feign__0">feign 配置

1. 针对单个feign接口进行配置

   feign:
     client:
       config:
         # feignName 注意这里与contextId一致，不能写成name（FeignClientFactoryBean#configureFeign）
         # 不能写成 client-b (微服务名称)，否则不生效
         helloFeignClient: # contextId
           connectTimeout: 50000 # 连接超时时间
           readTimeout: 50000 # 读超时时间
           loggerLevel: full #配置Feign的日志级别
         #default:
           # 其他默认配置
   

2. feign 全局默认配置

   feign:
     client:
       config:
         default:
           connectTimeout: 50000 # 连接超时时间
           readTimeout: 50000 # 读超时时间
           loggerLevel: full #配置Feign的日志级别
   

3. feign开启gzip支持

   feign:
     compression:
       request:
         enabled: true
         mime-types: "text/xml, application/xml, application/json"
         min-request-size: 2048
       response:
         enabled: true # 配置相应GZIP压缩
   

开启gzip支持后接口调用处理方式一

1. feign接口使用ResponseEntity<byte []>接收数据

   java">@FeignClient(contextId = "testFeignClient", 
           name = "client-a", configuration = FeignConfig.class)
   public interface TestFeignClient {
       @GetMapping(value = "/userInfo")
       ResponseEntity<byte []> userInfoCompress(
               @RequestParam("username") String username, @RequestParam("address") String address) ;
   }
   

2. 编写单元测试（注意需要对byte[] 数组使用Gzip解压）

   java">@Slf4j
   public class TestFeignClientTest extends BaseJunitTest {
       @Autowired
       private TestFeignClient testFeignClient ;
       @Test
       public void userInfoCompress() throws IOException {
           String username = "张三" ;
           String address = "北京" ;
           ResponseEntity<byte[]> responseEntity = testFeignClient.userInfoCompress(username, address);
           byte[] compressed = responseEntity.getBody();
           String decompressValue = GzipUtils.decompress(compressed);
           log.info("value : {}", decompressValue);
       }
   }
   

3. 编写gzip解压缩工具类

   java">public final class GzipUtils {
       public static String decompress(byte [] compressed) throws IOException {
           final StringBuilder output = new StringBuilder() ;
           try(GZIPInputStream gis = new GZIPInputStream(new ByteArrayInputStream(compressed));
               BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(gis, StandardCharsets.UTF_8))){
               String line ;
               while ((line = bufferedReader.readLine()) != null){
                   output.append(line) ;
               }
               return output.toString() ;
           }
       }
   }
   

开启gzip支持后接口调用处理方式二

1. 编写Decoder （内部使用方式一的Gzip解压缩工具类GzipUtils）

   java">public class FeignResponseDecoder implements Decoder {
       private final Decoder delegate;
       public FeignResponseDecoder(Decoder delegate) {
           Objects.requireNonNull(delegate, "Decoder must not be null. ");
           this.delegate = delegate;
       }
       @Override
       public Object decode(Response response, Type type) throws IOException {
           Collection<String> values = response.headers().get(HttpEncoding.CONTENT_ENCODING_HEADER);
           if (Objects.nonNull(values) && !values.isEmpty() && values.contains(HttpEncoding.GZIP_ENCODING)) {
               byte[] compressed = Util.toByteArray(response.body().asInputStream());
               if ((compressed == null) || (compressed.length == 0)) {
                   return delegate.decode(response, type);
               }
               //decompression part
               //after decompress we are delegating the decompressed response to default
               //decoder
               if (isCompressed(compressed)) {
                   String decompressValue = GzipUtils.decompress(compressed);
                   Response decompressedResponse = response.toBuilder().body(decompressValue.getBytes()).build();
                   return delegate.decode(decompressedResponse, type);
               } else {
                   return delegate.decode(response, type);
               }
           } else {
               return delegate.decode(response, type);
           }
       }
       private static boolean isCompressed(final byte[] compressed) {
           return (compressed[0] == (byte) (GZIPInputStream.GZIP_MAGIC)) && (compressed[1] == (byte) (GZIPInputStream.GZIP_MAGIC >> 8));
       }
   }
   

2. 将Decoder加入到Spring容器管理

   java">@Configuration
   public class AppConfig{
      @Bean
      public Decoder GZIPResponseDecoder(ObjectFactory<HttpMessageConverters> messageConverters) {
         Decoder decoder = new FeignResponseDecoder(new SpringDecoder(messageConverters));
         return decoder;
      }
   }
   

3. feign接口使用普通java对象接收数据

   java">@FeignClient(contextId = "testFeignClient", 
           name = "client-a", configuration = FeignConfig.class)
   public interface TestFeignClient {
       @GetMapping("/userInfo")
       UserInfoVO userInfo(@RequestParam("username") String username, @RequestParam("address") String address) ;
   }
   

4. 编写单元测试

   java">@Slf4j
   public class TestFeignClientTest extends BaseJunitTest {
       @Autowired
       private TestFeignClient testFeignClient ;
       
       @Test
       public void userInfo(){
           String username = "张三" ;
           String address = "北京" ;
           UserInfoVO userInfo = testFeignClient.userInfo(username, address);
           log.info("user info : {}", userInfo);
       }
   }
   

其他知识点补充

1. SpringBoot服务提供者开启gizp压缩

   server:
     port: 7070
     compression:
       enabled: true