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Springboot编程式事务使用方式详解

Spring全家桶实战案例

2021-12-01

导读：Springboot编程式事务使用方式详解

环境：springboot2.3.9.RELEASE

Spring提供两种编程式事务管理方法：

使用TransactionTemplate 或 TransactionalOperator
直接创建TransactionManager的实现

Spring官方推荐使用TransactionTemplate方式

准备

// 实体类@Entity@Table(name = "BC_USERS")@Datapublic class Users{  private String username ;  private String password ;  private Integer status = 0 ;}// DAOpublic interface UsersRepository extends JpaRepository<Users, String> {
  @Modifying  @Query("update Users u set u.status=?1,u.password='123123' where u.id=?2")  int updateUsers(Integer status, String id) ;  }@Mapperpublic interface UsersMapper {
  int insertUser(Users user) ;  }// Mapper.xml<insert id="insertUser" parameterType="com.pack.domain.Users">  insert into bc_users (id, username, password) values (#{id}, #{username}, #{password})</insert>

1 TransactionTemplate

1.1 有返回值的

@Servicepublic class UserService {      @Resource  private TransactionTemplate transactionTemplate ;  @Resource  private UsersRepository usersRepository ;      public Integer saveUsers(Users users) {    this.transactionTemplate.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRES_NEW);    Integer result = transactionTemplate.execute(new TransactionCallback<Integer>() {      @Override      public Integer doInTransaction(TransactionStatus status) {        return usersMapper.insertUser(users) ;      }    }) ;    return result ;  }    }

1.2 无返回值的

当没有返回值时可以使用
TransactionCallbackWithoutResult

public void saveUsers(Users users) {  transactionTemplate.execute(new TransactionCallbackWithoutResult() {    @Override    protected void doInTransactionWithoutResult(TransactionStatus status) {      usersMapper.insertUser(users) ;    }  }) ;}

1.3 事务回滚

事务的回滚通过
TransactionStatus.setRollbackOnly方法

public Users saveUser(Users users) {  return transactionTemplate.execute(new TransactionCallback<Users>() {    @Override    public Users doInTransaction(TransactionStatus status) {      try {        return usersMapper.insertUser(users) ;      } catch (Exception e) {        status.setRollbackOnly() ;      }      return null ;    }  }) ;}

1.4 配置事务属性

在实例化TransactionTemplate对象的时候我们可以对事务进行相关的属性配置，通过如下方式。

private TransactionTemplate transactionTemplate ;    public UserService(PlatformTransactionManager transactionManager) {  this.transactionTemplate = new TransactionTemplate(transactionManager) ;  this.transactionTemplate.setPropagationBehavior(TransactionDefinition.PROPAGATION_NOT_SUPPORTED);  this.transactionTemplate.setTimeout(30); //seconds}

测试代码

public Integer updateUsers(Integer statusValue, String id) {  return transactionTemplate.execute(new TransactionCallback<Integer>() {    @Override    public Integer doInTransaction(TransactionStatus status) {      return usersRepository.updateUsers(statusValue, id) ;    }  }) ;}@Modifying@Query("update Users u set u.status=?1 where u.id=?2")int updateUsers(Integer status, String id) ;

由于这里事务传播属性设置的NOT_SUPPORTED.所以程序会报错误

org.springframework.dao.InvalidDataAccessApiUsageException: Executing an update/delete query; nested exception is javax.persistence.TransactionRequiredException: Executing an update/delete query    at org.springframework.orm.jpa.EntityManagerFactoryUtils.convertJpaAccessExceptionIfPossible(EntityManagerFactoryUtils.java:403)    at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:257)    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.translateExceptionIfPossible(AbstractEntityManagerFactoryBean.java:531)

2 TransactionalOperator

TransactionalOperator适用于反应式编程，这里不做介绍。

3 TransactionManager

使用TransactionManager管理事务也有两种
PlatformTransactionManager，
ReactiveTransactionManager

ReactiveTransactionManager适用于反应式编程，这里不做介绍。

3.1 PlatformTransactionManager

在程序中可以使用
PlatformTransactionManager来控制事务的提交与回滚

示例：

private PlatformTransactionManager transactionManager ;private DefaultTransactionDefinition definition ;private TransactionStatus status ;@Resourceprivate UsersRepository usersRepository ;
public UserService3(PlatformTransactionManager transactionManager) {  this.transactionManager = transactionManager ;  definition = new DefaultTransactionDefinition() ;  definition.setName("pgName") ;  definition.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRED) ;}  public Integer saveUsers(Users users) {  TransactionStatus status = this.transactionManager.getTransaction(definition) ;  Integer result = null ;  try {    result = usersMapper.insertUser(users) ;  } catch (Exception e) {    transactionManager.rollback(status) ;    throw e ;  }  transactionManager.commit(status) ;  publisher.publishEvent(new UsersEvent(users));  return result ;    }

4 事务事件监听

通过@
TransactionalEventListener注解监听事务的不同阶段的事件信息

public @interface TransactionalEventListener {  TransactionPhase phase() default TransactionPhase.AFTER_COMMIT;  boolean fallbackExecution() default false;  @AliasFor(annotation = EventListener.class, attribute = "classes")  Class<?>[] value() default {};  @AliasFor(annotation = EventListener.class, attribute = "classes")  Class<?>[] classes() default {};  String condition() default "";}

fallbackExecution: 默认值false；如果设置为true，当前即便没有事务也会触发事件。

TransactionPhase：默认值是事务提交以后；有如下几个取值：

public enum TransactionPhase {  BEFORE_COMMIT, // 事务提交前触发  AFTER_COMMIT, // 事务提交后触发  AFTER_ROLLBACK, // 事务回滚触发  AFTER_COMPLETION // 事务完成后 触发}

注意：@
TransactionalEventListener注解只对声明式事务起作用，对编程式事务无效。仅适用于由PlatformTransactionManager管理的线程绑定事务

示例：

// 事件监听@Componentpublic class TxListenerComponent {  @TransactionalEventListener(phase = TransactionPhase.AFTER_COMMIT)  public void handleUsersAfterCommit(UsersEvent usersEvent) {    Users user = (Users) usersEvent.getSource() ;    System.out.println("AfterCommit收到事件通知：" + user.getPassword()) ;  }  @TransactionalEventListener(phase = TransactionPhase.AFTER_COMPLETION)  public void handleUsersAfterCompletion(UsersEvent usersEvent) {    Users user = (Users) usersEvent.getSource() ;    System.out.println("AfterCompletion收到事件通知：" + user.getPassword()) ;  }
  @TransactionalEventListener(phase = TransactionPhase.AFTER_ROLLBACK)  public void handleUsersAfterRollback(UsersEvent usersEvent) {    Users user = (Users) usersEvent.getSource() ;    System.out.println("AfterRollback收到事件通知：" + user.getPassword()) ;  }
  @TransactionalEventListener(phase = TransactionPhase.BEFORE_COMMIT)  public void handleUsersBeforeCommit(UsersEvent usersEvent) {    Users user = (Users) usersEvent.getSource() ;    System.out.println("BeforeCommit收到事件通知：" + user.getPassword()) ;  }}// 发布事件@Resourceprivate ApplicationEventPublisher publisher ;@Resourceprivate UsersMapper usersMapper ;
public Integer saveUsers(Users users) {  Integer result = transactionTemplate.execute(new TransactionCallback<Integer>() {    @Override    public Integer doInTransaction(TransactionStatus status) {      return usersMapper.insertUser(users) ;    }  }) ;  publisher.publishEvent(new UsersEvent(users));  return result ;}

运行结果：

2021-06-17 14:02:56.830 DEBUG 10000 --- [nio-8081-exec-1] com.pack.mapper.UsersMapper.insertUser   : ==>  Preparing: insert into bc_users (id, username, password) values (?, ?, ?)2021-06-17 14:02:56.840 DEBUG 10000 --- [nio-8081-exec-1] com.pack.mapper.UsersMapper.insertUser   : ==> Parameters: mmmmm(String), mmmmm(String), mmmmm(String)2021-06-17 14:02:56.842 DEBUG 10000 --- [nio-8081-exec-1] com.pack.mapper.UsersMapper.insertUser   : <==    Updates: 1BeforeCommit收到事件通知：mmmmmAfterCommit收到事件通知：mmmmmAfterCompletion收到事件通知：mmmmm