Java Hibernate Session.save() 不返回值？
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Hibernate Session.save() doesn't return a value?
提问by Dustin Sun
Below code throws a casting error
下面的代码抛出一个转换错误
Long newID = (Long)session.save(object);
Long newID = (Long)session.save(object);
I am new to hibernate. Don't know why.
我是休眠的新手。不知道为什么。
采纳答案by Martin Algesten
The return value of session.save()depends on your mapping. Most likely you have a type of ID that isn't a Long. Try doing this:
的返回值session.save()取决于您的映射。很可能您的 ID 类型不是 Long。尝试这样做：
System.out.println(session.save(object).getClass().getName());
Then you'll see the type name.
然后你会看到类型名称。
回答by Sourabh Sharma
There are two methods:
有两种方法：
public Serializable save(Object object) throws HibernateException
Persist the given transient instance, first assigning a generated identifier. (Or using the current value of the identifier property if the assigned generator is used.) This operation cascades to associated instances if the association is mapped withcascade="save-update".
Parameters:object - a transient instance of a persistent class
Returns:the generated identifierpublic Serializable save(String entityName, Object object) throws HibernateException
Persist the given transient instance, first assigning a generated identifier. (Or using the current value of the identifier property if the assigned generator is used.) This operation cascades to associated instances if the association is mapped withcascade="save-update".
Parameters:object - a transient instance of a persistent class
Returns:the generated identifier
public Serializable save(Object object) throws HibernateException
保留给定的瞬态实例，首先分配一个生成的标识符。（或者，如果使用分配的生成器，则使用标识符属性的当前值。）如果关联被映射到关联实例，则此操作级联到关联实例cascade="save-update"。
参数：object - 持久类的瞬态实例
返回：生成的标识符public Serializable save(String entityName, Object object) throws HibernateException
保留给定的瞬态实例，首先分配一个生成的标识符。（或者，如果使用分配的生成器，则使用标识符属性的当前值。）如果关联被映射到关联实例，则此操作级联到关联实例cascade="save-update"。
参数：object - 持久类的瞬态实例
返回：生成的标识符
