text: package com.example.algamoney.api.token;
  
  import java.io.IOException;
  import java.util.Map;
  
  import javax.servlet.Filter;
  import javax.servlet.FilterChain;
  import javax.servlet.FilterConfig;
  import javax.servlet.ServletException;
  import javax.servlet.ServletRequest;
  import javax.servlet.ServletResponse;
  import javax.servlet.http.Cookie;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletRequestWrapper;
  
  import org.apache.catalina.util.ParameterMap;
  import org.springframework.core.Ordered;
  import org.springframework.core.annotation.Order;
  import org.springframework.stereotype.Component;
  
  @Component
  @Order(Ordered.HIGHEST_PRECEDENCE)
  public class RefreshTokenCookiePreProcessorFilter implements Filter {
  
  	@Override
  	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
  			throws IOException, ServletException {
  		
  		HttpServletRequest req = (HttpServletRequest) request;
  		
  		if ("/oauth/token".equalsIgnoreCase(req.getRequestURI()) 
  				&& "refresh_token".equals(req.getParameter("grant_type"))
  				&& req.getCookies() != null) {
  			for (Cookie cookie : req.getCookies()) {
  				if (cookie.getName().equals("refreshToken")) {
  					String refreshToken = cookie.getValue();
  					req = new MyServletRequestWrapper(req, refreshToken);
  				}
  			}
  		}
  		
  		chain.doFilter(req, response);
  	}
  	
  	@Override
  	public void destroy() {
  		
  	}
  
  	@Override
  	public void init(FilterConfig arg0) throws ServletException {
  		
  	}
  	
  	static class MyServletRequestWrapper extends HttpServletRequestWrapper {
  
  		private String refreshToken;
  		
  		public MyServletRequestWrapper(HttpServletRequest request, String refreshToken) {
  			super(request);
  			this.refreshToken = refreshToken;
  		}
  		
  		@Override
  		public Map<String, String[]> getParameterMap() {
  			ParameterMap<String, String[]> map = new ParameterMap<>(getRequest().getParameterMap());
  			map.put("refresh_token", new String[] { refreshToken });
  			map.setLocked(true);
  			return map;
  		}
  		
  	}
  
  }
  