File I/O Please help!

[cupanTae]

Hi i need help with a simple I/O problem. I have a large text file, which i want to break up into smaller files. I want to break the file each time "From -" is found at the start of a new line.


public static void main(String[] args) throws Exception {

String path1 = "file1";

BufferedReader br = new BufferedReader( new InputStreamReader(new FileInputStream(path1)));

BufferedWriter out = new BufferedWriter(new FileWriter("Emails//out.txt"));
String line;
while((line = br.readLine()) != null)
{
if(line.startsWith("From -")){

//send from here to the next "from -" into a text file

}
}

}
}

Above is as far as ive come, i dont know how to send each block of text to an individual file, can anybody help, it would be greatly appreciated!
Thanks

[destin]

I'd recommend using the Scanner class, and setting the delimiter to "From -"

public static void main(String[] args) {
    try {
        Scanner scanner = new Scanner(new File("file.txt")).useDelimiter("From -");
        String line;
        for (int i = 0; scanner.hasNext(); i++) {
            PrintWriter pw = new PrintWriter(new FileWriter("file" + i + ".txt"));
            pw.println(scanner.next());
            pw.close();
        }
    } catch (IOException e) { e.printStackTrace(); }
}

Try something like that. I haven't tested it yet, so there's a good chance it won't compile, but yeah, hopefully you get the idea.

[edit] You're going to need to import java.util.Scanner for the Scanner class.

[cupanTae]

Thanks, this code compiles fine, but it doesn't write to the file specified. Im not familiar with the scanner class. What is the

PrintWriter pw = new PrintWriter(new FileWriter("file" + i + ".txt"));

i in the above piece of code?

[destin]

Thanks, this code compiles fine, but it doesn't write to the file specified. Im not familiar with the scanner class. What is the

PrintWriter pw = new PrintWriter(new FileWriter("file" + i + ".txt"));

i in the above piece of code?

Well, in the OP, you said that you wanted to write each one out to different
files, so that's what I made it do. It'll write the first post to file0.txt, the second
to file1.txt, the third to file2.txt, etc. i is defined in the for loop.

[major]

I have written some code that will split a file using a deliminator in the example below the deliminator is "-". Probably not the most clean code but it works. Let me know if it works out well for you.

import java.io.*;

public class SplitText

{
FileOutputStream Save; 
PrintStream printString;
String strWholeMessage="";
int i=0;

	public static void main(String args[])
	{
	String myFile="File.txt"; //Change the file to read here.
	SplitText newSplitText = new SplitText();
	newSplitText.ReadSplit(myFile);
	}


	public void ReadSplit(String myFile)
	{
		try
		{
			File my_File = new File(myFile);
			BufferedReader in = new BufferedReader(new FileReader(my_File));

				String strString;
        		
					while ((strString = in.readLine()) != null) 
				
					{			
						strWholeMessage = strWholeMessage + strString; 					
        				}
						
       						in.close();

						String[] splitText = strWholeMessage.split("-"); //Change the deliminator here.

					while(i < splitText.length)
					{ 

                				try
                				{
                       
                       					Save = new FileOutputStream("OutPut" + i + ".txt"); //Change the output file here. File starts from OutPut0.txt

                        				printString = new PrintStream(Save);
		
                        				printString.println (splitText[i]);

                        				printString.close();

                				}
                				catch (Exception e)
                				{
                       					System.err.println ("Unable to write to file");
                				}
					i++;
					}
		}
		catch (IOException e)
		{
		System.out.println("Unable to open file");
		}

	}

}

You can find some java examples from the following site www.java.codeyourself.com. Not many at the moment. Would really appreciate people sending in code.

[cupanTae]

Yes, got that working thanks very much for the help!