springcloud(二) eureka的使用

上一节讲到order微服务是通过rest调用user微服务的地址。但是，user微服务的地址是写死的，如果user微服务集群的话，那么order微服务该如何调用呢？这个时候注册中心该上场了

演示eureka的使用：

pom.xml:

<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.tuling.springcloud</groupId>
	<artifactId>04-eureka-server</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>04-eureka-server</name>
	<url>http://maven.apache.org</url>

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

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>1.5.10.RELEASE</version>
	</parent>

	<dependencyManagement>
		<dependencies>
			<dependency>
				<groupId>org.springframework.cloud</groupId>
				<artifactId>spring-cloud-dependencies</artifactId>
				<version>Edgware.SR3</version>
				<type>pom</type>
				<scope>import</scope>
			</dependency>
		</dependencies>
	</dependencyManagement>
	<dependencies>

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

		<!-- eureka server 注册中心依赖-->
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-eureka-server</artifactId>
		</dependency>

		<!-- 安全模块与属性文件配合使用 -->
<!--		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-security</artifactId>
		</dependency>-->
	</dependencies>

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

　　application.properties:

server.port=8761

#取消向eureka server(注册中心)注册，因为现在一台eureka，所以不需要把自己注册到别的eureka上，集群的时候就要改为true
eureka.client.register-with-eureka=false

#取消向eureka server(注册中心)获取注册信息，因为现在一台eureka，所以不需要同步其他rureka的数据，集群的时候就要改为true
eureka.client.fetch-registry=false

#eureka 提供服务发现的地址，注册中心地址
#打开安全模块，当访问http://localhost:8761/eureka的时候就需要输入帐号和密码
#eureka.client.service-url.defaultZone=http://likehow:777@localhost:8761/eureka
eureka.client.service-url.defaultZone=http://localhost:8761/eureka

# 安全模块，要添加maven依赖,
#security.basic.enabled=true   #是否打开
#security.user.name=likehow     #帐号
#security.user.password=777     #密码

　　EurekaServerStart.java:

package com.tuling.springcloud;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;

@SpringBootApplication
@EnableEurekaServer //作为EurekaServer注册中心，服务提供者如果挂机，它的URL将会在eureka存活90s，如果还没连接上就清除url
public class EurekaServerStart {

    // http://localhost:8761
	public static void main(String[] args) throws Exception {
        SpringApplication.run(EurekaServerStart.class, args);
    }
}

　　@EnableEurekaServer：开启Eureka Server ，表示这个应用是注册中心，服务提供者如果挂机，它的URL将会在eureka存活90s，如果还没连接上就清除url

启动之后：

恭喜你eureka 启动成功。

接下来使用 user微服务和order微服务和eureka 一起使用:

order微服务结构

pom.xml:

<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.tuling.springcloud</groupId>
    <artifactId>04-microservice-order</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>04-microservice-order</name>
    <url>http://maven.apache.org</url>

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

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.10.RELEASE</version>
    </parent>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Edgware.SR3</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    
    <dependencies>
        <!-- 此包包含了eurekaclient,ribbon-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
        </dependency>
        <!-- 监控和管理生产环境模块 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <!-- Spring WEB -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- Test -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!-- 集成Mybatis -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.1.1</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
    </dependencies>

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

View Code

OrderController:

package com.tuling.springcloud.api;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

import java.util.HashMap;
import java.util.Map;

@RestController
@RequestMapping("/order")
public class OrderController {
    private final Logger logger = LoggerFactory.getLogger(OrderController.class);
    
    @Autowired
    private RestTemplate restTemplate;

    @RequestMapping("")
    public Object testHttp() {
        Map<String , Object> map = new HashMap<String,Object>();
        map.put("result","success");
        return map;
    }

    //http://localhost:8082/order/user/getById?userId=1
    @RequestMapping("/user/getById")
    public Object getUserById(String userId) {
        String url = "http://localhost:8081/user/getById?id=" + userId;
        logger.debug("param userId : {}, request url : {}", userId, url);
        Object result = restTemplate.getForEntity(url, Object.class);
        return result;
    }
    
    @RequestMapping("/user/getByIdEureka")
    public Object getUserByIdEureka(String userId) {
        // 注意这里的IP换成了应用名称，order回去注册中心获取microservice-user提供者列表然后进行调用
        String url = "http://microservice-user/user/getById?id=" + userId;
        Object result = restTemplate.getForEntity(url, Object.class);
        return result;
    }
    
    
}

View Code

CommonConfig:

    package com.tuling.springcloud.config;

    import org.springframework.cloud.client.loadbalancer.LoadBalanced;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.web.client.RestTemplate;

    @Configuration
    public class CommonConfig {

        /*@Bean
        public RestTemplate restTemplate(){
            return new RestTemplate();
        }*/

        @Bean
        @LoadBalanced //轮询调用，作用是负载均衡，注意这个负载均衡的代码一定是写在调用方
        public RestTemplate restTemplate() {
            return new RestTemplate();
        }
    }

View Code

application.properties:

spring.application.name=microservice-order
# 假设服务的调用者以80开头
server.port=8082
## db config
spring.datasource.url=jdbc:mysql://localhost:3306/springcloud
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

## log
logging.level.root=INFO
logging.level.org.springframework.web=DEBUG
logging.level.com.tuling.springcloud=DEBUG

eureka.client.serviceUrl.defaultZone=http://localhost:8761/eureka/
#如果eureka开了安全模式，那么注册的时候也要换地址
#eureka.client.serviceUrl.defaultZone=http://zhangfei:777@localhost:8761/eureka

#是否显示ip地址
eureka.instance.prefer-ip-address=true
#微服务实例显示的格式
eureka.instance.instance-id=${spring.application.name}:${spring.application.instance_id:${server.port}}

View Code

order微服务结构:

pom.xml:

<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.tuling.springcloud</groupId>
    <artifactId>04-microservice-user</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>04-microservice-user</name>
    <url>http://maven.apache.org</url>

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

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.10.RELEASE</version>
    </parent>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Edgware.SR3</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <dependencies>
        <!-- 此包包含了eurekaclient,ribbon-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
        </dependency>
        <!-- 监控和管理生产环境模块 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <!-- Spring WEB -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- Test -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!-- 集成Mybatis -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.1.1</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
    </dependencies>

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

View Code

UserController:

package com.tuling.springcloud.api;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.serviceregistry.Registration;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.tuling.springcloud.bean.User;
import com.tuling.springcloud.service.UserService;

@RestController
@RequestMapping("/user")
public class UserController {
    private final Logger logger = LoggerFactory.getLogger(UserController.class);
    
    @Autowired
    private UserService userService;

    @Autowired
    private Registration registration;

    @RequestMapping("/getById")
    public User getUserById(String id) {
        logger.debug("param id : {}", id);
        logger.info("远程IP和端口 :{}" , registration.getHost() + ":" + registration.getPort());
        return this.userService.findById(Integer.parseInt(id));
    }

    
}

View Code

UserService:

package com.tuling.springcloud.service;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.tuling.springcloud.bean.User;
import com.tuling.springcloud.mapper.UserMapper;

@Service
public class UserService {
    private final Logger logger = LoggerFactory.getLogger(UserService.class);
    
    @Autowired
    private UserMapper userMapper;
    
    public User findById(Integer id){
        logger.debug("param id : {}" , id);
        User u = this.userMapper.findById(id);
        logger.debug("result name : {}" , u.getName());
        return u;
    }
}

View Code

UserMapper:

package com.tuling.springcloud.mapper;

import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;

import com.tuling.springcloud.bean.User;

@Mapper
public interface UserMapper {
    /**根据id查询用户*/
    @Select("SELECT * FROM T_USER WHERE ID = #{id}")
    User findById(@Param("id") Integer id);
    /**新增用户*/
    @Insert("INSERT INTO T_USER(NAME, AGE, ADDRESS, PHONE) VALUES(#{name}, #{age}, #{address}, #{phone})")
    int insert(@Param("name") String name, @Param("age") Integer age,@Param("address") String address,@Param("phone") String phone);
}

View Code

启动类UserMicroStart:

package com.tuling.springcloud;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

@SpringBootApplication
@EnableDiscoveryClient
//@EnableEurekaClient
public class UserMicroStart {

    public static void main(String[] args) throws Exception {
        SpringApplication.run(UserMicroStart.class, args);
    }
}

View Code

// @EnableDiscoveryClient和@EnableEurekaClient效果一样，他们是父子关系

User.java ：

package com.tuling.springcloud.bean;
public class User {
    private Integer id;
    private String name;
    private Integer age;
    private String address;
    private String phone;
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Integer getAge() {
        return age;
    }
    public void setAge(Integer age) {
        this.age = age;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    public String getPhone() {
        return phone;
    }
    public void setPhone(String phone) {
        this.phone = phone;
    }
    
}

View Code

application.properties：

spring.application.name=microservice-user
# 假设服务的提供者以90开头
server.port=9090
## db config
spring.datasource.url=jdbc:mysql://localhost:3306/springcloud
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

## log
logging.level.root=INFO
logging.level.org.springframework.web=DEBUG
logging.level.com.tuling.springcloud=DEBUG

eureka.client.serviceUrl.defaultZone=http://localhost:8761/eureka/
#eureka.client.serviceUrl.defaultZone=http://zhangfei:777@localhost:8761/eureka
#是否显示ip地址
eureka.instance.prefer-ip-address=true   
#微服务实例显示的格式
eureka.instance.instance-id=${spring.application.name}:${spring.application.instance_id:${server.port}}

View Code

分别启动order,user,eureka, 在修改成user服务的applciation.properties的端口并启动。结果是这样：

然后就可以访问http://localhost:8082/order/user/getByIdEureka?userId=1 。可以通过控制台看到user服务是被轮询调用的。

欢迎来QQ群：592495675 一起研究 java技术，群里技术大佬，还有所有springCloud 学习源代码

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原文地址：https://www.cnblogs.com/smallFishs/p/10555802.html

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