Feign的使用示列--呕心沥血之作(1)

以你之姓@ 2023-01-14 01:35 139阅读 0赞

### 文章目录 ###

*  1、前置
 *  2、GET请求
 *  3、POST请求
 *  4、配置请求头
 *  5、上传文件
 *  6、下载文件
 *  7、Body注解
 *  8、注意点

--------------------

# 1、前置 #

1、这里这是贴出了部分示列代码, 具体代码已经上传到码云: [代码地址][Link 1]  
2、本demo采用了feign的继承特性  
3、版本: Spring Cloud: Hoxton.SR3、spring-cloud-openfeign: 2.2.2.RELEASE, 服务发现: nacos

# 2、GET请求 #

package com.chaim.feignserver.service;
    
    import com.chaim.feignserver.DTO.TestEntity;
    import com.chaim.feignserver.util.CommonResult;
    import org.springframework.cloud.openfeign.SpringQueryMap;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    import org.springframework.web.bind.annotation.RequestParam;
    
    import java.util.Map;
    
    /**
     * @author Chaim
     * @date 2021/4/19 17:06
     */
    public interface GetService { 
        /**
         * GET 请求无参
         *
         * @return
         */
        @RequestMapping(value = "/get/getNoParameters", method = RequestMethod.GET)
        CommonResult getNoParameters();
    
        /**
         * GET 请求单参
         *
         * @return
         */
        @RequestMapping(value = "/get/getOneParameter", method = RequestMethod.GET)
        CommonResult getOneParameter(@RequestParam("id") String id);
    
        /**
         * GET 请求多参, 多参 单个传递
         *
         * @return
         */
        @RequestMapping(value = "/get/getParameters1", method = RequestMethod.GET)
        CommonResult getParameters(@RequestParam("id") String id, @RequestParam("name") String name);
    
        /**
         * GET 请求多参, 对象方式传递
         *
         * @return
         */
        @RequestMapping(value = "/get/getParameters2", method = RequestMethod.GET)
        CommonResult getParameters2(@RequestParam Map<String, Object> testEntity);
    
        /**
         * GET 请求多参, 对象方式传递
         *
         * @return
         */
        @RequestMapping(value = "/get/getParameters3", method = RequestMethod.GET)
        CommonResult getParameters3(@SpringQueryMap TestEntity testEntity);
    
        /**
         * GET 请求多参 + Restful 风格
         *
         * @return
         */
        @RequestMapping(value = "/get/getRestfulParameters/{id}", method = RequestMethod.GET)
        CommonResult getRestfulParameters(@RequestParam(value = "id") String id);
    }

package com.chaim.consumerserver.feignclien;
    
    import com.chaim.feignserver.service.GetService;
    import org.springframework.cloud.openfeign.FeignClient;
    
    /**
     * 远程 Feign 调用
     *
     * @author Chaim
     * @date 2021/4/19 17:28
     * @FeignClient: 表明是一个 feign 接口. name 微服务的名称
     */
    @FeignClient(name = "provider", contextId = "getProvider", path = "get")
    public interface GetFeignClient extends GetService { 
    }

# 3、POST请求 #

package com.chaim.feignserver.service;
    
    import com.chaim.feignserver.DTO.TestEntity;
    import com.chaim.feignserver.util.CommonResult;
    import org.springframework.web.bind.annotation.*;
    
    /**
     * @author Chaim
     * @date 2021/4/19 17:06
     */
    public interface PostService { 
        /**
         * POST 请求无参
         *
         * @return
         */
        @RequestMapping(value = "/testPost/postNoParameters", method = RequestMethod.POST)
        CommonResult postNoParameters();
    
        /**
         * POST 请求有参
         *
         * @return
         */
        @RequestMapping(value = "/testPost/postParameters", method = RequestMethod.POST)
        CommonResult postParameters(@RequestBody TestEntity testEntity);
    
        /**
         * POST 请求有参 + Restful 风格
         *
         * @return
         */
        @RequestMapping(value = "/testPost/postRestfulParameters/{count}", method = RequestMethod.POST)
        CommonResult postRestfulParameters(@RequestBody TestEntity testEntity, @PathVariable("count") String count);
    
        /**
         * POST 请求有参 + key=value 风格
         *
         * @return
         */
        @RequestMapping(value = "/testPost/postKeyValueParameters", method = RequestMethod.POST)
        CommonResult postKeyValueParameters(@RequestBody TestEntity testEntity, @RequestParam("count") String count);
    }

package com.chaim.consumerserver.feignclien;
    
    import com.chaim.feignserver.service.PostService;
    import org.springframework.cloud.openfeign.FeignClient;
    
    /**
     * 远程 Feign 调用
     *
     * @author Chaim
     * @date 2021/4/19 17:28
     * @FeignClient: 表明是一个 feign 接口. name 微服务的名称
     */
    @FeignClient(name = "${project.feign-prefix}", contextId = "postProvider")
    public interface PostFeignClient extends PostService { 
    }

# 4、配置请求头 #

package com.chaim.feignserver.service;
    
    import com.chaim.feignserver.DTO.TestEntity;
    import com.chaim.feignserver.util.CommonResult;
    import feign.HeaderMap;
    import feign.Headers;
    import feign.Param;
    import feign.RequestLine;
    import org.springframework.cloud.openfeign.SpringQueryMap;
    import org.springframework.web.bind.annotation.RequestBody;
    
    import java.util.Map;
    
    /**
     * @author Chaim
     * @date 2021/4/19 20:38
     */
    public interface HeaderServer { 
        /**
         * GET 请求多参, 携带头部
         *
         * @param data
         * @param headerMap
         * @return
         */
        @RequestLine("GET /testHeard/getHeard")
        CommonResult getHeard(@SpringQueryMap TestEntity data, @HeaderMap Map<String, Object> headerMap);
    
        /**
         * POST 请求多参, 携带头部
         *
         * @param data
         * @param authorization
         * @return
         */
        @RequestLine("POST /testHeard/postHeard")
        @Headers({ "Content-Type: application/json", "Authorization: {authorization}"})
        CommonResult postHeard(@RequestBody TestEntity data, @Param("authorization") String authorization);
    }

package com.chaim.consumerserver.feignclien;
    
    import com.chaim.feignserver.config.FooConfiguration;
    import com.chaim.feignserver.service.HeaderService;
    import org.springframework.cloud.openfeign.FeignClient;
    
    /**
     * 如果报错: Request method ‘POST‘ not supported
     * 参考: https://blog.csdn.net/qq_38637558/article/details/115913345
     *
     * 当我们将契约改为 feign 原生的默认契约, 就无法使用类似 @RequestMapping 等注解.
     *
     * @author Chaim
     * @date 2021/4/19 20:50
     */
    @FeignClient(name = "provider", contextId = "headerProvider", configuration = FooConfiguration.class)
    public interface HeaderFeignClient extends HeaderService { 
    }

package com.chaim.feignserver.config;
    
    import feign.Contract;
    import org.springframework.context.annotation.Bean;
    
    /**
     * 详情见 Readme.md
     *
     * @author Chaim
     * @date 2021/4/19 10:59
     */
    //@Configurable
    public class FooConfiguration { 
    
        /**
         * 将契约改为 feign 原生的默认契约.
         * 可以使用feign自带的注解
         *
         * @return
         */
        @Bean
        public Contract feignContract() { 
            return new feign.Contract.Default();
        }
    
    //    /**
    //     * 指定日志
    //     * @return
    //     */
    //    @Bean
    //    Logger.Level feignLoggerLevel() { 
    //        return Logger.Level.FULL;
    //    }
    }

# 5、上传文件 #

package com.chaim.feignserver.service;
    
    import com.chaim.feignserver.util.CommonResult;
    import org.springframework.http.MediaType;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    import org.springframework.web.bind.annotation.RequestParam;
    import org.springframework.web.bind.annotation.RequestPart;
    import org.springframework.web.multipart.MultipartFile;
    
    /**
     * 上传文件需要注意两点
     * RequestPart(value = "file")
     * consumes = { MediaType.MULTIPART_FORM_DATA_VALUE}
     *
     * @author Chaim
     * @date 2021/4/22 18:23
     */
    public interface UploadService { 
    
        @RequestMapping(value = "/upload/postUpload", method = RequestMethod.POST, consumes = { MediaType.MULTIPART_FORM_DATA_VALUE})
        CommonResult postUpload(@RequestPart(value = "file") MultipartFile file,
                              @RequestParam(value = "id") String id);
    }

package com.chaim.consumerserver.feignclien;
    
    import com.chaim.feignserver.service.UploadService;
    import org.springframework.cloud.openfeign.FeignClient;
    
    /**
     * @author Chaim
     * @date 2021/4/22 18:30
     */
    @FeignClient(name = "provider", contextId = "uploadProvider")
    public interface UploadFeignClient extends UploadService { 
    }

# 6、下载文件 #

package com.chaim.feignserver.service;
    
    import feign.Response;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    
    /**
     * @author Chaim
     * @date 2021/4/22 20:35
     */
    public interface DownloadService { 
    
        @RequestMapping(value = "/download/postDownload", method = RequestMethod.POST)
        Response postDownload();
    }

package com.chaim.consumerserver.feignclien;
    
    import com.chaim.feignserver.service.DownloadService;
    import org.springframework.cloud.openfeign.FeignClient;
    
    /**
     * 远程 Feign 调用
     *
     * @author Chaim
     * @date 2021/4/19 17:28
     * @FeignClient: 表明是一个 feign 接口. name 微服务的名称
     */
    @FeignClient(name = "provider", contextId = "downloadProvider")
    public interface DownloadFeignClient extends DownloadService { 
    }

# 7、Body注解 #

package com.chaim.feignserver.service;
    
    import com.chaim.feignserver.DTO.TestEntity;
    import com.chaim.feignserver.util.CommonResult;
    import feign.*;
    
    /**
     * @author Chaim
     * @date 2021/4/25 19:53
     */
    public interface BodyService { 
    
        /**
         * BODY POST 请求 JSON 格式
         * { }需转义: {  == %7B , } == %7D
         * 必须指定@Headers, 请求参数个格式
         *
         * @param id
         * @param name
         * @return
         */
        @RequestLine("POST /testBody/postJSONBody")
        @Headers("Content-Type: application/json")
        @Body("%7B\"id\": \"{id}\", \"name\": \"{name}\"%7D")
        CommonResult postJSONBody(@Param("id") String id, @Param("name") String name);
    
        /**
         * BODY POST 请求 JSONString 格式
         *
         * @param testJSONString
         * @return
         */
        @RequestLine("POST /testBody/postJSONBody")
        @Headers("Content-Type: application/json")
        @Body("{testJSONString}")
        CommonResult postJSONStringBody(@Param("testJSONString") String testJSONString);
    
        /**
         * BODY POST 请求 JSONString 格式 + Restful 风格
         *
         * @param testJSONString
         * @param count
         * @return
         */
        @RequestLine("POST /testBody/jsonRestfulBody/{count}")
        @Headers("Content-Type: application/json")
        @Body("{testJSONString}")
        CommonResult jsonRestfulBody(@Param("testJSONString") String testJSONString, @Param(value = "count") String count);
    
        /**
         * BODY POST 请求 JSONString 格式 + key=value 风格
         *
         * @param testJSONString
         * @param testEntity
         * @return
         */
        @RequestLine("POST /testBody/postKeyValueParametersBody")
        @Headers("Content-Type: application/json")
        @Body("{testJSONString}")
        CommonResult postKeyValueParametersBody(@Param("testJSONString") String testJSONString, @QueryMap TestEntity testEntity);
    }

package com.chaim.consumerserver.feignclien;
    
    import com.chaim.feignserver.config.FooConfiguration;
    import com.chaim.feignserver.service.BodyService;
    import org.springframework.cloud.openfeign.FeignClient;
    
    /**
     * 如果报错: Request method ‘POST‘ not supported
     * 参考: https://blog.csdn.net/qq_38637558/article/details/115913345
     * <p>
     * 当我们将契约改为 feign 原生的默认契约, 就无法使用类似 @RequestMapping 等注解.
     *
     * @author Chaim
     * @date 2021/4/19 20:50
     */
    @FeignClient(name = "provider", contextId = "bodyProvider", configuration = FooConfiguration.class)
    public interface BodyFeignClient extends BodyService { 
    }

# 8、注意点 #

1、呕心沥血之作, 这里只是罗列了几种方法, 具体的实现, 大概可以到查看我上传的代码, 都有详细的说明  
  
2、代码中涉及到的一些问题, 已经在注释中, 以及MD文件中进行了说明, 大家可以将代码下载下来进行查看  
  
3、[代码地址][Link 1]： https://gitee.com/xmaxm/test-code  
  
4、因为我是采用的继承的特性, 虽然官方有明确的说明, 不推荐使用这种方法, 但是这种方法真的很香, 故@FeignClient注解都在对应的实现类, 大家可以下载代码查看, 很详细

5、openfeign对应的其余文章:

[代码地址以及对应的postman文件][Link 1]  
[Feign的使用示列–呕心沥血之作(1)][Feign_1]  
[Feign的@FeignClient详解–呕心沥血之作(2)][Feign_FeignClient_2]  
[Feign的默认契约注解详解–呕心沥血之作(3)][Feign_3]  
[Feign异常–Request method ‘POST‘ not supported][Feign_Request method _POST_ not supported]  
[Feign异常–A bean with that name | HTTP method type (ex. GET, POST)][Feign_A bean with that name _ HTTP method type _ex. GET_ POST]

[Link 1]: https://gitee.com/xmaxm/test-code
[Feign_1]: https://blog.csdn.net/qq_38637558/article/details/115866969
[Feign_FeignClient_2]: https://blog.csdn.net/qq_38637558/article/details/116130453
[Feign_3]: https://blog.csdn.net/qq_38637558/article/details/116140950
[Feign_Request method _POST_ not supported]: https://blog.csdn.net/qq_38637558/article/details/115913345
[Feign_A bean with that name _ HTTP method type _ex. GET_ POST]: https://blog.csdn.net/qq_38637558/article/details/116141025