Stop java code execution until mysql query completes in Java?

Question

I am working on a project that uses REST service(Jersey implementation) for some features like login,register etc.

At the login time i want to store the current user details in DB and that is successfully done with the below piece of code:-

Userlogin userlogin = new Userlogin(user,loginDateTime,null,ipAddress,tokenEnc,salt);
userloginBean.persist(userlogin);
userLoginId = userlogin.getId();
logger.log(Level.INFO, "userLoginId: "+userLoginId);

Now look at the third line of the code, i am trying to get the recently inserted id from the userlogin object. But it giving me null. In 4th line when i try to print it in log it show null.

I put some logs to check the execution and i found that the actual mysql query is executing after the 4th line.

So please tell me how can i sure that mysql has completed its query?

Also Explain me if possible ,why it is behaving like this as i use the same type code and i never get such situation.

I am using eclipse Kepler, Jsf 2.2
My project is Dynamic web project not maven.
For mysql query execution i am using Criteria API in DAO class. I am persisting database using JPA.

Here is the persist method of my UserloginBean.java class:

public void persist(Userlogin transientInstance) {
    log.log(Level.INFO, "persisting Userlogin instance");
    try {
        entityManager.persist(transientInstance);
        log.log(Level.INFO, "persist successful");
    } catch (RuntimeException re) {
        log.log(Level.INFO, "persist failed", re);
        throw re;
    }
}

Here is some piece of my eclipse log:

2014-05-27T00:26:17.737+0530|INFO: persisting Userlogin instance
2014-05-27T00:26:17.813+0530|INFO: persist successful
2014-05-27T00:26:17.814+0530|INFO: userLoginId: null
2014-05-27T00:26:17.830+0530|FINE: INSERT INTO userlogin (help, ipaddress, 
login, logout, token, user_id) VALUES (?, ?, ?, ?, ?, ?)
    bind => [6 parameters bound]
2014-05-27T00:26:17.842+0530|FINE: SELECT LAST_INSERT_ID()

Thanks in advance. Sorry for my english mistake if i did any.

unless you're running the query in a separate thread, they should block the current thread until the query's completed and results are available. — Marc B, May 26 '14 at 19:23
i also thought the same but unfortunately this is not happening..i set the eclipse log level to FINE so that i can easily see that INSERT query printed in log long time after my 4th line of code.. — Vikas Sharma, May 26 '14 at 19:26
What type of persistence do you use? If you are using JPA, the insert might be delayed until you commit, explaining the observerd behaviour. — ruediste, May 26 '14 at 19:34
I am using JPA for persistense, i updated my question and try to put some necessary information, thanks @ruediste — Vikas Sharma, May 26 '14 at 19:40

score 1 · Accepted Answer · answered May 26 '14 at 19:56

1

If you're using JPA, you'll need to call flush on the entityManager to see the values of fields that come from the database. e.g. generated id's, columns with default values, etc...

answered May 26 '14 at 19:56

BillRobertson42

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Thanks @Bill, it is working properly, thanks again , i was not aware of the flush() of entitymanager. – Vikas Sharma May 26 '14 at 20:02

Stop java code execution until mysql query completes in Java?

1 Answers1