CharArrayReader
public
class
CharArrayReader
extends Reader
java.lang.Object | ||
↳ | java.io.Reader | |
↳ | java.io.CharArrayReader |
This class implements a character buffer that can be used as a character-input stream.
Summary
Fields | |
---|---|
protected
char[] |
buf
The character buffer. |
protected
int |
count
The index of the end of this buffer. |
protected
int |
markedPos
The position of mark in buffer. |
protected
int |
pos
The current buffer position. |
Inherited fields |
---|
Public constructors | |
---|---|
CharArrayReader(char[] buf)
Creates a CharArrayReader from the specified array of chars. |
|
CharArrayReader(char[] buf, int offset, int length)
Creates a CharArrayReader from the specified array of chars. |
Public methods | |
---|---|
void
|
close()
Closes the stream and releases any system resources associated with it. |
void
|
mark(int readAheadLimit)
Marks the present position in the stream. |
boolean
|
markSupported()
Tells whether this stream supports the mark() operation, which it does. |
int
|
read()
Reads a single character. |
int
|
read(char[] cbuf, int off, int len)
Reads characters into a portion of an array. |
int
|
read(CharBuffer target)
Attempts to read characters into the specified character buffer. |
boolean
|
ready()
Tells whether this stream is ready to be read. |
void
|
reset()
Resets the stream to the most recent mark, or to the beginning if it has never been marked. |
long
|
skip(long n)
Skips characters. |
Inherited methods | |
---|---|
Fields
count
protected int count
The index of the end of this buffer. There is not valid data at or beyond this index.
Public constructors
CharArrayReader
public CharArrayReader (char[] buf)
Creates a CharArrayReader from the specified array of chars.
Parameters | |
---|---|
buf |
char : Input buffer (not copied) |
CharArrayReader
public CharArrayReader (char[] buf, int offset, int length)
Creates a CharArrayReader from the specified array of chars.
The resulting reader will start reading at the given
offset
. The total number of char
values that can be
read from this reader will be either length
or
buf.length-offset
, whichever is smaller.
Parameters | |
---|---|
buf |
char : Input buffer (not copied) |
offset |
int : Offset of the first char to read |
length |
int : Number of chars to read |
Throws | |
---|---|
IllegalArgumentException |
If offset is negative or greater than
buf.length , or if length is negative, or if
the sum of these two values is negative. |
Public methods
close
public void close ()
Closes the stream and releases any system resources associated with it. Once the stream has been closed, further read(), ready(), mark(), reset(), or skip() invocations will throw an IOException. Closing a previously closed stream has no effect. This method will block while there is another thread blocking on the reader.
mark
public void mark (int readAheadLimit)
Marks the present position in the stream. Subsequent calls to reset() will reposition the stream to this point.
Parameters | |
---|---|
readAheadLimit |
int : Limit on the number of characters that may be
read while still preserving the mark. Because
the stream's input comes from a character array,
there is no actual limit; hence this argument is
ignored. |
Throws | |
---|---|
IOException |
If an I/O error occurs |
markSupported
public boolean markSupported ()
Tells whether this stream supports the mark() operation, which it does.
Returns | |
---|---|
boolean |
true if and only if this stream supports the mark operation. |
read
public int read ()
Reads a single character.
Returns | |
---|---|
int |
The character read, as an integer in the range 0 to 65535
(0x00-0xffff ), or -1 if the end of the stream has
been reached |
Throws | |
---|---|
IOException |
If an I/O error occurs |
read
public int read (char[] cbuf, int off, int len)
Reads characters into a portion of an array.
If len
is zero, then no characters are read and 0
is
returned; otherwise, there is an attempt to read at least one character.
If no character is available because the stream is at its end, the value
-1
is returned; otherwise, at least one character is read and
stored into cbuf
.
Parameters | |
---|---|
cbuf |
char : |
off |
int : |
len |
int : |
Returns | |
---|---|
int |
The number of characters read, or -1 if the end of the stream has been reached |
Throws | |
---|---|
IndexOutOfBoundsException |
|
IOException |
read
public int read (CharBuffer target)
Attempts to read characters into the specified character buffer. The buffer is used as a repository of characters as-is: the only changes made are the results of a put operation. No flipping or rewinding of the buffer is performed.
Parameters | |
---|---|
target |
CharBuffer : the buffer to read characters into |
Returns | |
---|---|
int |
The number of characters added to the buffer, or -1 if this source of characters is at its end |
Throws | |
---|---|
IOException |
ready
public boolean ready ()
Tells whether this stream is ready to be read. Character-array readers are always ready to be read.
Returns | |
---|---|
boolean |
True if the next read() is guaranteed not to block for input, false otherwise. Note that returning false does not guarantee that the next read will block. |
Throws | |
---|---|
IOException |
If an I/O error occurs |
reset
public void reset ()
Resets the stream to the most recent mark, or to the beginning if it has never been marked.
Throws | |
---|---|
IOException |
If an I/O error occurs |
skip
public long skip (long n)
Skips characters. If the stream is already at its end before this method is invoked, then no characters are skipped and zero is returned.
The n
parameter may be negative, even though the
skip
method of the Reader
superclass throws
an exception in this case. If n
is negative, then
this method does nothing and returns 0
.
Parameters | |
---|---|
n |
long : |
Returns | |
---|---|
long |
The number of characters actually skipped |
Throws | |
---|---|
IOException |