Almost all projects you develop with Java EE will contain a persistence layer and probably you will use JPA for dealing with SQL systems. One way to get an EntityManager is using @PersistenceContext. In this post we are going to explore the advantages of injecting EntityManager instead of using PersistenceContext annotation.
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Pistol shots ring out in the bar-room night, Enter Patty Valentine from the upper hall, She sees a bartender in a pool of blood, Cries out, "My God, they killed them all" (Hurricane - Bob Dylan)