public static void main(String[] arguments) {
try {
// read byte data into a byte buffer
String data = "friends.dat";
FileInputStream inData = new FileInputStream(data);
FileChannel inChannel = inData.getChannel();
long inSize = inChannel.size();
ByteBuffer source = ByteBuffer.allocate((int) inSize);
inChannel.read(source, 0);
source.position(0);
System.out.println("Original byte data:");
for (int i = 0; source.remaining() > 0; i++) {
System.out.print(source.get() + " ");
}
// convert byte data into character data
source.position(0);
Charset ascii = Charset.forName("US-ASCII");
CharsetDecoder toAscii = ascii.newDecoder();
CharBuffer destination = toAscii.decode(source);
destination.position(0);
System.out.println("\n\nNew character data:");
for (int i = 0; destination.remaining() > 0; i++) {
System.out.print(destination.get());
}
System.out.println();
} catch (FileNotFoundException fne) {
System.out.println(fne.getMessage());
} catch (IOException ioe) {
System.out.println(ioe.getMessage());
}
}
/**
* Gets a Reader for a text flavor, decoded, if necessary, for the expected charset (encoding).
* The supported representation classes are <code>java.io.Reader</code>, <code>java.lang.String
* </code>, <code>java.nio.CharBuffer</code>, <code>[C</code>, <code>java.io.InputStream</code>,
* <code>java.nio.ByteBuffer</code>, and <code>[B</code>.
*
* <p>Because text flavors which do not support the charset parameter are encoded in a
* non-standard format, this method should not be called for such flavors. However, in order to
* maintain backward-compatibility, if this method is called for such a flavor, this method will
* treat the flavor as though it supports the charset parameter and attempt to decode it
* accordingly. See <code>selectBestTextFlavor</code> for a list of text flavors which do not
* support the charset parameter.
*
* @param transferable the <code>Transferable</code> whose data will be requested in this flavor
* @return a <code>Reader</code> to read the <code>Transferable</code>'s data
* @exception IllegalArgumentException if the representation class is not one of the seven listed
* above
* @exception IllegalArgumentException if the <code>Transferable</code> has <code>null</code> data
* @exception NullPointerException if the <code>Transferable</code> is <code>null</code>
* @exception UnsupportedEncodingException if this flavor's representation is <code>
* java.io.InputStream</code>, <code>java.nio.ByteBuffer</code>, or <code>[B</code> and this
* flavor's encoding is not supported by this implementation of the Java platform
* @exception UnsupportedFlavorException if the <code>Transferable</code> does not support this
* flavor
* @exception IOException if the data cannot be read because of an I/O error
* @see #selectBestTextFlavor
* @since 1.3
*/
public Reader getReaderForText(Transferable transferable)
throws UnsupportedFlavorException, IOException {
Object transferObject = transferable.getTransferData(this);
if (transferObject == null) {
throw new IllegalArgumentException("getTransferData() returned null");
}
if (transferObject instanceof Reader) {
return (Reader) transferObject;
} else if (transferObject instanceof String) {
return new StringReader((String) transferObject);
} else if (transferObject instanceof CharBuffer) {
CharBuffer buffer = (CharBuffer) transferObject;
int size = buffer.remaining();
char[] chars = new char[size];
buffer.get(chars, 0, size);
return new CharArrayReader(chars);
} else if (transferObject instanceof char[]) {
return new CharArrayReader((char[]) transferObject);
}
InputStream stream = null;
if (transferObject instanceof InputStream) {
stream = (InputStream) transferObject;
} else if (transferObject instanceof ByteBuffer) {
ByteBuffer buffer = (ByteBuffer) transferObject;
int size = buffer.remaining();
byte[] bytes = new byte[size];
buffer.get(bytes, 0, size);
stream = new ByteArrayInputStream(bytes);
} else if (transferObject instanceof byte[]) {
stream = new ByteArrayInputStream((byte[]) transferObject);
}
if (stream == null) {
throw new IllegalArgumentException(
"transfer data is not Reader, String, CharBuffer, char array, InputStream, ByteBuffer, or byte array");
}
String encoding = getParameter("charset");
return (encoding == null)
? new InputStreamReader(stream)
: new InputStreamReader(stream, encoding);
}
public static void test(CharBuffer buff, CharBuffer slice) throws RuntimeException {
boolean marked = false;
try {
slice.reset();
marked = true;
} catch (InvalidMarkException ime) {
// expected
}
if (marked
|| slice.position() != 0
|| buff.remaining() != slice.limit()
|| buff.remaining() != slice.capacity()) {
throw new RuntimeException("Calling the CharBuffer.slice method failed.");
}
}