Spring GenericFilterBean中的异常处理

Question

我已经实现了基于令牌的身份验证（没有spring安全性）。 因此，在GenericFilterBean中，它会检查并声明令牌。

public class MyTokenFilter extends GenericFilterBean {

    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws MyAuthException {

        HttpServletRequest request = (HttpServletRequest) req;
        HttpServletResponse response = (HttpServletResponse) res;

        if (!"OPTIONS".equals(request.getMethod())) {

            String authHeader = request.getHeader("Authorization");

            if (authHeader == null || !authHeader.startsWith("Token ")) {
                throw new MyAuthException("Authorization header needed"); // Should return custom http status response like 400
            }

            String token = authHeader.substring(6);

            try {
                claimToken(token);
            } catch (Exception e) {
                throw new MyAuthException("Invalid token."); // Should return custom http status response like 401
            }

        }

        chain.doFilter(req, res);

    }

}

所以在这个过滤器中似乎一切都好。 但是我需要用json发送不同Http Statutes的响应。 我能够将ResponseEntitiyExceptionHandler与@ControllerAdvice一起使用。 所以我可以在我的控制器中处理异常。

@ControllerAdvice
public class MyPrettyExceptionHandler extends ResponseEntityExceptionHandler {

    @ExceptionHandler(MyAuthException.class)
    @ResponseBody
    public ResponseEntity<Object> handleCustomException(HttpServletRequest req, MyAuthException ex) {
        Map<String, String> responseBody = new HashMap<>();
        responseBody.put("error", "true");
        responseBody.put("message", ex.getMessage());
        return new ResponseEntity<Object>(responseBody, HttpStatus.INTERNAL_SERVER_ERROR);
    }
}

我知道它是如何工作的以及哪个顺序过滤器和控制器及其异常（过滤器在控制器之前完成它们的工作，所以它们与控制器的范围不同）。 所以我自然无法使用ControllerAdvice处理过滤器的异常。

那么在Filter中处理异常的有效方法是什么（比如我的例子）？ 你能用另一种方式建议我吗？

Answer 1

您应该使用response.sendError发送错误代码和状态：

public class MyTokenFilter extends GenericFilterBean {

    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) req;
        HttpServletResponse response = (HttpServletResponse) res;

        if (!"OPTIONS".equals(request.getMethod())) {

            String authHeader = request.getHeader("Authorization");
            if (authHeader == null || !authHeader.startsWith("Token ")) {
                //throw new MyAuthException("Authorization header needed"); // Should return custom http status response like 400
                response.sendError(HttpServletResponse.SC_BAD_REQUEST, "Authorization header needed");
                return ;
            }

            String token = authHeader.substring(6);
            try {
                claimToken(token);
            } catch (Exception e) {
                //throw new MyAuthException("Invalid token."); // Should return custom http status response like 401
                response.sendError(HttpServletResponse.SC_UNAUTHORIZED, "Invalid token.");
                return ;
            }
        }
        chain.doFilter(req, res);
    }
}