1 /*
   2  * Copyright (c) 1996, 2002, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package sun.io;
  27 import java.io.*;
  28 
  29 
  30 /**
  31  * Convert arrays containing Unicode characters into arrays of bytes, using the
  32  * platform-default byte order.
  33  *
  34  * @author      Mark Reinhold
  35  */
  36 
  37 public class CharToByteUnicode extends CharToByteConverter {
  38 
  39     static final char BYTE_ORDER_MARK = (char) 0xfeff;
  40     protected boolean usesMark = true;      /* A mark should be written */
  41     private boolean markWritten = false;  /* A mark has been written */
  42 
  43     static final int UNKNOWN = 0;
  44     static final int BIG = 1;
  45     static final int LITTLE = 2;
  46     protected int byteOrder = UNKNOWN;
  47 
  48     public CharToByteUnicode() {
  49         String enc = java.security.AccessController.doPrivileged(
  50            new sun.security.action.GetPropertyAction("sun.io.unicode.encoding",
  51                                                           "UnicodeBig"));
  52         if (enc.equals("UnicodeBig"))
  53             byteOrder = BIG;
  54         else if (enc.equals("UnicodeLittle"))
  55             byteOrder = LITTLE;
  56         else
  57             byteOrder = BIG;
  58     }
  59 
  60     public CharToByteUnicode(int byteOrder, boolean usesMark) {
  61         this.byteOrder = byteOrder;
  62         this.usesMark = usesMark;
  63     }
  64 
  65     public CharToByteUnicode(boolean usesMark) {
  66         this();
  67         this.usesMark = usesMark;
  68     }
  69 
  70     public String getCharacterEncoding() {
  71         switch (byteOrder) {
  72         case BIG:
  73             return usesMark ? "UnicodeBig" : "UnicodeBigUnmarked";
  74         case LITTLE:
  75             return usesMark ? "UnicodeLittle" : "UnicodeLittleUnmarked";
  76         default:
  77             return "UnicodeUnknown";
  78         }
  79     }
  80 
  81     public int convert(char in[], int inOff, int inEnd,
  82                        byte out[], int outOff, int outEnd)
  83         throws ConversionBufferFullException, MalformedInputException
  84     {
  85         charOff = inOff;
  86         byteOff = outOff;
  87 
  88         if (inOff >= inEnd)
  89             return 0;
  90 
  91         int inI = inOff,
  92             outI = outOff,
  93             outTop = outEnd - 2;
  94 
  95         if (usesMark && !markWritten) {
  96             if (outI > outTop)
  97                 throw new ConversionBufferFullException();
  98             if (byteOrder == BIG) {
  99                 out[outI++] = (byte) (BYTE_ORDER_MARK >> 8);
 100                 out[outI++] = (byte) (BYTE_ORDER_MARK & 0xff);
 101             }
 102             else {
 103                 out[outI++] = (byte) (BYTE_ORDER_MARK & 0xff);
 104                 out[outI++] = (byte) (BYTE_ORDER_MARK >> 8);
 105             }
 106             markWritten = true;
 107         }
 108 
 109         if (byteOrder == BIG) {
 110             while (inI < inEnd) {
 111                 if (outI > outTop) {
 112                     charOff = inI;
 113                     byteOff = outI;
 114                     throw new ConversionBufferFullException();
 115                 }
 116                 char c = in[inI++];
 117                 out[outI++] = (byte) (c >> 8);
 118                 out[outI++] = (byte) (c & 0xff);
 119             }
 120         }
 121         else {
 122             while (inI < inEnd) {
 123                 if (outI > outTop) {
 124                     charOff = inI;
 125                     byteOff = outI;
 126                     throw new ConversionBufferFullException();
 127                 }
 128                 char c = in[inI++];
 129                 out[outI++] = (byte) (c & 0xff);
 130                 out[outI++] = (byte) (c >> 8);
 131             }
 132         }
 133 
 134         charOff = inI;
 135         byteOff = outI;
 136         return outI - outOff;
 137     }
 138 
 139     public int flush(byte in[], int inOff, int inEnd) {
 140         byteOff = charOff = 0;
 141         return 0;
 142     }
 143 
 144     public void reset () {
 145         byteOff = charOff = 0;
 146         markWritten = false;
 147     }
 148 
 149     public int getMaxBytesPerChar() {
 150         return 4;               /* To allow for writing the byte-order mark */
 151     }
 152 
 153 }