Why my data does not get persisted?
I am using JPA and Java Embedded DB in my application. I try to write some data to the database and when i try to read it back I am able to do it. But the application is closed and when I open it again none of the data exists.
Here is my persistence.xml file开发者_运维技巧
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="1.0" 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_1_0.xsd">
<persistence-unit name="myMoneyPU" transaction-type="RESOURCE_LOCAL">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<class>mymoney.Money</class>
<properties>
<property name="eclipselink.jdbc.password" value="adminadmin"/>
<property name="eclipselink.jdbc.user" value="admin"/>
<property name="eclipselink.jdbc.driver" value="org.apache.derby.jdbc.EmbeddedDriver"/>
<property name="eclipselink.jdbc.url" value="jdbc:derby:pocketmoney;create=true"/>
<property name="eclipselink.ddl-generation" value="create-tables"/>
</properties>
</persistence-unit>
</persistence>
Is there any problem in my database URL.
jdbc:derby:pocketmoney
Is there any problem in my database URL.
No, it is correct and should create a database in the current working directory.
Some ideas to debug your issue:
- Use an absolute path for full control
jdbc:derby:/path/to/pocketmoney;create=true
. - Check that the data get written (i.e. that the files change).
Activate EcliseLink logging to see what is happening exactly using the following properties:
<properties> ... <property name="eclipselink.debug" value="ALL"/> <property name="eclipselink.logging.level" value="FINEST" /> <property name="eclipselink.logging.level.sql" value="FINEST" /> <property name="eclipselink.logging.level.cache" value="FINEST" /> </properties>
Double check that you do commit transactions appropriately (you are saying your code is doing things but you're not showing it so there is still a doubt).
References
- Derby JDBC database connection URL
- EclipseLink/Examples/JPA/Logging
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