title: converting the expression to lambda
body: <p>Can any one help me with converting this piece of code into lambda expression,
  I am struck with this </p>
  
  <pre><code>Observable.create(new OnSubscribe&lt;User&gt;() {
          @Override
          public void call(Subscriber&lt;? super User&gt; arg0) {
              User updatedUser = userService.updateuser(usermapper.userdtotoentity(user));
              arg0.onNext(updatedUser);
          }
      }).subscribe(new Action1&lt;User&gt;() {
          @Override
          public void call(User user) {
              if (user != null) {
                  response.resume(user);
              } else
                  response.resume(Response.status(Status.NOT_FOUND).build());
          }
      }, new Action1&lt;Throwable&gt;() {
          @Override
          public void call(Throwable t) {
              logger.debug("User with email_id:" + email_id + " is not present");
              response.resume(t);
          }
      });
  </code></pre>