OpenFeign配置代理调用

通常我们在写爬虫时候，为了规避目标网站限制通常采用代理方式调用，普遍的做法是通过定时任务去一些免费代理网站获取代理服务IP+Port，远程调用时候通过循环可用的代理去抓取目标网站内容；

OpenFeign配置代理服务器的步骤总结如下：

1. OpenFeign使用方式：见之前文章@FeignClient中的fallbackFactory，fallback不起作用的正确使用示例
2. application.yml添加配置，采用okhttp方式远程调用

feign:
  httpclient:
    enabled: false
  okhttp:
    enabled: true

3. pom.xml配置增加

	<dependency>
            <groupId>io.github.openfeign</groupId>
            <artifactId>feign-okhttp</artifactId>
        </dependency>
	<dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>

4. Feign自动化配置增加如下代码

    @Bean
    public OkHttpClientFactory okHttpClientFactory(OkHttpClient.Builder builder) {
        return new ProxyOkHttpClientFactory(builder);
    }
    
    static class ProxyOkHttpClientFactory extends DefaultOkHttpClientFactory {
        
        public ProxyOkHttpClientFactory(OkHttpClient.Builder builder) {
            super(builder);
            //配置IP、端口
            Proxy proxy = new Proxy(Proxy.Type.HTTP, new InetSocketAddress("222.162.185.176", 4524));
            builder.proxy(proxy);
            /*
            builder.proxyAuthenticator(new Authenticator() {
                @Override
                public Request authenticate(Route route, Response response) throws IOException {
                    //设置代理服务器账号密码
                    String credential = Credentials.basic("admin", "admin");
                    return response.request().newBuilder()
                            .header("Proxy-Authorization", credential)
                            .build();
                }
            });*/
            //如果要配置限制域则加上下面
            /*List<Proxy> proxyList = new ArrayList<>(1);
            proxyList.add(proxy);
            builder.proxySelector(new ProxySelector() {
                //限制域
                Set<String> domainList;
                @Override
                public List<Proxy> select(URI uri) {
                    if (uri == null || !domainList.contains(uri.getHost())) {
                        return Collections.singletonList(Proxy.NO_PROXY);
                    }
                    return proxyList;
                }
                @Override
                public void connectFailed(URI uri, SocketAddress sa, IOException ioe) {
                }
            });*/
        }
    }

5. 将自己的代理服务器ip+port替换即可；关于如何寻找高质量免费的代理有时间单独更新一篇博文总结一下；