1. springdatajpa手动控制事务，开启，提交，回滚

定义事务接口，开启提交回滚

import java.util.concurrent.Callable;

public interface TransactionService {

    void begin();

    void commit();

    void rollback();

    /**
     * 在事务中执行回调函数
     *
     * @param callable 回调函数
     */
    <V> V execute(Callable<V> callable);

}

实现事务接口

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

import java.util.concurrent.Callable;

@Service
public class TransactionServiceImpl implements TransactionService {

    @Autowired
    private PlatformTransactionManager transactionManager;

    private ThreadLocal<TransactionStatus> threadLocal = new ThreadLocal<>();

    @Override
    public void begin() {
        TransactionDefinition transactionDefinition = new DefaultTransactionDefinition();
        threadLocal.set(transactionManager.getTransaction(transactionDefinition));
    }

    @Override
    public void commit() {
        transactionManager.commit(threadLocal.get());
        threadLocal.remove();
    }

    @Override
    public void rollback() {
        transactionManager.rollback(threadLocal.get());
        threadLocal.remove();
    }

    @Override
    public <V> V execute(Callable<V> callable) {
        try {
            begin();
            V result = callable.call();
            commit();
            return result;
        } catch (Exception e) {
            rollback();
            throw new RuntimeException(e);
        }
    }
}

示例

@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UserRepository userRepository;
    @Autowired
    private TransactionService transactionService;

    @Override
    public void add(String userName, String password) {
        UserEntity userEntity = new UserEntity();
        userEntity.setUsername("test");
        userEntity.setPassword("test123");
        transactionService.execute(() -> userRepository.save(userEntity));
    }
    
    @Override
   public void add1(){
       UserEntity userEntity = new UserEntity();
       userEntity.setUsername("test");
       userEntity.setPassword("test123");
       //手动开启事务
       transactionService.begin();
        try {
          userRepository.save(userEntity);
            //手动提交事务
          transactionService.commit();
        } catch (TransactionException e) {
            //手动回滚事务
           //最好是放在catch 里面,防止程序异常而事务一直卡在哪里未提交
            transactionService.rollback();
            new RuntimeException("统一事务处理");
        }
   }