ojluni/src/main/java/sun/misc/CharacterEncoder.java - platform/libcore - Git at Google

 /*
  * 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("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);
     }

 }
	/*
	* 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("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);
	}

	}