Read/Find Substring/Write to new file

[hiklior]

Hi guys,

i would appreciate your help on this . I am trying to create a little program for myself. I needed a program to read a file and find 0000 (4 zeros) from that file and give me a number before each 4 zeros along with the 4 zeros and write it in a different file for me but each of the number in this new file should be in different line.

example:

10000 2121000044540000 0012000

Output
10000
10000
40000


This is what i have until now and i am stuck.

Please help

import java.io.*;
class FileReadTest
{
public static void main(String args[])
{
try{

FileInputStream fstream = new FileInputStream("c:/MyFile.txt");

DataInputStream in = new DataInputStream(fstream);
BufferedReader br = new BufferedReader(new InputStreamReader(in));
String strLine;


FileWriter fstream1 = new FileWriter("c:/out.txt");
BufferedWriter out = new BufferedWriter(fstream1);

while ((strLine = br.readLine()) != null)
{
System.out.println (strLine);
out.write(strLine);
}

in.close();
}catch (Exception e){//Catch exception if any
System.err.println("Error: " + e.getMessage());
}
}
}

[fireball2008]

Assume that String

FourZero ="0000";
String num = some String from input;
int difference = num.length()-FourZero.length();
for(int x=1; x<=difference; x++)
if(FourZero.equals(num.subString(x,x+4)));
System.out.println(num.subString(x-1,x+4));

I haven't tested the solution might be wrong.
you can just replace some output methods, but the genral idea is above.

[hiklior]

I actually need this program to read from a file . Find substring as i mentioned above and write it in a different file with new line for each substring that it finds.

[fireball2008]

you can use the scanner class to read from a file, and use the method above find the subString and write to the file line by line

[hiklior]

I am a beginner. and i would appreciate more elaboration.

[fireball2008]

I am a beginner. and i would appreciate more elaboration.

Scanner (Java 2 Platform SE 5.0)
here is the jave Scanner class
to use it you have to import java.util.Scanner;
they also give u example how to use it

[fireball2008]

import java.io.*;
import java.util.*;
import java.lang.Integer;
import java.io.PrintWriter;
import java.io.OutputStreamWriter;
public class fileWriter 
{
public void ok()throws IOException
{        BufferedWriter out = new BufferedWriter(new FileWriter("output"));
        out.write("aString");
        out.newLine();  // create a new line in file
        out.write("ok");
        out.close();
}
public static void main(String args[])throws IOException
{fileWriter f = new fileWriter();
f.ok();
}}

example of file writer
also shows how to create a new line in file