//1、如果方法a、b、c都在同一个service里面，事务传播行为不生效，共享一个事务
//  原理：事务是用代理对象来控制的，内部调用b(),c(),就相当于直接调用没有经过事务【绕过了代理对象】
//  解决：不能使用this.b()；也不能注入自己【要使用代理对象来调用事务方法】
    
    
@Transactional(timeout=30)
public void a() {
  b();// a事务传播给了b事务，并且b事务的设置失效
  c();// c单独创建一个新事务
}
@Transactional(propagation = Propagation.REQUIRED, timeout=2)
public void b() {
}
@Transactional(propagation = Propagation.REQUIRES_NEW)
public void c() {
}

<!-- 引入aop，解决本地事务失效问题 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-aop</artifactId>
        </dependency

@EnableAspectJAutoProxy(exposeProxy = true)  //开启了aspect动态代理模式,对外暴露代理对象

OrderServiceImpl orderService = (OrderServiceImpl)AopContext.currentProxy(); 
orderService.b(); 
orderService.c();

startup.cmd -m standalone

http://localhost:8082/order?userId=user202103032042012&commodityCode=100202003032041&count=2&money=200

http://localhost:8082/order?userId=user202103032042012&commodityCode=100202003032041&count=20&money=200

registry {
  ## tc服务的注册中心类，这里选择nacos，也可以是eureka、zookeeper等
  type = "nacos"    #注册中心类型是nacos
                    
  nacos {
    ## seata tc 服务注册到 nacos的服务名称，可以自定义
    application = "seata-tc-server"
    serverAddr = "127.0.0.1:8848"
    group = "DEFAULT_GROUP"
    namespace = ""
    cluster = "SH"
    username = "nacos"
    pass改成自己的密码word = "nacos"
  }
}
config {
  ## 读取tc服务端的配置文件的方式，这里是从nacos配置中心读取，这样如果tc是集群，可以共享配置
  type = "nacos"    #也可以设置成file类型配置，会从本目录下找"file.conf"读取配置
  ## 配置nacos地址等信息
  nacos {
    serverAddr = "127.0.0.1:8848"
    namespace = ""
    group = "SEATA_GROUP"
    username = "nacos"
    pass改成自己的密码word = "nacos"
    dataId = "seataServer.properties"
  }
}

#store事务日志存在哪里，这里设成数据库。也可以设成file类型
# 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.jdbc.Driver
store.db.url=jdbc:mysql://127.0.0.1:3306/seata?useUnicode=true&rewriteBatchedStatements=true
store.db.user=root
store.db.password=123
store.db.minConn=5
store.db.maxConn=30
store.db.globalTable=global_table    #全局事务的表
store.db.branchTable=branch_table    #分支事务的表
store.db.queryLimit=100
store.db.lockTable=lock_table        #锁的表
store.db.maxWait=5000
## 事务、日志等配置
server.recovery.committingRetryPeriod=1000
server.recovery.asynCommittingRetryPeriod=1000
server.recovery.rollbackingRetryPeriod=1000
server.recovery.timeoutRetryPeriod=1000
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

transport {
  # tcp udt unix-domain-socket
  type = "TCP"
  #NIO NATIVE
  server = "NIO"
  #enable heartbeat
  heartbeat = true
  #thread factory for netty
  thread-factory {
    boss-thread-prefix = "NettyBoss"
    worker-thread-prefix = "NettyServerNIOWorker"
    server-executor-thread-prefix = "NettyServerBizHandler"
    share-boss-worker = false
    client-selector-thread-prefix = "NettyClientSelector"
    client-selector-thread-size = 1
    client-worker-thread-prefix = "NettyClientWorkerThread"
    # netty boss thread size,will not be used for UDT
    boss-thread-size = 1
    #auto default pin or 8
    worker-thread-size = 8
  }
  shutdown {
    # when destroy server, wait seconds
    wait = 3
  }
  serialization = "seata"
  compressor = "none"
}
service {
  #vgroup->rgroup
  vgroup_mapping.gulimall-order-fescar-service-group = "default"
  #only support single node
  default.grouplist = "127.0.0.1:8091"
  #degrade current not support
  enableDegrade = false
  #disable
  disable = false
  #unit ms,s,m,h,d represents milliseconds, seconds, minutes, hours, days, default permanent
  max.commit.retry.timeout = "-1"
  max.rollback.retry.timeout = "-1"
}
client {
  async.commit.buffer.limit = 10000
  lock {
    retry.internal = 10
    retry.times = 30
  }
  report.retry.count = 5
}
## transaction log store
store {
  ## store mode: file、db
  mode = "file"
  ## file store
  file {
    dir = "sessionStore"
    # branch session size , if exceeded first try compress lockkey, still exceeded throws exceptions
    max-branch-session-size = 16384
    # globe session size , if exceeded throws exceptions
    max-global-session-size = 512
    # file buffer size , if exceeded allocate new buffer
    file-write-buffer-cache-size = 16384
    # when recover batch read size
    session.reload.read_size = 100
    # async, sync
    flush-disk-mode = async
  }
  ## database store
  db {
    ## the implement of javax.sql.DataSource, such as DruidDataSource(druid)/BasicDataSource(dbcp) etc.
    datasource = "dbcp"
    ## mysql/oracle/h2/oceanbase etc.
    db-type = "mysql"
    url = "jdbc:mysql://127.0.0.1:3306/seata"
    user = "mysql"
    passw改成自己密码ord = "mysql"
    min-conn = 1
    max-conn = 3
    global.table = "global_table"
    branch.table = "branch_table"
    lock-table = "lock_table"
    query-limit = 100
  }
}
lock {
  ## the lock store mode: local、remote
  mode = "remote"
  local {
    ## store locks in user's database
  }
  remote {
    ## store locks in the seata's server
  }
}
recovery {
  committing-retry-delay = 30
  asyn-committing-retry-delay = 30
  rollbacking-retry-delay = 30
  timeout-retry-delay = 30
}
transaction {
  undo.data.validation = true
  undo.log.serialization = "jackson"
}
## metrics settings
metrics {
  enabled = false
  registry-type = "compact"
  # multi exporters use comma divided
  exporter-list = "prometheus"
  exporter-prometheus-port = 9898
}

SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;
-- ----------------------------
-- 分支事务表
-- ----------------------------
DROP TABLE IF EXISTS `branch_table`;
CREATE TABLE `branch_table`  (
  `branch_id` bigint(20) NOT NULL,
  `xid` varchar(128) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
  `transaction_id` bigint(20) NULL DEFAULT NULL,
  `resource_group_id` varchar(32) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `resource_id` varchar(256) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `branch_type` varchar(8) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `status` tinyint(4) NULL DEFAULT NULL,
  `client_id` varchar(64) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `application_data` varchar(2000) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `gmt_create` datetime(6) NULL DEFAULT NULL,
  `gmt_modified` datetime(6) NULL DEFAULT NULL,
  PRIMARY KEY (`branch_id`) USING BTREE,
  INDEX `idx_xid`(`xid`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Compact;
-- ----------------------------
-- 全局事务表
-- ----------------------------
DROP TABLE IF EXISTS `global_table`;
CREATE TABLE `global_table`  (
  `xid` varchar(128) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
  `transaction_id` bigint(20) NULL DEFAULT NULL,
  `status` tinyint(4) NOT NULL,
  `application_id` varchar(32) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `transaction_service_group` varchar(32) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `transaction_name` varchar(128) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `timeout` int(11) NULL DEFAULT NULL,
  `begin_time` bigint(20) NULL DEFAULT NULL,
  `application_data` varchar(2000) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `gmt_create` datetime NULL DEFAULT NULL,
  `gmt_modified` datetime NULL DEFAULT NULL,
  PRIMARY KEY (`xid`) USING BTREE,
  INDEX `idx_gmt_modified_status`(`gmt_modified`, `status`) USING BTREE,
  INDEX `idx_transaction_id`(`transaction_id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Compact;
SET FOREIGN_KEY_CHECKS = 1;

<!--seata-->
<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-seata</artifactId>
    <exclusions>
        <!--版本较低，1.3.0，因此排除--> 
        <exclusion>
            <artifactId>seata-spring-boot-starter</artifactId>
            <groupId>io.seata</groupId>
        </exclusion>
    </exclusions>
</dependency>
<dependency>
    <groupId>io.seata</groupId>
    <artifactId>seata-spring-boot-starter</artifactId>
    <!--seata starter 采用1.4.2版本-->
    <version>${seata.version}</version>
</dependency>

seata:
  registry: # TC服务注册中心的配置，微服务根据这些信息去注册中心获取tc服务地址
    type: nacos # 注册中心类型 nacos
    nacos:
      server-addr: 127.0.0.1:8848 # nacos地址
      namespace: "" # namespace，默认为空
      group: DEFAULT_GROUP # 分组，默认是DEFAULT_GROUP
      application: seata-tc-server # seata服务名称
      username: nacos
      password: nacos
  tx-service-group: seata-demo # 事务组名称
  service:
    vgroup-mapping: # 事务组与cluster的映射关系
      seata-demo: SH

seata:
  data-source-proxy-mode: XA    #开启数据源代理的XA模式。代理数据源，拦截业务sql操作

update tb_account set money = money - 10 where id = 1

{
    "id": 1, "money": 100
}

<!--seata-->
<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-seata</artifactId>
</dependency>

-- 注意此处0.7.0+ 增加字段 context
CREATE TABLE `undo_log` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `branch_id` bigint(20) NOT NULL,
  `xid` varchar(100) NOT NULL,
  `context` varchar(128) NOT NULL,
  `rollback_info` longblob NOT NULL,
  `log_status` int(11) NOT NULL,
  `log_created` datetime NOT NULL,
  `log_modified` datetime NOT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `ux_undo_log` (`xid`,`branch_id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;

seata:
  data-source-proxy-mode: AT # 默认就是AT

@GlobalTransactional
@Transactional  // 本地事务，在分布式系统，只能控制住自己的回滚，控制不了其他服务的回滚。
@Override
public SubmitOrderResponseVo submitOrder(OrderSubmitVo vo) {
  //.....
}

@Configuration
public class MySeataConfig {
    @Autowired
    DataSourceProperties dataSourceProperties;
    @Bean
    public DataSource dataSource(DataSourceProperties dataSourceProperties) {
        HikariDataSource dataSource = dataSourceProperties.initializeDataSourceBuilder().type(HikariDataSource.class).build();
        if (StringUtils.hasText(dataSourceProperties.getName())) {
            dataSource.setPoolName(dataSourceProperties.getName());
        }
        return new DataSourceProxy(dataSource);
    }
}

@Configuration
public class DataSourceProxyConfig {
    @Bean
    @ConfigurationProperties(prefix = "spring.datasource")
    public DruidDataSource druidDataSource() {
        return new DruidDataSource();
    }
    @Primary
    @Bean
    public DataSourceProxy dataSource(DruidDataSource druidDataSource) {
        return new DataSourceProxy(druidDataSource);
    }
}

CREATE TABLE `account_freeze_tbl` (
  `xid` varchar(128) NOT NULL,
  `user_id` varchar(255) DEFAULT NULL COMMENT '用户id',
  `freeze_money` int(11) unsigned DEFAULT '0' COMMENT '冻结金额',
  `state` int(1) DEFAULT NULL COMMENT '事务状态，0:try，1:confirm，2:cancel',
  PRIMARY KEY (`xid`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8 ROW_FORMAT=COMPACT;

CREATE TABLE `account_freeze_tbl` (
  `xid` varchar(128) NOT NULL,
  `user_id` varchar(255) DEFAULT NULL COMMENT '用户id',
  `freeze_money` int(11) unsigned DEFAULT '0' COMMENT '冻结金额',
  `state` int(1) DEFAULT NULL COMMENT '事务状态，0:try，1:confirm，2:cancel',
  PRIMARY KEY (`xid`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8 ROW_FORMAT=COMPACT;

package cn.itcast.account.service;
import io.seata.rm.tcc.api.BusinessActionContext;
import io.seata.rm.tcc.api.BusinessActionContextParameter;
import io.seata.rm.tcc.api.LocalTCC;
import io.seata.rm.tcc.api.TwoPhaseBusinessAction;
//声明为ttc
@LocalTCC
public interface AccountTCCService {
    //在try方法上@TwoPhaseBusinessAction声明try、confirm、cancel的方法名
    @TwoPhaseBusinessAction(name = "deduct", commitMethod = "confirm", rollbackMethod = "cancel")
    //参数注解@BusinessActionContextParameter将参数放在上下文对象，在本接口所有方法都能拿到这个参数
    void deduct(@BusinessActionContextParameter(paramName = "userId") String userId,
                @BusinessActionContextParameter(paramName = "money")int money);
    //confirm方法名要跟@TwoPhaseBusinessAction声明的一致，BusinessActionContext上下文对象获取try方法注解@BusinessActionContextParameter的参数
    boolean confirm(BusinessActionContext ctx);
    boolean cancel(BusinessActionContext ctx);
}

package cn.itcast.account.service.impl;
import cn.itcast.account.entity.AccountFreeze;
import cn.itcast.account.mapper.AccountFreezeMapper;
import cn.itcast.account.mapper.AccountMapper;
import cn.itcast.account.service.AccountTCCService;
import io.seata.core.context.RootContext;
import io.seata.rm.tcc.api.BusinessActionContext;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
@Service
@Slf4j
public class AccountTCCServiceImpl implements AccountTCCService {
    @Autowired
    private AccountMapper accountMapper;
    @Autowired
    private AccountFreezeMapper freezeMapper;
    @Override
    //业务注解
    @Transactional
    public void deduct(String userId, int money) {
        // 0.获取事务id，RootContext是seata提供的工具类，用来获取id。
        String xid = RootContext.getXID();
        
        //判断事务悬挂，如果有冻结记录则是悬挂，直接return。对于已经空回滚的业务，之前被阻塞的try操作恢复，继续执行try，就永远不可能confirm或cancel ，事务一直处于中间状态，这就是业务悬挂。
        if(accountMapper.selectById(xid)==null) return;
        // 1.扣减可用余额，这里不用余额判断，因为数据库余额字段类型是非负，扣成负数就业务失败
        accountMapper.deduct(userId, money);
        // 2.记录冻结金额，事务状态
        AccountFreeze freeze = new AccountFreeze();
        freeze.setUserId(userId);
        freeze.setFreezeMoney(money);
        //自定义常量AccountFreeze.State.TRY值就是0
        freeze.setState(AccountFreeze.State.TRY);
        freeze.setXid(xid);
        freezeMapper.insert(freeze);
    }
    @Override
    public boolean confirm(BusinessActionContext ctx) {
        // 1.获取事务id，也可以用RootContext获取xid
        String xid = ctx.getXid();
        // 2.根据id删除冻结记录，confirm方法不用幂等处理，因为它是直接删除，删多少次都是删
        int count = freezeMapper.deleteById(xid);
        return count == 1;
    }
    @Override
    public boolean cancel(BusinessActionContext ctx) {
        // 0.查询冻结记录
        String xid = ctx.getXid();
        AccountFreeze freeze = freezeMapper.selectById(xid);
        
        //判断空回滚。当某分支事务的try阶段阻塞时，可能导致全局事务超时而触发二阶段的cancel操作。在未执行try操作时先执行了cancel操作，这时cancel不能做回滚，就是空回滚。
        if(freeze==null){freeze =new freeze;设置userId,state,xid;freezeMapper.insert(freeze);return true}
        //幂等判断，如果已经处理过一次cancel时不需要再cancel了（可能源于超时被认为失败其实没失败，再cancel了一次）。confirm方法不用幂等处理，因为它是直接删除，删多少次都是删
        if(freeze.getState()==AccountFreeze.State.CANCEL){return true;}
        // 1.恢复可用余额
        accountMapper.refund(freeze.getUserId(), freeze.getFreezeMoney());
        // 2.将冻结金额清零，状态改为CANCEL
        freeze.setFreezeMoney(0);
        freeze.setState(AccountFreeze.State.CANCEL);
        int count = freezeMapper.updateById(freeze);
        return count == 1;
    }
}

http://localhost:8082/order?userId=user202103032042012&commodityCode=100202003032041&count=1&money=2000000

registry {
  ## tc服务的注册中心类，这里选择nacos，也可以是eureka、zookeeper等
  type = "nacos"
  nacos {
    ## seata tc 服务注册到 nacos的服务名称，可以自定义
    application = "seata-tc-server"
    serverAddr = "127.0.0.1:8848"
    group = "DEFAULT_GROUP"
    namespace = ""
    cluster = "HZ"
    username = "nacos"
    pass改成自己的密码word = "nacos"
  }
}
config {
  ## 读取tc服务端的配置文件的方式，这里是从nacos配置中心读取，这样如果tc是集群，可以共享配置
  type = "nacos"
  ## 配置nacos地址等信息
  nacos {
    serverAddr = "127.0.0.1:8848"
    namespace = ""
    group = "SEATA_GROUP"
    username = "nacos"
    pass改成自己的密码word = "nacos"
    dataId = "seataServer.properties"
  }
}

seata-server.bat -p 8092

## 事务组映射关系
service.vgroupMapping.seata-demo=SH
service.enableDegrade=false
service.disableGlobalTransaction=false
## 与TC服务的通信配置
transport.type=TCP
transport.server=NIO
transport.heartbeat=true
transport.enableClientBatchSendRequest=false
transport.threadFactory.bossThreadPrefix=NettyBoss
transport.threadFactory.workerThreadPrefix=NettyServerNIOWorker
transport.threadFactory.serverExecutorThreadPrefix=NettyServerBizHandler
transport.threadFactory.shareBossWorker=false
transport.threadFactory.clientSelectorThreadPrefix=NettyClientSelector
transport.threadFactory.clientSelectorThreadSize=1
transport.threadFactory.clientWorkerThreadPrefix=NettyClientWorkerThread
transport.threadFactory.bossThreadSize=1
transport.threadFactory.workerThreadSize=default
transport.shutdown.wait=3
## RM配置
client.rm.asyncCommitBufferLimit=10000
client.rm.lock.retryInterval=10
client.rm.lock.retryTimes=30
client.rm.lock.retryPolicyBranchRollbackOnConflict=true
client.rm.reportRetryCount=5
client.rm.tableMetaCheckEnable=false
client.rm.tableMetaCheckerInterval=60000
client.rm.sqlParserType=druid
client.rm.reportSuccessEnable=false
client.rm.sagaBranchRegisterEnable=false
## TM配置
client.tm.commitRetryCount=5
client.tm.rollbackRetryCount=5
client.tm.defaultGlobalTransactionTimeout=60000
client.tm.degradeCheck=false
client.tm.degradeCheckAllowTimes=10
client.tm.degradeCheckPeriod=2000
## undo日志配置
client.undo.dataValidation=true
client.undo.logSerialization=jackson
client.undo.onlyCareUpdateColumns=true
client.undo.logTable=undo_log
client.undo.compress.enable=true
client.undo.compress.type=zip
client.undo.compress.threshold=64k
client.log.exceptionRate=100

seata:
  config:
    type: nacos
    nacos:
      server-addr: 127.0.0.1:8848
      username: nacos
      password: nacos
      group: SEATA_GROUP
      data-id: client.properties