如何使用 Objectify 在 Java GAE 中的无效 function 中设置事务？

Question

I am trying to set up a transaction in a void function in Java using Objectify. This is the wiki documentation.

import static com.googlecode.objectify.ObjectifyService.ofy;

Thing th = ofy().transact(() -> {
    Thing thing = ofy().load().key(thingKey).now();
    thing.modify();
    ofy().save().entity(thing);
    return thing;
});

I've read the docs but this is still unclear to me. How could I implement this transaction in this function?

public void addForm(
        String name, String link)
    throws Exception
    {
        Form newForm = new Form(name, link);
        ofy().save().entity(newForm).now();
    }

I need to be able to call addForm so I can't wrap that function inside the transaction since I won't be able to call it again. Is that correct?

Answer 1

I suppose this part of wiki is form here . In the same documentation there is an example of transaction in void function ( I know it's different topic, however code is proper):

public void doSomeWork() {
    ofy().transact(() -> {
        doSomeMoreWork();
    });
}

So translating this to the addForm this should be something like:

public void addForm(String name, String link)
    throws Exception
    {
        ofy().transact(() -> {
            Form newForm = new Form(name, link);
            ofy().save().entity(newForm).now();
        }
    }

I don't think there is a point to create transaction for one database operation, however I guess you want to add more in future. You can call the function any time you want.

I hope it will help!