Saving to a txt file

[Steve Shipman]

Ive got my program, it works exactly how I want it to, I just need to save my results into a text file, and ive tried a few different ways that I found on the internet and my book but none worked correctly. This is my code:

import java.util.*;
import java.io.*;
import java.lang.*;
 
public class LuckyNumbers2
{
private static LinkedList list;

public static void main(String [] args)
{
list = new LinkedList();
populateList(list, 3498);
deleteThird(list, 3498);
deleteSeventh(list, 3498);
System.out.println(list);
System.out.println("Done");
}

public static void populateList(LinkedList lst, int n)
{
for (int i = 1; i <= n; i += 2)
lst.add(new Integer(i));


 
}

public static void deleteThird(LinkedList lst, int n)
{

for (int i = 2; i <= n; i += 2)
{
lst.remove(i);

}

}

public static void deleteSeventh(LinkedList lst, int n)
{
for (int i = 6; i <= n; i += 6)
{
lst.remove(i);
}
}

 
}//end of Lucky Numbers class
 
class Node
{
protected Object item;
protected Node next;

Node() //constructor
{
item = null;
next = null;
}

public Node(Object item)
{
this.item = item;
this.next = null;
}

public String toString()
{
return "["+item+"]";
}

}//end of Node class
 
class LinkedList
{
protected Node head;
protected Node tail;
private int size;

LinkedList() //constuctor
{
head = null;
tail = null;
size = 0;
}

public void add(Object obj)
{
Node temp = new Node(obj);

if (head == null)
head = temp;
else
tail.next = temp;

tail = temp;
size++;
}

public Node remove(int index)
{
Node pointer = head;
Node delete;
int steps = 0;

if (index < 0)
{
return null;
}

if (index == 0)
{
delete = head;
head = head.next;
size--;
return delete;
}

while (pointer != null)
{
if (steps + 1 == index)
{
if (index >= 0 && index < size)
{
delete = pointer.next;
pointer.next = delete.next;
size--;
return delete;
}
}

pointer = pointer.next;
steps++;
}

//should never happen, just to satisfy compiler
return null;

}

public String toString()
{
if (size == 0)
return "<empty list>";

StringBuffer buffer = new StringBuffer();

Node pointer = head;

while (pointer != null)
{
buffer.append(pointer.toString());
buffer.append("--->");
pointer= pointer.next;
}

buffer.append("null");

return buffer.toString();
}

 }//end of LinkedList class

in main I have "System.out.println(list);" that prints my linkedlist, which is want to save into a text file called "LuckyNumbers.txt"....I just cant get it right, the stuff I have tried isnt working....I might have been putting it in the wrong place, I was putting it in the main method. Anyway, thanks for the help guys.

[Ken Blair]

try {
    System.setOut(new PrintStream(new BufferedOutputStream(new FileOutputStream("LuckyNumbers.txt"))));
} catch (FileNotFoundException e) {
    e.printStackTrace();
}

Keep in mind this is a really bad way of doing it, but for your simple example it's probably sufficient.

[marc weber]

Originally posted by Steve Shipman:
...I have "System.out.println(list);" that prints my linkedlist, which is want to save into a text file called "LuckyNumbers.txt"...

You could try a simple FileWriter.

Create a FileWriter with the desired filename.

Pass your String to the write method.

Call the close method.

import java.io.*;
 
//SNIPPET...
try {
  FileWriter listFile = new FileWriter("LuckyNumbers.txt");
  listFile.write(list);
  listFile.close();
} catch(IOException e) {
  System.out.println("Exception: " + e);
}