Feign声明式HTTP客户端
2021-09-25 本文已影响0人
WebGiser
1、项目结构
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2、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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.13.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.geovis</groupId>
<artifactId>usercenter</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>usercenter</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencyManagement>
<!--SpringBoot整合Spring Cloud-->
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Greenwich.SR1</version>
<type>pom</type>
<scope>import</scope>
</dependency>
<!--SpringBoot整合Spring Cloud Alibaba-->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-alibaba-dependencies</artifactId>
<version>0.9.0.RELEASE</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!--服务发现依赖-->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>
<!--openfeign 声明式http调用-->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>
<dependency>
<groupId>io.github.openfeign</groupId>
<artifactId>feign-httpclient</artifactId>
</dependency>
<!-- <dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.2.0</version>
</dependency>-->
<!--通用mapper依赖-->
<dependency>
<groupId>tk.mybatis</groupId>
<artifactId>mapper-spring-boot-starter</artifactId>
<version>2.1.5</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<jvmArguments>-Dfile.encoding=UTF-8</jvmArguments>
</configuration>
</plugin>
<plugin>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-maven-plugin</artifactId>
<version>1.3.6</version>
<configuration>
<configurationFile>
${basedir}/src/main/resources/generator/generatorConfig.xml
</configurationFile>
<overwrite>true</overwrite>
<verbose>true</verbose>
</configuration>
<dependencies>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.19</version>
</dependency>
<dependency>
<groupId>tk.mybatis</groupId>
<artifactId>mapper</artifactId>
<version>4.1.5</version>
</dependency>
</dependencies>
</plugin>
</plugins>
</build>
</project>
3、UsercenterApplication.java主类
package com.geovis.usercenter;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.cloud.openfeign.EnableFeignClients;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;
import tk.mybatis.spring.annotation.MapperScan;
@EnableFeignClients
@MapperScan("com.geovis.usercenter")
@SpringBootApplication
public class UsercenterApplication {
public static void main(String[] args) {
SpringApplication.run(UsercenterApplication.class, args);
}
}
4、application.properties
server.port=8080
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://192.168.1.13:3306/user_center?characterEncoding=UTF8&serverTimezone=GMT%2B8
spring.datasource.username=root
spring.datasource.password=123456
# 服务名称尽量用-，不要用_或特殊字符
spring.application.name=user-center
# nacos服务中心地址
spring.cloud.nacos.discovery.server-addr=localhost:8848
# 指定微服务实例所在的命名空间ID
spring.cloud.nacos.discovery.namespace=476e087f-6df4-499a-af4c-9dc933293655
# 指定微服务实例所在的集群名称
spring.cloud.nacos.discovery.cluster-name=NanJing
# ribbon负载均衡细粒度控制
# 饥饿加载(解决第一次访问缓慢问题)
ribbon.eager-load.enabled=true
ribbon.eager-load.clients=content-center
# 局部配置
content-center.ribbon.NFLoadBalanceRuleClassName=com.geovis.usercenter.configuration.NacosWeightedRule
# feign
# feign日志配置（NONE、BASIC、HEADERS、FULL）
logging.level.com.geovis.usercenter.feignclient.ContentCenterFeignClient = debug
# 让feign使用apache httpclient请求，而不是默认的urlconnection
feign.httpclient.enabled=true
# feign的最大连接数
feign.httpclient.max-connections=200
# feign单个路径的最大连接数
feign.httpclient.max-connections-per-route=50
# 采用配置文件的方式控制feign的日志级别
#feign.client.config.content-center.loggerLevel = basic
5、configuration/ContentCenterFeignConfiguration.java
java代码方式细粒度控制 feign日志级别
package com.geovis.usercenter.configuration;
import feign.Logger;
import org.springframework.context.annotation.Bean;
/*
* 设置feign的日志级别：NONE、BASIC、HEADERS、FULL
* */
public class ContentCenterFeignConfiguration {
@Bean
public Logger.Level level(){
return Logger.Level.BASIC;
}
}
6、feignclient/ContentCenterFeignClient.java
package com.geovis.usercenter.feignclient;
import com.geovis.usercenter.configuration.ContentCenterFeignConfiguration;
import com.geovis.usercenter.domain.dto.ShareDto;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.cloud.openfeign.SpringQueryMap;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
@FeignClient(name = "content-center", configuration = ContentCenterFeignConfiguration.class)
public interface ContentCenterFeignClient {
@GetMapping(value = "/share/findById/{id}")
ShareDto findShareById(@PathVariable(value = "id") Integer id);
// 解决多参数请求问题：http://content-center/share/query?id=xx&title=xx&key=value...
@GetMapping(value = "/share/query")
ShareDto query(@SpringQueryMap ShareDto shareDto);
// 解决多参数请求问题
@PostMapping(value = "/share/insert")
ShareDto insert(@RequestBody ShareDto shareDto);
}
7、feignclient/BaiduFeignClient.java
package com.geovis.usercenter.feignclient;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
/*
* feign脱离ribbon使用
* */
@FeignClient(name = "baidu", url = "http://www.baidu.com")
public interface BaiduFeignClient {
@GetMapping(value = "")
String index();
}
8、TestController.java
package com.geovis.usercenter.controller.user;
import com.geovis.usercenter.domain.dto.ShareDto;
import com.geovis.usercenter.feignclient.BaiduFeignClient;
import com.geovis.usercenter.feignclient.ContentCenterFeignClient;
import lombok.RequiredArgsConstructor;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
import tk.mybatis.mapper.entity.Example;
import java.util.List;
// 解决idea自动注入的警告
@RequiredArgsConstructor(onConstructor = @__(@Autowired))
@RestController
@RequestMapping("/test")
public class TestController {
private final ContentCenterFeignClient contentCenterFeignClient;
private final BaiduFeignClient baiduFeignClient;
/*
* 根据id查询share
* */
@GetMapping(value = "/findShare/{id}")
public ShareDto findShare(@PathVariable Integer id){
return this.contentCenterFeignClient.findShareById(id);
}
/*
* 访问百度网页
* */
@GetMapping(value = "/index")
public String baidu(){
return this.baiduFeignClient.index();
}
}
9、接口测试
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10、现有架构的问题
如果某个微服务停止，高并发的访问会导致线程池阻塞，发生雪崩效应。
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