Springcloud学习笔记26--JeecgBoot 新建一个微服务模块，同时配置动态数据源(使用两个数据库)

1.创建一个新的module

创建完成后，项目结构为：

2.创建文件目录、启动类

(1)在pom文件中添加依赖和打包插件

<?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>jeecg-cloud-module</artifactId>
        <groupId>org.jeecgframework.boot</groupId>
        <version>2.4.6</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.jeecgframework.boot</groupId>
    <artifactId>jeecg-cloud-test</artifactId>

    <dependencies>
        <dependency>
            <groupId>org.jeecgframework.boot</groupId>
            <artifactId>jeecg-boot-base-core</artifactId>
        </dependency>
        <!--引入微服务启动依赖 starter-->
        <dependency>
            <groupId>org.jeecgframework.boot</groupId>
            <artifactId>jeecg-boot-starter-cloud</artifactId>
        </dependency>

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

(2)添加配置文件application.yml

server:
  port: 7004
spring:
  application:
    name: jeecg-cloud-test

(3)添加启动类

package org.jeecg;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.openfeign.EnableFeignClients;

@SpringBootApplication(scanBasePackages = "org.jeecg")
@EnableFeignClients(basePackages = "org.jeecg")
public class JeecgCloudTestApplication {

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

启动JeecgCloudTestApplication类，可以看到项目启动成功。

注意：@EnableFeignClients(basePackages = "org.jeecg")这个注解一定要加上，否则会报‘org.jeecg.common.api.CommonAPI' not be found 错误。

模块的启动顺序为(1)JeecgNacosApplication nacos应用 (2)JeecgGatewayApplication 网关应用 (3)JeecgCloudTestApplication 测试应用

此时，查看http://192.168.141.128:8848/nacos/index.html可见

3.在jeecg-cloud-gateway中配置路由信息

打开jeecg-cloud-gateway模块中的application.yml文件

添加如下内容

        - id: jeecg-cloud-test
          uri: lb://jeecg-cloud-test
          predicates:
            - Path=/test/**

4.创建测试类与postman测试

(1)首先，创建目录和TestController

@Slf4j
@Api(tags = "test")
@RestController
@RequestMapping("/test")
public class TestController {
    @GetMapping(value = "/demo")
    @ApiOperation(value = "测试方法", notes = "测试方法")
    public Result methodTest() {

        return Result.OK("这是测试方法TestController");
    }

}

(2)修改gateway网关模块中的路由配置

        - id: jeecg-cloud-test
          uri: lb://jeecg-cloud-test
          predicates:
            - Path=/test/**

(3)绕开网关，直接访问http://127.0.0.1:7006/test/demo

5.利用jeecg-boot代码生成器自动生成代码

具体使用见：https://www.cnblogs.com/luckyplj/p/15393648.html

注意：代码生成器生成的代码，务必按照包名规则 org.jeecg.modules.*进行初始化，其他请了解jeecgboot mybatis的包扫描规则，不然bean扫描不到！

如果未按包名规则正确配置，会报如下错误。

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'pmSubsysHostsController': Unsatisfied dependency expressed through field 'service'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'pmSubsysHostsServiceImpl': Unsatisfied dependency expressed through field 'baseMapper'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'org.jeecg.flep.mapper.PmSubsysHostsMapper' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:643) ~[spring-beans-5.2.10.RELEASE.jar:5.2.10.RELEASE]
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:130) ~[spring-beans-5.2.10.RELEASE.jar:5.2.10.RELEASE]  
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'pmSubsysHostsServiceImpl': Unsatisfied dependency expressed through field 'baseMapper'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'org.jeecg.flep.mapper.PmSubsysHostsMapper' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:643) ~[spring-beans-5.2.10.RELEASE.jar:5.2.10.RELEASE]
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:130) ~[spring-beans-5.2.10.RELEASE.jar:5.2.10.RELEASE]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399) ~[spring-beans-5.2.10.RELEASE.jar:5.2.10.RELEASE]
    ... 20 common frames omitted
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'org.jeecg.flep.mapper.PmSubsysHostsMapper' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1717) ~[spring-beans-5.2.10.RELEASE.jar:5.2.10.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1273) ~[spring-beans-5.2.10.RELEASE.jar:5.2.10.RELEASE] 
    ... 33 common frames omitted

正常的模块结构应该如下所示：

若要自定义包结构，可参考https://www.cnblogs.com/luckyplj/p/15397610.html

6 配置动态数据源

(1)动态数据源配置

      datasource:
        master:
          url: jdbc:mysql://jeecg-boot-mysql:3306/jeecg-boot?characterEncoding=UTF-8&useUnicode=true&useSSL=false&tinyInt1isBit=false&allowPublicKeyRetrieval=true&serverTimezone=Asia/Shanghai
          username: root
          password: plj824
          driver-class-name: com.mysql.cj.jdbc.Driver
          # 多数据源配置
        multi-datasource1:
          url: jdbc:mysql://localhost:3306/flep?useUnicode=true&characterEncoding=utf8&autoReconnect=true&zeroDateTimeBehavior=convertToNull&transformedBitIsBoolean=true&allowPublicKeyRetrieval=true&serverTimezone=Asia/Shanghai
          username: root
          password: plj824
          driver-class-name: com.mysql.cj.jdbc.Driver

master 为主数据源，系统默认数据源
multi-datasource1 ：自定义的第三方数据源，multi-datasource1名称随便定义

(2)使用 @DS 切换数据源。
@DS 可以注解在方法上和类上，同时存在方法注解优先于类上注解。

注解在service实现或mapper接口方法上，但强烈不建议同时在service和mapper注解。 (可能会有问题)

注解	结果
没有@DS	默认数据源
@DS("dsName")	dsName可以为组名也可以为具体某个库的名称

代码示例：

@Service
@DS("multi-datasource1")
public class BsClientSubsysServiceImpl extends ServiceImpl<BsClientSubsysMapper, BsClientSubsys> implements IBsClientSubsysService {

}

此时，利用postman测试。

参考文献：

jeecg-boot:注解扫描范围问题 https://blog.csdn.net/gwcgwcjava/article/details/95967349