说在前面

本文基于seata1.6.1 AT模式，以nacos作为配置、注册中心。本篇我们先使用，正确使用后再看下一篇相关概念和原理，这样可以掌握的更透彻。

1、seata服务的安装与配置

下载seata-server：https://seata.io/zh-cn/blog/download.html

解压后找到conf目录下的application.yml文件，从示例文件中找我们需要的配置复制到application.yml

温馨提示：复制以下代码注意修改【namespace】【data-id】【url】【user】【password】

server:
  port: 7091
spring:
  application:
    name: seata-server
logging:
  config: classpath:logback-spring.xml
  file:
    path: ${user.home}/logs/seata
  extend:
    logstash-appender:
      destination: 127.0.0.1:4560
    kafka-appender:
      bootstrap-servers: 127.0.0.1:9092
      topic: logback_to_logstash
console:
  user:
    username: seata
    password: seata
seata:
  config:
    # support: nacos 、 consul 、 apollo 、 zk  、 etcd3
    type: nacos
    nacos:
      server-addr: 127.0.0.1:8848
      namespace: 434e7801-0b5d-4fd2-b96a-acbac849fd84
      group: SEATA_GROUP
      username:
      password:
      context-path:
      ##if use MSE Nacos with auth, mutex with username/password attribute
      #access-key:
      #secret-key:
      data-id: seataServer.properties
  registry:
    # support: nacos 、 eureka 、 redis 、 zk  、 consul 、 etcd3 、 sofa
    type: nacos
    preferred-networks: 30.240.*
    nacos:
      application: seata-server
      server-addr: 127.0.0.1:8848
      group: SEATA_GROUP
      namespace: 434e7801-0b5d-4fd2-b96a-acbac849fd84
      cluster: default
      username:
      password:
      context-path:
      ##if use MSE Nacos with auth, mutex with username/password attribute
      #access-key:
      #secret-key:
  store:
    # support: file 、 db 、 redis
    mode: db
    db:
      datasource: druid
      db-type: mysql
      driver-class-name: com.mysql.jdbc.Driver
      url: jdbc:mysql://127.0.0.1:3306/seata?useUnicode=true&rewriteBatchedStatements=true&serverTimezone=GMT
      user: root
      password: 1234
      min-conn: 10
      max-conn: 100
      global-table: global_table
      branch-table: branch_table
      lock-table: lock_table
      distributed-lock-table: distributed_lock
      query-limit: 1000
      max-wait: 5000  
#  server:
#    service-port: 8091 #If not configured, the default is '${server.port} + 1000'
  security:
    secretKey: SeataSecretKey0c382ef121d778043159209298fd40bf3850a017
    tokenValidityInMilliseconds: 1800000
    ignore:
      urls: /,/**/*.css,/**/*.js,/**/*.html,/**/*.map,/**/*.svg,/**/*.png,/**/*.ico,/console-fe/public/**,/api/v1/auth/login

此时我们去nacos中新建一个配置，这里的Data ID就是上述配置中需要的。

配置文件的内容：【注意修改url、user、password】

#Transaction routing rules configuration, only for the client
service.vgroupMapping.default_tx_group=default
service.default.grouplist=127.0.0.1:8091
# 数据存储方式，db代表数据库
store.mode=db
store.db.datasource=druid
store.db.dbType=mysql
store.db.driverClassName=com.mysql.cj.jdbc.Driver
store.db.url=jdbc:mysql://127.0.0.1:3306/seata?useUnicode=true&rewriteBatchedStatements=true&serverTimezone=GMT
store.db.user=root
store.db.password=1234
store.db.minConn=5
store.db.maxConn=30
store.db.globalTable=global_table
store.db.branchTable=branch_table
store.db.queryLimit=100
store.db.lockTable=lock_table
store.db.maxWait=5000
# 事务、日志等配置
server.recovery.committingRetryPeriod=3000
server.recovery.asynCommittingRetryPeriod=3000
server.recovery.rollbackingRetryPeriod=3000
server.recovery.timeoutRetryPeriod=3000
server.maxCommitRetryTimeout=-1
server.maxRollbackRetryTimeout=-1
server.rollbackRetryTimeoutUnlockEnable=false
server.undo.logSaveDays=7
server.undo.logDeletePeriod=86400000
# 客户端与服务端传输方式
transport.serialization=seata
transport.compressor=none
# 关闭metrics功能，提高性能
metrics.enabled=false
metrics.registryType=compact
metrics.exporterList=prometheus
metrics.exporterPrometheusPort=9898

注意【service.vgroupMapping.default_tx_group=default】，后续需要使用。

我这里是用的windows，直接去bin目录下双击seata-server.bat

之后去nacos看一下，有健康实例就说明seata服务注册成功了。

2、使用seata

首先是sql脚本，在seata服务目录的\script\server\db下找到mysql的脚本执行一下

除此之外，我们还需要一个undo_log表

SET NAMES utf8mb4;SET FOREIGN_KEY_CHECKS =0;-- ------------------------------ Table structure for undo_log-- ----------------------------DROPTABLE IF EXISTS `undo_log`;CREATETABLE `undo_log`  (  `id` bigint(20)NOTNULL AUTO_INCREMENT,  `branch_id` bigint(20)NOTNULL,  `xid` varchar(100) CHARACTER SET utf8 COLLATE utf8_general_ci NOTNULL,  `context` varchar(128) CHARACTER SET utf8 COLLATE utf8_general_ci NOTNULL,  `rollback_info` longblobNOTNULL,  `log_status` int(11)NOTNULL,  `log_created` datetimeNOTNULL,  `log_modified` datetimeNOTNULL,  PRIMARY KEY (`id`) USING BTREE,  UNIQUE INDEX `ux_undo_log`(`xid`, `branch_id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT =12 CHARACTER SET= utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;SET FOREIGN_KEY_CHECKS =1;

以及我们的两张业务表

SET NAMES utf8mb4;SET FOREIGN_KEY_CHECKS =0;-- ------------------------------ Table structure for sys_order-- ----------------------------DROPTABLE IF EXISTS `sys_order`;CREATETABLE `sys_order`  (  `id` bigint(20)UNSIGNEDNOTNULL,  `product_id` bigint(20)UNSIGNEDNULL DEFAULT NULL,  `number` int(10)UNSIGNEDNULL DEFAULT NULL,  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET= utf8mb4 COLLATE = utf8mb4_general_ci ROW_FORMAT = Dynamic;SET FOREIGN_KEY_CHECKS =1;SET NAMES utf8mb4;SET FOREIGN_KEY_CHECKS =0;-- ------------------------------ Table structure for sys_stock-- ----------------------------DROPTABLE IF EXISTS `sys_stock`;CREATETABLE `sys_stock`  (  `id` bigint(20)UNSIGNEDNOTNULL,  `product_id` bigint(20)UNSIGNEDNULL DEFAULT NULL,  `number` int(10)UNSIGNEDNULL DEFAULT NULL,  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET= utf8mb4 COLLATE = utf8mb4_general_ci ROW_FORMAT = Dynamic;-- ------------------------------ Records of sys_stock-- ----------------------------INSERTINTO `sys_stock` VALUES(1629394254497902593,1629394038201819138,10);SET FOREIGN_KEY_CHECKS =1;

然后创建一个订单服务、一个库存服务，两个服务的pom依赖引入一致，我这里springboot版本号是2.2.5.RELEASE

<!-- nacos-discovery --><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId><version>2.2.1.RELEASE</version></dependency><!-- nacos-config --><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId><version>2.2.1.RELEASE</version></dependency><!-- org.springframework.cloud/spring-cloud-starter-openfeign --><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-openfeign</artifactId><version>2.2.2.RELEASE</version></dependency><dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-boot-starter</artifactId><version>3.5.2</version></dependency><!-- mysql-connector-java --><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.30</version></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.24</version><scope>provided</scope></dependency><!-- seata-spring-boot-starter --><dependency><groupId>io.seata</groupId><artifactId>seata-spring-boot-starter</artifactId><version>1.6.1</version></dependency><!-- druid-spring-boot-starter --><dependency><groupId>com.alibaba</groupId><artifactId>druid-spring-boot-starter</artifactId><version>1.1.10</version></dependency>

库存项目代码：properties 相关的值自己改一下。

spring.cloud.nacos.discovery.server-addr=localhost:8848
spring.cloud.nacos.discovery.namespace=434e7801-0b5d-4fd2-b96a-acbac849fd84
spring.cloud.nacos.discovery.group=SEATA_GROUP
spring.application.name=sparrow-stock
server.port=8082
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.druid.driver-class-name=com.mysql.cj.jdbc.Driver
#spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driverspring.datasource.url=jdbc:mysql://localhost:3306/demo?useUnicode=true&characterEncoding=UTF-8&serverTimezone=GMT%2B8
spring.datasource.username=root
spring.datasource.password=1234
##要和seataServer.properties中的保持一致seata.tx-service-group=default_tx_group
seata.service.vgroup-mapping.default_tx_group=default

//-----------controller

@RestController@RequestMapping("/stock")
publicclassStockController {
@AutowiredprivateStockServicestockService;
@PostMapping("/minus")
publicStringminus(@RequestParam("productId") LongproductId){
returnstockService.minus(productId);
    }
}

//---------entity

@TableName("sys_stock")
@DatapublicclassStock {
@TableIdprivateLongid;
@TableField("product_id")
privateLongproductId;
@TableField("number")
privateIntegernumber;
}

//------------service

publicinterfaceStockServiceextendsIService<Stock> {
Stringminus(LongproductId);
}

//-------------impl

@Service("stockService")
publicclassStockServiceImplextendsServiceImpl<StockMapper, Stock>implementsStockService {
@AutowiredprivateStockMapperstockMapper;
@OverridepublicStringminus(LongproductId) {
//int a =1/0;System.out.println("----------"+RootContext.getXID());
stockMapper.minus(productId);
return"库存-1";
    }
}

//-------------mapper

@MapperpublicinterfaceStockMapperextendsBaseMapper<Stock> {
@Update("update sys_stock set number=number-1 where product_id=#{productId}")
Integerminus(LongproductId);
}

订单服务代码：

spring.cloud.nacos.discovery.server-addr=localhost:8848
spring.cloud.nacos.discovery.namespace=434e7801-0b5d-4fd2-b96a-acbac849fd84
spring.cloud.nacos.discovery.group=SEATA_GROUP
spring.application.name=sparrow-order
server.port=8083
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.druid.driver-class-name=com.mysql.cj.jdbc.Driver
#spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driverspring.datasource.url=jdbc:mysql://localhost:3306/demo?useUnicode=true&characterEncoding=UTF-8&serverTimezone=GMT%2B8
spring.datasource.username=root
spring.datasource.password=1234
##要和seataServer.properties中的保持一致seata.tx-service-group=default_tx_group
seata.service.vgroup-mapping.default_tx_group=default

//--------------Controller

@RestControllerpublicclassOrderController {
@AutowiredprivateOrderServiceorderService;
@GlobalTransactional@PostMapping("/add")
publicStringadd(LongproductId){
returnorderService.add(productId);
    }
}

//--------------entity

@TableName("sys_order")
@DatapublicclassOrder {
@TableIdprivateLongid;
@TableField("product_id")
privateLongproductId;
@TableField("number")
privateIntegernumber;
}

//-----------feign

@FeignClient(value="sparrow-stock",path="/stock")
publicinterfaceStockService {
@PostMapping("/minus")
Stringminus(@RequestParam("productId")LongproductId);
}

//----------service

publicinterfaceOrderServiceextendsIService<Order> {
Stringadd(LongproductId);
}

//-----------impl

@Service("orderService")
publicclassOrderServiceImplextendsServiceImpl<OrderMapper, Order>implementsOrderService {
@AutowiredprivateStockServicestockService;
@OverridepublicStringadd(LongproductId) {
System.out.println("----------"+RootContext.getXID());
//减库存stockService.minus(productId);
Orderorder=newOrder();
order.setId(IdWorker.getId());
order.setProductId(productId);
order.setNumber(1);
this.save(order);
inta=1/0;
return"商品下单成功";
    }
}

//-------------mapper

@MapperpublicinterfaceOrderMapperextendsBaseMapper<Order> {
}

先演示不用seata，使用spring事务注解@Transactional

两种情况：1、本地服务代码先执行，然后再调远程服务接口，比如我在减库存的时候失败了，其实两边数据都会回滚

2、调用远程服务接口后，还需要执行本地服务的业务代码。比如先减库存成功了，但是订单服务这边还需要执行其他业务，但是这些业务失败了，那么订单这里会回滚数据，库存服务那边就没法回滚了。这里为了方便演示，我把库存业务放到前面去，结果就是库存减成功了，而订单服务这边数据回滚了。

使用seata的@GlobalTransactional 在本地服务的controller上加。

再次调用接口，库存表中的数量没有减少

想看undo_log表中数据是临时数据，想看的话可以debug。至此，配置与使用篇完结。下一篇我们看看seata的相关概念和实现原理。

SEATA1.6.1的配置与使用

说在前面

1、seata服务的安装与配置

2、使用seata

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