spring的一个事务管理，在controller层和dao层都可以用

import org.springframework.transaction.support.DefaultTransactionDefinition;   

 public PlatformTransactionManager getTransactionManager() {
        return transactionManager;
    }
    public void setTransactionManager(PlatformTransactionManager transactionManager) {
        this.transactionManager = transactionManager;
    }

    private PlatformTransactionManager transactionManager;

    public String addAppUser(){
        DefaultTransactionDefinition def = new DefaultTransactionDefinition();
        TransactionStatus status = transactionManager.getTransaction(def);
        try {
           
            transactionManager.commit(status);
        } catch (Exception e) {
            transactionManager.rollback(status);
            e.printStackTrace();
        }
        return "addappuser";
    }