How to read files outside the jar ?

Question

Hi all,
One of my classes inside jar needs to read XML file that resides in the same location where the jar sits. I use MyClass.getClass().getResource("MyXMLFile.xml") but it keeps returning null.
If I place the XML file inside the JAR, I can find it using above methods, but since I want the user to easily edit the XML file without opening the jar file and detach the XML file, I choose not to include the XML file inside the jar.
Any help would be greatly appreciated.
Setya

Answer 1

Thanks for the dukes.
My JDBC post on this forum discusses the issues of
using Class-Path in your jar file. It works, but it
may vary from system to system.
Thanks also from my side: I have read recently your discussion about reading files in the jar's directory, since I had the same problem. So I was really glad to see your solution. However, I had one more problem, namely that I'm running my application sometimes from the jar, sometimes from the classes directly (debugging). In order to have always the correct path (although a different one) I have added some more lines to deal with that case. I hope that will be useful for you as well!
Dieter Profos
import java.awt.*;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import java.net.URL;
* @author pkwooster
* @author Dieter Profos
* @version 1.01 04/03/26
public class ReadOutside extends Frame {
private TextArea textArea;
public static void main(String[] args) {
// Create application frame.
ReadOutside tc = new ReadOutside();
tc.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent we) {
System.exit(0);
// Show frame
tc.setSize(600,250);
tc.setVisible(true);
public ReadOutside() {
textArea = new TextArea(20,80);
add(textArea);
readOutside(this);
public void readOutside(Object o) {
System.out.println(getCodeBasePath(o));
/** Gets the absolute path of the directory where the JAR or CLASS file is
* located. If the application is run from a jar file, the directory of the
* jar file is returned; if it is run from a class file, the method will
* return the directory path of the class file.
* @param o The main class of the application.
* @return The absolute directory path, or null if neither the class nor a
* jar file could be found.
public String getCodeBasePath(Object o) {
Class c = o.getClass();
URL url;
// get the class name
String className = c.getName();
textArea.append("class name = " + className + "\n");
// replace package periods by file separators
className = className.replace('.','/');
ClassLoader cl = c.getClassLoader();
if (cl == null)
cl = ClassLoader.getSystemClassLoader();
url = cl.getResource(className + ".class");
String xPath = url.toExternalForm();
textArea.append("url = " + url + "\n");
textArea.append("extPath = " + xPath + "\n");
// make sure that the path starts with jar:file:
if (xPath.startsWith("jar:file:")) {
// remove jar:file: + the subsequent file separator
xPath = xPath.substring("jar:file:".length()+1);
int n = xPath.indexOf("!");
if (n < 0)
n = xPath.length();
String jarPath = xPath.substring(0, n);
textArea.append("jar file path = " + jarPath + "\n");
n = jarPath.lastIndexOf("/");
String jarDir = jarPath.substring(0, n+1);
textArea.append("jar dir = " + jarDir + "\n");
return jarDir;
else { // if program is run from its class file (development phase!)
if (xPath.startsWith("file:")) {
// remove file: + the subsequent file separator
xPath = xPath.substring("file:".length()+1);
textArea.append("class file path = " + xPath + "\n");
int n = xPath.lastIndexOf("/");
String classDir = xPath.substring(0, n+1);
textArea.append("class dir = " + classDir + "\n");
return classDir;
return null;