openfeign配置和使用

背景

传统使用restTemplate来发送http请求，在springcloud大军下，基于完善自己的生态系统，springcloud开发自己的http组件openfeign，区别于restTemplate，openfeign基于接口注解编程。

使用时候，只需要定义自己的接口和标注对应openfeign注解即可发送http请求

使用方式

1 基于ip和端口、域名需添加属性url

2 只基于服务名，如ribbin，只需name即可

/**
 * @author yingcly003
 * @description: TODO
 */
@FeignClient(name = SERVICE_NAME , url = SERVICE_URL)
public interface TestFeignClient extends ITestApi {
}

/**
 * @version 1.0
 * @Author yingcly003
 * @Date 2019/12/4 9:10
 */
@RestController
@RequestMapping("/test/test1/test2")
@Validated
public class TestController {

    @Autowired
    private TestFeignClient testFeignClient;

    /**
     * 品牌列表
     *
     * @return
     */
    @GetMapping("/getAllBrand")
    @ApiOperation("品牌列表")
    public ReturnVo getAllBrand() throws Exception {
        ReturnVo returnVo = testFeignClient.getAllBrand();
        return returnVo;
    }

}

配置

1 pom配置，需要openfeign基础包，okhttp包提供http连接池，基础包不含有改功能

        
            org.springframework.cloud
            spring-cloud-starter-openfeign
            2.1.5.RELEASE
        
        
            io.github.openfeign
            feign-okhttp
            10.2.3
        

2 连接池配置和client配置

/**
 * 
 * date 2021/12/14 18:13
 */
@Configuration
@ConditionalOnClass(Feign.class)
@AutoConfigureBefore(FeignAutoConfiguration.class)
public class FeignOkHttpConfig {

    @Bean
    @ConditionalOnMissingBean({Client.class})
    public Client feignClient(okhttp3.OkHttpClient client) {
        return new feign.okhttp.OkHttpClient(client);
    }

    @Bean
    @ConditionalOnMissingBean({ConnectionPool.class}) //只允许只有一个ConnectionPool存在
    public ConnectionPool httpClientConnectionPool(FeignHttpClientProperties httpClientProperties, OkHttpClientConnectionPoolFactory connectionPoolFactory) {
        Integer maxTotalConnections = httpClientProperties.getMaxConnections();
        Long timeToLive = httpClientProperties.getTimeToLive();
        TimeUnit ttlUnit = httpClientProperties.getTimeToLiveUnit();
        return connectionPoolFactory.create(maxTotalConnections, timeToLive, ttlUnit);
    }

    @Bean
    public OkHttpClient client(OkHttpClientFactory httpClientFactory, ConnectionPool connectionPool, FeignHttpClientProperties httpClientProperties) {
        Boolean followRedirects = httpClientProperties.isFollowRedirects();
        Integer connectTimeout = httpClientProperties.getConnectionTimeout();
        Boolean disableSslValidation = httpClientProperties.isDisableSslValidation();
        return httpClientFactory.createBuilder(disableSslValidation)
                .connectTimeout((long) connectTimeout, TimeUnit.MILLISECONDS)
                .followRedirects(followRedirects)
                .connectionPool(connectionPool)
                //.addInterceptor(new OkHttpLogInterceptor()) // 自定义请求日志拦截器
                .build();
    }

}

3 其它Feign应用，给http增加头部参数，可实现RequestInterceptor

/**
 * 
 * date 2021/12/21 11:51
 */
@Component
public class FeignInterceptor implements RequestInterceptor {

    @Autowired
    private HttpServletRequest request;


    public void apply(RequestTemplate requestTemplate) {
        // 获取request请求中的 params[lang] 信息放到requestTemplate params里
        requestTemplate.query("lang", request.getHeader("lang"));
        requestTemplate.query("access_token", request.getHeader("access_token"));
        requestTemplate.query("client_ip", request.getHeader("client_ip"));
        requestTemplate.header("lang", request.getHeader("lang"));
        requestTemplate.header("access_token", request.getHeader("access_token"));
        requestTemplate.header("client_ip", request.getHeader("client_ip"));
        requestTemplate.header("User-Agent", "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.87 Safari/537.36");
//        requestTemplate.query("lang", request.getHeader("lang"));
//        requestTemplate.query("access_token", request.getHeader("access_token"));
    }

}