使用Feign实现Form表单提交

之前，笔者写了《使用Spring Cloud Feign上传文件》。近日，有同事在对接遗留的Struts古董系统，需要使用Feign实现Form表单提交。其实步骤大同小异，本文附上步骤，算是对之前那篇的补充。

1 添加依赖：

1. <dependency>

2.  <groupId>io.github.openfeign.form</groupId>

3.  <artifactId>feign-form</artifactId>

4.  <version>3.2.2</version>

5. </dependency>

6. <dependency>

7.  <groupId>io.github.openfeign.form</groupId>

8.  <artifactId>feign-form-spring</artifactId>

9.  <version>3.2.2</version>

10. </dependency>

2 Feign Client示例：

1. @FeignClient(name = "xxx", url = "http://www.itmuch.com/", configuration = TestFeignClient.FormSupportConfig.class)

2. public interface TestFeignClient {

3.    @PostMapping(value = "/test",

4.            consumes = {MediaType.APPLICATION_FORM_URLENCODED_VALUE},

5.            produces = {MediaType.APPLICATION_JSON_UTF8_VALUE}

6.            )

7.    void post(Map<String, ?> queryParam);

8.    class FormSupportConfig {

9.        @Autowired

10.        private ObjectFactory<HttpMessageConverters> messageConverters;

11.        // new一个form编码器，实现支持form表单提交

12.        @Bean

13.        public Encoder feignFormEncoder() {

14.            return new SpringFormEncoder(new SpringEncoder(messageConverters));

15.        }

16.        // 开启Feign的日志

17.        @Bean

18.        public Logger.Level logger() {

19.            return Logger.Level.FULL;

20.        }

21.    }

22. }

3 调用示例：

1. @GetMapping("/user/{id}")

2. public User findById(@PathVariable Long id) {

3.  HashMap<String, String> param = Maps.newHashMap();

4.  param.put("username","zhangsan");

5.  param.put("password","pwd");

6.  this.testFeignClient.post(param);

7.  return new User();

8. }

4日志：

1. ...[TestFeignClient#post] ---> POST http://www.baidu.com/test HTTP/1.1

2. ...[TestFeignClient#post] Accept: application/json;charset=UTF-8

3. ...[TestFeignClient#post] Content-Type: application/x-www-form-urlencoded; charset=UTF-8

4. ...[TestFeignClient#post] Content-Length: 30

5. ...[TestFeignClient#post]

6. ...[TestFeignClient#post] password=pwd&username=zhangsan

7. ...[TestFeignClient#post] ---> END HTTP (30-byte body)

由日志可知，此时Feign已能使用Form表单方式提交数据。

参考文档

• https://github.com/OpenFeign/feign-form

• https://stackoverflow.com/questions/35803093/how-to-post-form-url-encoded-data-with-spring-cloud-feign

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