package java.io;
/**
* A <code>ByteArrayInputStream</code> 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 <code>read</code> method.
* <p>
* Closing a <tt>ByteArrayInputStream</tt> has no effect. The methods in
* this class can be called after the stream has been closed without
* generating an <tt>IOException</tt>.
*
* @author Arthur van Hoff
* @see java.io.StringBufferInputStream
* @since JDK1.0
*/
public
class ByteArrayInputStream extends InputStream {
/**
* An array of bytes that was provided
* by the creator of the stream. Elements <code>buf[0]</code>
* through <code>buf[count-1]</code> are the
* only bytes that can ever be read from the
* stream; element <code>buf[pos]</code> is
* the next byte to be read.
*/
protected byte buf[];
/**
* 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 <code>count</code>.
* The next byte to be read from the input stream buffer
* will be <code>buf[pos]</code>.
*/
protected int pos;
/**
* 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 <code>mark()</code> method.
* The current buffer position is set to this point by the
* <code>reset()</code> method.
* <p>
* 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).
*
* @since JDK1.1
*/
protected int mark = 0;
/**
* 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 <code>buf</code>.
* It is one greater than the position of
* the last byte within <code>buf</code> that
* can ever be read from the input stream buffer.
*/
protected int count;
/**
* Creates a <code>ByteArrayInputStream</code>
* so that it uses <code>buf</code> as its
* buffer array.
* The buffer array is not copied.
* The initial value of <code>pos</code>
* is <code>0</code> and the initial value
* of <code>count</code> is the length of
* <code>buf</code>.
*
* @param buf the input buffer.
*/
public ByteArrayInputStream(byte buf[]) {
this.buf = buf;
this.pos = 0;
this.count = buf.length;
}
/**
* Creates <code>ByteArrayInputStream</code>
* that uses <code>buf</code> as its
* buffer array. The initial value of <code>pos</code>
* is <code>offset</code> and the initial value
* of <code>count</code> is the minimum of <code>offset+length</code>
* and <code>buf.length</code>.
* 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.
*/
public ByteArrayInputStream(byte buf[], int offset, int length) {
this.buf = buf;
this.pos = offset;
this.count = Math.min(offset + length, buf.length);
this.mark = offset;
}
/**
* Reads the next byte of data from this input stream. The value
* byte is returned as an <code>int</code> in the range
* <code>0</code> to <code>255</code>. If no byte is available
* because the end of the stream has been reached, the value
* <code>-1</code> is returned.
* <p>
* This <code>read</code> method
* cannot block.
*
* @return the next byte of data, or <code>-1</code> if the end of the
* stream has been reached.
*/
public synchronized int read() {
return (pos < count) ? (buf[pos++] & 0xff) : -1;
}
/**
* Reads up to <code>len</code> bytes of data into an array of bytes
* from this input stream.
* If <code>pos</code> equals <code>count</code>,
* then <code>-1</code> is returned to indicate
* end of file. Otherwise, the number <code>k</code>
* of bytes read is equal to the smaller of
* <code>len</code> and <code>count-pos</code>.
* If <code>k</code> is positive, then bytes
* <code>buf[pos]</code> through <code>buf[pos+k-1]</code>
* are copied into <code>b[off]</code> through
* <code>b[off+k-1]</code> in the manner performed
* by <code>System.arraycopy</code>. The
* value <code>k</code> is added into <code>pos</code>
* and <code>k</code> is returned.
* <p>
* This <code>read</code> method cannot block.
*
* @param b the buffer into which the data is read.
* @param off the start offset in the destination array <code>b</code>
* @param len the maximum number of bytes read.
* @return the total number of bytes read into the buffer, or
* <code>-1</code> if there is no more data because the end of
* the stream has been reached.
* @exception NullPointerException If <code>b</code> is <code>null</code>.
* @exception IndexOutOfBoundsException If <code>off</code> is negative,
* <code>len</code> is negative, or <code>len</code> is greater than
* <code>b.length - off</code>
*/
public synchronized int read(byte b[], int off, int len) {
if (b == null) {
throw new NullPointerException();
} else if (off < 0 || len < 0 || len > b.length - off) {
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;
}
/**
* Skips <code>n</code> bytes of input from this input stream. Fewer
* bytes might be skipped if the end of the input stream is reached.
* The actual number <code>k</code>
* of bytes to be skipped is equal to the smaller
* of <code>n</code> and <code>count-pos</code>.
* The value <code>k</code> is added into <code>pos</code>
* and <code>k</code> is returned.
*
* @param n the number of bytes to be skipped.
* @return the actual number of bytes skipped.
*/
public synchronized long skip(long n) {
if (pos + n > count) {
n = count - pos;
}
if (n < 0) {
return 0;
}
pos += n;
return n;
}
/**
* Returns the number of remaining bytes that can be read (or skipped over)
* from this input stream.
* <p>
* The value returned is <code>count - pos</code>,
* which is the number of bytes remaining to be read from the input buffer.
*
* @return the number of remaining bytes that can be read (or skipped
* over) from this input stream without blocking.
*/
public synchronized int available() {
return count - pos;
}
/**
* Tests if this <code>InputStream</code> supports mark/reset. The
* <code>markSupported</code> method of <code>ByteArrayInputStream</code>
* always returns <code>true</code>.
*
* @since JDK1.1
*/
public boolean markSupported() {
return true;
}
/**
* 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.
* <p>
* 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).
*
* <p> Note: The <code>readAheadLimit</code> for this class
* has no meaning.
*
* @since JDK1.1
*/
public void mark(int readAheadLimit) {
mark = pos;
}
/**
* 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.
*/
public synchronized void reset() {
pos = mark;
}
/**
* Closing a <tt>ByteArrayInputStream</tt> has no effect. The methods in
* this class can be called after the stream has been closed without
* generating an <tt>IOException</tt>.
* <p>
*/
public void close() throws IOException {
}
}
package java.io;
import java.util.Arrays;
/**
* This class implements an output stream in which the data is
* written into a byte array. The buffer automatically grows as data
* is written to it.
* The data can be retrieved using <code>toByteArray()</code> and
* <code>toString()</code>.
* <p>
* Closing a <tt>ByteArrayOutputStream</tt> has no effect. The methods in
* this class can be called after the stream has been closed without
* generating an <tt>IOException</tt>.
*
* @author Arthur van Hoff
* @since JDK1.0
*/
public class ByteArrayOutputStream extends OutputStream {
/**
* The buffer where data is stored.
*/
protected byte buf[];
/**
* The number of valid bytes in the buffer.
*/
protected int count;
/**
* Creates a new byte array output stream. The buffer capacity is
* initially 32 bytes, though its size increases if necessary.
*/
public ByteArrayOutputStream() {
this(32);
}
/**
* Creates a new byte array output stream, with a buffer capacity of
* the specified size, in bytes.
*
* @param size the initial size.
* @exception IllegalArgumentException if size is negative.
*/
public ByteArrayOutputStream(int size) {
if (size < 0) {
throw new IllegalArgumentException("Negative initial size: "
+ size);
}
buf = new byte[size];
}
/**
* Writes the specified byte to this byte array output stream.
*
* @param b the byte to be written.
*/
public synchronized void write(int b) {
int newcount = count + 1;
if (newcount > buf.length) {
buf = Arrays.copyOf(buf, Math.max(buf.length << 1, newcount));
}
buf[count] = (byte)b;
count = newcount;
}
/**
* Writes <code>len</code> bytes from the specified byte array
* starting at offset <code>off</code> to this byte array output stream.
*
* @param b the data.
* @param off the start offset in the data.
* @param len the number of bytes to write.
*/
public synchronized void write(byte b[], int off, int len) {
if ((off < 0) || (off > b.length) || (len < 0) ||
((off + len) > b.length) || ((off + len) < 0)) {
throw new IndexOutOfBoundsException();
} else if (len == 0) {
return;
}
int newcount = count + len;
if (newcount > buf.length) {
buf = Arrays.copyOf(buf, Math.max(buf.length << 1, newcount));
}
System.arraycopy(b, off, buf, count, len);
count = newcount;
}
/**
* Writes the complete contents of this byte array output stream to
* the specified output stream argument, as if by calling the output
* stream's write method using <code>out.write(buf, 0, count)</code>.
*
* @param out the output stream to which to write the data.
* @exception IOException if an I/O error occurs.
*/
public synchronized void writeTo(OutputStream out) throws IOException {
out.write(buf, 0, count);
}
/**
* Resets the <code>count</code> field of this byte array output
* stream to zero, so that all currently accumulated output in the
* output stream is discarded. The output stream can be used again,
* reusing the already allocated buffer space.
*
* @see java.io.ByteArrayInputStream#count
*/
public synchronized void reset() {
count = 0;
}
/**
* Creates a newly allocated byte array. Its size is the current
* size of this output stream and the valid contents of the buffer
* have been copied into it.
*
* @return the current contents of this output stream, as a byte array.
* @see java.io.ByteArrayOutputStream#size()
*/
public synchronized byte toByteArray()[] {
return Arrays.copyOf(buf, count);
}
/**
* Returns the current size of the buffer.
*
* @return the value of the <code>count</code> field, which is the number
* of valid bytes in this output stream.
* @see java.io.ByteArrayOutputStream#count
*/
public synchronized int size() {
return count;
}
/**
* Converts the buffer's contents into a string decoding bytes using the
* platform's default character set. The length of the new <tt>String</tt>
* is a function of the character set, and hence may not be equal to the
* size of the buffer.
*
* <p> This method always replaces malformed-input and unmappable-character
* sequences with the default replacement string for the platform's
* default character set. The {@linkplain java.nio.charset.CharsetDecoder}
* class should be used when more control over the decoding process is
* required.
*
* @return String decoded from the buffer's contents.
* @since JDK1.1
*/
public synchronized String toString() {
return new String(buf, 0, count);
}
/**
* Converts the buffer's contents into a string by decoding the bytes using
* the specified {@link java.nio.charset.Charset charsetName}. The length of
* the new <tt>String</tt> is a function of the charset, and hence may not be
* equal to the length of the byte array.
*
* <p> This method always replaces malformed-input and unmappable-character
* sequences with this charset's default replacement string. The {@link
* java.nio.charset.CharsetDecoder} class should be used when more control
* over the decoding process is required.
*
* @param charsetName the name of a supported
* {@linkplain java.nio.charset.Charset </code>charset<code>}
* @return String decoded from the buffer's contents.
* @exception UnsupportedEncodingException
* If the named charset is not supported
* @since JDK1.1
*/
public synchronized String toString(String charsetName)
throws UnsupportedEncodingException
{
return new String(buf, 0, count, charsetName);
}
/**
* Creates a newly allocated string. Its size is the current size of
* the output stream and the valid contents of the buffer have been
* copied into it. Each character <i>c</i> in the resulting string is
* constructed from the corresponding element <i>b</i> in the byte
* array such that:
* <blockquote><pre>
* c == (char)(((hibyte & 0xff) << 8) | (b & 0xff))
* </pre></blockquote>
*
* @deprecated This method does not properly convert bytes into characters.
* As of JDK 1.1, the preferred way to do this is via the
* <code>toString(String enc)</code> method, which takes an encoding-name
* argument, or the <code>toString()</code> method, which uses the
* platform's default character encoding.
*
* @param hibyte the high byte of each resulting Unicode character.
* @return the current contents of the output stream, as a string.
* @see java.io.ByteArrayOutputStream#size()
* @see java.io.ByteArrayOutputStream#toString(String)
* @see java.io.ByteArrayOutputStream#toString()
*/
@Deprecated
public synchronized String toString(int hibyte) {
return new String(buf, hibyte, 0, count);
}
/**
* Closing a <tt>ByteArrayOutputStream</tt> has no effect. The methods in
* this class can be called after the stream has been closed without
* generating an <tt>IOException</tt>.
* <p>
*
*/
public void close() throws IOException {
}
}
