以编程方式处理Grails交易 [英] Handling Grails transactions programmatically

问题描述

当我需要保存一个对象列表时，每个对象都应该保存在它自己的事务中（这样如果一个失败，它们不会全部失败），我这样做：

When I need to save a list of objects, and each object should be saved in it's own transaction (so that if one fails they don't all fail), I do it like this:

List<Book> books = createSomeBooks()
books.each { book ->
  Book.withNewSession {
    Book.withTransaction {TransactionStatus status ->
      try {
        book.save(failOnError: true)
      } catch (ex) {
        status.setRollbackOnly()
      }
    }
  }
} 

我使用 Book.withNewSession ，因为如果一本书无法保存并且事务回滚，则该会话将无效，这将阻止后续书籍保存。但是，这种方法存在一些问题：

I use Book.withNewSession because if one book fails to save and the transaction is rolled back, the session will be invalid which will prevent subsequent books from saving. However, there are a couple of problems with this approach:

1. 有点冗长


2. A新书会始终为每本书创建，即使上一本书成功了

有更好的方法吗？发生在我身上的一种可能性是依赖注入Hibernate SessionFactory ，而不是执行此操作

Is there a better way? One possibility that occurred to me is to dependency-inject the Hibernate SessionFactory and do this instead

List<Book> books = createSomeBooks()
books.each { book ->
  try {
    Book.withTransaction {
      book.save(failOnError: true)
    }
  } catch (ex) {
    // use the sessionFactory to create a new session, but how....?
  }
}

推荐答案

应该这样做：

List<Book> books = createSomeBooks()
books.each { book ->
  Book.withNewTransaction {TransactionStatus status ->
    try {
      book.save(failOnError: true)
    } catch (ex) {
      status.setRollbackOnly()
    }
  }
} 

如果您回滚，会话不会失效，它只会被清除。因此，任何尝试访问从数据库读取的实体都会失败，但写入尚未保留的实体将会很好。但是，您确实需要使用单独的事务来防止一切后退，因此需要使用withNewTransaction。

The session isn't invalid if you rollback, it is just cleared. So any attempts to access entities read from the DB would fail, but writes of not-yet-persisted entities will be just fine. But, you do need to use separate transactions to keep one failure from rolling back everything, hence the withNewTransaction.

这篇关于以编程方式处理Grails交易的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！