seata1.3.0 系列学习（二、nacos+seata使用）

上篇文章讲了如何安装seata,这篇文章主要讲如何使用，分布讲解什么情况回滚，不回滚

一、新建父级maven

pom.xml文件导入

<?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">
    <modelVersion>4.0.0</modelVersion>
    <groupId>nacosprovider</groupId>
    <artifactId>minenacos</artifactId>
    <version>1.0-SNAPSHOT</version>


    <modules>
        <module>nacosprovider</module>
        <module>consumer</module>
        <module>alibabaconfig</module>
        <module>nacosprovidertwo</module>
    </modules>

    <properties>
        <spring-cloud-starter-alibaba-nacos-discovery.version>2.2.0.RELEASE</spring-cloud-starter-alibaba-nacos-discovery.version>
    </properties>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
                <version>2.2.4.RELEASE</version>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>2.2.1.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <dependencies>
        <!-- https://mvnrepository.com/artifact/com.alibaba.cloud/spring-cloud-starter-alibaba-nacos-discovery -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
            <!--<scope>provided</scope>-->
            <!--<version>${spring-cloud-starter-alibaba-nacos-discovery.version}</version>-->
        </dependency>

        <!-- https://mvnrepository.com/artifact/com.alibaba.nacos/nacos-client -->
        <dependency>
            <groupId>com.alibaba.nacos</groupId>
            <artifactId>nacos-client</artifactId>
            <!--<version>1.2.0-beta.1</version>-->
        </dependency>

        <dependency>
             <groupId>org.springframework.cloud</groupId>
             <artifactId>spring-cloud-starter-openfeign</artifactId>
             <version>2.2.2.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>2.2.4.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.5.11</version>
        </dependency>
    </dependencies>

</project>

二、整合nacos服务提供者

接着上篇文章的代码，加入mybatis和feign

目录结构

pom.xml导入了seata

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>nacosprovider</groupId>
        <artifactId>minenacos</artifactId>
        <version>1.0-SNAPSHOT</version>
        <relativePath/>
    </parent>
    <groupId>com.apiprovider</groupId>
    <artifactId>nacosprovider</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>nacosprovider</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-data-jpa -->
        <!--<dependency>-->
            <!--<groupId>org.springframework.boot</groupId>-->
            <!--<artifactId>spring-boot-starter-data-jpa</artifactId>-->
            <!--<version>2.2.5.RELEASE</version>-->
        <!--</dependency>-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>2.3.1.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>io.seata</groupId>
            <artifactId>seata-spring-boot-starter</artifactId>
            <version>1.3.0</version>
        </dependency>

        <dependency>
            <groupId>com.fasterxml.jackson.datatype</groupId>
            <artifactId>jackson-datatype-jsr310</artifactId>
            <version>2.11.2</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.20</version>
        </dependency>
        <!--mybatis-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.0</version>
            <exclusions>
            <exclusion>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
            </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
            <version>2.3.1.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <version>2.3.1.RELEASE</version>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>6</source>
                    <target>6</target>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

启动类

package com.apiprovider.nacosprovider;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.openfeign.EnableFeignClients;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@EnableDiscoveryClient
@MapperScan("com.apiprovider.nacosprovider.Mapper")//使用MapperScan批量扫描所有的Mapper接口；
@EnableFeignClients    //feigin扫描
public class NacosproviderApplication {

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

}

其中usercontroller代码

package com.apiprovider.nacosprovider.Controller;


import com.apiprovider.nacosprovider.Entity.User;
import com.apiprovider.nacosprovider.Service.UserService;
import io.seata.spring.annotation.GlobalTransactional;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import sun.nio.ch.ThreadPool;

import java.util.List;

@RestController
@RequestMapping("/user")
public class UserController {
    @Autowired
    private UserService userService;

    @Autowired
    IUserCreateService UserCreateService;

    @RequestMapping("/findAll")
    public List<User> findAll(){
        return userService.findAll();
    }

    @RequestMapping("/getUserByID")
    public User getUserByID(Integer id){
        return userService.getUserByID(id);
    }

    @RequestMapping("/CreateUser")
    @GlobalTransactional(name = "my_test_tx_group",rollbackFor = Exception.class)
    public  void CreateUser(User user) throws Exception
    {
        userService.CreateUser(user);
        String name = user.getUsername()+"111111";
        user.setUsername(name);
        UserCreateService.CreateUser(user);
    }

    @RequestMapping("/DeleteUser")
    public  void DeleteUser(Integer id)
    {
        userService.DeleteUser(id);

    }

    @RequestMapping("/UpdateUser")
    public  void  UpdateUser(User user)
    {
        userService.UpdateUser(user);
    }
}

@GlobalTransactional(name = "my_test_tx_group",rollbackFor = Exception.class)注解作用为开启seata事务

新增application.yml

spring:
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848
  application:
    name: service-provider
    #数据库连接配置
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://192.168.0.10:3306/test?characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=false&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=GMT%2B8&allowMultiQueries=true&allowPublicKeyRetrieval=true
    username: root
    password: piaost123
server:
  port: 4444


#mybatis的相关配置
mybatis:
  #mapper配置文件
  mapper-locations: classpath:mapper/*.xml
  type-aliases-package: com.apiprovider.nacosprovider.Entity
  #开启驼峰命名
  configuration:
    map-underscore-to-camel-case: true

seata:
  enabled: true
  # 应用 id 为唯一便于区分
  application-id: order
  # 事务分组，这个是默认分组
  tx-service-group: my_test_tx_group
  config:
    type: nacos
    nacos:
      namespace:
      serverAddr: 127.0.0.1:8848
      group: SEATA_GROUP
      username: ""
      password: ""
      cluster: default
  registry:
    type: nacos
    nacos:
      application: seata-server
      server-addr: 127.0.0.1:8848
      group : DEFAULT_GROUP
      namespace:
      username: ""
      password: ""
      cluster: default

此时需要，往你数据库中新增一张表，安装Seata时提供的

注解：

tx-service-group: my_test_tx_group为

config下的group为注册再nacos中的group

registry的配置来源也是安装时的配置

三、复制第二个服务，新建成第三个

只修改applicaiton.yml

spring:
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848
  application:
    name: service-providertwo
    #数据库连接配置
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://192.168.0.10:3306/test?characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=false&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=GMT%2B8&allowMultiQueries=true&allowPublicKeyRetrieval=true
    username: root
    password: piaost123
server:
  port: 4445


#mybatis的相关配置
mybatis:
  #mapper配置文件
  mapper-locations: classpath:mapper/*.xml
  type-aliases-package: com.nacosprovidertwo.nacosprovidertwo.Entity
  #开启驼峰命名
  configuration:
    map-underscore-to-camel-case: true

seata:
  enabled: true
  # 应用 id 为唯一便于区分
  application-id: order
  # 事务分组，这个是默认分组
  tx-service-group: my_test_tx_group
  config:
    type: nacos
    nacos:
      namespace:
      serverAddr: 127.0.0.1:8848
      group: SEATA_GROUP
      username: ""
      password: ""
      cluster: default
  registry:
    type: nacos
    nacos:
      application: seata-server
      server-addr: 127.0.0.1:8848
      group : DEFAULT_GROUP
      namespace:
      username: ""
      password: ""
      cluster: default

和usercontroller

package com.nacosprovidertwo.nacosprovidertwo.Controller;


import com.nacosprovidertwo.nacosprovidertwo.Entity.User;
import com.nacosprovidertwo.nacosprovidertwo.Service.UserService;
import io.seata.spring.annotation.GlobalTransactional;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
@RequestMapping("/user")
public class UserController {
    @Autowired
    private UserService userService;

    @RequestMapping("/findAll")
    public List<User> findAll(){
        return userService.findAll();
    }

    @RequestMapping("/getUserByID")
    public User getUserByID(Integer id){
        return userService.getUserByID(id);
    }

    @RequestMapping("/CreateUser")
    @GlobalTransactional(name = "my_test_tx_group",rollbackFor = Exception.class)
    public  void CreateUser(@RequestBody User user) throws Exception
    {
        userService.CreateUser(user);
       throw  new Exception("分布式事务回滚");
    }

    @RequestMapping("/DeleteUser")
    public  void DeleteUser(Integer id)
    {
        userService.DeleteUser(id);

    }

    @RequestMapping("/UpdateUser")
    public  void  UpdateUser(User user)
    {
        userService.UpdateUser(user);
    }
}

ok，到此位置搭建完毕

开始启动服务

NacosproviderApplication，

NacosprovidertwoApplication

当前在第二个服务手动抛了异常

此时数据库为空

使用postman发送数据请求服务1

实现预期效果，服务二抛出异常

此时数据被回滚

为再次确认，我们去掉第二个手动抛异常的代码，预测新增两条数据

请求后正常返回

再看数据库正常新增了两条数据，此时初步实现了seata管理分布式事务

我们去掉第二个服务中的事务注解试一下会不会回滚，此时清空数据库，注释注解，抛出异常

在此纠正一个问题：除了发起时需要添加注解@GlobalTransactional，被调服务只要添加Transactional即可

再次启动服务

如期，抛出异常，再看数据库

很明显第二条没有回滚掉，说明不加事务回滚注解，是不行的

初步认知到此为止，在实验的过程中我发现个问题，第一次启动时，请求，第一个服务插入一条数据（没问题），但是第二个服务会往数据库插入两条相同的数据

如：我们重启服务，清空数据库，不抛异常

此时请求，返回成功

我们去看数据库

发现第二个服务执行了两次，初步怀疑，第一个服务请求了两次，这个问题 留到下个文章解决