docker之开发课程EdgeService

课程的edgeService依赖于课程服务的dubbo服务，对外提供的restAPI，跟用户的EdgeService有点类似，只是一个调用的是thrift，一个调用的是dubbo，比较特殊的是课程的EdgeService需要用户登录后才可以访问，如果没有登录的话，需要跳转到登录系统才可以访问。

新建模块course-edge-servce

• pom增加依賴

<?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>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.3.RELEASE</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.idig8</groupId>
    <artifactId>course-edge-service</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>commons-lang</groupId>
            <artifactId>commons-lang</artifactId>
            <version>2.6</version>
        </dependency>
        <dependency>
            <groupId>io.dubbo.springboot</groupId>
            <artifactId>spring-boot-starter-dubbo</artifactId>
            <version>1.0.0</version>
        </dependency>
        <dependency>
            <groupId>com.idig8</groupId>
            <artifactId>course-dubbo-service-api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>com.idig8</groupId>
            <artifactId>user-edge-service-client</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>

    </dependencies>

</project>

• controller 调用course-dubbo-service-api 中的接口

package com.idig8.course.controller;

import com.alibaba.dubbo.config.annotation.Reference;
import com.idig8.course.dto.CourseDTO;
import com.idig8.course.service.ICourseService;
import com.idig8.thrift.user.dto.UserDTO;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;

import javax.servlet.http.HttpServletRequest;
import java.util.List;

/**
 * Created by Michael on 2017/11/4.
 */
@Controller
@RequestMapping("/course")
public class CourseController {

    @Reference
    private ICourseService courseService;

    @RequestMapping(value = "/courseList", method = RequestMethod.GET)
    @ResponseBody
    public List<CourseDTO> courseList(HttpServletRequest request) {

        UserDTO user = (UserDTO)request.getAttribute("user");
        System.out.println(user.toString());

        return courseService.courseList();
    }
}

• 增加filter组件

package com.idig8.course.filter;

import com.idig8.thrift.user.dto.UserDTO;
import com.idig8.user.client.LoginFilter;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Created by liming.
 */
@Component
public class CourseFilter extends LoginFilter {

    @Value("${user.edge.service.addr}")
    private String userEdgeServiceAddr;

    @Override
    protected String userEdgeServiceAddr() {
        return userEdgeServiceAddr;
    }

    @Override
    protected void login(HttpServletRequest request, HttpServletResponse response, UserDTO userDTO) {

        request.setAttribute("user", userDTO);
    }
}

• 启动类

package com.idig8.course;

import com.idig8.course.filter.CourseFilter;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;

import java.util.ArrayList;
import java.util.List;

/**
 * Created by liming
 */
@SpringBootApplication
public class ServiceApplication {

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

    @Bean
    public FilterRegistrationBean filterRegistrationBean(CourseFilter courseFilter ) {
        FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
        filterRegistrationBean.setFilter(courseFilter);

        List<String> urlPatterns = new ArrayList<String>();
        urlPatterns.add("/*");
        filterRegistrationBean.setUrlPatterns(urlPatterns);
        return filterRegistrationBean;
    }
}

• application.properties

server.port=8081

#dubbo config
spring.dubbo.application.name=course-service
spring.dubbo.registry.address=zookeeper://47.98.183.16:2181
spring.dubbo.scan=com.idig8.course

user.edge.service.addr=127.0.0.1:8082

业务流程梳理

1. 课程EdgeService 依赖用户EdgeService服务，Thrift用户服务，课程服务。
2. 课程 EdgeService pom 依赖了用户登录user-edge-service-client，user-edge-service-client用于检测用户是否登录功能。需要调用用户的服务。
3. 当用户完成登录后，课程EdgeService 访问课程服务，获取课程的列表信息。
4. 课程EdgeService 依赖用户EdgeService服务，Thrift用户服务登录控制，登录后的跳转功能。
5. 课程EdgeService 依赖与course-dubbo-service-api服务，用于获取课程信息和用户的课程信息。

梳理下dubbo的思路

1. 建立对应的api项目定义方法。最终提供一个jar包供调用方和服务提供方使用。
2. 服务实现方引用api项目，实现里面的功能，提供端口，名称，地址，zookeeper监控中心。
3. 服务调用方引用api项目，引用zookeeper的监控中心发现服务。直接调用服务就可以用服务实现方的方法了。

程序演示

• 启动服务（按照顺序）

1. user-thrift-service
2. user-edge-service
3. course-dubbo-service
4. course-edge-service

• 界面演示

1. 访问http://127.0.0.1:8081 自动跳转到http://127.0.0.1:8082/user/login
2. 登录获取到token
   3.访问地址http://127.0.0.1:8081/course/courseList?token=ux4g5z98mowv0qr6r6e6ietdo00nh0vl

PS：微服务跟之前说的一样就是互相通过RPC的方式进行通信，之间有自己的数据库，只是RPC暴露接口的方式来获取其他的微服务之间的数据。