org.datanucleus.sco.backed.ArrayList不能转换为java.util.Set [英] org.datanucleus.sco.backed.ArrayList cannot be cast to java.util.Set

问题描述

自4天前，在随机短时间内，我部署的应用程序抛出这个错误：

Since 4 days ago, in random short periods of time, my deployed application is throwing this error:

org.datanucleus.sco.backed.ArrayList不能转换为java.util.Set

org.datanucleus.sco.backed.ArrayList cannot be cast to java.util.Set

我们正在使用GWT 2.4 / Java 1.7（我们最近从1.6迁移到1.7）

We are using GWT 2.4 / Java 1.7 (We recently migrate from 1.6 to 1.7)

它在检索或持久保存带有字符串集的实体时发生：

It happens when retrieving or persisting an entity with a String set:

import java.util.HashSet;
import java.util.Set;
...
@PersistenceCapable(identityType = IdentityType.APPLICATION, detachable = "true")
public class DbAccount {
    @PrimaryKey
    @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
    private Key key;
...
    @Persistent
    private Set<String> accounts;
...
    public DbAccount(SerAccount account) throws Exception {
        ...
        this.accounts= new HashSet<String>();
        ...
        key = KeyFactory.createKey(DbCuentas.class.getSimpleName(), this.id);
    }
}

我已经检查过整个项目， strong> org.datanucleus.sco.backed.ArrayList ，它不存在。

I have checked my entire project for a reference to org.datanucleus.sco.backed.ArrayList and it does not exist.

有什么想法？

推荐答案

这可能听起来很愚蠢，但是您是否尝试过使用 List 而不是 Set ？

It may sound stupid, but have you tried to use List instead of Set ?

再次检出文档后，我找不到Google提供的任何示例，并带有集合> 列表。

After checking out the docs again, I can't find any example from Google with a Collection other than List.

阅读你的问题，它看起来像无论你做什么，JPA datanucleus impl都在使用他们自己的ArrayList实现。我不知道为什么这个问题会随机发生......

Reading your issue, it looks like the JPA datanucleus impl is indeed using their own ArrayList implementation whatever you do. I don't know why the problem happens randomly though...

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