reading files from a directory and printing

[philthee]

Hi there,

can someine give me a hand with the above problem.
I have code here that can read a file from a given path but i would like to be able to read a directory from a given path and do something with the file names.
The file names are of type catA1.cyt, catA1.jpg, catA2.cyt, catA2.jpg etc..

i want to split up the filenames (only interested in the .cyt ones) and keep the A1, A2 etc to put them somewhere.

[code]

/*
* splitString.java
*
* Created on 28 October 2004, 13:05
*/

package Strings;
import java.io.*;
import java.util.*;

/**
*
* @author devallp
*/
public class splitString {

/** Creates a new instance of splitString */
public splitString() {
}

/**
* @param args the command line arguments
*/
public static void main(String[] args) {
try {
String path = "/mnt/rinetapp1a/users/devallp/src/demoChromosomeStuff
/cat/catA1.cyt";
File catFile = new File(path);
FileInputStream stuff = new FileInputStream(catFile);
FileReader fr = new FileReader(catFile);
BufferedReader in = new BufferedReader(fr);
String line;


while ((line = in.readLine()) != null) {

System.out.println(line);


}
}

catch (FileNotFoundException e) {
System.out.println("File disappeared");
}

catch (java.io.IOException e) {
System.out.println("hmmmmm??");
}
// TODO code application logic here
}

}
[\code]


so this reads a file from a path and prints out the contents.
what would i do firstly to read a directory and print the contents?

[Belisarius]

You probably haven't looked at the Javadocs for File. File can either represent a standard file, or a directory. If it's the latter, you can use the list() method to get an array of Strings listing the contents of the directory.

[philthee]

Originally Posted by Belisarius

You probably haven't looked at the Javadocs for File. File can either represent a standard file, or a directory. If it's the latter, you can use the list() method to get an array of Strings listing the contents of the directory.

Cheers, had a wee blast and with some help i got this which works.

*/import java.io.*;
public class retrieveName {


    /** Creates a new instance of retirveName */
 public void listNames(String startName) {
        File startFile = new File(startName);
        File[] contents = startFile.listFiles();
        if (contents == null) {
            System.err.println("Could not list " + startFile);
            return;
        }
        java.util.Arrays.sort(contents);
        for (int i = 0; i < contents.length; i++) {
            System.out.println(contents[i]);
        }

      

    public static void main(String[] args) {
        try {
            ListFileNames myList = new ListFileNames();
            myList.listNames(".");
            //myList.listNames(args[0]);
        } catch (Exception e) {
            System.err.println(e);

        }


    }
}

apologies for the bad indentation.

how do i catch what is in contents[i] and do something with each line of contents?

i.e my results are
./catF1.cyt
./catF1.jpg
./catF2.cyt
./catF2.jpg

i want to take each member of the list (ignoring the jpg files) and save the F1, F2 etc into an array of names.

[philthee]

ok, i don't know how to join one bit of code onto the next but here is the next bit (kind of) working from a stated string similar to what they will work

on*/import java.util.*;
 import java.lang.*;

public class SplitLines {



    public static void main(String[] Args)
    {


        SplitLines s = new SplitLines();

    }

/** Creates a new instance of SplitLines */
    public SplitLines() {
        String text = "catA1.cyt";
        String[] fields = text.split("\\W");


        for(int x=0;x<1;x++)
        System.out.println(fields[0]);
    }

}

this splits the sting in to catA1 and .cyt printing just catA1.
not figured out how to get rid of cat yet.

[Belisarius]

You'll want to look at the Javadoc for String. Instead of split, you could use endsWith() to figure out which ones end with .cyt. Also, provided all the .cyt files have the same naming scheme, you could use substring to cut off the first 3 letters.