src/main/java/ognl/JavaCharStream.java
public char readChar() throws java.io.IOException
  {
     if (inBuf > 0)
     {
        --inBuf;

        if (++bufpos == bufsize)
           bufpos = 0;

        return buffer[bufpos];
     }

     char c;

     if (++bufpos == available)
        AdjustBuffSize();

     if ((buffer[bufpos] = c = ReadByte()) == '\\')
     {
        UpdateLineColumn(c);

        int backSlashCnt = 1;

        for (;;) // Read all the backslashes
        {
           if (++bufpos == available)
              AdjustBuffSize();

           try
           {
              if ((buffer[bufpos] = c = ReadByte()) != '\\')
              {
                 UpdateLineColumn(c);
                 // found a non-backslash char.
                 if ((c == 'u') && ((backSlashCnt & 1) == 1))
                 {
                    if (--bufpos < 0)
                       bufpos = bufsize - 1;

                    break;
                 }

                 backup(backSlashCnt);
                 return '\\';
              }
           }
           catch(java.io.IOException e)
           {
              if (backSlashCnt > 1)
                 backup(backSlashCnt-1);

              return '\\';
           }

           UpdateLineColumn(c);
           backSlashCnt++;
        }

        // Here, we have seen an odd number of backslash's followed by a 'u'
        try
        {
           while ((c = ReadByte()) == 'u')
              ++column;

           buffer[bufpos] = c = (char)(hexval(c) << 12 |
                                       hexval(ReadByte()) << 8 |
                                       hexval(ReadByte()) << 4 |
                                       hexval(ReadByte()));

           column += 4;
        }
        catch(java.io.IOException e)
        {
           throw new Error("Invalid escape character at line " + line +
                                         " column " + column + ".");
        }

        if (backSlashCnt == 1)
           return c;
        else
        {
           backup(backSlashCnt - 1);
           return '\\';
        }
     }
     else
     {
        UpdateLineColumn(c);
        return c;
     }
  }
public char readChar() throws java.io.IOException
  {
     if (inBuf > 0)
     {
        --inBuf;

        if (++bufpos == bufsize)
           bufpos = 0;

        return buffer[bufpos];
     }

     char c;

     if (++bufpos == available)
        AdjustBuffSize();

     if ((buffer[bufpos] = c = ReadByte()) == '\\')
     {
        UpdateLineColumn(c);

        int backSlashCnt = 1;

        for (;;) // Read all the backslashes
        {
           if (++bufpos == available)
              AdjustBuffSize();

           try
           {
              if ((buffer[bufpos] = c = ReadByte()) != '\\')
              {
                 UpdateLineColumn(c);
                 // found a non-backslash char.
                 if ((c == 'u') && ((backSlashCnt & 1) == 1))
                 {
                    if (--bufpos < 0)
                       bufpos = bufsize - 1;

                    break;
                 }

                 backup(backSlashCnt);
                 return '\\';
              }
           }
           catch(java.io.IOException e)
           {
              if (backSlashCnt > 1)
                 backup(backSlashCnt-1);

              return '\\';
           }

           UpdateLineColumn(c);
           backSlashCnt++;
        }

        // Here, we have seen an odd number of backslash's followed by a 'u'
        try
        {
           while ((c = ReadByte()) == 'u')
              ++column;

           buffer[bufpos] = c = (char)(hexval(c) << 12 |
                                       hexval(ReadByte()) << 8 |
                                       hexval(ReadByte()) << 4 |
                                       hexval(ReadByte()));

           column += 4;
        }
        catch(java.io.IOException e)
        {
           throw new Error("Invalid escape character at line " + line +
                                         " column " + column + ".");
        }

        if (backSlashCnt == 1)
           return c;
        else
        {
           backup(backSlashCnt - 1);
           return '\\';
        }
     }
     else
     {
        UpdateLineColumn(c);
        return c;
     }
  }
Read a character.