Class CharArrayReader
- java.lang.Object
-
- java.io.Reader
-
- java.io.CharArrayReader
- All Implemented Interfaces:
- Closeable, AutoCloseable, Readable
public class CharArrayReader extends Reader
This class implements a character buffer that can be used as a character-input stream.
- Since:
- JDK1.1
Fields
Modifier and Type | Field and Description |
---|---|
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. |
Fields inherited from class java.io.Reader
lock
Constructors
Constructor and Description |
---|
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. |
Methods
Modifier and Type | Method and Description |
---|---|
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[] b,
int off,
int len) Reads characters into a portion of an array. |
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. |
Methods inherited from class java.io.Reader
read, read
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Fields
buf
protected char[] buf
The character buffer.
pos
protected int pos
The current buffer position.
markedPos
protected int markedPos
The position of mark in buffer.
count
protected int count
The index of the end of this buffer. There is not valid data at or beyond this index.
Constructors
CharArrayReader
public CharArrayReader(char[] buf)
Creates a CharArrayReader from the specified array of chars.
- Parameters:
-
buf
- 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
- Input buffer (not copied) -
offset
- Offset of the first char to read -
length
- Number of chars to read - Throws:
-
IllegalArgumentException
- Ifoffset
is negative or greater thanbuf.length
, or iflength
is negative, or if the sum of these two values is negative.
Methods
read
public int read() throws IOException
Reads a single character.
- Overrides:
-
read
in classReader
- Returns:
- 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[] b, int off, int len) throws IOException
Reads characters into a portion of an array.
- Specified by:
-
read
in classReader
- Parameters:
-
b
- Destination buffer -
off
- Offset at which to start storing characters -
len
- Maximum number of characters to read - Returns:
- The actual number of characters read, or -1 if the end of the stream has been reached
- Throws:
-
IOException
- If an I/O error occurs
skip
public long skip(long n) throws IOException
Skips characters. Returns the number of characters that were skipped.
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
.
- Overrides:
-
skip
in classReader
- Parameters:
-
n
- The number of characters to skip - Returns:
- The number of characters actually skipped
- Throws:
-
IOException
- If the stream is closed, or an I/O error occurs
ready
public boolean ready() throws IOException
Tells whether this stream is ready to be read. Character-array readers are always ready to be read.
- Overrides:
-
ready
in classReader
- Returns:
- 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
markSupported
public boolean markSupported()
Tells whether this stream supports the mark() operation, which it does.
- Overrides:
-
markSupported
in classReader
- Returns:
- true if and only if this stream supports the mark operation.
mark
public void mark(int readAheadLimit) throws IOException
Marks the present position in the stream. Subsequent calls to reset() will reposition the stream to this point.
- Overrides:
-
mark
in classReader
- Parameters:
-
readAheadLimit
- 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
reset
public void reset() throws IOException
Resets the stream to the most recent mark, or to the beginning if it has never been marked.
- Overrides:
-
reset
in classReader
- Throws:
-
IOException
- If an I/O error occurs
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.
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
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https://docs.oracle.com/javase/8/docs/api/java/io/CharArrayReader.html