Removing unwanted characters..

Question

Hey guys,
I'm back for help again. Unfortunately my brain isn't creative enough, so please help! :-)
Ok, I need to remove unwanted characters from a file...the problem is that the characters look like this:
in any text editor. I'm using JEdit, and it's ISO-8859-1 encoding. The text was initally from a html file, and i think that most of the html is displayed well as text in JEdit. But these squares, which are bits of info that I don't need, are making it a little trick to do my extraction.
Ex: the word I want to extract is "trouble". But in the file, it looks like this:
troble....
Anyone know how to get rid of all that stuff???
Thanks in advance.
...DJVege...

Answer 1

you could try to set a filter on the characters you accept. Process each character and only accept those that fall into some ASCII boundary. If you accept ASCII characters that have values between 33-255, most blocks should be eliminated.
Something like this should help:
import java.io.*;
public class Example {
     protected static final int MIN_ASCII = 33;
     protected static final int MAX_ASCII = 255;
     public Example(String file) throws IOException {
          BufferedReader b = new BufferedReader(new InputStreamReader(new FileInputStream(file)));
          PrintStream p = new PrintStream(new FileOutputStream(file+"_fix.txt"));
          String s = "";
          int j;
          while ((s = b.readLine()) != null) {
               for (j = 0;j < s.length();j++) {
                    if (valid(s.charAt(j))) {
                         p.print(s.charAt(j));
               p.println();
          b.close();
          p.close();
     protected boolean valid(char c) {
          int asc = (int)c;
          // allow for tabs and spaces
          if (asc == 9 || asc == 32) {
               return true;
          return (asc >= MIN_ASCII && asc <= MAX_ASCII);
     public static void main(String args[]) {
          if (args.length > 0) {
               try {
                    new Example(args[0]);
               catch (IOException e) {
                    e.printStackTrace();
}useage: java Example <file>
of course, something like this will probably only work on "english" files as I dont have an understanding on how foreign characters are encoded..
if this doesnt solve your problem, you might want to adjust the range to 33-127, which will eliminate all "block" characters and all "special formatted" characters (i.e. accented characters, currency signs, etc.)
see http://asciitable.com/ for more information on ASCII characters