Spring Cloud Request Filter

OncePerRequestFilter

For our one request, this filter will execute exactly one time (no more no less). This behavior is very useful while working with security authentication.

class AuthorizationFilter : OncePerRequestFilter() {
    override fun doFilterInternal(request: HttpServletRequest, response: HttpServletResponse, filter: FilterChain) {
        val token = request.getHeader(HttpHeaders.AUTHORIZATION)
        if (token == null) {
            val error = ErrorInfo(ErrorCode.ILLEGAL_TOKEN)
            writeError(response, error, HttpStatus.UNAUTHORIZED.value())
            return
        }

        val claims = JwtUtil.parseAuthToken(token)
        if (claims == null) {
            val error = ErrorInfo(ErrorCode.ILLEGAL_TOKEN)
            writeError(response, error, HttpStatus.UNAUTHORIZED.value())
            return
        }

        filter.doFilter(request, response)
    }

    private fun writeError(response: HttpServletResponse, error: ErrorInfo, code: Int) {
        response.writer.write(JsonUtil.objToJson(error))
        response.status = code
        response.writer.flush()
    }
}

@SpringBootApplication
class GatewayApplication {
    @Bean
    fun configFilter(): FilterRegistrationBean<AuthorizationFilter> {
        val registration = FilterRegistrationBean<AuthorizationFilter>()
        registration.filter = AuthorizationFilter()
        registration.addUrlPatterns("/*")
        registration.setName("AuthorizationFilter")
        registration.order = Ordered.HIGHEST_PRECEDENCE
        return registration
    }
}

//  contracts
StandaloneMockMvcBuilder mockMvc = MockMvcBuilders.standaloneSetup(
        new OrderController(),
        new PositionController()
).addFilters(new AuthorizationFilter());
RestAssuredMockMvc.standaloneSetup(mockMvc);