[JAVA] About image upload of jsp (servlet)

Installation of upload button in POST Servlet

Upload.java

package pakage;

@WebServlet("/upload")
@MultipartConfig(location="/tmp",maxFileSize=1048576)
public class UploadServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
      @Override

	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //Create a variable called part
		Part part = request.getPart("file");
        //part(Mainly jsp)Get the file name sent from
		String name = this.getFileName(part);

		part.write(getServletContext().getRealPath("/WEB-INF/lib/upload")+ "/" + name);
		response.sendRedirect("jsp/upload.jsp");
	}
      private String getFileName(Part part){
          String name = null;
          for(String dispotion : part.getHeader("Content-Disposition").split(";")){
              if(dispotion.trim().startsWith("filename")){
                  name = dispotion.substring(dispotion.indexOf("=") + 1).replace("\"","").trim();
                  name = name.substring(name.lastIndexOf("\\") + 1 );
                  break;
              }
          }
          return name;
    }
}

CreateServlet.java

package controllers;


@WebServlet("/create")
public class CreateServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
    }

	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		String _token = (String)request.getParameter("_token");
		if(_token != null && _token.equals(request.getSession().getId())){
		    EntityManager em = DBUtil.createEntityManager();

		    Reshipi r = new Reshipi();

		    String name = request.getParameter("name");
		    r.setName(name);

		    String content = request.getParameter("content");
		    r.setContent(content);

		    Timestamp currentTime = new Timestamp(System.currentTimeMillis());
		    r.setCreated_at(currentTime);
		    r.setUpdated_at(currentTime);

		    em.getTransaction().begin();
		    em.persist(r);
		    em.getTransaction().commit();
		    em.close();

		    response.sendRedirect(request.getContextPath() + "/index");

		}
	}
}

When combining the two

package controllers;

@WebServlet("/create")
public class CreateServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;

    public CreateServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		String _token = (String)request.getParameter("_token");
		if(_token != null && _token.equals(request.getSession().getId())){
		    EntityManager em = DBUtil.createEntityManager();

		    Reshipi r = new Reshipi();

		    String name = request.getParameter("name");
		    r.setName(name);

		    String content = request.getParameter("content");
		    r.setContent(content);


		    Part part = request.getPart("file");
		    String filename = this.getFileName(part);

		    Timestamp currentTime = new Timestamp(System.currentTimeMillis());
		    r.setCreated_at(currentTime);
		    r.setUpdated_at(currentTime);

		    em.getTransaction().begin();
		    em.persist(r);
		    em.getTransaction().commit();
		    em.close();

		    response.sendRedirect(request.getContextPath() + "/index");
		}
	}
    private String getFileName(Part part){
        String filename = null;
        for(String dispotion : part.getHeader("Content-Disposition").split(";")){
            if(dispotion.trim().startsWith("filename")){
                filename = dispotion.substring(dispotion.indexOf("=") + 1).replace("\"", "").trim();
                filename = filename.substring(filename.lastIndexOf("\\") + 1);
                break;
            }
        }
        return filename;
    }
}

Private String getFileName (Part part) Always write the method outside the POST method, not inside it. Put what was in the POST method into the POST method, and what was in the GET method into the GET method.