Edit File

[Mathew Mintalm]

Hello, I made little Swing program, I have also one button, now im wondering how to create this kind of function:

After Presing X button it should automaticaly open Hosts file, edit it, add some lines, and save.

Would be great if someone can help me, thanks in advice.

[fred rosenberger]

what do you mean by "edit it' and "add some lines"?

[Mathew Mintalm]

Ok, anyway I made it:

 package test;

import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.LineNumberReader;
import java.util.List;
import java.util.StringTokenizer;

import javolution.util.FastList;

public class Test
{
	private static final List<String> _FullText = new FastList<String>();
	
	static String text1 = "something";
	
	public static void main(String[] args)
	{
		loadText();
		addText(text1);
		saveToDisk();
	}
	
	public static void loadText()
	{
		File file = new File("C:/WINDOWS/system32/drivers/etc/hosts");
		if (file.exists())
		{
			readFromDisk(file);
		}
		else
		{
			System.out.println("Nie znalazlo pliku!");
		}
	}
	
	private static void readFromDisk(File file)
	{
		LineNumberReader lnr = null;
		try
		{
			int i = 0;
			String line = null;
			lnr = new LineNumberReader(new FileReader(file));
			while ((line = lnr.readLine()) != null)
			{
				StringTokenizer st = new StringTokenizer(line, "\n\r");
				if (st.hasMoreTokens())
				{
					String announcement = st.nextToken();
					FullText.add(announcement);
					i++;
				}
			}
		}
		catch (IOException e1)
		{
			System.out.println("Error!");
		}
		finally
		{
			try
			{
				lnr.close();
			}
			catch (Exception e2)
			{
				// nothing
			}
		}
	}
	
	private static void saveToDisk()
	{
		File file = new File("C:/WINDOWS/system32/drivers/etc/hosts");
		FileWriter save = null;

		try
		{
			save = new FileWriter(file);
			for (final String announcement : FullText)
			{
				save.write(announcement);
				save.write("\r\n");
			}
		}
		catch (IOException e)
		{
			System.out.println("Saving to the file has failed: ");
		}
		finally
		{
			try
			{
				save.close();
			}
			catch (Exception e)
			{
			}
		}
	}
		
	public static void addText(String text)
	{
		FullText.add(text);
		saveToDisk();
	}
}
   

[Campbell Ritchie]

Why are you using StringTokenizer, which is a legacy class?
What is supposed to happen and what goes wrong? Please look at this FAQ.
Why are you doing anything to a file in system32?
Why have you written an empty catch block?