getProgramFromDesktopFile.java

/**
 * Search for the right program by parsing the desktopfile
 *
 * @param desktopfile
 *
 * @return
 */
private String getProgramFromDesktopFile(String desktopfile) {
    // -- Identify all the places where the desktop file could be stored
    Path userhome = Paths.get(System.getProperty("user.home"));
    Path localPlace = userhome.resolve(Paths.get(".local", "share", "applications")); // = /home/myuser/.local/share/applications/
    Stream<Path> places = Stream.of(localPlace);

    String xdgdatadirs = System.getenv("XDG_DATA_DIRS"); // all the official places for storing a desktop file
    if (xdgdatadirs != null)
        places = Stream.concat(places, Stream.of(xdgdatadirs.split(":")).map(s -> Paths.get(s)));

    logger.trace("Searching for " + desktopfile + " in :");

    // -- Find where is located the desktop file we are searching for
    Path dfile = places
            .peek(f -> logger.trace("\t" + f))
            .map(f -> f.resolve(desktopfile))
            .filter(p -> Files.exists(p))
            .findAny()
            .orElse(null);

    if (dfile == null) {
        logger.warn("Could not find any desktop file name " + desktopfile);
        return null;
    }

    logger.debug("Desktopfile found at " + dfile);

    // Read the desktopfile as a regulary Property file
    Properties dprop = null;
    try {
        dprop = new Properties();
        InputStream stream = Files.newInputStream(dfile);
        dprop.load(stream);
    } catch (IOException ex) {
        logger.error("Fail to read " + dfile, ex);
        return null;
    }

    logger.debug("Exec >> " + dprop.getOrDefault("Exec", "???"));

    String program = dprop.getProperty("Exec");
    if (program == null)
        return null;

    // Strip the %1, %F, ...
    if (program.contains("%")) {
        program = program.substring(0, program.indexOf('%')).trim();
    }

    logger.debug("Program >> " + program);

    return program;
}