Is it possible load all properties files contained in a package dynamically? i.e. MyClass.class.getResource('*.properties');

Question

I am familiar with obtaining the contents of a properties file given the name of the file, and obviously MyClass.class.getResource('*.properties') will not work, but how can I obtain a list of ALL the properties files located in the same package as my class?

Answer 1

Assuming that it's not JAR-packaged, you can use File#listFiles() for this. Here's a kickoff example:

String path = MyClass.class.getResource("").getPath();
File[] propertiesFiles = new File(path).listFiles(new FilenameFilter() {
    public boolean accept(File dir, String name) {
        return name.endsWith(".properties");
    }
});

If it's JAR-packaged, then you need a bit more code, to start with JarFile API. You can find another example in this answer.

Answer 2

You can do these sort of things with Spring. See 4. Resources, particurlarely (or notabily ? ) (or principalementely ? ) (or mainly ? ) at 4.7.2 Wildcards in application context constructor resource paths.

Answer 3

This is how I did it,

    Class<? extends Object> clazz = AnyKnownClassInTheJar.class;
    String className = clazz.getSimpleName() + ".class";
    String classPath = clazz.getResource(className).toString();
    if (!classPath.startsWith("jar")) {
      // Class not from JAR
      return;
    }
    URL url = new URL(classPath);
    JarURLConnection conn = (JarURLConnection)url.openConnection();
    JarFile jf = conn.getJarFile();
    for (Enumeration<JarEntry> i = jf.entries(); i.hasMoreElements();) {
        JarEntry je = i.nextElement();
        String name = je.getName();
        if (name.indexOf(".properties") != -1) {
            // Load the property file
        }
    }