Comparing version number strings (major, minor, revision, beta)

Question

I have an application that communicates with the firmware of a device. As there are changes to the firmware, it is versioned with the format {major}.{minor}.{revision}

Answer 1

I would implement a comparable class:

class Version implements Comparable {
    int major;
    int minor;
    int rev;
    int beta = Integer.MAX_VALUE;


    public int compareTo(Version o) {
        if (this.major != o.major) {
            return Integer.compare(this.major, o.major);
        }
        if (this.minor != o.minor) {
            return Integer.compare(this.minor, o.minor);
        }
        if (this.rev != o.rev) {
            return Integer.compare(this.rev, o.rev);
        }
        if (this.beta != o.beta) {
            return Integer.compare(this.beta, o.beta);
        }
        return 0;
    }


    public static Version parse(String version) {
        // TODO: implement parsing here
        // 1.1.1      - beta = MAX_VALUE
        // 1.1.1beta  - beta = 1
        // 1.1.1beta2 - beta = 2
        return new Version();
    }


    @Override
    public String toString() {
        return "" + major + "." + minor + "." + rev
                + (beta == Integer.MAX_VALUE ? "" 
                        : (beta == 1 ? "beta" : 
                            ("beta" + beta)));
    }


}

Then compare in a standard java way:

if (Version.parse(testFW).compareTo(Version.parse(baseFW)) < 0) {
   // Version is newer!
}