content: /*******************************************************************************
  Title: T2Ti ERP Fenix                                                                
  Description: Classe responsável por interceptar todas as requisições realizadas 
  para o servidor que necessitam de autenticação.
                                                                                  
  The MIT License                                                                 
                                                                                  
  Copyright: Copyright (C) 2020 T2Ti.COM                                          
                                                                                  
  Permission is hereby granted, free of charge, to any person                     
  obtaining a copy of this software and associated documentation                  
  files (the "Software"), to deal in the Software without                         
  restriction, including without limitation the rights to use,                    
  copy, modify, merge, publish, distribute, sublicense, and/or sell               
  copies of the Software, and to permit persons to whom the                       
  Software is furnished to do so, subject to the following                        
  conditions:                                                                     
                                                                                  
  The above copyright notice and this permission notice shall be                  
  included in all copies or substantial portions of the Software.                 
                                                                                  
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,                 
  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES                 
  OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND                        
  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT                     
  HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,                    
  WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING                    
  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR                   
  OTHER DEALINGS IN THE SOFTWARE.                                                 
                                                                                  
         The author may be contacted at:                                          
             t2ti.com@gmail.com                                                   
                                                                                  
  @author Albert Eije (alberteije@gmail.com)                    
  @version 1.0.0
  *******************************************************************************/
  package com.t2ti.fenix.jwt;
  
  import java.io.IOException;
  import java.util.ArrayList;
  
  import javax.servlet.FilterChain;
  import javax.servlet.ServletException;
  import javax.servlet.ServletRequest;
  import javax.servlet.ServletResponse;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
  import org.springframework.security.core.Authentication;
  import org.springframework.security.core.context.SecurityContextHolder;
  import org.springframework.web.filter.GenericFilterBean;
  
  /*
   * Classe responsável por interceptar todas as requisições realizadas para o servidor
   * 
   * */
  public class JWTFilter extends GenericFilterBean {
  
  	@Override
  	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
  			throws IOException, ServletException {
  		try {
  			String token = null;
  			Authentication authentication = null;
  			if (((HttpServletRequest) request).getHeader("Authorization") != null) {
  				// pega o token que foi enviado no cabeçalho da requisição. Por padrão é utilizado a string "Bearer " seguida do token conforme a RFC 6750: https://tools.ietf.org/html/rfc6750
  				token = ((HttpServletRequest) request).getHeader("Authorization").replace("Bearer ", "");
  			}
  			
  			if (token != null) {
  				// verifica se o token é válido
  				String login = JWTManager.verificaToken(token);
  
  				// define os dados do usuário autenticado
  				authentication = new UsernamePasswordAuthenticationToken(login, null, new ArrayList<>());
  			}
  			
  			SecurityContextHolder.getContext().setAuthentication(authentication);
  			
  			chain.doFilter(request, response);
  		} catch (Exception e) {
  			//e.printStackTrace();
  			((HttpServletResponse) response).sendError(HttpServletResponse.SC_UNAUTHORIZED, e.getMessage());
  		}
  	}
  
  }
  