Rest微服务案例（二）

1. 创建父工程 Maven Project

新建父工程microservicecloud，packaging是pom模式，pom.xml内容如下：

<!-- SpringBoot父依赖 -->
<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.1.8.RELEASE</version>
    <relativePath />
</parent>
<properties>
    <!-- jdk version -->
    <java.version>1.8</java.version>
    <!-- springcloud version -->
    <cloud.version>Finchley.RELEASE</cloud.version>
    <!-- mysql version -->
    <mysql.version>5.1.48</mysql.version>
    <!-- druid version -->
    <druid.version>1.1.6</druid.version>
    <!-- junit version -->
    <junit.version>4.12</junit.version>
    <!-- log4j version -->
    <log4j.version>1.2.17</log4j.version>
</properties>

<!-- dependencyManagement 主要是对dependency的版本进行管理，如果dependency没有生命版本，则继承该标签声明的版本 -->
<dependencyManagement>
    <dependencies>
        <!-- spring cloud -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>${cloud.version}</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>

        <!-- mysql -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>${mysql.version}</version>
        </dependency>

        <!-- druid datSource -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>${druid.version}</version>
        </dependency>

        <!-- junit -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>

        <!-- mybatis -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.5</version>
        </dependency>

        <!-- log4j -->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>${log4j.version}</version>
        </dependency>
    </dependencies>

</dependencyManagement>

2. 公共模块

(1) 右键父项目名称，创建Maven Module，项目名称是microservicecloud-api，packaging是jar模式即可，这是一个子项目。

(2) 新建部门Entity

public class Dept {

    private Long deptNo;
    private String deptName;
    private String dbSource;

    public Dept(){}

    public Dept(Long deptNo, String deptName, String dbSource) {
        this.deptNo = deptNo;
        this.deptName = deptName;
        this.dbSource = dbSource;
    }

    public Long getDeptNo() {
        return deptNo;
    }
    public void setDeptNo(Long deptNo) {
        this.deptNo = deptNo;
    }
    public String getDeptName() {
        return deptName;
    }
    public void setDeptName(String deptName) {
        this.deptName = deptName;
    }
    public String getDbSource() {
        return dbSource;
    }
    public void setDbSource(String dbSource) {
        this.dbSource = dbSource;
    }

    @Override
    public String toString() {
        return "Dept [deptNo=" + deptNo + ", deptName=" + deptName + ", dbSource=" + dbSource + "]";
    }

}

公共模块可以达到通用目的，也即需要用到部门实体的话，不用每个工程都定义一份，直接引用本模块即可。

3. 微服务提供者

(1) 右键父项目名称，新建Maven Module, 名称为microservicecloud-provider-dept-8001，packaging是jar模式即可，pom.xml内容如下：

<dependencies>
    <!-- 引入自己定义的api通用包，可以使用Dept部门Entity -->
    <dependency>
        <groupId>com.linhw.demo</groupId>
        <artifactId>microservicecloud-api</artifactId>
        <version>${project.version}</version>
    </dependency>

    <!-- 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>
    </dependency>

    <!-- mysql -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
    </dependency>

    <!-- druid datSource -->
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid</artifactId>
    </dependency>

    <!-- junit -->
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
    </dependency>

    <!-- mybatis-spring -->
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
    </dependency>

    <!-- 修改后立即生效，热部署 -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
    </dependency>

</dependencies>

(2) 在src/main/resources目录下创建application.properties

server.port=8001

#mybatis
#全局配置文件所在路径
mybatis.config-location=classpath:mybatis/mybatis.cfg.xml
#所有Entity别名类所在包
mybatis.type-aliases-package=com.linhw.demo.entities
#mapper映射文件
mybatis.mapper-locations=classpath:mybatis/mapper/**/*.xml

#应用名称
spring.application.name=microservicecloud-dept
#当前数据源操作类型
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
#mysql驱动包
spring.datasource.driver-class-name=org.gjt.mm.mysql.Driver
spring.datasource.url=jdbc:mysql://192.168.178.5:12345/cloudDB01?characterEncoding=utf-8
spring.datasource.username=root
spring.datasource.password=123456
#数据库连接池的最小维持连接数
spring.datasource.dbcp2.min-idle=5
#初始化连接数
spring.datasource.dbcp2.initial-size=5
#最大连接数
spring.datasource.dbcp2.max-idle=5
#等待连接获取的最大超时时间
spring.datasource.dbcp2.max-wait-millis=200

(3) 在src/main/resources目录下创建mybatis文件夹，并在文件夹下创建mybatis.cfg.xml，这是mybatis的全局配置文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
  PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
  "http://mybatis.org/dtd/mybatis-3-config.dtd">

<configuration>

    <settings>
        <setting name="cacheEnabled" value="true" /><!-- 二级缓存开启 -->
    </settings>

</configuration>

(4) mysql数据库创建部门数据表

DROP DATABASE IF EXISTS cloudDB01;
CREATE DATABASE cloudDB01 CHARACTER SET UTF8;
USE cloudDB01;
CREATE TABLE dept
(
  deptno BIGINT NOT NULL PRIMARY KEY AUTO_INCREMENT,
  dname VARCHAR(60),
  db_source   VARCHAR(60)
);
INSERT INTO dept(dname,db_source) VALUES('开发部',DATABASE());
INSERT INTO dept(dname,db_source) VALUES('人事部',DATABASE());
INSERT INTO dept(dname,db_source) VALUES('财务部',DATABASE());
INSERT INTO dept(dname,db_source) VALUES('市场部',DATABASE());
INSERT INTO dept(dname,db_source) VALUES('运维部',DATABASE());
SELECT * FROM dept;

(5) DAO接口和映射文件

@Mapper
public interface DeptDao {

    public boolean addDept(Dept dept);
    public Dept findById(Long deptno);
    public List findAll();
}

在src/main/resources/mybatis目录下创建DeptMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.linhw.demo.dao.DeptDao">

    <select id="findById" resultType="Dept" parameterType="Long">
        select deptno as deptNo,dname as deptName,db_source as dbSource from dept where deptno=#{deptno};
    </select>

    <select id="findAll" resultType="Dept">
        select deptno as deptNo,dname as deptName,db_source as dbSource from dept;
    </select>

    <insert id="addDept" parameterType="Dept">
        insert into dept(dname, db_source) values(#{deptName},DATABASE());
    </insert>
</mapper>

(6) 服务接口

public interface DeptService {

    public boolean add(Dept dept);
    public Dept get(Long id);
    public List list();
}

@Service
public class DeptServiceImpl implements DeptService {

    @Autowired
    private DeptDao dao;

    @Override
    public boolean add(Dept dept) {
        return dao.addDept(dept);
    }

    @Override
    public Dept get(Long id) {
        return dao.findById(id);
    }

    @Override
    public List list() {
        return dao.findAll();
    }
}

(7) 微服务提供者REST（Controller）

@RestController
@RequestMapping("/dept")
public class DeptController {

    @Autowired
    private DeptService service;

    @RequestMapping(value = "/add", method = RequestMethod.POST)
    public boolean add(@RequestBody Dept dept) {
        return service.add(dept);
    }

    @RequestMapping(value = "/get/{id}", method = RequestMethod.GET)
    public Dept get(@PathVariable("id") Long id) {
        return service.get(id);
    }

    @RequestMapping(value = "/list", method = RequestMethod.GET)
    public List list() {
        return service.list();
    }
}

(8) 启动类：放在包的最顶层，一边可以扫描同级包或子包的相关注解类

@SpringBootApplication
public class Provider_8001_App {

    public static void main(String[] args) {
        SpringApplication.run(Provider_8001_App.class, args);
    }

}

(9) 启动服务提供者，访问测试：http://localhost:8001/dept/list

4. 微服务消费者

(1) 右键父项目名称，新建Maven Module, 名称为microservicecloud-consumer-dept-80，packageing是jar模式即可，pom.xml内容如下：

<dependencies>
    <!-- 引入自己定义的api通用包，可以使用Dept部门Entity -->
    <dependency>
        <groupId>com.linhw.demo</groupId>
        <artifactId>microservicecloud-api</artifactId>
        <version>${project.version}</version>
    </dependency>

    <!-- 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>
    </dependency>

    <!-- junit -->
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
    </dependency>

    <!-- 修改后立即生效，热部署 -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
    </dependency>
</dependencies>

(2) 在src/main/resources目录下创建application.properties

server.port=80

(3) 配置类

@Configuration //添加该注解，相当于是applicationContext.xml配置文件
public class ConfigBean {

    @Bean //添加该注解相当于是<bean id=".." class="" />
    public RestTemplate getRestTemplate(){
        return new RestTemplate();
    }
}

RestTemplate提供了多种便捷访问远程Http服务的方法， 是一种简单便捷的访问restful服务模板类，是Spring提供的用于访问Rest服务的客户端模板工具集

(4) 微服务消费者（Controller）

@RestController
@RequestMapping("/consumer")
public class DeptController_Consumer {
    private static final String REST_URL_PREFIX = "http://localhost:8001";

    @Autowired
    private RestTemplate restTemplate;

    @RequestMapping(value = "/dept/add")
    public boolean add(Dept dept) {
        return restTemplate.postForObject(REST_URL_PREFIX + "/dept/add", dept, Boolean.class);
    }

    @RequestMapping(value = "/dept/get/{id}")
    public Dept get(@PathVariable("id") Long id) {
        return restTemplate.getForObject(REST_URL_PREFIX + "/dept/get/" + id, Dept.class);
    }

    @RequestMapping(value = "/dept/list")
    public List list() {
        return restTemplate.getForObject(REST_URL_PREFIX + "/dept/list", List.class);
    }
}

(5) 启动类

@SpringBootApplication
public class Consumer_80_App {

    public static void main(String[] args) {
        SpringApplication.run(Consumer_80_App.class, args);
    }

}

(6) 启动项目，测试访问：http://localhost/consumer/dept/list