conversion of HTML data to TEXT

The contents from HTML page is extracted and diplayed in text format. The HTML page is given as input where the java code removes the HTML tags and the text is extracted.

import java.io.File;
import java.io.FileInputStream;

import java.io.Reader;
import java.io.StringReader;

import java.io.IOException;

/**
 * Convert text/html into text/plain
 */

public class HTML2Text
{
 boolean body_found = false;
 boolean in_body = false;
 boolean center = false;
 boolean pre = false;
 String href = "";

 public String convert(String source) throws Exception
 {
  StringBuffer result = new StringBuffer();
  StringBuffer result2 = new StringBuffer();
  StringReader input = new StringReader(source);

  try
  {
   String text = null;
   int c = input.read();

   while (c != -1) // Convert until EOF
   {
    text = "";
    if (c == '<') // It's a tag!!
    {
     String CurrentTag = getTag(input); // Get the rest of the tag
     text = convertTag(CurrentTag);
    }
    else if (c == '&')
    {
     String specialchar = getSpecial(input);
     if (specialchar.equals("lt;") || specialchar.equals("#60"))
      text = "<";
     else if (specialchar.equals("gt;") || specialchar.equals("#62"))
      text = ">";
     else if (specialchar.equals("amp;") || specialchar.equals("#38"))
      text = "&";
     else if (specialchar.equals("nbsp;"))
      text = " ";
     else if (specialchar.equals("quot;") || specialchar.equals("#34"))
      text = """;
      else if (specialchar.equals("copy;") || specialchar.equals("#169"))
       text = "[Copyright]";
      else if (specialchar.equals("reg;") || specialchar.equals("#174"))
       text = "[Registered]";
      else if (specialchar.equals("trade;") || specialchar.equals("#153"))
       text = "[Trademark]";
      else
       text = "&" + specialchar;
    }
    else if (!pre && Character.isWhitespace((char)c))
    {
     StringBuffer s = in_body ? result : result2;
     if (s.length() > 0 && Character.isWhitespace(s.charAt(s.length()-1)))
      text = "";
     else text = " ";
    }
    else
    {
     text = "" + (char)c;
    }

    StringBuffer s = in_body ? result : result2;
    s.append(text);

    c = input.read();
   }
  }
  catch (Exception e)
  {
   input.close();
   throw e;
  }

  StringBuffer s = body_found ? result : result2;
  return s.toString().trim();
 }

 String getTag(Reader r) throws IOException
 {
  StringBuffer result = new StringBuffer();
  int level = 1;

  result.append('<');
  while (level > 0)
  {
   int c = r.read();
   if (c == -1) break; // EOF
   result.append((char)c);
   if (c == '<') level++; else if (c == '>') level--;
  }

  return result.toString();
 }

 String getSpecial(Reader r) throws IOException
 {
  StringBuffer result = new StringBuffer();
  r.mark(1);//Mark the present position in the stream
  int c = r.read();

  while (Character.isLetter((char)c))
  {
   result.append((char)c);
   r.mark(1);
   c = r.read();
  }

  if (c == ';') result.append(';');
  else r.reset();

  return result.toString();
 }

 boolean isTag(String s1, String s2)
 {
  s1 = s1.toLowerCase();
  String t1 = "<" + s2.toLowerCase() + ">";
  String t2 = "<" + s2.toLowerCase() + " ";

  return s1.startsWith(t1) || s1.startsWith(t2);
 }

 String convertTag(String t) throws IOException
 {
  String result = "";

  if (isTag(t,"body"))
  { in_body = true; body_found = true; }
  else if (isTag(t,"/body"))
  { in_body = false; result = "
  "; }
  else if (isTag(t,"center"))
  { result = "
  "; center = true; }
  else if (isTag(t,"/center"))
  { result = "
  "; center = false; }
  else if (isTag(t,"pre"))
  { result = "
  "; pre = true; }
  else if (isTag(t,"/pre"))
  { result = "
  "; pre = false; }
  else if (isTag(t,"p"))
   result = "

   ";
   else if (isTag(t,"br"))
    result = "
    ";
    else if (isTag(t,"h1") || isTag(t,"h2") || 
      isTag(t,"h3") ||isTag(t,"h4") || isTag(t,"h5") || isTag(t,"h6") || isTag(t,"h7"))
     result = "
     ";
     else if (isTag(t,"/h1") || isTag(t,"/h2") || 
       isTag(t,"/h3") ||isTag(t,"/h4") || isTag(t,"/h5") || isTag(t,"/h6") || isTag(t,"/h7"))
      result = "
      ";
      else if (isTag(t,"/dl"))
       result = "
       ";
       else if (isTag(t,"dd"))
        result = "
        * ";
        else if (isTag(t,"dt"))
         result = "      ";
        else if (isTag(t,"li"))
         result = "
         * ";
         else if (isTag(t,"/ul"))
          result = "
          ";
          else if (isTag(t,"/ol"))
           result = "
           ";
           else if (isTag(t,"hr"))
            result = "_________________________________________

            ";
            else if (isTag(t,"table"))
             result = "
             ";
             else if (isTag(t,"/table"))
              result = "
              ";
              else if (isTag(t,"form"))
               result = "
               ";
               else if (isTag(t,"/form"))
                result = "
                ";
                else if (isTag(t,"b"))
                 result = "*";
                else if (isTag(t,"/b"))
                 result = "*";
                else if (isTag(t,"i"))
                 result = """;
                 else if (isTag(t,"/i"))
                  result = """;
                  else if (isTag(t,"img"))
                  {
                   int idx = t.indexOf("alt="");
                     if (idx != -1)
                     {
                      idx += 5;
                      int idx2 = t.indexOf(""",idx);
                        result = t.substring(idx,idx2);
                     }
                  }
                  else if (isTag(t,"a"))
                  {
                   int idx = t.indexOf("href="");
                     if (idx != -1)
                     {
                      idx += 6;
                      int idx2 = t.indexOf(""",idx);
                        href = t.substring(idx,idx2);
                     }
                     else
                     {
                      href = "";
                     }
                  }
                  else if (isTag(t,"/a"))
                  {
                   if (href.length() > 0)
                   {
                    result = " [ " + href + " ]";
                    href = "";
                   }
                  }

  return result;
  }

  public static void main(String argv[]) throws Exception
  {
   FileInputStream fis = null;
   String s = null;

   try
   {
    File file;
    if (argv[0] != null) file = new File(argv[0]);
    else file = new File("html_test_file.html");
    fis = new FileInputStream(file);
    byte buf[] = new byte[fis.available()];
    //bytes that can be read from this file input stream without blocking

    fis.read(buf);
    fis.close();
    fis = null;
    s = new String(buf);
    HTML2Text h = new HTML2Text();
    System.out.println(h.convert(s));
   }
   catch (Exception e)
   {
    if (fis != null) fis.close();
    throw e;
   }
  }
  }