Java分布式事务（七）

🔥Seata提供XA模式实现分布式事务_业务说明

业务说明
本实例通过Seata中间件实现分布式事务，模拟两个账户的转账交易
过程。两个账户在两个不同的银行（张三在bank1、李四在bank2），bank1和bank2是两个微服务。交易过程中，张三给李四转账制定金额。上述交易步骤，要么一起成功，要么一起失败，必须是一个整体性的事务。

工程环境

创建数据库
bank1库，包含张三账户

CREATE DATABASE /*!32312 IF NOT EXISTS*/bank1;
/*!40100 DEFAULT CHARACTER SET utf8 */;
USE bank1;
/*Table structure for table account_info */
DROP TABLE IF EXISTS account_info;
CREATE TABLE account_info (id bigint(20) NOT NULL AUTO_INCREMENT,
account_name varchar(100) COLLATE utf8_bin DEFAULT NULL COMMENT '户主姓名',
account_no varchar(100) COLLATE utf8_bin DEFAULT NULL COMMENT '银行卡号',
account_password varchar(100) COLLATE utf8_bin DEFAULT NULL COMMENT '帐户密码',account_balance double DEFAULT NULL COMMENT '帐户余额',
PRIMARY KEY (id) USING BTREE) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULTCHARSET=utf8 COLLATE=utf8_bin
ROW_FORMAT=DYNAMIC;
/*Data for the table `account_info` */
insert  into
account_info(id,account_name,account_no ,account_password,account_balance) values
(2,'张三','1',NULL,1000);

bank2库，包含李四账户

CREATE DATABASE /*!32312 IF NOT EXISTS*/bank2
/*!40100 DEFAULT CHARACTER SET utf8 */;
USE bank2;
/*Table structure for table account_info */
DROP TABLE IF EXISTS account_info;
CREATE TABLE account_info (
id bigint(20) NOT NULL AUTO_INCREMENT,
account_name varchar(100) COLLATE utf8_bin DEFAULT NULL COMMENT '户主姓名',
account_no varchar(100) COLLATE utf8_bin DEFAULT NULL COMMENT '银行卡号',
account_password varchar(100) COLLATE utf8_bin DEFAULT NULL COMMENT '帐户密码', account_balance double DEFAULT NULL COMMENT  '帐户余额',
PRIMARY KEY (id) USING BTREE) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT
CHARSET=utf8 COLLATE=utf8_bin ROW_FORMAT=DYNAMIC;
/*Data for the table `account_info` */
insert  into account_info(id,account_name,account_no,account_password,account_balance) values(3,'李四','2',NULL,0);

🔥Seata提供XA模式实现分布式事务_下载启动Seata服务

下载seata服务器
下载地址:https://github.com/seata/seata/releases

解压并启动

tar -zxvf seata-server-1.4.2.tar.gz -C
/usr/local/
#后台运行
nohup sh seata-server.sh -p 9999 -h
192.168.66.100 -m file &> seata.log &

注意：
其中9999为服务端口号；file为启动模式,这里指seata服务将采用文件的方式存储信息。

测试
查看启动日志

cat seata.log

Seata提供XA模式实现分布式事务_搭建聚合父工程构建
创建工程distribute-transaction
tar -zxvf seata-server-1.4.2.tar.gz -C
/usr/local/
#后台运行
nohup sh seata-server.sh -p 9999 -h
192.168.66.100 -m file &> seata.log &
cat seata.log
71
字符编码
注解生效激活
72
Java编译版本选择

org.apache.maven.plugins
maven-compilerplugin

1.8
1.8
UTF-8

73
File Type过滤
pom配置版本

<spring-boot.version>2.6.3</springboot.version>

<spring.cloud.version>2021.0.1</spring.cloud.v
ersion>

<spring.cloud.alibaba.version>2021.0.1.0</spri
ng.cloud.alibaba.version>

<lombok.version>1.18.22</lombok.version>

74
75

org.springframework.boot
spring-bootstarter-parent
${spring-boot.version}

pom
import

org.springframework.cloud
spring-clouddependencies

${spring.cloud.version}
pom
import

com.alibaba.cloud
spring-cloudalibaba-dependencies

${spring.cloud.alibaba.version}

IDEA开启Dashboard
普通的Run面板
Run Dashboard面板
pom
import

org.projectlombok
lombok
${lombok.version}

76
修改配置文件
在.idea/workspace.xml 文件中找到
添加配置
Seata提供XA模式实现分布式事务_转账功能实现上

🔥Seata提供XA模式实现分布式事务_转账功能实现上

实现如下功能
⭐李四账户增加金额。

创建bank2

pom引入依赖

 <dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starterweb</artifactId></dependency><dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-bootstarter</artifactId><version>3.5.1</version></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connectorjava</artifactId><version>5.1.49</version></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></dependency><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starteralibaba-nacos-discovery</artifactId></dependency>

编写主启动类

//添加对mapper包扫描 Mybatis-plus
@MapperScan("com.it.mapper")
@SpringBootApplication
@Slf4j
//开启发现注册
@EnableDiscoveryClient
public class SeataBank2Main6002 {public static void main(String[] args) {SpringApplication.run(SeataBank1Main6002.class
,args);log.info("**************
SeataBank1Main6002 *************");}
}

编写YML配置文件

server:port: 6002
spring:application:name: seata-bank2
cloud:nacos:discovery:# Nacos server地址server-addr: 192.168.66.101:8848datasource:url: jdbc:mysql://localhost:3306/bank2?
useUnicode=true&characterEncoding=utf-
8&useSSL=false&serverTimezone=UTCusername: rootpassword: 123456driver-class-name: com.mysql.jdbc.Driver   

代码生成

引入Mybatis Plus代码生成依赖

<dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plusgenerator</artifactId><version>3.5.2</version></dependency><!-- 模板引擎 --><dependency><groupId>org.apache.velocity</groupId><artifactId>velocity-enginecore</artifactId><version>2.0</version></dependency>

生成代码

package com.it.utils;
import
com.baomidou.mybatisplus.generator.FastAutoGenerator;
import
com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;
import java.util.Arrays;
import java.util.List;
public class CodeGenerator {public static void main(String[] args) {FastAutoGenerator.create("jdbc:mysql://192.168.66.100:3306/bank2", "root", "123456").globalConfig(builder -> {builder.author("it")
// 设置作者.commentDate("MM-dd") // 注释日期格式.outputDir(System.getProperty("user.dir")+
"/xa-seata/bank2"+ "/src/main/java/") // 指定输出目录.fileOverride(); // 覆盖文件})// 包配置.packageConfig(builder -> {
builder.parent("com.it") // 包名前缀.entity("entity")
//实体类包名.mapper("mapper")
//mapper接口包名.service("service"); //service包名}).strategyConfig(builder -> {// 设置需要生成的表名List<String> strings =
Arrays.asList("account_info");builder.addInclude(strings)
// 开始实体类配置
.entityBuilder()
// 开启lombok模型
.enableLombok()
//表名下划线转驼峰
.naming(NamingStrategy.underline_to_camel)
//列名下划线转驼峰
.columnNaming(NamingStrategy.underline_to_camel
);}).execute();}
}               

编写转账接口

public interface IAccountInfoService {//李四增加金额void updateAccountBalance(String accountNo,Double amount);
}

编写转账接口实现类

@Service
@Slf4j
public class AccountInfoServiceImpl implements IAccountInfoService {@AutowiredAccountMapper accountMapper;@Overridepublic void updateAccountBalance(String
accountNo, Double amount) {// 1. 获取用户信息AccountInfo accountInfo =
accountMapper.selectById(accountNo);accountInfo.setAccountBalance(accountInfo.getAccountBalance() + amount);accountMapper.updateById(accountInfo);}
}

编写控制层

@RestController
@RequestMapping("/bank2")
public class Bank2Controller {@AutowiredIAccountInfoService accountInfoService;//接收张三的转账@GetMapping("/transfer")public String transfer(Double amount){//李四增加金额accountInfoService.updateAccountBalance("3",amount);return "bank2"+amount;}
}

🔥Seata提供XA模式实现分布式事务_转账功能实现下

实现如下功能
⭐张三账户减少金额
⭐远程调用bank2向李四转账。

pom引入依赖

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-bootstarter</artifactId><version>3.5.1</version></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connectorjava</artifactId><version>5.1.49</version></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></dependency><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starteralibaba-nacos-discovery</artifactId></dependency><!-- openfeign --><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starteropenfeign</artifactId></dependency><dependency> 
<groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starterloadbalancer</artifactId></dependency>             

编写主启动类

//添加对mapper包扫描 Mybatis-plus
@MapperScan("com.it.mapper")
//开启OpenFiegn
@EnableFeignClients
@SpringBootApplication
@Slf4j
//开启发现注册
@EnableDiscoveryClient
public class SeataBank1Main6001 {public static void main(String[] args) {SpringApplication.run(SeataBank1Main6001.class,args);log.info("**************
SeataBank1Main6001 *************");}
}

编写YML配置文件

server:port: 6001
spring:application:name: seata-bank1cloud:nacos:discovery:# Nacos server地址server-addr: 192.168.66.101:8848datasource:url: jdbc:mysql://localhost:3306/bank1?
useUnicode=true&characterEncoding=utf-
8&useSSL=true&serverTimezone=UTCusername: rootpassword: 123456driver-class-name: com.mysql.jdbc.Driver

创建实体类

@AllArgsConstructor
@NoArgsConstructor
@Builder
@TableName("account_info")
@Data
public class AccountInfo {//id@TableIdprivate Long id;//户主姓名@TableField("account_name")private String accountName;//银行卡号@TableField("account_no")private String accountNo;//账户密码@TableField("account_password")private String accountPassword;//账户余额@TableField("account_balance")private Double accountBalance;
}   

编写持久层

@Component
@Mapper
public interface AccountMapper extends
BaseMapper<AccountInfo> {
}

编写转账接口

public interface IAccountInfoService {//张三扣减金额public void updateAccountBalance(String
accountNo, Double amount);
}

编写远程调用接口

@Component
@FeignClient(value="seata-bank2")
public interface Bank2Client {//远程调用李四的微服务@GetMapping("/bank2/transfer")String transfer(@RequestParam("amount")
Double amount);
}

编写转账接口实现类

@Service
@Slf4j
public class AccountInfoServiceImpl implements IAccountInfoService {@AutowiredAccountMapper accountMapper;@AutowiredBank2Client bank2Client;@Overridepublic void updateAccountBalance(String
accountNo, Double amount) {// 1. 获取用户信息AccountInfo accountInfo =
accountMapper.selectById(2);// 2. 判断张三账户余额是否有钱if (accountInfo.getAccountBalance() >
amount){//扣减张三的金额accountInfo.setAccountBalance(accountInfo.getAccountBalance()-amount);int result =
accountMapper.updateById(accountInfo);if (result!=0){//调用李四微服务，转账bank2Client.transfer(amount);}}}
}

编写控制层

@RestController
public class Bank1Controller {@AutowiredIAccountInfoService IAccountInfoService;//张三转账@GetMapping("/transfer")public String transfer(Double amount){IAccountInfoService.updateAccountBalance("1",amount);return "bank1"+amount;}}