如何在Spring WebFlux中获取当前控制器方法的URL？

Question

@GetMapping("/greeting")
public Mono<Greeting> greeting() {
   String linkToCurrentResource = .. // How do I get this?
   Greeting greeting = new Greeting("hello",  linkToCurrentResource);
   return Mono.just(greeting);
}

如果运行在负载均衡器之后，LinkToCurrentResource最好应该理解X-Forwarded-？？？头。因此，在本例中，我想让LinkToCurrentResource类似于https://external-uri.com/api/greeting。如果需要的话，我将使用Netty服务器实现。

Answer 1

您可以使用ServerHttpRequest作为方法参数来获取URI:

@RestController
public class GreetingController {
  @GetMapping("/greeting")
  public Mono<Greeting> getGreeting(ServerHttpRequest serverHttpRequest) {
    return Mono.just(new Greeting("greeting", serverHttpRequest.getURI().toString()));
  }
}

如果运行在负载均衡器之后，LinkToCurrentResource最好应该理解X-Forwarded-？？？头。

然后可以公开forwardedheadertransformer@bean。

从“forwarded”和“x-forwarded-*”头中提取值，以覆盖请求URI（即HttpRequest.getURI())，使其反映源自客户端的协议和地址。

@Configuration
open class MvcConfig {
    @Bean
    open fun forwardedHeaderTransformer() = ForwardedHeaderTransformer()
}

以下是一些测试：

@ExtendWith(SpringExtension::class)
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.DEFINED_PORT,
        properties = ["server.port=4333"])
class GreetingController2Test {
    @Autowired
    private lateinit var restTemplate: TestRestTemplate

    @Test
    fun `should return uri`() {
        val responseEntity = restTemplate.getForEntity("/greeting", Greeting::class.java)
        val greeting = responseEntity.body!!
        assertEquals("http://localhost:4333/greeting", greeting.uri)
    }

    @Test
    fun `should return uri composed from forwarded-??? headers`() {
        val headers = HttpHeaders()
        headers["X-Forwarded-Host"] = "external-uri.com"
        headers["X-Forwarded-Proto"] = "https"
        headers["X-Forwarded-Prefix"] = "/prefix"

        val httpEntity = HttpEntity(null, headers)
        val responseEntity = restTemplate.exchange("/greeting", HttpMethod.GET, httpEntity, Greeting::class.java)
        val greeting = responseEntity.body!!
        assertEquals("https://external-uri.com/prefix/greeting", greeting.uri)
    }
}

和greeting.kt:

data class Greeting(
        val g: String? = null,
        val uri: String? = null
)