Logo Search packages:      
Sourcecode: zeroc-ice-java version File versions  Download package

StringUtil.java

// **********************************************************************
//
// Copyright (c) 2003-2006 ZeroC, Inc. All rights reserved.
//
// This copy of Ice is licensed to you under the terms described in the
// ICE_LICENSE file included in this distribution.
//
// **********************************************************************

package IceUtil;

public final class StringUtil
{
    //
    // Return the index of the first character in str to
    // appear in match, starting from 0. Returns -1 if none is
    // found.
    //
    public static int
    findFirstOf(String str, String match)
    {
        return findFirstOf(str, match, 0);
    }

    //
    // Return the index of the first character in str to
    // appear in match, starting from start. Returns -1 if none is
    // found.
    //
    public static int
    findFirstOf(String str, String match, int start)
    {
        final int len = str.length();
        for(int i = start; i < len; i++)
        {
            char ch = str.charAt(i);
            if(match.indexOf(ch) != -1)
            {
                return i;
            }
        }

        return -1;
    }

    //
    // Return the index of the first character in str which does
    // not appear in match, starting from 0. Returns -1 if none is
    // found.
    //
    public static int
    findFirstNotOf(String str, String match)
    {
        return findFirstNotOf(str, match, 0);
    }

    //
    // Return the index of the first character in str which does
    // not appear in match, starting from start. Returns -1 if none is
    // found.
    //
    public static int
    findFirstNotOf(String str, String match, int start)
    {
        final int len = str.length();
        for(int i = start; i < len; i++)
        {
            char ch = str.charAt(i);
            if(match.indexOf(ch) == -1)
            {
                return i;
            }
        }

        return -1;
    }

    //
    // Write the byte b as an escape sequence if it isn't a printable ASCII
    // character and append the escape sequence to sb. Additional characters
    // that should be escaped can be passed in special. If b is any of these
    // characters, b is preceded by a backslash in sb.
    //
    private static void
    encodeChar(byte b, StringBuffer sb, String special)
    {
        switch(b)
        {
          case (byte)'\\':
          {
            sb.append("\\\\");
            break;
          }
          case (byte)'\'':
          {
            sb.append("\\'");
            break;
          }
          case (byte)'"':
          {
            sb.append("\\\"");
            break;
          }
          case (byte)'\b':
          {
            sb.append("\\b");
            break;
          }
          case (byte)'\f':
          {
            sb.append("\\f");
            break;
          }
          case (byte)'\n':
          {
            sb.append("\\n");
            break;
          }
          case (byte)'\r':
          {
            sb.append("\\r");
            break;
          }
          case (byte)'\t':
          {
            sb.append("\\t");
            break;
          }
          default:
          {
            if(!(b >= 32 && b <= 126))
            {
                sb.append('\\');
                String octal = Integer.toOctalString(b < 0 ? b + 256 : b);
                //
                // Add leading zeroes so that we avoid problems during
                // decoding. For example, consider the encoded string
                // \0013 (i.e., a character with value 1 followed by
                // the character '3'). If the leading zeroes were omitted,
                // the result would be incorrectly interpreted by the
                // decoder as a single character with value 11.
                //
                for(int j = octal.length(); j < 3; j++)
                {
                  sb.append('0');
                }
                sb.append(octal);
            }
            else if(special != null && special.indexOf((char)b) != -1)
            {
                sb.append('\\');
                sb.append((char)b);
            }
            else
            {
                sb.append((char)b);
            }
          }
        }
    }

    //
    // Add escape sequences (such as "\n", or "\007") to make a string
    // readable in ASCII. Any characters that appear in special are
    // prefixed with a backlash in the returned string.
    //
    public static String
    escapeString(String s, String special)
    {
        if(special != null)
      {
          for(int i = 0; i < special.length(); ++i)
          {
            if(special.charAt(i) < 32 || special.charAt(i) > 126)
            {
                throw new IllegalArgumentException("special characters must be in ASCII range 32-126");
            }
          }
      }

        byte[] bytes = null;
        try
        {
            bytes = s.getBytes("UTF8");
        }
        catch(java.io.UnsupportedEncodingException ex)
        {
            assert(false);
            return null;
        }

        StringBuffer result = new StringBuffer(bytes.length);
        for(int i = 0; i < bytes.length; i++)
        {
            encodeChar(bytes[i], result, special);
        }

        return result.toString();
    }

    private static char
    checkChar(char c)
    {
      if(!(c >= 32 && c <= 126))
      {
          throw new IllegalArgumentException("illegal input character");
      }
      return c;
    }

    //
    // Decode the character or escape sequence starting at start and return it.
    // newStart is set to the index of the first character following the decoded character
    // or escape sequence.
    //
    private static char decodeChar(String s, int start, int end, Ice.IntHolder nextStart)
    {
      assert(start >= 0);
      assert(start < end);
      assert(end <= s.length());

      char c;

      if(s.charAt(start) != '\\')
      {
          c = checkChar(s.charAt(start++));
      }
      else
      {
          if(start + 1 == end)
          {
            throw new IllegalArgumentException("trailing backslash in argument");
          }
          switch(s.charAt(++start))
          {
            case '\\': 
            case '\'': 
            case '"': 
            {
                c = s.charAt(start++);
                break;
            }
            case 'b': 
            {
                ++start;
                c = '\b';
                break;
            }
            case 'f': 
            {
                ++start;
                c = '\f';
                break;
            }
            case 'n': 
            {
                ++start;
                c = '\n';
                break;
            }
            case 'r': 
            {
                ++start;
                c = '\r';
                break;
            }
            case 't': 
            {
                ++start;
                c = '\t';
                break;
            }
            case '0':
            case '1':
            case '2':
            case '3':
            case '4':
            case '5':
            case '6':
            case '7':
            {
                int oct = 0;
                for(int j = 0; j < 3 && start < end; ++j)
                {
                    int charVal = s.charAt(start++) - '0';
                  if(charVal < 0 || charVal > 7)
                  {
                      --start;
                      break;
                  }
                  oct = oct * 8 + charVal;
                }
                if(oct > 255)
                {
                    throw new IllegalArgumentException("octal value out of range");
                }
                c = (char)oct;
                break;
            }
            default:
            {
                c = checkChar(s.charAt(start++));
                break;
            }
          }
      }
      nextStart.value = start;
      return c;
    }

    //
    // Remove escape sequences from s and append the result to sb.
    // Return true if successful, false otherwise.
    //
    private static void
    decodeString(String s, int start, int end, StringBuffer sb)
    {
      Ice.IntHolder nextStart = new Ice.IntHolder();
        while(start < end)
      {
          sb.append(decodeChar(s, start, end, nextStart));
          start = nextStart.value;
      }
    }

    //
    // Remove escape sequences added by escapeString.
    //
    public static boolean
    unescapeString(String s, int start, int end, Ice.StringHolder result)
    {
        if(start < 0)
      {
          throw new IllegalArgumentException("start offset must be >= 0");
      }
      if(end > s.length())
      {
          throw new IllegalArgumentException("end offset must <= s.length()");
      }
      if(start > end)
      {
          throw new IllegalArgumentException("start offset must <= end offset");
      }

      try
      {
          StringBuffer sb = new StringBuffer();
          decodeString(s, start, end, sb);
          String decodedString = sb.toString();

          byte[] arr = new byte[decodedString.length()];
          for(int i = 0; i < arr.length; ++i)
          {
              arr[i] = (byte)decodedString.charAt(i);
          }

          result.value = new String(arr, 0, arr.length, "UTF8");
          return true;
      }
      catch(java.lang.Exception ex)
      {
          return false;
      }
    }

    public static int
    checkQuote(String s)
    {
        return checkQuote(s, 0);
    }

    //
    // If a single or double quotation mark is found at the start position,
    // then the position of the matching closing quote is returned. If no
    // quotation mark is found at the start position, then 0 is returned.
    // If no matching closing quote is found, then -1 is returned.
    //
    public static int
    checkQuote(String s, int start)
    {
        char quoteChar = s.charAt(start);
        if(quoteChar == '"' || quoteChar == '\'')
        {
            start++;
            final int len = s.length();
            int pos;
            while(start < len && (pos = s.indexOf(quoteChar, start)) != -1)
            {
                if(s.charAt(pos - 1) != '\\')
                {
                    return pos;
                }
                start = pos + 1;
            }
            return -1; // Unmatched quote
        }
        return 0; // Not quoted
    }
}

Generated by  Doxygen 1.6.0   Back to index