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POJPA.em().find returns null for existing object
 

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  1. POJPA.em().find returns null for existing object
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    <p>I have a problem with JPA in play framework 2.1. Here is my situation:</p> <p>I have action method which handles sign up for my application (User fills email and password and submits the form). In this method I check if the user exists in my database and if not I create new one. Here is simplified code which shows how it works:</p> <pre><code>public Result signUpSubmit(String email, String password) { User existingUser = (User) User.find("SELECT u FROM User u WHERE u.email=?", email).get(0); if (existingUser != null) { // code which handles existing user } else { User newUser = new User(email, password); Users.persistUserAsync(newUser); // calls JPA.em().persist(newUser) asynchronously // but I wait until the save is done // After this call I have new row in DB with newUser (with assigned id) System.out.println(newUser.id); // prints id which was assigned to new user in DB User u = (User)JPA.em().find(User.class, newUser.id) System.out.println(u.id); // throws NullPointer exception, because u is null } return renderJapid(); } </code></pre> <p>Can you tell me the reason why I get the null from the second find query?</p> <pre><code>public boolean persistUserAsync(User) { final ModelCreatingJob modelCreatingJob = new ModelCreatingJob(user); final Promise&lt;Boolean&gt; promisedSave = modelCreatingJob.now(); final Boolean saved = promisedSave.get(20000L); return saved; } </code></pre> <p>The ModelCreatingJob does only this:</p> <pre><code>return JPA.withTransaction(new F.Function0&lt;Boolean&gt;() { @Override public Boolean apply() throws UserLockedException, UserNotFoundException { return model.validateAndCreate(); } }); </code></pre> <p>Strange is that when I remove first find (just leave newUser = null) on second find I get valid user object.</p>
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    1. PTQuestion
    1. USuser2545521
    1. USuser2545521
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    1. COwhich could mean, that the record is not committed yet.`Users.persistUserAsync` is not committing the record.
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      1. POJPA.em().find returns null for existing object
      1. USSajan Chandran
    2. COplease post the code for persistUserAsync. (I'm also wondering why you need to do it asynchronously)
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      1. POJPA.em().find returns null for existing object
      1. USben75
    3. CO@ben75 Persist part of the user can take very long time. In play 1.2.x there is some problem with number of threads for controller (I don't know how it works for play 2.x). I was told that this will help to improve performance, because it won't block the thread with controller.
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      1. POJPA.em().find returns null for existing object
      1. USuser2545521
 

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