springboot事务工具类

以下是一个简单的SpringBoot事务工具类的示例代码：

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.TransactionDefinition;
import org.springframework.transaction.TransactionStatus;
import org.springframework.transaction.support.DefaultTransactionDefinition;

@Component
public class TransactionUtils {

    @Autowired
    private PlatformTransactionManager transactionManager;

    public <T> T executeInTransaction(TransactionCallback<T> callback) {
        TransactionDefinition transactionDefinition = new DefaultTransactionDefinition();
        TransactionStatus transactionStatus = transactionManager.getTransaction(transactionDefinition);
        try {
            T result = callback.doInTransaction();
            transactionManager.commit(transactionStatus);
            return result;
        } catch (Exception e) {
            transactionManager.rollback(transactionStatus);
            throw e;
        }
    }

    public interface TransactionCallback<T> {
        T doInTransaction();
    }
}

这个工具类中的`executeInTransaction`方法接受一个`TransactionCallback`参数，该参数是一个函数式接口，用于执行需要在事务中执行的代码。如果执行成功，则提交事务，否则回滚事务。

使用该工具类的示例代码如下：

@Service
public class UserService {

    @Autowired
    private UserRepository userRepository;

    @Autowired
    private TransactionUtils transactionUtils;

    public void transferMoney(int fromUserId, int toUserId, double amount) {
        transactionUtils.executeInTransaction(() -> {
            User fromUser = userRepository.findById(fromUserId).orElseThrow(() -> new RuntimeException("User not found"));
            User toUser = userRepository.findById(toUserId).orElseThrow(() -> new RuntimeException("User not found"));
            fromUser.setBalance(fromUser.getBalance() - amount);
            toUser.setBalance(toUser.getBalance() + amount);
            userRepository.save(fromUser);
            userRepository.save(toUser);
            return null;
        });
    }
}

在上面的示例代码中，`transferMoney`方法需要在事务中执行，因此我们将其放在了`executeInTransaction`方法中，并将其作为参数传递给了`TransactionUtils`工具类。