For testing purposes, I'd like to have a console where I can just enter an HQL command and see what it returns on the grails hibernate DB (in my case a MySQL DB) while it's running e.g. in the test environment. What's the best way to do that?
I'm using Eclipse and already came across the JBoss Hibernate Tools, but I'm not sure how to configure them to use my grails MySQL DB. What Type (Core, Annotations, JPA) do I have to choose there and what to fill in the 'Configuration File' / 'Persistence unit' fields? I already set up a property file (see below).
hibernate.connection.username=sa
hibernate.connection.password=
hibernate.connection.driver_class=org.hsqldb.jdbcDriver
hibernate.connection.url=jdbc:mysql://localhost/myproject
hibernate.connection.provider_class=org.hibernate.connection.DriverManagerConnectionProvider
But is this the best approach anyway?
I am not 100% sure if your close, but the Driver_class property is wrong for MySQL. Try
hibernate.connection.username=sa
hibernate.connection.password=
hibernate.connection.driver_class=com.mysql.jdbc.Driver
hibernate.connection.url=jdbc:mysql://localhost/myproject
hibernate.connection.provider_class=org.hibernate.connection.DriverManagerConnectionProvider
The Class needs to be com.mysql.jdbc.Driver
Hope this helps
Related
I develop a webApp which is connecting to many similar database.
The target databases are set by the final user in an administration GUI.
They work with differents database engine.
I use JPA and Eclipselink 2.6.4 to query theses databases.
Actually I've no other choice than writing a persistence.xml file on the fly and to use it to create an EntityManagerFactory.
pros.setProperty(PersistenceUnitProperties.ECLIPSELINK_PERSISTENCE_XML, persistenceFilesPath + "/" + persistenceFileName);
Persistence.createEntityManagerFactory(envCode, pros);
I would like to bypass this step to get directly an EntityManagerFactory without writing an persitence.xml file.
I've read some things on PersistenceUnitInfo and createContainerEntityManagerFactory but nothing really concrete.
I'm looking for ideas to reach my goal. I hope you will have somes.
Thanks
I have an application written with spring-boot (i am new to it so please forgive me if question is dumb) that uses hibernate 4 and postgresql as DB backend.
I noticed a bunch of connections on the DB that belong to the connection pool stating: "SET extra_float_digits = 3"
Googling around, I've found that it is probably due to the use of the old protocol and that could be avoided using the assumeMinServerVersion parameter of the jdbc driver.
Now my question is: how do i pass / set that parameter from a spring-boot application?
According to this page you could set a assumeMinServerVersion parameter in the jdbc url, something like
spring.datasource.url=jdbc:postgresql://localhost/test?assumeMinServerVersion=XYZ
How can I start a stand-alone Spring Boot JPA application -- not via cli -- with a choice of databases to get data, e.g., localhost:5432/my_db; or 192.168.1.100:5432/our_db, or example.com:5432/their_db?
Mine currently uses the one in the application.properties file that contains:
spring.datasource.driverClassName=org.postgresql.Driver
spring.datasource.url=jdbc:postgresql://localhost:5432/my_db
spring.datasource.username=postgres
spring.datasource.password=postgres
spring.jpa.database-platform=org.hibernate.dialect.PostgreSQLDialect
spring.jpa.generate-ddl=true
spring.jpa.show-sql=true
spring.jpa.hibernate.ddl-auto=create
Thanks in advance
Since you probably need to configure username and password as well, I recommend creating separate application-mydatasource.properties files for each data source configuration. You will then activate the datasource you want to use based on setting the active profile. You can set the active profile either in application.properties (spring.profiles.active) or via a command line argument:
$ java -jar -Dspring.profiles.active=mydatasource demo-0.0.1-SNAPSHOT.jar
The application-mydatasource.properties will then override any properties in your application.properties. I believe you will also need to set spring.profiles= to the list of profiles available.
See Profile specific properties.
Another options besides the #Profile label, that you will have to declare in every enviroment that you will deploy the application, you could use in Spring Boot the label:
#ConditionalOnProperty(name="propertyName", havingValue="propertyValue")
And declare a property to decide wich database you want to load in each case!
Hope being helping!!
I am trying to create a jdbc connection to a postgresql database. I would like to use a datasource. In the documentation of postgresql is stated that one should not use their own implementations of the datasource, but use the implementations of org.apache.commons.dbcp instead. The SharedPoolDatasource looks perfect to me.
The jdbc driver must be postgresql. Glassfish v3.1 offers the opportunity to create a jdbc connection pool. I would like to use that one, but do not know how to make the connection between the commons datasource implementation and the jdbc driver. When I fill in the document on the glassfish server that particular field blanks out forcing me to use the postgresql datasource implementation.
Is this impossible to achieve or do I have to enter data manually in config files? So far I did not have any luck nor feedback. Exceptions should appear in the server.log, but the server.log currently does not show anything (it did show exceptions deploying jsf and ejb applications).
Should be possible....
1. Create a new JDBC Connection Pool:
2. Choose your desired Datasource Implementation Class:
You'll have to setup the details for databasename, user and password in the additional properties tab.
3. Create a new JDBC Resource:
I've been working on a web application, deployed on Tomcat 7, which use EclipseLink JPA to handle the persistence layer.
Everything works fine in a test environment but we're having serious issues in the production environment due to a firewall cutting killing inactive connections. Basically if a connection is inactive for a while a firewall the sits between the Tomcat server and the DB server kill it, with the result of leaving "stale" connections in the pool.
The next time that connection is used the code never returns, until it gets a "Connection timed out" SQLException (full ex.getMessage() below).
EL Fine]: 2012-07-13
18:24:39.479--ServerSession(309463268)--Connection(69352859)--Thread(Thread[http-bio-8080-exec-5,5,main])--
MY QUERY REPLACED TO POST IT TO SO [EL Config]: 2012-07-13
18:40:10.229--ServerSession(309463268)--Connection(69352859)--Thread(Thread[http-bio-8080-exec-5,5,main])--disconnect
[EL Info]: 2012-07-13
18:40:10.23--UnitOfWork(1062365884)--Thread(Thread[http-bio-8080-exec-5,5,main])--Communication
failure detected when attempting to perform read query outside of a
transaction. Attempting to retry query. Error was: Exception
[EclipseLink-4002] (Eclipse Persistence Services -
2.3.0.v20110604-r9504): org.eclipse.persistence.exceptions.DatabaseException Internal
Exception: java.sql.SQLException: Eccezione IO: Connection timed out
I already tried several configuration in the persistence.xml, but since I have no access to the firewall configuration I had no luck with these methods. I also tried to use setCheckConnections()
ConnectionPool cp = ((JpaEntityManager)em).getServerSession().getDefaultConnectionPool();
cp.setCheckConnections();
cp.releaseConnection(cp.acquireConnection());
I managed to solve the issue in a test script using testOnBorrow, testWhileIdle and other features that are avalaible from DBCP Apache Commons. I'd like to know how to override the EclipseLink internal connection pool to use a custom connection pool so that I can provide an already configured pool, based on DBCP rather than just configuring the internal one using persistence.xml.
I know I should provide a SessionCustomizer, I'm uncertain which one is the correct pattern to use. Basically I would like to preserve the performance of DBCP in a JPA-like way.
I'm deploying on Tomcat 7, I know that if I switch to GF I won't have this problem, but for a matter of consistency with other webapp on the same server I'd prefere to stay on Tomcat.
What you want is definitely possible, but you might be hitting the limits of the "do it yourself" approach.
This is one of the more difficult things to explain, but there are effectively two ways to configure your EntityManagerFactory. The "do it yourself" approach and the "container" approach.
When you call Persistence.createEntityManagerFactory it eventually delegates to this method of the PersistenceProvider interface implemented by EclipseLink:
EntityManagerFactory createEntityManagerFactory(String emName, Map map)
The deal here is EclipseLink will then take it upon itself to do all the work, including its own connection creation and handling. This is the "do it yourself" approach. I don't know EclipseLink well enough to know if there is a way to feed it connections using this approach. After two days on Stackoverflow it doesn't seem like anyone else has that info either.
So here is why this "works in GF". When you let the container create the EntityManagerFactory for you by having it injected or looking it up, the container uses a different method on the PersistenceProvider interface implemented by EclipseLink:
EntityManagerFactory createContainerEntityManagerFactory(PersistenceUnitInfo info, Map map)
The long and short of it is that this PersistenceUnitInfo is an interface that the container implements and has these two very key methods on it:
public DataSource getJtaDataSource();
public DataSource getNonJtaDataSource();
With this mode EclipseLink will not try to do its own connection handling and will simply call these methods to get the DataSource from the container. This is really what you need.
There are two possible approaches you could take to solving this:
You could attempt to instantiate the EclipseLink PersistenceProvider implementation yourself and call the createContainerEntityManagerFactory method passing in your own implementation of the PersistenceUnitInfo interface and feed the DBCP configured DataSource instances into EclipseLink that way. You would need to parse the persistence.xml file yourself and feed that data in through the PersistenceUnitInfo. As well EclipseLink might also expect a TransactionManager, in which case you'll be stuck unless you hunt down a TransactionManager you can add to Tomcat.
You could use the Java EE 6 certified version of Tomcat, TomEE. DataSources are configured in the tomee.xml, created using DBCP with full support for all the options you need, and passed to the PersistenceProvider using the described createContainerEntityManagerFactory call. You then get the EntityManagerFactory injected via #PersistenceUnit or look it up.
If you do attempt to use TomEE, make sure your persistence.xml is updated to explicitly set transaction-type="RESOURCE_LOCAL" because the default is JTA. Even though it's non-compliant to use JTA with the Persistence.createEntityManagerFactory approach, there aren't any persistence providers that will complain and let you know you're doing something wrong, they treat it as RESOURCE_LOCAL ignoring the schema. So when you go to port your app to an actual certified server, it blows up.
Another note on TomEE is that in the current release, you'll have to put your EclipseLink libs in the <tomcat>/lib/ directory. This is fixed in trunk, just not released yet.
I'm not sure how useful these slides will be without the explanation that goes along with them, but the second part of this presentation is a deep dive into how container-managed EntityManager's work, specifically with regards to connection handling and transactions. You can ignore the transaction part as you aren't using them and already have an in production you're not likely to dramatically change, but it might be interesting for future development.
Best of luck!