关于Spring中声明式事务的使用详解

@Service
public class JdbcTransaction {
    @Autowired
    private DataSource dataSource;

    public int insertStudent(Student student) {
        Connection connection = null;
        int result = 0;
        try {
            // 获取数据连接
            connection = dataSource.getConnection();
            // 开始事务
            connection.setAutoCommit(false);
            // 设置隔离级别
            connection.setTransactionIsolation(Connection.TRANSACTION_READ_COMMITTED);
            // 执行sql
            PreparedStatement prepareStatement = connection.prepareStatement("insert into t_student(name,gender,age) values (?,?,?)");
            prepareStatement.setString(1, student.getName());
            prepareStatement.setString(2, student.getGender());
            prepareStatement.setInt(3, student.getAge());
            result = prepareStatement.executeUpdate();
            // 提交事务
            connection.commit();
        } catch (Exception e1) {
            if (connection != null) {
                try {
                    // 事务回滚
                    connection.rollback();
                } catch (Exception e2) {
                    e2.printStackTrace();
                }
            }
            e1.printStackTrace();
        } finally {
            try {
                if (connection != null && !connection.isClosed()) {
                    // 关闭连接
                    connection.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        return result;
    }
}

select * from T where ID=2 lock in share mode;
select * from T where ID=2 for update;

@Service
public class StudentServiceImpl implements IStudentService {

    @Autowired
    private StudentRepository studentRepository;

    @Transactional(rollbackFor = RuntimeException.class)
    @Override
    public Student findStudentById(Long id) {
        return studentRepository.getOne(id);
    }

    ...

    @Transactional(rollbackFor = RuntimeException.class)
    @Override
    public void deleteStudent(Long id) {
        Student student = findStudentById(id);
        if(student == null){
            // data not exists
        }
        studentRepository.deleteById(id);
    }
    
    ...
}

package org.springframework.transaction.annotation;

import org.springframework.transaction.TransactionDefinition;

public enum Propagation {

	
	REQUIRED(TransactionDefinition.PROPAGATION_REQUIRED),

	
	SUPPORTS(TransactionDefinition.PROPAGATION_SUPPORTS),

	
	MANDATORY(TransactionDefinition.PROPAGATION_MANDATORY),

	
	
	REQUIRES_NEW(TransactionDefinition.PROPAGATION_REQUIRES_NEW),

	
	NOT_SUPPORTED(TransactionDefinition.PROPAGATION_NOT_SUPPORTED),

	
	NEVER(TransactionDefinition.PROPAGATION_NEVER),

	
	NESTED(TransactionDefinition.PROPAGATION_NESTED);


	private final int value;


	Propagation(int value) {
		this.value = value;
	}

	public int value() {
		return this.value;
	}

}

@Service
public class StudentServiceImpl implements IStudentService {

    ...
        
    @Transactional
    @Override
    public Student insertStudent(Student student) {
        return studentRepository.save(student);
    }

    ...
}

@Target({ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Inherited
@Documented
public @interface Transactional {
    // 通过bean name执行事务管理器
    @AliasFor("transactionManager")
    String value() default "";
	// 同value属性
    @AliasFor("value")
    String transactionManager() default "";
	// 指定事务传播行为，默认是Propagation.REQUIRED
    Propagation propagation() default Propagation.REQUIRED;
	// 指定事务的隔离级别，默认是使用底层数据存储的默认隔离级别。如MySQL是可重复读
    Isolation isolation() default Isolation.DEFAULT;
	// 指定超时时间，单位时间秒
    int timeout() default -1;
	// 是否是只读事务
    boolean readOnly() default false;
	// 在发生指定的异常是回滚事务，默认是所有异常都回滚
    Class<? extends Throwable>[] rollbackFor() default {};
	// 方法在发生指定异常名称时回滚事务，默认是所有异常都回滚
    String[] rollbackForClassName() default {};
	// 在发生指定的异常是不回滚事务
    Class<? extends Throwable>[] noRollbackFor() default {};
	// 方法在发生指定异常名称时不回滚事务
    String[] noRollbackForClassName() default {};
}

public interface PlatformTransactionManager extends TransactionManager {
	// 获取事务m还可以设置数据属性
	TransactionStatus getTransaction(@Nullable TransactionDefinition definition)
			throws TransactionException;
	// 提交事务
	void commit(TransactionStatus status) throws TransactionException;
	// 回滚事务
	void rollback(TransactionStatus status) throws TransactionException;

}

@Service
public class StudentServiceImpl implements IStudentService {

    @Autowired
    private StudentRepository studentRepository;

    @Transactional(rollbackFor = RuntimeException.class, isolation = Isolation.REPEATABLE_READ, propagation = Propagation.REQUIRES_NEW)
    @Override
    public Student insertStudent(Student student) {
        return studentRepository.save(student);
    }

}

@Service
public class BatchServiceImpl implements IBatchService {

    @Autowired
    private IStudentService studentService;

    @Transactional(rollbackFor = RuntimeException.class, isolation = Isolation.REPEATABLE_READ, propagation = Propagation.REQUIRED)
    @Override
    public void batchInsertStudent(List<Student> students) {
        for (Student student : students) {
            studentService.insertStudent(student);
        }
    }
}

@Service
public class StudentServiceImpl implements IStudentService {

    @Autowired
    private StudentRepository studentRepository;

    @Transactional(rollbackFor = RuntimeException.class, propagation = Propagation.REQUIRES_NEW)
    @Override
    public Student findStudentById(Long id) {
        return studentRepository.getOne(id);
    }

    @Transactional(rollbackFor = RuntimeException.class, isolation = Isolation.REPEATABLE_READ)
    @Override
    public void deleteStudent(Long id) {
        // 自调用
        Student db = findStudentById(id);
        if (db == null) {
            throw new RuntimeException("数据不存在");
        }
        studentRepository.deleteById(id);
    }

}

@Service
public class StudentServiceImpl implements IStudentService {

    @Autowired
    private StudentRepository studentRepository;
    
    // 注入Spring上下文对象
    @Autowired
    private ApplicationContext context;

    @Transactional(rollbackFor = RuntimeException.class, propagation = Propagation.REQUIRES_NEW)
    @Override
    public Student findStudentById(Long id) {
        return studentRepository.getOne(id);
    }

    @Transactional(rollbackFor = RuntimeException.class, isolation = Isolation.REPEATABLE_READ)
    @Override
    public void deleteStudent(Long id) {
        // 从上下文中获取IStudentService
        IStudentService studentService = context.getBean(IStudentService.class);
        Student db = findStudentById(id);
        if (db == null) {
            throw new RuntimeException("数据不存在");
        }
        studentRepository.deleteById(id);
    }

}