters `"null"` are appended to this writer. Returns:Writer This writer Annotations @Override

public Writer append(CharSequence csq)

Overrides java.io.Writer.append.

Implements java.lang.Appendable.append.

Doc from java.io.Writer.append.

Appends the specified character sequence to this writer.

An invocation of this method of the form out.append(csq) behaves in exactly the same way as the invocation

out.write(csq.toString())

Depending on the specification of toString for the character sequence csq, the entire sequence may not be appended. For instance, invoking the toString method of a character buffer will return a subsequence whose content depends upon the buffer's position and limit.

Parameters

csq:CharSequence: The character sequence to append. If csq is null, then the four characters "null" are appended to this writer.

Returns:Writer

This writer

Annotations

@Override

append back to summary

append	back to summary
public Writer append(CharSequence csq, int start, int end) Overrides java.io.Writer.append. Implements java.lang.Appendable.append. Doc from java.io.Writer.append. Appends a subsequence of the specified character sequence to this writer. `Appendable`. An invocation of this method of the form `out.append(csq, start, end)` when `csq` is not `null` behaves in exactly the same way as the invocation `out.write(csq.subSequence(start, end).toString())` out.write(csq.subSequence(start, end).toString()) Parameters csq:CharSequence The character sequence from which a subsequence will be appended. If `csq` is `null`, then characters will be appended as if `csq` contained the four characters `"null"`. start:int The index of the first character in the subsequence end:int The index of the character following the last character in the subsequence Returns:Writer This writer Annotations @Override

public Writer append(CharSequence csq, int start, int end)

Overrides java.io.Writer.append.

Implements java.lang.Appendable.append.

Doc from java.io.Writer.append.

Appends a subsequence of the specified character sequence to this writer. Appendable.

An invocation of this method of the form out.append(csq, start, end) when csq is not null behaves in exactly the same way as the invocation

out.write(csq.subSequence(start, end).toString())

Parameters

csq:CharSequence: The character sequence from which a subsequence will be appended. If csq is null, then characters will be appended as if csq contained the four characters "null".
start:int: The index of the first character in the subsequence
end:int: The index of the character following the last character in the subsequence

Returns:Writer

This writer

Annotations

@Override

append back to summary

append	back to summary
public Writer append(char c) Overrides java.io.Writer.append. Implements java.lang.Appendable.append. Doc from java.io.Writer.append. Appends the specified character to this writer. An invocation of this method of the form `out.append(c)` behaves in exactly the same way as the invocation `out.write(c)` out.write(c) Parameters c:char The 16-bit character to append Returns:Writer This writer Annotations @Override

public Writer append(char c)

Overrides java.io.Writer.append.

Implements java.lang.Appendable.append.

Doc from java.io.Writer.append.

Appends the specified character to this writer.

An invocation of this method of the form out.append(c) behaves in exactly the same way as the invocation

out.write(c)

Parameters

c:char: The 16-bit character to append

Returns:Writer

This writer

Annotations

@Override

close	back to summary
public void close() Implements abstract java.io.Writer.close. Implements java.io.Closeable.close. Doc from java.io.Writer.close. Closes the stream, flushing it first. Once the stream has been closed, further write() or flush() invocations will cause an IOException to be thrown. Closing a previously closed stream has no effect. Annotations @Override

back to summary

public void close()

Implements abstract java.io.Writer.close.

Implements java.io.Closeable.close.

Doc from java.io.Writer.close.

Closes the stream, flushing it first. Once the stream has been closed, further write() or flush() invocations will cause an IOException to be thrown. Closing a previously closed stream has no effect.

Annotations

@Override

flush	back to summary
public void flush() Implements abstract java.io.Writer.flush. Implements java.io.Flushable.flush. Doc from java.io.Writer.flush. Flushes the stream. If the stream has saved any characters from the various write() methods in a buffer, write them immediately to their intended destination. Then, if that destination is another character or byte stream, flush it. Thus one flush() invocation will flush all the buffers in a chain of Writers and OutputStreams. If the intended destination of this stream is an abstraction provided by the underlying operating system, for example a file, then flushing the stream guarantees only that bytes previously written to the stream are passed to the operating system for writing; it does not guarantee that they are actually written to a physical device such as a disk drive. Annotations @Override

flush

back to summary

public void flush()

Implements abstract java.io.Writer.flush.

Implements java.io.Flushable.flush.

Doc from java.io.Writer.flush.

Flushes the stream. If the stream has saved any characters from the various write() methods in a buffer, write them immediately to their intended destination. Then, if that destination is another character or byte stream, flush it. Thus one flush() invocation will flush all the buffers in a chain of Writers and OutputStreams.

If the intended destination of this stream is an abstraction provided by the underlying operating system, for example a file, then flushing the stream guarantees only that bytes previously written to the stream are passed to the operating system for writing; it does not guarantee that they are actually written to a physical device such as a disk drive.

Annotations

@Override

toString	back to summary
public String toString() Overrides java.lang.Object.toString. Doc from java.lang.Object.toString. Returns a string representation of the object. Returns:String a string representation of the object Annotations @Override

toString

back to summary

public String toString()

Overrides java.lang.Object.toString.

Doc from java.lang.Object.toString.

Returns a string representation of the object.

Returns:String

a string representation of the object

Annotations

@Override

write	back to summary
public void write(int c) Overrides java.io.Writer.write. Doc from java.io.Writer.write. Writes a single character. The character to be written is contained in the 16 low-order bits of the given integer value; the 16 high-order bits are ignored. Subclasses that intend to support efficient single-character output should override this method. Parameters c:int int specifying a character to be written Annotations @Override

write

back to summary

public void write(int c)

Overrides java.io.Writer.write.

Doc from java.io.Writer.write.

Writes a single character. The character to be written is contained in the 16 low-order bits of the given integer value; the 16 high-order bits are ignored.

Subclasses that intend to support efficient single-character output should override this method.

Parameters

c:int: int specifying a character to be written

Annotations

@Override

write	back to summary
public void write(char[] cbuf) Overrides java.io.Writer.write. Doc from java.io.Writer.write. Writes an array of characters. Parameters cbuf:char[] Array of characters to be written Annotations @Override

write

back to summary

public void write(char[] cbuf)

Overrides java.io.Writer.write.

Doc from java.io.Writer.write.

Writes an array of characters.

Parameters

cbuf:char[]: Array of characters to be written

Annotations

@Override

write	back to summary
public void write(char[] cbuf, int off, int len) Implements abstract java.io.Writer.write. Doc from java.io.Writer.write. Writes a portion of an array of characters. Parameters cbuf:char[] Array of characters off:int Offset from which to start writing characters len:int Number of characters to write Annotations @Override

write

back to summary

public void write(char[] cbuf, int off, int len)

Implements abstract java.io.Writer.write.

Doc from java.io.Writer.write.

Writes a portion of an array of characters.

Parameters

cbuf:char[]: Array of characters
off:int: Offset from which to start writing characters
len:int: Number of characters to write

Annotations

@Override

write	back to summary
public void write(String str) Overrides java.io.Writer.write. Doc from java.io.Writer.write. Writes a string. Parameters str:String String to be written Annotations @Override

write

back to summary

public void write(String str)

Overrides java.io.Writer.write.

Doc from java.io.Writer.write.

Writes a string.

Parameters

str:String: String to be written

Annotations

@Override

write	back to summary
public void write(String str, int off, int len) Overrides java.io.Writer.write. Doc from java.io.Writer.write. Writes a portion of a string. Parameters str:String A String off:int Offset from which to start writing characters len:int Number of characters to write Annotations @Override

write

back to summary

public void write(String str, int off, int len)

Overrides java.io.Writer.write.

Doc from java.io.Writer.write.

Writes a portion of a string.

Parameters

str:String: A String
off:int: Offset from which to start writing characters
len:int: Number of characters to write

Annotations

@Override

public final Class CharStreams

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

private final Class CharStreams.NullWriter

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail