简介java
上一节,咱们讨论了怎么经过,restTemlate调用cloud的生产者,实现起来仍是比较复杂的,尤为是在消费复杂的Restful服务的时候,还须要进行一系列的转换,编解码等,使用Feign就彻底不用考虑这个问题.。web
1、feinn介绍spring
Feign是一种声明式、模板化的HTTP客户端。在Spring Cloud中使用Feign, 咱们能够作到使用HTTP请求远程服务时能与调用本地方法同样的编码体验,开发者彻底感知不到这是远程方法,更感知不到这是个HTTP请求,这整个调用过程和Dubbo的RPC很是相似。开发起来很是的优雅。docker
2、建立模块(microservice-consumer-movie-feign)apache
项目结构以下:api
3、pom.xmlbash
<?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">
<parent>
<artifactId>microservice-spring-cloud</artifactId>
<groupId>com.jacky</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>microservice-consumer-movie-feign</artifactId>
<packaging>jar</packaging>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<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.cloud</groupId>
<artifactId>spring-cloud-starter-eureka</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-feign</artifactId>
</dependency>
<!--<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-oauth2</artifactId>
</dependency>-->
</dependencies>
<build>
<plugins>
<plugin>
<groupId>com.spotify</groupId>
<artifactId>docker-maven-plugin</artifactId>
<executions>
<!--设置在执行maven 的install时构建镜像-->
<execution>
<id>build-image</id>
<phase>install</phase>
<goals>
<goal>build</goal>
</goals>
</execution>
</executions>
<configuration>
<!--安装了docker的主机,而且打开了api remote接口设置-->
<dockerHost>http://192.168.6.130:5678</dockerHost>
<pushImage>true</pushImage><!--设置上传镜像到私有仓库,须要docker设置指定私有仓库地址-->
<!--镜像名称-->
<imageName>${docker.repostory}/${docker.image.prefix}/${project.artifactId}:${project.version}</imageName>
<!--镜像的基础版本-->
<baseImage>java:openjdk-8-jdk-alpine</baseImage>
<!--镜像启动参数-->
<entryPoint>["java", "-jar", "/${project.build.finalName}.jar"]</entryPoint>
<resources>
<resource>
<targetPath>/</targetPath>
<directory>${project.build.directory}</directory>
<include>${project.build.finalName}.jar</include>
</resource>
</resources>
</configuration>
</plugin>
</plugins>
</build>
</project>复制代码
4、配置文件application.ymlapp
spring:
application:
name: microservice-consumer-movie-feign
server:
port: 7901
eureka:
client:
healthcheck:
enabled: true
serviceUrl:
defaultZone: http://jacky:admin@peer1:8761/eureka/,http://jacky:admin@peer2:8762/eureka/,http://jacky:admin@peer3:8763/eureka/
instance:
prefer-ip-address: true
instance-id: ${spring.application.name}:${spring.cloud.client.ipAddress}:${spring.application.instance_id:${server.port}}复制代码
5、MovieController.javamaven
package com.jacky.cloud.controller;
import com.jacky.cloud.entity.User;
import com.jacky.cloud.feign.UserFeignClient;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
/**
* Created by jacky on 2017/7/14.
*/
@RestController
public class MovieController {
@Autowired
private UserFeignClient userFeignClient;
@GetMapping("/movie/{id}")
public User findById(@PathVariable Long id) {
return this.userFeignClient.findById(id);
}
@GetMapping("/test")
public User testPost(User user) {
return this.userFeignClient.postUser(user);
}
@GetMapping("/test-get")
public User testGet(User user) {
return this.userFeignClient.getUser(user);
}
}复制代码
6、实体类User.java分布式
package com.jacky.cloud.entity;
import java.math.BigDecimal;
public class User {
private Long id;
private String username;
private String name;
private Short 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 Short getAge() {
return this.age;
}
public void setAge(Short age) {
this.age = age;
}
public BigDecimal getBalance() {
return this.balance;
}
public void setBalance(BigDecimal balance) {
this.balance = balance;
}
}复制代码
7、UserFeignClient.java
package com.jacky.cloud.feign;
import com.jacky.cloud.entity.User;
import org.springframework.cloud.netflix.feign.FeignClient;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
/**
* Created by jacky on 2017/7/14.
*/
@FeignClient("microservice-provider-user")
public interface UserFeignClient {
/**
* 根据Id得到User
* 两个坑:1. @GetMapping不支持 2. @PathVariable得设置value
* @param id
* @return
*/
@RequestMapping(value = "/simple/{id}", method = RequestMethod.GET)
public User findById(@PathVariable("id") Long id);
@RequestMapping(value = "/user", method = RequestMethod.POST)
public User postUser(@RequestBody User user);
// 该请求不会成功,只要参数是复杂对象,即便指定了是GET方法,feign依然会以POST方法进行发送请求。多是我没找到相应的注解或使用方法错误。
// 也就是说复杂对象,feign必定要post的请求方式
@RequestMapping(value = "/get-user", method = RequestMethod.GET)
public User getUser(User user);
}复制代码
8、启动类(MicroserviceSimpleConsumerMovieApplication.java)
package com.jacky.cloud;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.netflix.feign.EnableFeignClients;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;
@SpringBootApplication
@EnableEurekaClient
@EnableFeignClients
public class MicroserviceSimpleConsumerMovieApplication {
public static void main(String[] args) {
SpringApplication.run(MicroserviceSimpleConsumerMovieApplication.class, args);
}
}复制代码
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