persistence.xml

问题 I'm developping a program that uses JPA, and I deployed it in a single jar. I wish to modify (or ask to the user, in an menú item) the configuration of the connection data with the database server. It's possible to modify the data (user, password, ip) of the server "on the fly"? (I apologize my bad english) 回答1: The JPA spec doesn't allow for dynamic modification of persistence-units. Some implementations may provide an implementation-specific way of defining a persistence-unit dynamically.

问题 I'm developping a program that uses JPA, and I deployed it in a single jar. I wish to modify (or ask to the user, in an menú item) the configuration of the connection data with the database server. It's possible to modify the data (user, password, ip) of the server "on the fly"? (I apologize my bad english) 回答1: The JPA spec doesn't allow for dynamic modification of persistence-units. Some implementations may provide an implementation-specific way of defining a persistence-unit dynamically.

问题 I have Java EE application, and my EJB module have persistence.xml . I deploy my app on 3 app servers: JBoss, GlassFish and WebLogic, and every server needs own hibernate.transaction.manager_lookup_class property. WL needs <property name="transaction.manager_lookup_class" value="org.hibernate.transaction.WeblogicTransactionManagerLookup" /> JBoss needs <property name="transaction.manager_lookup_class" value="org.hibernate.transaction.JBossTransactionManagerLookup" /> Glass fish <property name

问题 I am using JPA for a java class and having trouble putting the persistence XML file where it should be. The IDE i am using is Eclipse Helios. Eclipselink jar files are downloaded and added to my JRE System Library and all. I wrote up the persistence.xml with the tag after getting the following error : Exception in thread "main" javax.persistence.PersistenceException: No Persistence provider for EntityManager named customers Provider tag: <provider>org.eclipse.persistence.jpa

问题 In my application, I use Hibernate with SQL Server database, so I set <property name="hibernate.dialect" value="org.hibernate.dialect.SQLServerDialect"> in my persistence.xml. In some case, I want to sort records with NULL include, I use keyword NULLS FIRST. Because it is not supported by default by CriteriaQuery/CriteriaBuilder in Hibernate, then I use Interceptor to modify the native query. The problem is, keyword NULLS FIRST is not supported in SQL Server, so I use keyword: case when

问题 I just downloaded http://www.apache.org/dyn/closer.cgi/openejb/4.0.0-beta-1/apache-tomee-1.0.0-beta-1-webprofile.zip to use OpenEJB with OpenJPA2.1.1. I can't get my persistence.xml working. The top of the stack trace: org.xml.sax.SAXException: file:/D:/Workspaces/sandbox/tomcat_ejb_jpa2_tomEE/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/testEE/WEB-INF/classes/META-INF/persistence.xml [Location: Line: 2, C: 248]: org.xml.sax.SAXParseException: cvc-elt.1: Cannot find the

问题 I'm writing a Java SE (desktop) application that has to access different databases all of which will have the same data model (same schema, tables, etc.). I want to reuse the JPA Entities that I already use in a Java EE application that front each database. To reuse the existing entity.jar file I'll have to repackage it with a different persistence.xml that has a resource_local data source. That's an build time inconvenience but not a big problem. The problem is that my desktop application

问题 I've created a jar file through spring roo (maven project - persistence archive) unit tests are running fine, the concerned files are on the following location jarFile/META-INF/persistence.xml jarFile/META-INF/applicationContext.xml jarFile/META-INF/applicationContext-jpa.xml jarFile/META-INF/database.properties Unit tests are running fine. Because its a maven project I added it to local repository by executing the command "mvn install" and after that I added it as a dependency to another

问题 Although it seems many users faced the same problem, I have to post my own issue, taking in account that for now, no suggestion from those already present worked for me. Or maybe am I missing something? Here is my persistence.xml file (located uner resources/META-INF/ directory, in a maven project): <?xml version="1.0" encoding="UTF-8"?> <persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http:/

问题 Error "No persistence.xml file found in project" in Eclipse. Aim: Create a new project GWT+App engine+Maven Steps to create this: Google eclipse plugin: select "New Web Application Project". set the name etc. right-click on the project > Configure > Convert to Maven... Fix jdoconfig.xml file: xsi has the wrong value. see Validating jdoconfig with incorrect url Then I get the above error. The file exists at scr/META-INF/persistence.xml and also war/WEB-INF/classes/META-INF/persistence.xml But