How can I convert a tab to a String

Question

Hello,
I want to read a file, and check if in some place from the text there is a tab there, in case there exist one, repmplace for <tab8> or something like that.
I have the following.
import java.io.*;
import java.util.*;
public class Expander {
  // other declarations ...
  public static void expand(String[] args) {
//    BufferedWriter br = new BufferedReader();
    try{
      if(args[0].equals("-v")){
        System.out.println("Expander Version 1.0\nCopyright (C)");
      if(args[0].equals("-h")){
        System.out.println("");
        System.out.println("Usage: java Expander [OPTION] ... [FILE] ...");
        System.out.println("Convert tabs in each FILE to spaces, writing to standard output.");
        System.out.println("Without FILE or with FILE = -, read from standard input.");
        System.out.println("");
        System.out.println("-i    do not convert TABs after non-whitespace.");
        System.out.println("-i=N  have tabs (positive) N spaces apart, not the default 8.");
        System.out.println("-h    display this help message and exit.");
        System.out.println("-v    display version information and exit.");
      if(args[0].equals("-i")){
        BufferedReader in = new BufferedReader(new FileReader(args[1]));
        String tempLine;
        while((tempLine = in.readLine()) != null){
          String temp = check(tempLine);
          System.out.println(temp);
          writeNew(temp,"1"+args[1]);
      else
        System.err.println("Command not Accepted, please check -h for more help");
    catch(IOException e){System.out.println(e);}
    catch(NoClassDefFoundError i){System.out.println(i);System.exit(0);}
  }// closes readLoadData
  public static String check(String line){
    if ( line.equals("\t") )
      return "<TAB8>";
    else
      return line;
  public static void writeNew(String line, String args){
    String name = args+".txt";
    try
      BufferedWriter out = new BufferedWriter(new FileWriter(name, true));
      PrintWriter fw = new PrintWriter(out);
      fw.print(line);
      out.close();
    catch(IOException e)
    { System.out.println(e);}
  public static void main(String[] args) {
    Expander.expand(args);
}any ideas?
Tahnks =)

Answer 1

Hi,
I guess the best way is to use regular expressions (must use SDK 1.4.1 or higher):
Add the line:
import java.util.regex.*;
and use one of the methods:
//Regex method to replace all \\t by <tab>
public String replaceTabs1(String line, String tab) {
Matcher matcher = Pattern.compile("\t").matcher(line);
tab = matcher.replaceAll("<tab>");
return line;
//Regex method to replace \\t by <tab> one by one
public String replaceTabs2(String line) {
Matcher matcher = Pattern.compile("\t").matcher(line);
while(matcher.find()){
line = matcher.replaceFirst("<tab>");
return line;
Or, use more general method to find and replace any string by any other string in your file
public String replaceText(String source, String find, String replace) {
Matcher matcher = Pattern.compile(find).matcher(source);
source = matcher.replaceAll(replace);
return source;
Hope it will work,
VM