【SpringCloud学习】Rest学习环境搭建：服务提供者、服务消费者

Rest学习环境搭建：服务提供者、服务消费者

1、首先创建一个父工程，在pom.xml文件中，将所有需要的依赖导入，方便控制几个模块的依赖版本号一致

 
    <packaging>pompackaging>
    <properties>
        <project.build.sourceEncoding>UTF-8project.build.sourceEncoding>
        <maven.compiler.source>1.8maven.compiler.source>
        <maven.compiler.target>1.8maven.compiler.target>
        <junit.version>4.12junit.version>
        <lombok.version>1.18.22lombok.version>
    properties>

    <dependencyManagement>
        <dependencies>

            
            <dependency>
                <groupId>org.springframework.cloudgroupId>
                <artifactId>spring-cloud-dependenciesartifactId>
                <version>2.2.5.RELEASEversion>
                <type>pomtype>
                <scope>importscope>
            dependency>

            <dependency>
                <groupId>org.springframework.bootgroupId>
                <artifactId>spring-boot-dependenciesartifactId>
                <version>2.3.3.RELEASEversion>
                <type>pomtype>
                <scope>importscope>
            dependency>

            <dependency>
                <groupId>mysqlgroupId>
                <artifactId>mysql-connector-javaartifactId>
                <version>5.1.47version>
            dependency>
            <dependency>
                <groupId>com.alibabagroupId>
                <artifactId>druidartifactId>
                <version>1.2.6version>
            dependency>

            <dependency>
                <groupId>org.mybatis.spring.bootgroupId>
                <artifactId>mybatis-spring-boot-starterartifactId>
                <version>1.3.5version>
            dependency>


            <dependency>
                <groupId>ch.qos.logbackgroupId>
                <artifactId>logback-coreartifactId>
                <version>1.2.10version>
            dependency>

            <dependency>
                <groupId>junitgroupId>
                <artifactId>junitartifactId>
                <version>${junit.version}version>
            dependency>

            <dependency>
                <groupId>org.projectlombokgroupId>
                <artifactId>lombokartifactId>
                <version>${lombok.version}version>
            dependency>

            <dependency>
                <groupId>log4jgroupId>
                <artifactId>log4jartifactId>
                <version>1.2.15version>
            dependency>
        dependencies>
    dependencyManagement>

2、pom.xml配置 版本号会改的情况下 这样写比较容易改

3、第一个模块springcloud-api，存放实体类，

3.1 pom.xml导入依赖

<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>springcloudartifactId>
        <groupId>com.freezegroupId>
        <version>1.0-SNAPSHOTversion>
    parent>
    <modelVersion>4.0.0modelVersion>

    <artifactId>springcloud-apiartifactId>

    <dependencies>
        <dependency>
            <groupId>org.projectlombokgroupId>
            <artifactId>lombokartifactId>
        dependency>
    dependencies>
project>

3.2创建实体类，与类表关系映射，这里用数据库db01中的dept表，deptno自增，db_source 利用mysql的DATABASE()函数，所以构造函数只需要dname.

import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.experimental.Accessors;

import java.io.Serializable;

@Data
@NoArgsConstructor
@Accessors(chain = true)//链式写法 支持 dept.setDname("xxx").setDb_source("xxx")
public class Dept implements Serializable { //dept实体类  orm 类表关系映射
    private Long deptno;//主键
    private String dname;//部门名称
    private String db_source;//这个数据存在哪个数据库的字段   一个服务对应一个数据库，同一个信息可能存在不同的数据库

    public Dept(String dname){
        this.dname = dname;
    }

}

4、创建第二个模块springcloud-provider，服务提供者。

4.1pom.xml导入需要的依赖

<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>springcloudartifactId>
        <groupId>com.freezegroupId>
        <version>1.0-SNAPSHOTversion>
    parent>
    <modelVersion>4.0.0modelVersion>

    <artifactId>springcloud-provider-dept-8001artifactId>

    <dependencies>
    
        <dependency>
            <groupId>com.freezegroupId>
            <artifactId>springcloud-apiartifactId>
            <version>1.0-SNAPSHOTversion>
        dependency>
		
        <dependency>
            <groupId>junitgroupId>
            <artifactId>junitartifactId>
        dependency>
        
        <dependency>
            <groupId>mysqlgroupId>
            <artifactId>mysql-connector-javaartifactId>
        dependency>
        <dependency>
            <groupId>com.alibabagroupId>
            <artifactId>druidartifactId>
        dependency>
        <dependency>
            <groupId>ch.qos.logbackgroupId>
            <artifactId>logback-coreartifactId>
        dependency>
        <dependency>
            <groupId>org.mybatis.spring.bootgroupId>
            <artifactId>mybatis-spring-boot-starterartifactId>
        dependency>
		
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-testartifactId>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>
		
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-jettyartifactId>
        dependency>
		
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-devtoolsartifactId>
        dependency>
    dependencies>
project>

4.2配置application.yml文件，设置端口(这里用8001)，配置mybatis和spring 数据库数据源采用Druid

​ gjt的驱动是继承类，功能更好

server:
  port: 8001
#mybatis配置
mybatis:
  type-aliases-package: com.freeze.springcloud.pojo
  mapper-locations: classpath:mybatis/mapper/*.xml
  config-location: classpath:mybatis/mybatis-config.xml

#spring配置
spring:
  application:
    name: springcloud-provider-dept
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource #数据源
    driver-class-name: org.gjt.mm.mysql.Driver
    url: jdbc:mysql://localhost:3306/db01?useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC&useSSL=false
    username: root
    password: xxxx

4.3配置一下 mybatis-config.xml(非必要)

<configuration>
    <settings>

        <setting name="cacheEnabled" value="true"/>
    settings>
configuration>

4.4编写Dept的Dao、Service、Controller层

DeptDao

package com.freeze.springcloud.dao;

import com.freeze.springcloud.pojo.Dept;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import org.springframework.stereotype.Repository;

import java.util.List;

@Mapper
@Repository
public interface DeptDao {

    public boolean addDept(Dept dept);

    public Dept queryById(@Param("deptno") Long deptno);

    public List<Dept> queryAll();
}

DeptMapper.xml

<mapper namespace="com.freeze.springcloud.dao.DeptDao">
    <insert id="addDept" parameterType="Dept">
        insert into dept(dname,db_source)
        values(#{dname},DATABASE());
    insert>
    
    <select id="queryById" resultType="Dept" parameterType="Long">
        select * from dept where deptno = #{deptno};
    select>
    
    <select id="queryAll" resultType="Dept">
        select * from dept;
    select>
mapper>

DeptService

package com.freeze.springcloud.service;

import com.freeze.springcloud.pojo.Dept;

import java.util.List;

public interface DeptService {
    public boolean addDept(Dept dept);

    public Dept queryById(Long id);

    public List<Dept> queryAll();
}

DeptServiceImpl

package com.freeze.springcloud.service;

import com.freeze.springcloud.dao.DeptDao;
import com.freeze.springcloud.pojo.Dept;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class DeptServiceImpl implements DeptService {
    @Autowired
    private DeptDao deptDao;
    
    @Override
    public boolean addDept(Dept dept) {
        return deptDao.addDept(dept);
    }
    @Override
    public Dept queryById(Long id) {
        return deptDao.queryById(id);
    }
    @Override
    public List<Dept> queryAll() {
        return deptDao.queryAll();
    }
}

DeptController

服务提供者Controller接口要写Restful风格请求，参数为一个实体类时，在参数前面添加@RequestBody即可。

package com.freeze.springcloud.controller;

import com.freeze.springcloud.pojo.Dept;
import com.freeze.springcloud.service.DeptService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

//提供Restful服务
@RestController
public class DeptController {
    @Autowired
    private DeptService deptService;

    @PostMapping("/dept/add")
    public boolean addDept(@RequestBody Dept dept){
        return deptService.addDept(dept);
    }

    @GetMapping("/dept/get/{id}")
    public Dept get(@PathVariable("id") Long id){
        return deptService.queryById(id);
    }

    @GetMapping("/dept/list")
    public List<Dept> quertAll(){
        return deptService.queryAll();
    }
}

学习springboot太久（或者说没去记），忘记了下面几个的关系

4.5RestController和Controller有什么区别？

RestController 相当于 ResponseBody+Controller

1. 如果只是使用@RestController注解Controller，则Controller中的方法无法返回jsp页面，或者html，配置的视图解析器 InternalResourceViewResolver不起作用，返回的内容就是Return 里的内容。

2. 如果需要返回到指定页面，则需要用 @Controller配合视图解析器InternalResourceViewResolver才行。
   如果需要返回JSON，XML或自定义mediaType内容到页面，则需要在对应的方法上加上@ResponseBody注解。

3)如果需要返回JSON，XML或自定义mediaType内容到页面，则需要在对应的方法上加上@ResponseBody注解。

4.6@RequestMapping的作用？

@RequestMapping 是一个注解，用来标识http 请求地址与Controller 类的方法之间的映射。

5、创建第三个模块springcloud-consumer，服务消费者，并不需要写Service或者实体类的其他东西，所以依赖只需要web能够访问服务提供者即可。

5.1pom.xml配置

<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>springcloudartifactId>
        <groupId>com.freezegroupId>
        <version>1.0-SNAPSHOTversion>
    parent>
    <modelVersion>4.0.0modelVersion>

    <artifactId>springcloud-consumer-dept-80artifactId>


    <dependencies>
        <dependency>
            <groupId>com.freezegroupId>
            <artifactId>springcloud-apiartifactId>
            <version>1.0-SNAPSHOTversion>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-devtoolsartifactId>
        dependency>
    dependencies>
project>

5.2客户端一般端口应该默认是80，但电脑的80端口已经被占用，这里使用端口8002，配置application.yml

server:
  port: 8002

5.3这里要使用到RestTemplate来远程调用服务提供者 提供的服务，需要将它注册到Bean容器中，启动时才能自动配置,创建一个ConfigBean类。

在spring时，我们是使用applicationContext.xml来注册bean

package com.freeze.springcloud.config;

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

@Configuration //相当于spring  applicationContext.xml
public class ConfigBean {

    @Bean
    public RestTemplate getRestTemplate(){
        return new RestTemplate();
    }
}

5.4写一个Controller接口给消费者进行调用，Controller的方法通过RestTemplate来远程调用服务提供者写好的接口，实现了解耦合。服务的方法完全和消费者没有关系。消费者只需要知道服务提供者提供的接口地址，进行调用即可。

package com.freeze.springcloud.controller;

import com.freeze.springcloud.pojo.Dept;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
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 java.util.HashMap;
import java.util.List;
import java.util.Map;

@RestController
public class DeptConsumerController {
    //消费者不应该有Service层
    //RestTamplate 供我们直接调用 注册到Spring
    //(url,实体：map，Class responseType)
    @Autowired
    private RestTemplate restTemplate;//提供多种便捷访问远程http服务的方法，简单的RESTFUL服务模板

    private static final String REST_URL_PREFIX="http://localhost:8001";//前缀固定的

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

    @RequestMapping("/consumer/dept/get/{id}")
    public Dept get(@PathVariable("id") Long id){
        Map<String,String> map = new HashMap<>();
        map.put("id",String.valueOf(id));
        //用map 需要在url添加占位符 对应
        return restTemplate.getForObject(REST_URL_PREFIX+"/dept/get/{id}",Dept.class,map);
    }

    @RequestMapping("/consumer/dept/list")
    public List<Dept> list(){
        return restTemplate.getForObject(REST_URL_PREFIX+"/dept/list",List.class);
    }
}

与zookeeper+dubbo对比：消费者是将Service复制过来，用@DubboReference注解，配置了zookeeper注册中心地址，消费者到注册中心获取服务,而这里（还没用注册中心Eureka）消费者直接通过RestTemplate远程调用服务提供者抛出的接口地址（）。