Databases
StackOverflow2013
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    <p>With the code you show above, the only way that a <code>NullPointerException</code> could be thrown at the line indicated is if the <code>businessInterface</code> field in the managed bean is null. References cannot mysteriously become null when passed from one object to another, and the <code>PojoClass</code> doesn't do anything which would cause the variable to become null. I suggest you do some debugging or logging to definitively determine the value of the field in the managed bean at the point at which the constructor is called. If it is null, then the problem is with injection into the bean, and is not anything to do with the POJO, and you should fix that.</p> <p>If the exception being thrown is actually from deeper than the line you show, then this could be a problem with the use of an EJB proxy in the wrong context. As you may know, a reference to an EJB is typically not a reference to the EJB itself, but rather to some sort of proxy which passes method calls on to the EJB; the proxy exists so that the container can step in and do things like start transactions, check authorization, and so on. The proxy may need to call on certain contextual resources to do its work which are available when the EJB is accessed from the managed bean but not, for some non-obvious and twisted reason, from the POJO. The unavailability of those resources could lead to a <code>NullPointerException</code>. Now, i think it is highly unlikely that simply passing a reference from a managed bean to a POJO would get you into that situation; this would only happen if you did something like accessing the managed bean from a different thread. So, it's probably not this!</p>
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    1. POUsing EJB injection in a POJO
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    1. USTom Anderson
    1. USTom Anderson
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    1. COIs it null in the managed bean at that point in time?
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    2. COWith the code you've shown, that cannot happen. Check your assumptions.
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    3. COIf you may allow me to further investigate this problem, and I'll get back to you as soon as possible, but I'm pretty sure that what you're saying is the most reasonable of all
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      1. USSabry Shawally
 

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