如何在 POST 请求中向其他 Feign 客户端发出 GET 请求？

Question

我有一个 REST API 端点，它使用多个 Feign 客户端来执行验证和处理。有问题的端点接受 POST 请求，但用于验证的 Feign 客户端接受 GET 请求。当我向我的 API 端点发出 POST 请求时，我从需要 GET 的 Feign 客户端收到以下错误。我的 Feign 客户端方法用 @GetMapping 注释，但似乎请求仍在作为 POST 发送。如何在 POST 请求中向 Feign 客户端发出 GET 请求？

feign.FeignException: status 405 reading ValidationClient#checkData(String); content:
{"timestamp":"2018-08-06T14:43:45.998+0000","status":405,"error":"Method Not Allowed","message":"Request method 'POST' not supported","path":"/"}
    at feign.FeignException.errorStatus(FeignException.java:62) ~[feign-core-9.5.1.jar:na]
    at feign.codec.ErrorDecoder$Default.decode(ErrorDecoder.java:91) ~[feign-core-9.5.1.jar:na]
    at feign.SynchronousMethodHandler.executeAndDecode(SynchronousMethodHandler.java:138) ~[feign-core-9.5.1.jar:na]
    at feign.SynchronousMethodHandler.invoke(SynchronousMethodHandler.java:76) ~[feign-core-9.5.1.jar:na]
    at feign.ReflectiveFeign$FeignInvocationHandler.invoke(ReflectiveFeign.java:103) ~[feign-core-9.5.1.jar:na]
    at com.sun.proxy.$Proxy129.checkFormat(Unknown Source) ~[na:na]
    at com.example.datainput.DataInputController.acceptData(DataInputController.java:20) ~[classes/:na]
    at sun.reflect.GeneratedMethodAccessor126.invoke(Unknown Source) ~[na:na]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:45005) ~[na:1.8.0_172]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_172]
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:877) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:661) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.StandardContextValve.__invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:40002) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:493) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:800) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:800) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1471) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_172]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_172]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at java.lang.Thread.run(Thread.java:748) [na:1.8.0_172]

编辑：

伪装客户端

@FeignClient("validation")
public interface ValidationClient {

    @GetMapping("/")
    boolean checkFormat(String data);

}

客户端的控制器

@RestController
public class ValidationController {

    @Autowired
    ValidationProperties properties;

    @GetMapping("/")
    public boolean isValidFormat(@RequestParam String inputData) {
        return inputData.matches(properties.getValidFormat());
    }

}

使用客户端的 REST 端点

@RestController
public class DataInputController {

    @Autowired
    ValidationClient validationClient;

    @PostMapping("/")
    public String saveData(@RequestParam(name = "inputData") String inputData) {

        if (!validationClient.checkFormat(inputData)) {
            return "Invalid Format";
        }

        // save data here

        return "Input Success";
    }

}

我使用的是 FINCHLEY.SR1 版本

编辑 2：

我注意到我的控制器中的 Feign 客户端似乎配置错误。它们的类型是 HardCodedTarget 而 url 属性只是 http://<service-name>（在本例中是 http://validation），它实际上并不指向客户端应该提供的真实服务正在使用。

编辑 3： 我添加了功能区

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
</dependency>

我的服务应用程序和我的 api 使用 Feign 客户端。不幸的是我仍然有同样的问题。我刷新并重建了所有内容。

编辑 4： 我为这个问题创建了一个 GitHub 项目。

https://github.com/zero01alpha/spring-cloud-demo

input-entry 模块使用 input-format 和 input-parse 模块作为 Feign 客户端来验证输入字符串的长度和 parse/print 项。我一直在使用字母表作为输入，所以输入参数的最小长度设置为 26。input-format 在端口 8080 上运行，input-parse 在 8081 上运行，input-entry 在 8082 上运行，都使用默认路径 / 作为他们唯一的端点并需要一个名为 input 的请求参数。所以要重现我遇到的问题

启动配置服务器
启动尤里卡服务器
启动输入格式服务
启动输入解析服务
启动输入法服务

然后，向localhost:8082发送一个POST请求，请求参数为input，至少26个字符。当我这样做时，我得到了这个响应体。

{
    "timestamp": "2018-08-09T13:29:34.536+0000",
    "status": 500,
    "error": "Internal Server Error",
    "message": "status 405 reading InputFormatClient#checkFormat(String); content:\n{\"timestamp\":\"2018-08-09T13:29:34.504+0000\",\"status\":405,\"error\":\"Method Not Allowed\",\"message\":\"Request method 'POST' not supported\",\"path\":\"/\"}",
    "path": "/"
}

Answer 1

默认情况下，feign 方法的任何参数都被视为正文，因此您的 checkFormat() 方法将发送 post 因为它有正文（get 不能）。所以这个：

@FeignClient("input-format")
public interface InputFormatClient {

    @GetMapping("/")
    boolean checkFormat(String input);

}

需要：

@FeignClient("input-format")
public interface InputFormatClient {

    @GetMapping("/")
    boolean checkFormat(@RequestParam("input") String input);

}

另外一个客户端也需要进行类似的更新

@FeignClient("input-parse")
public interface InputParseClient {

    @GetMapping("/")
    Map<String, String> getParsedItems(@RequestParam("input") String input);

}

如何在 POST 请求中向其他 Feign 客户端发出 GET 请求？

How to make GET requests to other Feign clients inside of a POST request?

java

spring

spring-cloud