SpringBoot 配置 okhttp3的操作

1. Maven 添加依赖

<dependency>
 <groupId>com.squareup.okhttp3</groupId>
 <artifactId>okhttp</artifactId>
 <version>3.10.0</version>
</dependency>

2. application.properties 配置文件

ok.http.connect-timeout=30
ok.http.read-timeout=30
ok.http.write-timeout=30
# 连接池中整体的空闲连接的最大数量
ok.http.max-idle-connections=200
# 连接空闲时间最多为 300 秒
ok.http.keep-alive-duration=300

3. OkHttpConfiguration 配置类

import okhttp3.ConnectionPool;
import okhttp3.OkHttpClient;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import javax.net.ssl.*;
import java.security.*;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;
import java.util.concurrent.TimeUnit;
/**
 * @author Answer.AI.L
 * @date 2019-04-09
 */
@Configuration
public class OkHttpConfiguration {
 @Value("${ok.http.connect-timeout}")
 private Integer connectTimeout;
 @Value("${ok.http.read-timeout}")
 private Integer readTimeout;
 @Value("${ok.http.write-timeout}")
 private Integer writeTimeout;
 @Value("${ok.http.max-idle-connections}")
 private Integer maxIdleConnections;
 @Value("${ok.http.keep-alive-duration}")
 private Long keepAliveDuration;
 @Bean
 public OkHttpClient okHttpClient() {
  return new OkHttpClient.Builder()
    .sslSocketFactory(sslSocketFactory(), x509TrustManager())
    // 是否开启缓存
    .retryOnConnectionFailure(false)
    .connectionPool(pool())
    .connectTimeout(connectTimeout, TimeUnit.SECONDS)
    .readTimeout(readTimeout, TimeUnit.SECONDS)
    .writeTimeout(writeTimeout,TimeUnit.SECONDS)
   	.hostnameVerifier((hostname, session) -> true)
   	// 设置代理
//   	.proxy(new Proxy(Proxy.Type.HTTP, new InetSocketAddress("127.0.0.1", 8888)))
    // 拦截器
//    .addInterceptor()
    .build();
 }
 @Bean
 public X509TrustManager x509TrustManager() {
  return new X509TrustManager() {
   @Override
   public void checkClientTrusted(X509Certificate[] chain, String authType)
     throws CertificateException {
   }
   @Override
   public void checkServerTrusted(X509Certificate[] chain, String authType)
     throws CertificateException {
   }
   @Override
   public X509Certificate[] getAcceptedIssuers() {
    return new X509Certificate[0];
   }
  };
 }
 @Bean
 public SSLSocketFactory sslSocketFactory() {
  try {
   // 信任任何链接
   SSLContext sslContext = SSLContext.getInstance("TLS");
   sslContext.init(null, new TrustManager[]{x509TrustManager()}, new SecureRandom());
   return sslContext.getSocketFactory();
  } catch (NoSuchAlgorithmException | KeyManagementException e) {
   e.printStackTrace();
  }
  return null;
 }
 @Bean
 public ConnectionPool pool() {
  return new ConnectionPool(maxIdleConnections, keepAliveDuration, TimeUnit.SECONDS);
 }
}

4. OkHttp 类

import lombok.extern.slf4j.Slf4j;
import okhttp3.*;
import org.apache.commons.lang3.exception.ExceptionUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import java.util.Map;
/**
 * @author Answer.AI.L
 * @date 2019-04-09
 */
@Slf4j
@Component
public class OkHttpCli {
 private static final MediaType JSON = MediaType.parse("application/json; charset=utf-8");
 private static final MediaType XML = MediaType.parse("application/xml; charset=utf-8");
 @Autowired
 private OkHttpClient okHttpClient;
 /**
  * get 请求
  * @param url  请求url地址
  * @return string
  * */
 public String doGet(String url) {
  return doGet(url, null, null);
 }
 /**
  * get 请求
  * @param url  请求url地址
  * @param params 请求参数 map
  * @return string
  * */
 public String doGet(String url, Map<String, String> params) {
  return doGet(url, params, null);
 }
 /**
  * get 请求
  * @param url  请求url地址
  * @param headers 请求头字段 {k1, v1 k2, v2, ...}
  * @return string
  * */
 public String doGet(String url, String[] headers) {
  return doGet(url, null, headers);
 }
 /**
  * get 请求
  * @param url  请求url地址
  * @param params 请求参数 map
  * @param headers 请求头字段 {k1, v1 k2, v2, ...}
  * @return string
  * */
 public String doGet(String url, Map<String, String> params, String[] headers) {
  StringBuilder sb = new StringBuilder(url);
  if (params != null && params.keySet().size() > 0) {
   boolean firstFlag = true;
   for (String key : params.keySet()) {
    if (firstFlag) {
     sb.append("?").append(key).append("=").append(params.get(key));
     firstFlag = false;
    } else {
     sb.append("&").append(key).append("=").append(params.get(key));
    }
   }
  }
  Request.Builder builder = new Request.Builder();
  if (headers != null && headers.length > 0) {
   if (headers.length % 2 == 0) {
    for (int i = 0; i < headers.length; i = i + 2) {
     builder.addHeader(headers[i], headers[i + 1]);
    }
   } else {
    log.warn("headers's length[{}] is error.", headers.length);
   }
  }
  Request request = builder.url(sb.toString()).build();
  log.info("do get request and url[{}]", sb.toString());
  return execute(request);
 }
 /**
  * post 请求
  * @param url  请求url地址
  * @param params 请求参数 map
  * @return string
  */
 public String doPost(String url, Map<String, String> params) {
  FormBody.Builder builder = new FormBody.Builder();
  if (params != null && params.keySet().size() > 0) {
   for (String key : params.keySet()) {
    builder.add(key, params.get(key));
   }
  }
  Request request = new Request.Builder().url(url).post(builder.build()).build();
  log.info("do post request and url[{}]", url);
  return execute(request);
 }
 /**
  * post 请求, 请求数据为 json 的字符串
  * @param url  请求url地址
  * @param json  请求数据, json 字符串
  * @return string
  */
 public String doPostJson(String url, String json) {
  log.info("do post request and url[{}]", url);
  return exectePost(url, json, JSON);
 }
 /**
  * post 请求, 请求数据为 xml 的字符串
  * @param url  请求url地址
  * @param xml  请求数据, xml 字符串
  * @return string
  */
 public String doPostXml(String url, String xml) {
  log.info("do post request and url[{}]", url);
  return exectePost(url, xml, XML);
 }
 private String exectePost(String url, String data, MediaType contentType) {
  RequestBody requestBody = RequestBody.create(contentType, data);
  Request request = new Request.Builder().url(url).post(requestBody).build();
  return execute(request);
 }
 private String execute(Request request) {
  Response response = null;
  try {
   response = okHttpClient.newCall(request).execute();
   if (response.isSuccessful()) {
    return response.body().string();
   }
  } catch (Exception e) {
   log.error(ExceptionUtils.getStackTrace(e));
  } finally {
   if (response != null) {
    response.close();
   }
  }
  return "";
 }
}

5. 使用验证

@RestController
public class AnswerController {
 @Autowired
 private OkHttpCli okHttpCli;

 @RequestMapping(value = "show", method = RequestMethod.GET)
 public String show() {
  String url = "https://www.baidu.com/";
 String message = okHttpCli.doGet(url);
  return message;
 }

}

6. 双向认证(待证)

@Bean
public SSLSocketFactory sslSocketFactory() {
 String certPath = "";
 String caPath = "";
 String certPwd = "";
 String caPwd = "";
 try {
  ClassPathResource selfcertPath = new ClassPathResource(certPath);
  ClassPathResource trustcaPath = new ClassPathResource(caPath);
  KeyStore selfCert = KeyStore.getInstance("pkcs12");
  selfCert.load(selfcertPath.getInputStream(), certPwd.toCharArray());
  KeyManagerFactory kmf = KeyManagerFactory.getInstance("sunx509");
  kmf.init(selfCert, certPwd.toCharArray());
  KeyStore caCert = KeyStore.getInstance("jks");
  caCert.load(trustcaPath.getInputStream(), caPwd.toCharArray());
  TrustManagerFactory tmf = TrustManagerFactory.getInstance("sunx509");
  tmf.init(caCert);
  SSLContext sslContext = SSLContext.getInstance("TLS");
  sslContext.init(kmf.getKeyManagers(), tmf.getTrustManagers(), null);
  return sslContext.getSocketFactory();
 } catch (Exception e) {
  e.printStackTrace();
 }
 return null;
}

补充：Spring Cloud Feign 总结问题，注意点，性能调优，切换okhttp3

Feign常见问题总结

FeignClient接口如使用@PathVariable ，必须指定value属性

//在一些早期版本中， @PathVariable("id") 中的 "id" ，也就是value属性，必须指定，不能省略。
@FeignClient("microservice-provider-user")
public interface UserFeignClient {
 @RequestMapping(value = "/simple/{id}", method = RequestMethod.GET)
 public User findById(@PathVariable("id") Long id);
 ...
}

Java代码自定义Feign Client的注意点与坑

@FeignClient(name = "microservice-provider-user", configuration = UserFeignConfig.class)
public interface UserFeignClient {
 @GetMapping("/users/{id}")
 User findById(@PathVariable("id") Long id);
}
/**
 * 该Feign Client的配置类，注意：
 * 1. 该类可以独立出去；
 * 2. 该类上也可添加@Configuration声明是一个配置类；
 * 配置类上也可添加@Configuration注解，声明这是一个配置类；
 * 但此时千万别将该放置在主应用程序上下文@ComponentScan所扫描的包中，
 * 否则，该配置将会被所有Feign Client共享，无法实现细粒度配置！
 * 个人建议：像我一样，不加@Configuration注解
 *
 * @author zhouli
 */
class UserFeignConfig {
 @Bean
 public Logger.Level logger() {
 return Logger.Level.FULL;
 }
}

配置类上也可添加@Configuraiton 注解，声明这是一个配置类；但此时千万别将该放置在主应用程序上下文@ComponentScan 所扫描的包中，否则，该配置将会被所有Feign Client共享（相当于变成了通用配置，其实本质还是Spring父子上下文扫描包重叠导致的问题），无法实现细粒度配置！

个人建议：像我一样，不加@Configuration注解，省得进坑。

最佳实践：尽量用配置属性自定义Feign的配置！！！

@FeignClient 注解属性

//@FeignClient(name = "microservice-provider-user")
//在早期的Spring Cloud版本中，无需提供name属性，从Brixton版开始，@FeignClient必须提供name属性，否则应用将无法正常启动！
//另外，name、url等属性支持占位符。例如：
@FeignClient(name = "${feign.name}", url = "${feign.url}")

类级别的@RequestMapping会被Spring MVC加载

@RequestMapping("/users")
@FeignClient(name = "microservice-user")
public class TestFeignClient {
 // ...
}

类上的@RequestMapping 注解也会被Spring MVC加载。该问题现已经被解决，早期的版本有两种解决方案：方案1：不在类上加@RequestMapping 注解；方案2：添加如下代码：

@Configuration
@ConditionalOnClass({ Feign.class })
public class FeignMappingDefaultConfiguration {
 @Bean
 public WebMvcRegistrations feignWebRegistrations() {
  return new WebMvcRegistrationsAdapter() {
   @Override
   public RequestMappingHandlerMapping getRequestMappingHandlerMapping() {
    return new FeignFilterRequestMappingHandlerMapping();
   }
  };
 }
 private static class FeignFilterRequestMappingHandlerMapping extends RequestMappingHandlerMapping {
  @Override
  protected boolean isHandler(Class<?> beanType) {
   return super.isHandler(beanType) && !beanType.isInterface();
  }
 }
}

首次请求失败Ribbon的饥饿加载(eager-load)模式

如需产生Hystrix Stream监控信息，需要做一些额外操作Feign本身已经整合了Hystrix，可直接使用@FeignClient(value = "microservice-provider-user", fallback = XXX.class) 来指定fallback类，fallback类继承@FeignClient所标注的接口即可。

但是假设如需使用Hystrix Stream进行监控，默认情况下，访问http://IP:PORT/actuator/hystrix.stream 是会返回404，这是因为Feign虽然整合了Hystrix，但并没有整合Hystrix的监控。如何添加监控支持呢？需要以下几步：

第一步：添加依赖，示例：

<!-- 整合hystrix，其实feign中自带了hystrix，引入该依赖主要是为了使用其中的hystrix-metrics-event-stream，用于dashboard -->
<dependency>
 <groupId>org.springframework.cloud</groupId>
 <artifactId>spring-cloud-starter-hystrix</artifactId>
</dependency>

第二步：在启动类上添加@EnableCircuitBreaker 注解，示例：

@SpringBootApplication
@EnableFeignClients
@EnableDiscoveryClient
@EnableCircuitBreaker
public class MovieFeignHystrixApplication {
 public static void main(String[] args) {
 SpringApplication.run(MovieFeignHystrixApplication.class, args);
 }
}

第三步：在application.yml中添加如下内容，暴露hystrix.stream端点：

management:
 endpoints:
 web:
  exposure:
  include: 'hystrix.stream'

这样，访问任意Feign Client接口的API后，再访问http://IP:PORT/actuator/hystrix.stream ，就会展示一大堆Hystrix监控数据了。

Feign 上传文件

加依赖

<dependency>
 <groupId>io.github.openfeign.form</groupId>
 <artifactId>feign-form</artifactId>
 <version>3.0.3</version>
</dependency>
<dependency>
 <groupId>io.github.openfeign.form</groupId>
 <artifactId>feign-form-spring</artifactId>
 <version>3.0.3</version>
</dependency>

编写Feign Client

@FeignClient(name = "ms-content-sample", configuration = UploadFeignClient.MultipartSupportConfig.class)
public interface UploadFeignClient {
 @RequestMapping(value = "/upload", method = RequestMethod.POST,
   produces = {MediaType.APPLICATION_JSON_UTF8_VALUE},
   consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
 @ResponseBody
 String handleFileUpload(@RequestPart(value = "file") MultipartFile file);
 class MultipartSupportConfig {
  @Bean
  public Encoder feignFormEncoder() {
   return new SpringFormEncoder();
  }
 }
}

如代码所示，在这个Feign Client中，我们引用了配置类MultipartSupportConfig ，在MultipartSupportConfig 中，我们实例化了SpringFormEncoder 。这样这个Feign Client就能够上传啦。

注意点

//RequestMapping注解中的produeces 、consumes 不能少；
@RequestMapping(value = "/upload", method = RequestMethod.POST,
   produces = {MediaType.APPLICATION_JSON_UTF8_VALUE},
   consumes = MediaType.MULTIPART_FORM_DATA_VALUE)

接口定义中的注解@RequestPart(value = "file") 不能写成@RequestParam(value = "file"） 。

最好将Hystrix的超时时间设长一点，例如5秒，否则可能文件还没上传完，Hystrix就超时了，从而导致客户端侧的报错。

Feign实现Form表单提交

添加依赖：

<dependency>
 <groupId>io.github.openfeign.form</groupId>
 <artifactId>feign-form</artifactId>
 <version>3.2.2</version>
</dependency>
<dependency>
 <groupId>io.github.openfeign.form</groupId>
 <artifactId>feign-form-spring</artifactId>
 <version>3.2.2</version>
</dependency>

Feign Client示例：

@FeignClient(name = "xxx", url = "http://www.itmuch.com/", configuration = TestFeignClient.FormSupportConfig.class)
public interface TestFeignClient {
 @PostMapping(value = "/test",
   consumes = {MediaType.APPLICATION_FORM_URLENCODED_VALUE},
   produces = {MediaType.APPLICATION_JSON_UTF8_VALUE}
   )
 void post(Map<String, ?> queryParam);
 class FormSupportConfig {
  @Autowired
  private ObjectFactory<HttpMessageConverters> messageConverters;
  // new一个form编码器，实现支持form表单提交
  @Bean
  public Encoder feignFormEncoder() {
   return new SpringFormEncoder(new SpringEncoder(messageConverters));
  }
  // 开启Feign的日志
  @Bean
  public Logger.Level logger() {
   return Logger.Level.FULL;
  }
 }
}

调用示例：

@GetMapping("/user/{id}")
public User findById(@PathVariable Long id) {
 HashMap<String, String> param = Maps.newHashMap();
 param.put("username","zhangsan");
 param.put("password","pwd");
 this.testFeignClient.post(param);
 return new User();
}

日志：

...[TestFeignClient#post] ---> POST http://www.baidu.com/test HTTP/1.1
...[TestFeignClient#post] Accept: application/json;charset=UTF-8
...[TestFeignClient#post] Content-Type: application/x-www-form-urlencoded; charset=UTF-8
...[TestFeignClient#post] Content-Length: 30
...[TestFeignClient#post]
...[TestFeignClient#post] password=pwd&username=zhangsan
...[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。

Feign GET请求如何构造多参数

假设需请求的URL包含多个参数，例如http://microservice-provider-user/get?id=1&username=张三 ，该如何使用Feign构造呢？我们知道，Spring Cloud为Feign添加了Spring MVC的注解支持，那么我们不妨按照Spring MVC的写法尝试一下：

@FeignClient("microservice-provider-user")
public interface UserFeignClient {
 @RequestMapping(value = "/get", method = RequestMethod.GET)
 public User get0(User user);
}

然而，这种写法并不正确，控制台会输出类似如下的异常。

feign.FeignException: status 405 reading UserFeignClient#get0(User); content:
{"timestamp":1482676142940,"status":405,"error":"Method Not Allowed","exception":"org.springframework.web.HttpRequestMethodNotSupportedException","message":"Request method 'POST' not supported","path":"/get"}

由异常可知，尽管我们指定了GET方法，Feign依然会使用POST方法发送请求。于是导致了异常。正确写法如下

方法一[推荐]注意:使用该方法无法使用Fegin的继承模式

@FeignClient("microservice-provider-user")
public interface UserFeignClient {
 @GetMapping("/get")
 public User get0(@SpringQueryMap User user);
}

方法二[推荐]

@FeignClient(name = "microservice-provider-user")
public interface UserFeignClient {
 @RequestMapping(value = "/get", method = RequestMethod.GET)
 public User get1(@RequestParam("id") Long id, @RequestParam("username") String username);
}

这是最为直观的方式，URL有几个参数，Feign接口中的方法就有几个参数。使用@RequestParam注解指定请求的参数是什么。

方法三[不推荐]多参数的URL也可使用Map来构建。当目标URL参数非常多的时候，可使用这种方式简化Feign接口的编写。

@FeignClient(name = "microservice-provider-user")
public interface UserFeignClient {
 @RequestMapping(value = "/get", method = RequestMethod.GET)
 public User get2(@RequestParam Map<String, Object> map);
}

在调用时，可使用类似以下的代码。

public User get(String username, String password) {
 HashMap<String, Object> map = Maps.newHashMap();
 map.put("id", "1");
 map.put("username", "张三");
 return this.userFeignClient.get2(map);
}

注意：这种方式不建议使用。主要是因为可读性不好，而且如果参数为空的时候会有一些问题，例如map.put("username", null); 会导致服务调用方（消费者服务）接收到的username是"" ，而不是null。

切换为 Okhttp3 提升 QPS 性能优化

加依赖引入okhttp3

<dependency>
 <groupId>io.github.openfeign</groupId>
 <artifactId>feign-okhttp</artifactId>
 <version>${version}</version>
</dependency>

写配置

feign:
 # feign启用hystrix，才能熔断、降级
 # hystrix:
 # enabled: true
 # 启用 okhttp 关闭默认 httpclient
 httpclient:
 enabled: false #关闭httpclient
 # 配置连接池
 max-connections: 200 #feign的最大连接数
 max-connections-per-route: 50 #fegin单个路径的最大连接数
 okhttp:
 enabled: true
 # 请求与响应的压缩以提高通信效率
 compression:
 request:
  enabled: true
  min-request-size: 2048
  mime-types: text/xml,application/xml,application/json
 response:
  enabled: true

参数配置

/**
 * 配置 okhttp 与连接池
 * ConnectionPool 默认创建5个线程，保持5分钟长连接
 */
@Configuration
@ConditionalOnClass(Feign.class)
@AutoConfigureBefore(FeignAutoConfiguration.class) //SpringBoot自动配置
public class OkHttpConfig {
 // 默认老外留给你彩蛋中文乱码，加上它就 OK
 @Bean
 public Encoder encoder() {
  return new FormEncoder();
 }
 @Bean
 public okhttp3.OkHttpClient okHttpClient() {
  return new okhttp3.OkHttpClient.Builder()
    //设置连接超时
    .connectTimeout(10, TimeUnit.SECONDS)
    //设置读超时
    .readTimeout(10, TimeUnit.SECONDS)
    //设置写超时
    .writeTimeout(10, TimeUnit.SECONDS)
    //是否自动重连
    .retryOnConnectionFailure(true)
    .connectionPool(new ConnectionPool(10, 5L, TimeUnit.MINUTES))
    .build();
 }
}

以上为个人经验，希望能给大家一个参考，也希望大家多多支持我们。如有错误或未考虑完全的地方，望不吝赐教。