File	Doc	Category	Size	Date	Package
ByteArrayInputStream.java	API Doc	Java SE 5 API	8589	Fri Aug 26 14:56:58 BST 2005	java.io

ByteArrayInputStream

• java.lang.Object
  • java.io.InputStream

Fields Summary
protected byte[]	buf 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.
protected int	pos 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].
protected int	mark 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. If no mark has been set, then the value of mark is the offset passed to the constructor (or 0 if the offset was not supplied).
protected int	count 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.

Constructors Summary
public ByteArrayInputStream(byte[] buf) 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. param buf the input buffer. this.buf = buf; this.pos = 0; this.count = buf.length;
public ByteArrayInputStream(byte[] buf, int offset, int length) Creates ByteArrayInputStream that uses buf as its buffer array. The initial value of pos is offset and the initial value of count is the minimum of offset+length and buf.length. The buffer array is not copied. The buffer's mark is set to the specified offset. param buf the input buffer. param offset the offset in the buffer of the first byte to read. param length the maximum number of bytes to read from the buffer. this.buf = buf; this.pos = offset; this.count = Math.min(offset + length, buf.length); this.mark = offset;

Methods Summary
public synchronized int	available() 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. return the number of bytes that can be read from the input stream without blocking. return count - pos;
public void	close() Closing a ByteArrayInputStream has no effect. The methods in this class can be called after the stream has been closed without generating an IOException.
public void	mark(int readAheadLimit) 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. If no mark has been set, then the value of the mark is the offset passed to the constructor (or 0 if the offset was not supplied). Note: The readAheadLimit for this class has no meaning. since JDK1.1 mark = pos;
public boolean	markSupported() Tests if this InputStream supports mark/reset. The markSupported method of ByteArrayInputStream always returns true. since JDK1.1 return true;
public synchronized int	read() 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. return the next byte of data, or -1 if the end of the stream has been reached. return (pos < count) ? (buf[pos++] & 0xff) : -1;
public synchronized int	read(byte[] b, int off, int len) 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. param b the buffer into which the data is read. param off the start offset of the data. param len the maximum number of bytes read. return 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. if (b == null) { throw new NullPointerException(); } else if ((off < 0) || (off > b.length) || (len < 0) || ((off + len) > b.length) || ((off + len) < 0)) { throw new IndexOutOfBoundsException(); } if (pos >= count) { return -1; } if (pos + len > count) { len = count - pos; } if (len <= 0) { return 0; } System.arraycopy(buf, pos, b, off, len); pos += len; return len;
public synchronized void	reset() Resets the buffer to the marked position. The marked position is 0 unless another position was marked or an offset was specified in the constructor. pos = mark;
public synchronized long	skip(long n) 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. param n the number of bytes to be skipped. return the actual number of bytes skipped. if (pos + n > count) { n = count - pos; } if (n < 0) { return 0; } pos += n; return n;