android打开rar压缩文件

private void open(string filestring) {
 intent intent = new intent();
 intent.setclassname("com.rarlab.rar", "com.rarlab.rar.mainactivity");
 file file = new file(filestring);
 uri data = uri.fromfile(file);
 intent.setdata(data);
 try {
  startactivity(intent);
 } catch (activitynotfoundexception e) {
  try {
   uri uri = uri.parse("market://search?q=" + "rar");
   intent it = new intent(intent.action_view, uri);
   startactivity(it);
  } catch (activitynotfoundexception e2) {
   log.i(tag, "market no found");
  }
 }
}