3.【Spring Cloud Alibaba】声明式HTTP客户端-Feign

drf认证组件、权限组件、jwt认证、签发、jwt框架使用

运用Feign完成长途HTTP挪用

什么是Feign

• Feign是Netflix开源的声明式HTTP客户端

完成

pom.xml

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

@MapperScan("com.itmuch.contentcenter.dao")
@SpringBootApplication
@EnableFeignClients// (defaultConfiguration = GlobalFeignConfiguration.class)
@EnableBinding({Source.class})
public class ContentCenterApplication {

@FeignClient(name = "user-center")
public interface UserCenterFeignClient {
    /**
     * http://user-center/users/{id}
     *
     * @param id
     * @return
     */
    @GetMapping("/users/{id}")
    UserDTO findById(@PathVariable Integer id);
}

private final UserCenterFeignClient userCenterFeignClient;

// 1. 代码不可读
// 2. 庞杂的url难以保护：https://user-center/s?ie={ie}&f={f}&rsv_bp=1&rsv_idx=1&tn=baidu&wd=a&rsv_pq=c86459bd002cfbaa&rsv_t=edb19hb%2BvO%2BTySu8dtmbl%2F9dCK%2FIgdyUX%2BxuFYuE0G08aHH5FkeP3n3BXxw&rqlang=cn&rsv_enter=1&rsv_sug3=1&rsv_sug2=0&inputT=611&rsv_sug4=611
// 3. 难以响应需求的变化，变化很没有幸福感
// 4. 编程体验不一致
UserDTO userDTO = this.userCenterFeignClient.findById(userId);

Feign的构成

细粒度设置自定义

• Java代码体式格局
• 设置属性要领

指定日记级别

Java代码体式格局

UserCenterFeignClient

@FeignClient(name = "user-center", configuration = GlobalFeignConfiguration.class)
public interface UserCenterFeignClient {
    /**
     * http://user-center/users/{id}
     *
     * @param id
     * @return
     */
    @GetMapping("/users/{id}")
    UserDTO findById(@PathVariable Integer id);
}

GlobalFeignConfiguration

/**
 * feign的设置类
 * 这个类别加@Configuration注解了，不然必需挪到@ComponentScan能扫描的包之外
 */
public class GlobalFeignConfiguration {
    @Bean
    public Logger.Level level(){
        // 让feign打印一切要求的细节
        return Logger.Level.FULL;
    }
}

application.yml

logging:
  level:
    com.itmuch.contentcenter.feignclient.UserCenterFeignClient: debug

设置属性要领

全局设置

• Java代码体式格局
• 设置属性体式格局

Java代码体式格局

ContentCenterApplication

EnableFeignClients

// 扫描mybatis哪些包内里的接口
@MapperScan("com.itmuch.contentcenter.dao")
@SpringBootApplication
@EnableFeignClients(defaultConfiguration = GlobalFeignConfiguration.class)
@EnableBinding({Source.class})
public class ContentCenterApplication {

/**
 * feign的设置类
 * 这个类别加@Configuration注解了，不然必需挪到@ComponentScan能扫描的包之外
 */
public class GlobalFeignConfiguration {
    @Bean
    public Logger.Level level(){
        // 让feign打印一切要求的细节
        return Logger.Level.FULL;
    }
}

设置属性体式格局

// 扫描mybatis哪些包内里的接口
@MapperScan("com.itmuch.contentcenter.dao")
@SpringBootApplication
@EnableFeignClients// (defaultConfiguration = GlobalFeignConfiguration.class)
@EnableBinding({Source.class})
public class ContentCenterApplication {

支撑的设置项

Java代码体式格局支撑的设置项

设置属性体式格局支撑的设置项

设置最好实践

Ribbon设置 VS Feign设置

Feign代码体式格局 vs 属性体式格局

最好实践

Feign的继续

关于继续的争议

• 官方看法：官方不引荐运用
• 业界看法：许多公司运用
• 个人看法：权衡利弊

多参数要求组织

Get要求

TestController

@GetMapping("test-get")
public UserDTO query(UserDTO userDTO) {
    return testUserCenterFeignClient.query(userDTO);
}

要领1

TestUserCenterFeignClient

import com.itmuch.contentcenter.domain.dto.user.UserDTO;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.cloud.openfeign.SpringQueryMap;
import org.springframework.web.bind.annotation.GetMapping;

@FeignClient(name = "user-center")
public interface TestUserCenterFeignClient {
    @GetMapping("/q")
    UserDTO query(@SpringQueryMap UserDTO userDTO);
}

要领二

@FeignClient(name = "user-center")
public interface UserFeignClient {
  @RequestMapping(value = "/q", method = RequestMethod.GET)
  public UserDTO query(@RequestParam("id") Long id, @RequestParam("username") String username);
}

POST要求包括多个参数

下面来议论怎样运用Feign组织包括多个参数的POST要求。假定效劳提供者的Controller是如许编写的：

@RestController
public class UserController {
  @PostMapping("/post")
  public User post(@RequestBody User user) {
    ...
  }
}

我们要怎样运用Feign去要求呢？答案异常简朴，示例：

@FeignClient(name = "microservice-provider-user")
public interface UserFeignClient {
  @RequestMapping(value = "/post", method = RequestMethod.POST)
  public User post(@RequestBody User user);
}

Feign离开Ribbon的运用

import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;

// 离开ribbon的运用
@FeignClient(name = "baidu", url = "http://www.baidu.com")
public interface TestBaiduFeignClient {
    @GetMapping("")
    String index();
}

RestTemplate vs Feign

Feign机能优化

• 连接池[提拔15%摆布]

feign:
  sentinel:

    # 为feign整合sentinel
    enabled: true
  client:
    config:
      # 全局设置
      default:
        loggerLevel: full
        requestInterceptors:
          - com.itmuch.contentcenter.feignclient.interceptor.TokenRelayRequestIntecepor
  httpclient:
    # 让feign运用apache httpclient做要求；而不是默许的urlconnection
    enabled: true
    # feign的最大连接数
    max-connections: 200
    # feign单个途径的最大连接数
    max-connections-per-route: 50

现在，在Spring cloud中效劳之间经由过程restful体式格局挪用有两种体式格局

• restTemplate+Ribbon
• feign

从实践上看，采纳feign的体式格局更文雅（feign内部也运用了ribbon做负载平衡）。

分析思维 第四篇：数据分析入门阶段——描述性统计分析和相关分析