java.io
ByteArrayInputStream
Declaration
public class ByteArrayInputStream extends InputStream
java.lang.Object
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+--java.io.InputStream
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+--java.io.ByteArrayInputStream
Description
A ByteArrayInputStream contains an internal buffer that contains bytes that may be read from the
stream. An internal counter keeps track of the next byte to be supplied by the read method.
Since: JDK1.0, CLDC 1.0
Member Summary
Fields
protected byte[] buf
protected int count
protected int mark
protected int pos
Constructors
ByteArrayInputStream(byte[] buf)
ByteArrayInputStream(byte[] buf, int offset, int length)
Methods
int available()
void close()
void mark(int readAheadLimit)
boolean markSupported()
int read()
int read(byte[] b, int off, int len)
void reset()
long skip(long n)
Inherited Member Summary
Methods inherited from class InputStream
read(byte[])
Methods inherited from class Object
ByteArrayInputStream java.io
buf
4
Fields
buf
Declaration:
protected byte[] buf
Description:
An array of bytes that was provided by the creator of the stream. Elements buf[0] through buf[count-
1] are the only bytes that can ever be read from the stream; element buf[pos] is the next byte to be read.
pos
Declaration:
protected int pos
Description:
The index of the next character to read from the input stream buffer. This value should always be
nonnegative and not larger than the value of count. The next byte to be read from the input stream buffer
will be buf[pos].
mark
Declaration:
protected int mark
Description:
The currently marked position in the stream. ByteArrayInputStream objects are marked at position zero by
default when constructed. They may be marked at another position within the buffer by the mark()
method. The current buffer position is set to this point by the reset() method.
Since: JDK1.1
count
Declaration:
protected int count
Description:
The index one greater than the last valid character in the input stream buffer. This value should always be
nonnegative and not larger than the length of buf. It is one greater than the position of the last byte within
buf that can ever be read from the input stream buffer.
equals(Object), getClass(), hashCode(), notify(), notifyAll(), toString(), wait(),
wait(), wait()
Inherited Member Summary
java.io ByteArrayInputStream
ByteArrayInputStream(byte[])
5
Constructors
ByteArrayInputStream(byte[])
Declaration:
public ByteArrayInputStream(byte[] buf)
Description:
Creates a ByteArrayInputStream so that it uses buf as its buffer array. The buffer array is not
copied. The initial value of pos is 0 and the initial value of count is the length of buf.
Parameters:
buf - the input buffer.
ByteArrayInputStream(byte[], int, int)
Declaration:
public ByteArrayInputStream(byte[] buf, int offset, int length)
Description:
Creates ByteArrayInputStream that uses buf as its buffer array. The initial value of pos is offset
and the initial value of count is offset+length. The buffer array is not copied.
Note that if bytes are simply read from the resulting input stream, elements buf[pos] through
buf[pos+len-1] will be read; however, if a reset operation is performed, then bytes buf[0]
through buf[pos-1] will then become available for input.
Parameters:
buf - the input buffer.
offset - the offset in the buffer of the first byte to read.
length - the maximum number of bytes to read from the buffer.
Methods
read()
Declaration:
public int read()
Description:
Reads the next byte of data from this input stream. The value byte is returned as an int in the range 0 to
255. If no byte is available because the end of the stream has been reached, the value -1 is returned.
This read method cannot block.
Overrides: read in class InputStream
Returns: the next byte of data, or -1 if the end of the stream has been reached.
read(byte[], int, int)
Declaration:
public int read(byte[] b, int off, int len)
ByteArrayInputStream java.io
skip(long)
6
Description:
Reads up to len bytes of data into an array of bytes from this input stream. If pos equals count, then -1
is returned to indicate end of file. Otherwise, the number k of bytes read is equal to the smaller of len and
count-pos. If k is positive, then bytes buf[pos] through buf[pos+k-1] are copied into b[off]
through b[off+k-1] in the manner performed by System.arraycopy. The value k is added into
pos and k is returned.
This read method cannot block.
Overrides: read in class InputStream
Parameters:
b - the buffer into which the data is read.
off - the start offset of the data.
len - the maximum number of bytes read.
Returns: the total number of bytes read into the buffer, or -1 if there is no more data because the end of
the stream has been reached.
skip(long)
Declaration:
public long skip(long n)
Description:
Skips n bytes of input from this input stream. Fewer bytes might be skipped if the end of the input stream is
reached. The actual number k of bytes to be skipped is equal to the smaller of n and count-pos. The
value k is added into pos and k is returned.
Overrides: skip in class InputStream
Parameters:
n - the number of bytes to be skipped.
Returns: the actual number of bytes skipped.
available()
Declaration:
public int available()
Description:
Returns the number of bytes that can be read from this input stream without blocking. The value returned is
count - pos, which is the number of bytes remaining to be read from the input buffer.
Overrides: available in class InputStream
Returns: the number of bytes that can be read from the input stream without blocking.
markSupported()
Declaration:
public boolean markSupported()
Description:
Tests if ByteArrayInputStream supports mark/reset.
Overrides: markSupported in class InputStream
java.io ByteArrayInputStream
mark(int)
7
Returns: true if this true type supports the mark and reset method; false otherwise.
Since: JDK1.1
mark(int)
Declaration:
public void mark(int readAheadLimit)
Description:
Set the current marked position in the stream. ByteArrayInputStream objects are marked at position zero by
default when constructed. They may be marked at another position within the buffer by this method.
Overrides: mark in class InputStream
Parameters:
readlimit - the maximum limit of bytes that can be read before the mark position becomes invalid.
Since: JDK1.1
reset()
Declaration:
public void reset()
Description:
Resets the buffer to the marked position. The marked position is the beginning unless another position was
marked. The value of pos is set to 0.
Overrides: reset in class InputStream
close()
Declaration:
public void close()
throws IOException
Description:
Closes this input stream and releases any system resources associated with the stream.
Overrides: close in class InputStream
Throws:
IOException - if an I/O error occurs.