Duvida Java IO

public static void main(String[] args) {

		try {
			File f = new File("c:/temp/teste.txt");
			BufferedWriter bw = new BufferedWriter( new FileWriter( f ) );
						
			for (int i = 0; i < 100; i++) {
				bw.write(""+i);
				bw.write( System.getProperty("line.separator"));
			}
			
			bw.close();
			
			System.exit(0);
			
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
	}

import java.io.File;

import java.io.FileWriter;

import java.io.BufferedWriter;

import java.io.IOException;

public static void main(String...args){
	
	try{
			
		File f = new File("arquivo.txt"); 
	
		FileWriter fw = new FileWriter(f);
	
		BufferedWriter bw = new BufferedWriter(fw);
	
		for (int i = 0; i < 10; i++){
							
			bw.write("Linha " + i);
			bw.newLine();
		
		}	
	
		bw.flush();
	
		bw.close();	
		
	}catch(IOException e){
		
		e.printStackTrace();
		
	}			
	
}