mnj/lua/StringReader.java

   1 /*  $Header: //info.ravenbrook.com/project/jili/version/1.1/code/mnj/lua/StringReader.java#1 $
   2  * Copyright (c) 2006 Nokia Corporation and/or its subsidiary(-ies).
   3  * All rights reserved.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining
   6  * a copy of this software and associated documentation files (the
   7  * "Software"), to deal in the Software without restriction, including
   8  * without limitation the rights to use, copy, modify, merge, publish,
   9  * distribute, sublicense, and/or sell copies of the Software, and to
  10  * permit persons to whom the Software is furnished to do so, subject
  11  * to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be
  14  * included in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  17  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  18  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  19  * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
  20  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
  21  * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  22  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 package mnj.lua;
  26
  27 import java.io.IOException;
  28
  29 /** Ersatz replacement for {@link java.io.StringReader} from JSE. */
  30 final class StringReader extends java.io.Reader
  31 {
  32   private String s;
  33   /** Index of the current read position.  -1 if closed. */
  34   private int current;  // = 0
  35   /**
  36    * Index of the current mark (set with {@link #mark}).
  37    */
  38   private int mark;     // = 0;
  39
  40   StringReader(String s)
  41   {
  42     this.s = s;
  43   }
  44
  45   public void close()
  46   {
  47     current = -1;
  48   }
  49
  50   public void mark(int limit)
  51   {
  52     mark = current;
  53   }
  54
  55   public boolean markSupported()
  56   {
  57     return true;
  58   }
  59
  60   public int read() throws IOException
  61   {
  62     if (current < 0)
  63     {
  64       throw new IOException();
  65     }
  66     if (current >= s.length())
  67     {
  68       return -1;
  69     }
  70     return s.charAt(current++);
  71   }
  72
  73   public int read(char[] cbuf, int off, int len) throws IOException
  74   {
  75     if (current < 0 || len < 0)
  76     {
  77       throw new IOException();
  78     }
  79     if (current >= s.length())
  80     {
  81       return 0;
  82     }
  83     if (current + len > s.length())
  84     {
  85       len = s.length() - current;
  86     }
  87     for (int i=0; i<len; ++i)
  88     {
  89       cbuf[off+i] = s.charAt(current+i);
  90     }
  91     current += len;
  92     return len;
  93   }
  94
  95   public void reset()
  96   {
  97     current = mark;
  98   }
  99 }