def j2se_version(os=nil, arch=nil)
      j2se = j2ses.detect { |j2se| j2se.os == os && j2se.arch == arch}
      j2se ? j2se.version : nil
    end
def j2se_version(os=nil, arch=nil)
      j2se = j2ses.detect { |j2se| j2se.os == os && j2se.arch == arch}
      j2se ? j2se.version : nil
    end
Create a new Jnlp by loading and parsing the Java Web Start
 Jnlp located at url -- url can be a local path or a url.
 * if you include _cache_dir_ then the jnlp resources will be cached locally when the object is created
 You can pass a hash with these options:

    :include_pack_gz => true    download and cache the pack.gz jar files also
    :verbose => true            display a log