SpringCloud中覆写Feign的默认配置

本文介绍了如何在SpringCloud中覆写Feign的默认配置,以使用feign.Contract.Default替换SpringMvcContract契约,并详细展示了创建工程、调用用户微服务以及访问Eureka中注册服务的步骤。主要内容包括配置FeignConfiguration类、定义UserFeignClient以及在MovieController中进行测试。此外,还讨论了在处理服务调用过程中遇到的问题及解决方案。

摘要生成于 C知道 ,由 DeepSeek-R1 满血版支持, 前往体验 >

创建工程



调用用户微服务



pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.itmuch.cloud</groupId>
  <artifactId>microservice-consumer-movie-feign-customizing</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <!-- 引入spring boot的依赖 -->
  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.4.3.RELEASE</version>
  </parent>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <java.version>1.8</java.version>
  </properties>

  <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-actuator</artifactId>
    </dependency>

    <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-starter-eureka</artifactId>
    </dependency>

    <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-starter-feign</artifactId>
    </dependency>
  </dependencies>

  <!-- 引入spring cloud的依赖 -->
  <dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-dependencies</artifactId>
        <version>Camden.SR4</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
    </dependencies>
  </dependencyManagement>

  <!-- 添加spring-boot的maven插件 -->
  <build>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>
    </plugins>
  </build>
</project>

说明:

1)加入依赖:

    <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-starter-feign</artifactId>
    </dependency>



application.yml
server:
  port: 8010
spring:
  application:
    name: microservice-consumer-movie
eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/
  instance:
    prefer-ip-address: true

说明:

    1)基本跟其他一样,不变;


User

package com.itmuch.cloud.study.user.entity;

import java.math.BigDecimal;

public class User {
  private Long id;
  private String username;
  private String name;
  private Integer age;
  private BigDecimal balance;

  public Long getId() {
    return this.id;
  }

  public void setId(Long id) {
    this.id = id;
  }

  public String getUsername() {
    return this.username;
  }

  public void setUsername(String username) {
    this.username = username;
  }

  public String getName() {
    return this.name;
  }

  public void setName(String name) {
    this.name = name;
  }

  public Integer getAge() {
    return this.age;
  }

  public void setAge(Integer age) {
    this.age = age;
  }

  public BigDecimal getBalance() {
    return this.balance;
  }

  public void setBalance(BigDecimal balance) {
    this.balance = balance;
  }
}

说明:

    1)用户实体;


FeignConfiguration

com.itmuch.cloud.config.FeignConfiguration

package com.itmuch.cloud.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import feign.Contract;

/**
 * 该类为Feign的配置类
 * 注意:该不应该在主应用程序上下文的@ComponentScan中。
 */
@Configuration
public class FeignConfiguration {
  /**
   * 将契约改为feign原生的默认契约。这样就可以使用feign自带的注解了。
   * 用feign.Contract.Default替换SpringMvcContract契约
   * @return 默认的feign契约
   */
  @Bean
  public Contract feignContract() {
    //Spring Cloud Netflix默认的SpringMvcController将替换为feign.Contract.Default。
    return new feign.Contract.Default();
  }
}

说明:

    1)该类为Feign的配置类;
    2)注意:该不应该在主应用程序上下文的@ComponentScan中。
    3)将契约改为feign原生的默认契约。这样就可以使用feign自带的注解了,用feign.Contract.Default替换  SpringMvcContract契约;





UserFeignClient

com.itmuch.cloud.study.user.feign.UserFeignClient

package com.itmuch.cloud.study.user.feign;

import org.springframework.cloud.netflix.feign.FeignClient;

import com.itmuch.cloud.config.FeignConfiguration;
import com.itmuch.cloud.study.user.entity.User;

import feign.Param;
import feign.RequestLine;

/**
 * 使用@FeignClient的configuration属性,指定feign的配置类。
 * 使用@FeignClient的configuration属性指定配置类,同时,将findById上的Spring MVC注解修改为Feign自带的注解。
 */
@FeignClient(name = "microservice-provider-user", configuration = FeignConfiguration.class)
public interface UserFeignClient {
  /**
   * 使用feign自带的注解@RequestLine
   * @see https://github.com/OpenFeign/feign
   * @param id 用户id
   * @return 用户信息
   */
  @RequestLine("GET /{id}")
  public User findById(@Param("id") Long id);
}

说明:
    1)使用@FeignClient的configuration属性,指定feign的配置类;
    2)同时,将findById上的Spring MVC注解修改为Feign自带的注解;
    3)使用feign自带的注解@RequestLine;




MovieController

com.itmuch.cloud.study.user.controller.MovieController

package com.itmuch.cloud.study.user.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

import com.itmuch.cloud.study.user.entity.User;
import com.itmuch.cloud.study.user.feign.UserFeignClient;

@RestController
public class MovieController {
  @Autowired
  private UserFeignClient userFeignClient;

  @GetMapping("/user/{id}")
  public User findById(@PathVariable Long id) {
    return this.userFeignClient.findById(id);
  }
}


测试

启动相关服务,略,具体前面其他文章,

http://localhost:8010/user/1



小结1

    1)SpringCloud中覆写Feign的默认配置,用feign.Contract.Default替换  SpringMvcContract契约;

    2)将findById上的Spring MVC注解修改为Feign自带的注解;



访问Eureka中注册的服务





FeignConfiguration2



package com.itmuch.cloud.config;

import feign.Contract;
import feign.auth.BasicAuthRequestInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * 该类为Feign的配置类
 * 注意:该不应该在主应用程序上下文的@ComponentScan中。
 */
@Configuration
public class FeignConfiguration2 {
  @Bean
  public BasicAuthRequestInterceptor basicAuthRequestInterceptor() {
    return new BasicAuthRequestInterceptor("user", "password123");
  }
}
说明:
    1)由于eureka设置了密码,所以需要认证,否则会报错;

    2)feign.FeignException:

          status 401 reading UserFeignClient2#findServiceInfoFromEurekaByServiceName(String); content:{"timestamp":1531228194010,"status":401,"error":"Unauthorized","message":"Bad credentials","path":"/eureka/apps/microservice-provider-user"}


UserFeignClient

package com.itmuch.cloud.study.user.feign;

import org.springframework.cloud.netflix.feign.FeignClient;

import com.itmuch.cloud.config.FeignConfiguration;
import com.itmuch.cloud.study.user.entity.User;

import feign.Param;
import feign.RequestLine;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

/**
 * 使用@FeignClient的configuration属性,指定feign的配置类。
 * 使用@FeignClient的configuration属性指定配置类,同时,将findById上的Spring MVC注解修改为Feign自带的注解。
 */
@FeignClient(name = "microservice-provider-user",   configuration = FeignConfiguration.class)
public interface UserFeignClient {
  /**
   * 使用feign自带的注解@RequestLine
   * @see https://github.com/OpenFeign/feign
   * @param id 用户id
   * @return 用户信息
   */
//  @RequestLine("GET /{id}")
//  public User findById(@Param("id") Long id);

  @RequestMapping(value="/{id}", method= RequestMethod.GET)
  public User findById(@PathVariable("id") Long id);
}

说明:
    1)报错java.lang.IllegalStateException: Method findById not annotated with HTTP method type (ex. GET, POST);
    2)处理方法,使用@RequestMapping(value="/{id}", method= RequestMethod.GET)即可;



UserFeignClient2

package com.itmuch.cloud.study.user.feign;

import com.itmuch.cloud.config.FeignConfiguration;
import com.itmuch.cloud.config.FeignConfiguration2;
import com.itmuch.cloud.study.user.entity.User;
import feign.Param;
import feign.RequestLine;
import org.springframework.cloud.netflix.feign.FeignClient;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * 使用@FeignClient的configuration属性,指定feign的配置类。
 * 使用@FeignClient的configuration属性指定配置类,同时,将findById上的Spring MVC注解修改为Feign自带的注解。
 */
@FeignClient(name = "microservice-provider-user",url="http://localhost:8761/", configuration = FeignConfiguration2.class)
public interface UserFeignClient2 {
  @RequestMapping(value = "/eureka/apps/{serviceName}")
  public String findServiceInfoFromEurekaByServiceName(@PathVariable("serviceName") String serviceName);
}

说明:

    1)这里需要加上url="http://localhost:8761/",要不访问会报错;



MovieController

package com.itmuch.cloud.study.user.controller;

import com.itmuch.cloud.study.user.feign.UserFeignClient2;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import com.itmuch.cloud.study.user.entity.User;
import com.itmuch.cloud.study.user.feign.UserFeignClient;

@RestController
public class MovieController {
  @Autowired
  private UserFeignClient userFeignClient;

  @Autowired
  private UserFeignClient2 userFeignClient2;


  @GetMapping("/user/{id}")
  public User findById(@PathVariable Long id) {
    return this.userFeignClient.findById(id);
  }

  @GetMapping("/{serviceName}")
  public String findServiceInfoFromEurekaByServiceName(@PathVariable String serviceName) {
    return this.userFeignClient2.findServiceInfoFromEurekaByServiceName(serviceName);
  }
}




测试


http://localhost:8761/eureka/apps/microservice-provider-user



http://localhost:8010/microservice-provider-user



小结2

    1)通过Feign的方式访问Eureka中注册的服务;







==============================

QQ群:143522604

欢迎和大家一起学习、交流、提升!

==============================


评论 1
添加红包

请填写红包祝福语或标题

红包个数最小为10个

红包金额最低5元

当前余额3.43前往充值 >
需支付:10.00
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值