--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.base/share/classes/sun/misc/CharacterEncoder.java Sun Aug 17 15:54:13 2014 +0100
@@ -0,0 +1,354 @@
+/*
+ * Copyright (c) 1995, 2005, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package sun.misc;
+
+import java.io.InputStream;
+import java.io.ByteArrayInputStream;
+import java.io.OutputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+
+/**
+ * This class defines the encoding half of character encoders.
+ * A character encoder is an algorithim for transforming 8 bit binary
+ * data into text (generally 7 bit ASCII or 8 bit ISO-Latin-1 text)
+ * for transmition over text channels such as e-mail and network news.
+ *
+ * The character encoders have been structured around a central theme
+ * that, in general, the encoded text has the form:
+ *
+ * <pre>
+ * [Buffer Prefix]
+ * [Line Prefix][encoded data atoms][Line Suffix]
+ * [Buffer Suffix]
+ * </pre>
+ *
+ * In the CharacterEncoder and CharacterDecoder classes, one complete
+ * chunk of data is referred to as a <i>buffer</i>. Encoded buffers
+ * are all text, and decoded buffers (sometimes just referred to as
+ * buffers) are binary octets.
+ *
+ * To create a custom encoder, you must, at a minimum, overide three
+ * abstract methods in this class.
+ * <DL>
+ * <DD>bytesPerAtom which tells the encoder how many bytes to
+ * send to encodeAtom
+ * <DD>encodeAtom which encodes the bytes sent to it as text.
+ * <DD>bytesPerLine which tells the encoder the maximum number of
+ * bytes per line.
+ * </DL>
+ *
+ * Several useful encoders have already been written and are
+ * referenced in the See Also list below.
+ *
+ * @author Chuck McManis
+ * @see CharacterDecoder;
+ * @see UCEncoder
+ * @see UUEncoder
+ * @see BASE64Encoder
+ */
+public abstract class CharacterEncoder {
+
+ /** Stream that understands "printing" */
+ protected PrintStream pStream;
+
+ /** Return the number of bytes per atom of encoding */
+ abstract protected int bytesPerAtom();
+
+ /** Return the number of bytes that can be encoded per line */
+ abstract protected int bytesPerLine();
+
+ /**
+ * Encode the prefix for the entire buffer. By default is simply
+ * opens the PrintStream for use by the other functions.
+ */
+ protected void encodeBufferPrefix(OutputStream aStream) throws IOException {
+ pStream = new PrintStream(aStream);
+ }
+
+ /**
+ * Encode the suffix for the entire buffer.
+ */
+ protected void encodeBufferSuffix(OutputStream aStream) throws IOException {
+ }
+
+ /**
+ * Encode the prefix that starts every output line.
+ */
+ protected void encodeLinePrefix(OutputStream aStream, int aLength)
+ throws IOException {
+ }
+
+ /**
+ * Encode the suffix that ends every output line. By default
+ * this method just prints a <newline> into the output stream.
+ */
+ protected void encodeLineSuffix(OutputStream aStream) throws IOException {
+ pStream.println();
+ }
+
+ /** Encode one "atom" of information into characters. */
+ abstract protected void encodeAtom(OutputStream aStream, byte someBytes[],
+ int anOffset, int aLength) throws IOException;
+
+ /**
+ * This method works around the bizarre semantics of BufferedInputStream's
+ * read method.
+ */
+ protected int readFully(InputStream in, byte buffer[])
+ throws java.io.IOException {
+ for (int i = 0; i < buffer.length; i++) {
+ int q = in.read();
+ if (q == -1)
+ return i;
+ buffer[i] = (byte)q;
+ }
+ return buffer.length;
+ }
+
+ /**
+ * Encode bytes from the input stream, and write them as text characters
+ * to the output stream. This method will run until it exhausts the
+ * input stream, but does not print the line suffix for a final
+ * line that is shorter than bytesPerLine().
+ */
+ public void encode(InputStream inStream, OutputStream outStream)
+ throws IOException {
+ int j;
+ int numBytes;
+ byte tmpbuffer[] = new byte[bytesPerLine()];
+
+ encodeBufferPrefix(outStream);
+
+ while (true) {
+ numBytes = readFully(inStream, tmpbuffer);
+ if (numBytes == 0) {
+ break;
+ }
+ encodeLinePrefix(outStream, numBytes);
+ for (j = 0; j < numBytes; j += bytesPerAtom()) {
+
+ if ((j + bytesPerAtom()) <= numBytes) {
+ encodeAtom(outStream, tmpbuffer, j, bytesPerAtom());
+ } else {
+ encodeAtom(outStream, tmpbuffer, j, (numBytes)- j);
+ }
+ }
+ if (numBytes < bytesPerLine()) {
+ break;
+ } else {
+ encodeLineSuffix(outStream);
+ }
+ }
+ encodeBufferSuffix(outStream);
+ }
+
+ /**
+ * Encode the buffer in <i>aBuffer</i> and write the encoded
+ * result to the OutputStream <i>aStream</i>.
+ */
+ public void encode(byte aBuffer[], OutputStream aStream)
+ throws IOException {
+ ByteArrayInputStream inStream = new ByteArrayInputStream(aBuffer);
+ encode(inStream, aStream);
+ }
+
+ /**
+ * A 'streamless' version of encode that simply takes a buffer of
+ * bytes and returns a string containing the encoded buffer.
+ */
+ public String encode(byte aBuffer[]) {
+ ByteArrayOutputStream outStream = new ByteArrayOutputStream();
+ ByteArrayInputStream inStream = new ByteArrayInputStream(aBuffer);
+ String retVal = null;
+ try {
+ encode(inStream, outStream);
+ // explicit ascii->unicode conversion
+ retVal = outStream.toString("ISO-8859-1");
+ } catch (Exception IOException) {
+ // This should never happen.
+ throw new Error("CharacterEncoder.encode internal error");
+ }
+ return (retVal);
+ }
+
+ /**
+ * Return a byte array from the remaining bytes in this ByteBuffer.
+ * <P>
+ * The ByteBuffer's position will be advanced to ByteBuffer's limit.
+ * <P>
+ * To avoid an extra copy, the implementation will attempt to return the
+ * byte array backing the ByteBuffer. If this is not possible, a
+ * new byte array will be created.
+ */
+ private byte [] getBytes(ByteBuffer bb) {
+ /*
+ * This should never return a BufferOverflowException, as we're
+ * careful to allocate just the right amount.
+ */
+ byte [] buf = null;
+
+ /*
+ * If it has a usable backing byte buffer, use it. Use only
+ * if the array exactly represents the current ByteBuffer.
+ */
+ if (bb.hasArray()) {
+ byte [] tmp = bb.array();
+ if ((tmp.length == bb.capacity()) &&
+ (tmp.length == bb.remaining())) {
+ buf = tmp;
+ bb.position(bb.limit());
+ }
+ }
+
+ if (buf == null) {
+ /*
+ * This class doesn't have a concept of encode(buf, len, off),
+ * so if we have a partial buffer, we must reallocate
+ * space.
+ */
+ buf = new byte[bb.remaining()];
+
+ /*
+ * position() automatically updated
+ */
+ bb.get(buf);
+ }
+
+ return buf;
+ }
+
+ /**
+ * Encode the <i>aBuffer</i> ByteBuffer and write the encoded
+ * result to the OutputStream <i>aStream</i>.
+ * <P>
+ * The ByteBuffer's position will be advanced to ByteBuffer's limit.
+ */
+ public void encode(ByteBuffer aBuffer, OutputStream aStream)
+ throws IOException {
+ byte [] buf = getBytes(aBuffer);
+ encode(buf, aStream);
+ }
+
+ /**
+ * A 'streamless' version of encode that simply takes a ByteBuffer
+ * and returns a string containing the encoded buffer.
+ * <P>
+ * The ByteBuffer's position will be advanced to ByteBuffer's limit.
+ */
+ public String encode(ByteBuffer aBuffer) {
+ byte [] buf = getBytes(aBuffer);
+ return encode(buf);
+ }
+
+ /**
+ * Encode bytes from the input stream, and write them as text characters
+ * to the output stream. This method will run until it exhausts the
+ * input stream. It differs from encode in that it will add the
+ * line at the end of a final line that is shorter than bytesPerLine().
+ */
+ public void encodeBuffer(InputStream inStream, OutputStream outStream)
+ throws IOException {
+ int j;
+ int numBytes;
+ byte tmpbuffer[] = new byte[bytesPerLine()];
+
+ encodeBufferPrefix(outStream);
+
+ while (true) {
+ numBytes = readFully(inStream, tmpbuffer);
+ if (numBytes == 0) {
+ break;
+ }
+ encodeLinePrefix(outStream, numBytes);
+ for (j = 0; j < numBytes; j += bytesPerAtom()) {
+ if ((j + bytesPerAtom()) <= numBytes) {
+ encodeAtom(outStream, tmpbuffer, j, bytesPerAtom());
+ } else {
+ encodeAtom(outStream, tmpbuffer, j, (numBytes)- j);
+ }
+ }
+ encodeLineSuffix(outStream);
+ if (numBytes < bytesPerLine()) {
+ break;
+ }
+ }
+ encodeBufferSuffix(outStream);
+ }
+
+ /**
+ * Encode the buffer in <i>aBuffer</i> and write the encoded
+ * result to the OutputStream <i>aStream</i>.
+ */
+ public void encodeBuffer(byte aBuffer[], OutputStream aStream)
+ throws IOException {
+ ByteArrayInputStream inStream = new ByteArrayInputStream(aBuffer);
+ encodeBuffer(inStream, aStream);
+ }
+
+ /**
+ * A 'streamless' version of encode that simply takes a buffer of
+ * bytes and returns a string containing the encoded buffer.
+ */
+ public String encodeBuffer(byte aBuffer[]) {
+ ByteArrayOutputStream outStream = new ByteArrayOutputStream();
+ ByteArrayInputStream inStream = new ByteArrayInputStream(aBuffer);
+ try {
+ encodeBuffer(inStream, outStream);
+ } catch (Exception IOException) {
+ // This should never happen.
+ throw new Error("CharacterEncoder.encodeBuffer internal error");
+ }
+ return (outStream.toString());
+ }
+
+ /**
+ * Encode the <i>aBuffer</i> ByteBuffer and write the encoded
+ * result to the OutputStream <i>aStream</i>.
+ * <P>
+ * The ByteBuffer's position will be advanced to ByteBuffer's limit.
+ */
+ public void encodeBuffer(ByteBuffer aBuffer, OutputStream aStream)
+ throws IOException {
+ byte [] buf = getBytes(aBuffer);
+ encodeBuffer(buf, aStream);
+ }
+
+ /**
+ * A 'streamless' version of encode that simply takes a ByteBuffer
+ * and returns a string containing the encoded buffer.
+ * <P>
+ * The ByteBuffer's position will be advanced to ByteBuffer's limit.
+ */
+ public String encodeBuffer(ByteBuffer aBuffer) {
+ byte [] buf = getBytes(aBuffer);
+ return encodeBuffer(buf);
+ }
+
+}