Java persistence.xml 事务类型=“JTA”
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persistence.xml transaction-type="JTA"
提问by kuba44
Is this perisistence.xmlfile correct, especially when i transaction-type="JTA"?
这个perisistence.xml文件是否正确，尤其是当我 transaction-type="JTA"？
<?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://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
<persistence-unit name="CollDocPU" transaction-type="JTA">
<provider>org.apache.openjpa.persistence.PersistenceProviderImpl</provider>
<class>model.entity.StudentAddSolution</class>
<class>model.entity.Lecturer</class>
<class>model.entity.Solution</class>
<class>model.entity.Student</class>
<class>model.entity.Course</class>
<class>model.entity.File</class>
<class>model.entity.CourseHasLecturer</class>
<class>model.entity.Mail</class>
<class>model.entity.StudentAtCourse</class>
<class>model.entity.Roles</class>
<class>model.entity.Task</class>
<class>model.entity.User</class>
<exclude-unlisted-classes>false</exclude-unlisted-classes>
<properties>
<property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:11080/myBase?zeroDateTimeBehavior=convertToNull"/>
<property name="javax.persistence.jdbc.password" value="pass,"/>
<property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
<property name="javax.persistence.jdbc.user" value="myBase"/>
<property name="openjpa.jdbc.SynchronizeMappings" value="buildSchema(ForeignKeys=true)"/>
</properties>
采纳答案by Daniel Hernández
Are you getting an error?
你有错误吗？
If you are using JTA I will suggest you use a DataSource as a provider of your connections.
如果您使用 JTA，我建议您使用 DataSource 作为连接的提供者。
Such as:
如：
<?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://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
<persistence-unit name="CollDocPU" transaction-type="JTA">
<provider>org.apache.openjpa.persistence.PersistenceProviderImpl</provider>
<jta-data-source>datasource</jta-data-source>
<class>model.entity.StudentAddSolution</class>
<class>model.entity.Lecturer</class>
<class>model.entity.Solution</class>
<class>model.entity.Student</class>
<class>model.entity.Course</class>
<class>model.entity.File</class>
<class>model.entity.CourseHasLecturer</class>
<class>model.entity.Mail</class>
<class>model.entity.StudentAtCourse</class>
<class>model.entity.Roles</class>
<class>model.entity.Task</class>
<class>model.entity.User</class>
<exclude-unlisted-classes>false</exclude-unlisted-classes>
</persistence-unit>
</persistence>
BTW, you need to close all yours tags
顺便说一句，您需要关闭所有标签
Regards
问候
回答by Daniel Hernández
My friend, Maybe that is another error, try this, after doing what I told you, just print the EntityManager by System.out.println(em.toString()); If you are getting something, It is because It is OK, the nullpointer that you are getting in the other method could be by the program logic
我的朋友，也许这是另一个错误，试试这个，按照我告诉你的，只需通过 System.out.println(em.toString()); 打印 EntityManager; 如果你得到一些东西，那是因为没关系，你在另一个方法中得到的空指针可能是程序逻辑
