Java.persistence jar file

The Persistence Unit defines all the metadata required to bootstrap an EntityManagerFactory , like entity mappings, data source, and transaction settings, as well as JPA provider configuration properties. The goal of the EntityManagerFactory is used to create EntityManager objects we can for entity state transitions.

So, the persistence. Traditionally, the persistence. The transaction-type attribute defines the JPA transaction strategy, and it can take one of the following two values:. The description element allows you to provide more details about the goals of the current Persistence Unit. If you are using Hibernate 4. HibernatePersistenceProvider class name.

HibernatePersistence class name instead. There should have been a single data-source attribute for that since the transaction-type already specifies whether JTA is used or not. However, if you want to explicitly set the entity classes to be be used, and exclude any other entity classes found on the current Java classpath, then you need to set the exclude-unlisted-classes element to the value of true :.

After setting the exclude-unlisted-classes XML element above, you need to specify the list of entity classes registered by the current Persistence Unit via the class XML element:. The vast majority of JPA and Hibernate applications use annotations to build the object-relational mapping metadata.

However, even if you are using annotations, you can still use XML mappings to override the static annotation metadata with the one provided via an orm. If you package the persistence unit as a set of classes in a WAR file, persistence. This is no longer supported. Persistence Units A persistence unit defines a set of all entity classes that are managed by EntityManager instances in an application. ConnectExcep tion : Error connecting to server localhost on port with message Connection refused: connect.

ConnectException: Connection refused: connect at java. Improve this question. Nitesh Verma. Nitesh Verma Nitesh Verma 1, 4 4 gold badges 27 27 silver badges 46 46 bronze badges. What error does it give you — cowls. It shows no error. When i double click on the jar file nothing happens. Error: Could not find main class persist.

Show 7 more comments. Active Oldest Votes. ConnectException : Error connecting to server localhost on port with messageConnection refused: connect. Improve this answer. Community Bot 1 1 1 silver badge. Less Less 2, 3 3 gold badges 31 31 silver badges 46 46 bronze badges.

Actually i have no idea how do i set up the database on the other system. So, as it seems, you don't have the database at all on that other system, there's your answer : Frankly, you didn't even mention what that "other" system is, what OS and stuff, but you can google for "how to install DB derby on xxx" — Less.

Alright, it means that i need to install Derby on the 'other ' system apart from my development pc , make the database and then try to run the application, right? Of course. Show 2 more comments.