How to list files and folders in Java ME
Overview
This article shows, how to list files and folders in a folder on a mobile device. FileConnection API (JSR-75) has FileConnection.list() method for this purpose. It is also possible to get directory and file sizes by using FileConnection.directorySize() and FileConnection.fileSize() methods.
The full source code for a test MIDlet:
Source code: FileListMIDlet.java
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import java.util.Enumeration;
import javax.microedition.io.file.*;
import javax.microedition.io.*;
import java.io.*;
public class FileListMIDlet extends MIDlet implements CommandListener {
private Form form;
private Command exitCommand;
public void startApp() {
form = new Form("C:/ contents");
exitCommand = new Command("Exit", Command.EXIT, 1);
form.addCommand(exitCommand);
form.setCommandListener(this);
Display.getDisplay(this).setCurrent(form);
getFileList("file:///c:/");
}
public void pauseApp() {
}
public void destroyApp(boolean unconditional) {
}
protected void getFileList(String path) {
try {
FileConnection fc = (FileConnection)Connector.open(path, Connector.READ);
Enumeration filelist = fc.list("*", true); //also hidden files are shown
String filename;
while(filelist.hasMoreElements()) {
filename = (String) filelist.nextElement();
fc = (FileConnection)Connector.open(path + filename, Connector.READ);
if(fc.isDirectory()) {
long size = fc.directorySize(false);
form.append(filename+" - "+Integer.toString((int)size)+"B\n");
} else {
long size = fc.fileSize();
form.append(filename+" - "+Integer.toString((int)size)+"B\n");
}
}
fc.close();
}
catch (IOException ioe) {
System.out.println("IOException: "+ioe.getMessage());
}
catch (SecurityException se) {
System.out.println("SecurityException: "+se.getMessage());
}
}
public void commandAction(Command c, Displayable d) {
if (c == exitCommand) this.notifyDestroyed();
}
}
