[Correct bugs] Java - spring framework Web-Applicatip

Dear sirs, I have a modular application (modular - because the algorithms can be uploaded to the system if they preserve defined interface) written in JAVA (spring framework) which should be rebuilt from the beginning, since it has some logical problems with autorisation, data mapping, UI problems. Since, it was written via not that big knowledge of Java, even not considering the Spring Framework. - From the beginning it was not considered that there will be an admin user, so doing it manually (tried to add spring Security later, but it caused severe difficulties with the angular JS) caused many logical problems, such that a normal user can access to the admin pages, which should not be allowed. Or, once admin logged in and logged out it somehow possible to access pages without logging in just via writing the link in url box. - The main logic behind is to scrap the users publications from DBLP digital library. Once its done the system runs a thread which also crawls the users coauthors publications. But, somehow the mapping of the publications is incorrect. For ex. If the user A’s publications are extracted and they are not found in the system – they are assigned to him. Then, once crawling his coauthors publications are extracted and the system finds the publication which was already in the system, it should also be mapped to the coauthor. So that, is the publication is written by 5 authors it should be assigned to every author that took part in writing it. For now, the logic is incorrect, since it assignes only publications that were not previously in the system. - Coming out of the previous, the system should check the publications for the existence in the system using the <ee> tag after crawling the page using JSOUP - Make UI changes in order for the system to be more user friendly: o Some better loading animations once crawling data and recommending publications o Once the system makes the recommendations there is a possibility to make a feedback. Create a better view for the feedback styles (1 to 10 rating, 5 star rating, yes no rating) o More minor UI changes as repositioning and etc. - Maybe more minor changes as well. The main idea of the application is that it has to show recommendations provided by the recommendations algorithm. I can send the application report written by me in order to decide, should it be fully reworked or can be corrected. System is based on Spring, MySQL, JSOUP, Bootstrap, Javascript and Angular JS.