We using Kundera ORM for connecting to Cassandra from REST service. In the persistence.xml we are specifying client lookup class as ThriftClientFactory as below
<property name="kundera.client.lookup.class"
value="com.impetus.client.cassandra.thrift.ThriftClientFactory" />
Is this the right way to connect to cassandra or is there any way we can connect to Cassandra using CQL through Kundera?
Yes, Kundera's ThriftClient uses CQL for communicating with Cassandra. Also, make sure you are enabling CQL3 from your application while using this client.
Setting CQL3: You can choose any method given below
In EntityManagerFactory
HashMap propertyMap = new HashMap();
propertyMap.put(CassandraConstants.CQL_VERSION, CassandraConstants.CQL_VERSION_3_0);
EntityManagerFactory emf = Persistence.createEntityManagerFactory("cassandra_pu", propertyMap);
In EntityManager
EntityManagerFactory emf = Persistence.createEntityManagerFactory("cassandra_pu");
EntityManager em = emf.createEntityManager();
em.setProperty("cql.version", "3.0.0");
Related
JOOQ manual states the following:
Out of the box, all jOOQ provided publishers will block on the
underlying JDBC connection, but if you provide jOOQ with a
io.r2dbc.spi.Connection or io.r2dbc.spi.ConnectionFactory, then the
publishers will execute queries in a non-blocking fashion on an R2DBC
driver.
How do I provide DSLContext with io.r2dbc.spi.Connection or io.r2dbc.spi.ConnectionFactory ?
I tried DSL.using() but it does not accept this interface.
Also - can I define the DSLContext with reactive driver through Spring Boot ?
Thank you.
How do I provide DSLContext with io.r2dbc.spi.Connection or io.r2dbc.spi.ConnectionFactory ?
At the time of this question, jOOQ 3.14 did not yet support R2DBC. With jOOQ 3.15, you can write this:
DSLContext ctx1 = DSL.using(connection);
DSLContext ctx2 = DSL.using(connectionFactory);
Just like with JDBC connections.
Also - can I define the DSLContext with reactive driver through Spring Boot ?
I suspect that this will be possible once jOOQ 3.15 is released (~ end of Q2 2021, no promises). Until then, just expose a #Bean of type DSLContext that you build manually from an injected ConnectionFactory
I'm doing my first steps with Camel and currently working on writing a simple junit test using jms as a transport.
Here is a code I wrote:
public class FirstMockTest extends CamelTestSupport {
#Override
protected RoutesBuilder createRouteBuilder() throws Exception {
return new RouteBuilder() {
#Override
public void configure() throws Exception {
from("jms:topic:quote")
.to("mock:quote");
}
};
}
#Test
public void testMessageCount() throws InterruptedException {
MockEndpoint mockEndpoint = getMockEndpoint("mock:quote");
mockEndpoint.setExpectedMessageCount(1);
template.sendBody("jms:topic:quote", "Camel rocks");
mockEndpoint.assertIsSatisfied();
}
}
Because of missing connectionFactory I got the following exception:
org.apache.camel.FailedToCreateRouteException: Failed to create route route1: Route(route1)[[From[jms:topic:quote]] -> [To[mock:quote]]] because of connectionFactory must be specified
I'm able to fix it adding the following lines to my route:
ConnectionFactory connectionFactory =
new ActiveMQConnectionFactory("vm://localhost?roker.persistent=false");
context.addComponent("jms", JmsComponent.jmsComponent(connectionFactory));
But I don't like I'm adding some components to my context inside the route. Also, If i want to have another route I will need to do it again.
Obviously, there should be another way to tell my test about connection factory.
Thank you in advance!
It's a good idea to define the JMS connection factory outside of your Camel context and, if possible, reuse it. How to do that depends on your component model / execution environment.
If you're using a Java SE version that supports CDI, that would be an obvious choice. You'd define your JMS connection factory as a named component once and inject it everywhere you need it. Have a look at http://camel.apache.org/cdi.html and for testing support at http://camel.apache.org/cdi-testing.html
If you're using Spring, define your connection factory as a spring bean and inject it wherever you need it.
If you're using Java EE on an application server, you'd usually define the JMS connection factory using the mechanisms of that app server. You'd then look up the JMS connection factory using JNDI.
If you're running in an OSGi container, you should define the JMS connection factory in its own bundle and export it as an OSGi service. In the bundle of your Camel context, import that OSGi servide and inject it into the Camel context.
In all above cases you should consider using a pooled JMS connection factory.
For CDI, Spring and OSGi, have a look at: http://activemq.apache.org/maven/5.14.5/apidocs/org/apache/activemq/jms/pool/PooledConnectionFactory.html
For Java EE the way how to set pooling parameters depends on your app server.
Note of caution: for Java SE CDI and Spring there should be only one Camel context per application (you can have many routes, though). So if the JMS connection factory is only used in that one Camel context, there is not much reuse. Despite that I still think it's preferable to define the JMS connection outside of the Camel context in a separate component. It's, well, cleaner.
Since you are writing a junit you can avoid creating a ConnectionFactory if you stub the jms endpoint. You can name the endpoint as stub:jms:topic:quote. Have a look at sample example at link https://github.com/camelinaction/camelinaction2/blob/master/chapter9/mock/src/test/java/camelinaction/FirstMockTest.java
I've been reading dozens of topics here with no real enlightment: I'm running a standalone java app, on a Synology NAS with Java 8. I also installed MariaDB on the same NAS. So everything is local.
I am able to setup a datasource and get a connection, but I would like to be able to access it in any instance of any of my classes / threads for connection pooling. Everything seem to show that I would need JNDI. But I don't have a J2EE container and this seems overkill for my need. Idem for developping my own implementation of JNDI.
I've seen replies to similar questions where people suggest C3PO. But this is just another datasource implementation. I don't think it solves the standalone app issue with no way to access datasource from anywhere in the code :
How to retrieve DB connection using DataSource without JNDI?
Is there another way to share a datasource across java threads ?
Can I pass the Datasource instance as a parameter to each thread, so
they can get a connection when they need ?
Should I assign a given connection to each thread - also passed as a
parameter ? and in this case, never really close it properly ?
Or should I really install something like tomcat, jboss, jetty ? are
they equivalent ? Is there a super light J2EE container that could
provide JNDI ?
Thanks
Vincent
You could use the singleton pattern, like this for example:
public class DataSourceFactory {
private static DataSource instance = null;
private DataSourceFactory() { }
public static synchronized DataSource getDataSource(){
if(instance == null){
instance = // initialize your datasource
}
return instance;
}
}
Then any from any thread you can call DataSourceFactory.getDataSource() to get a reference to your DataSource object.
I have a problem when I acces my MySql Database from an EJB. After deploying my EAR to the Glassfish server, and calling the method that use the entity class I get an exception like this:
java.lang.NoClassDefFoundError: com/mysql/jdbc/ResultSetMetaData
I am using a local MySql Database, the connection to these still works. To acces the tables of these Databese I am using entity classes generated by Netbeans. This classes are situated in external Library (OthelloLibrarie). Here you can also find the remote interface of my Session Bean.
I had to put the entity classes in an external library because I'm using them in an Enterprise Client Application which is connected to my EAR.
My Enterprise Application Project contains the main Session bean and somes Session beans from entity classes which uses my entity classes in the external Library. It also contains the persistence XML and it includes my JDBC driver:
The error appears when I call the method createPartie from the Client Application:
Partie p = eJBOthelloGame.createPartie(jTextFieldPseudo.getText());
SessionBeanOthelloRemote.java:
#Stateless
public class SessionBeanOthello implements SessionBeanOthelloRemote {
#EJB
private PlayerFacadeLocal playerFacade;
#EJB
private PartieFacadeLocal partieFacade;
#Override
public Partie createPartie(String player) {
//Ajout du tuple
Partie p = new Partie();
Player p1 = new Player();
p1.setId(1);
p1.setNom(player);
playerFacade.create(p1);
p.setPlayer1(p1);
partieFacade.create(p);
return p;
}
Partie and Player are Entity classes used with generated facades.
I searched yet on the web but I never found this kind of error. It seems that only the package or class ResultSetMetaData from JDBC has a problem and not the entire driver.
Can you help me?
You need to include in your project the mysql-connector-java.jar file that provides the MySql JDBC driver classes. As you are using Netbeans, just add it as a library jar.
You can find it, along with download and installation instructions, at this link.
I have a Spring MVC app that is running fine on local tomcat etc. Its a Spring 3.1 MVC/Hibernate app.
I am using (where possible) pure Java #Configuration for the app - and I am now trying to deploy the app to CloudFoundry (via STS), but I am struggling to get the MySql db configured (from memory, with xml config you dont need to do anything and Spring/CloudFoundry auto-injects the required user/password etc, but its been a while since I deployed anything to CF).
I have tried both of the following configurations:
#Bean
public BasicDataSource dataSource() throws PropertyVetoException {
//CloudFoundry config
final CloudEnvironment cloudEnvironment = new CloudEnvironment();
final List<MysqlServiceInfo> mysqlServices = cloudEnvironment.getServiceInfos(MysqlServiceInfo.class);
final MysqlServiceInfo serviceInfo = mysqlServices.get(0);
BasicDataSource bean = new BasicDataSource();
bean.setDriverClassName("com.mysql.jdbc.Driver");
bean.setUrl(serviceInfo.getUrl());
bean.setUsername(serviceInfo.getUserName());
bean.setPassword(serviceInfo.getPassword());
return bean;
}
The above failed on out of bounds on the .get(0) line of the mysqlServices. This was based on the answer suggested here.
I also tried leaving the datasource as what it runs on as local to see if the properties just get injected, but no luck there either. (the below was tried with the values as per the Spring sample code here, and also using property placeholders from my db.connection props file)
#Bean
public BasicDataSource dataSource() throws PropertyVetoException {
BasicDataSource bean = new BasicDataSource();
bean.setDriverClassName("com.mysql.jdbc.Driver");
bean.setUrl("");
bean.setUsername("spring");
bean.setPassword("spring");
return bean;
}
Edit
I have also used the getServiceInfo(String, Class) method passing in the name of the MySql service that I have created and bound to the application, but that just NPEs similar to the getServiceInfos(..) approach
Ok, this was just a stupid mistake - when I deployed the app via STS I had selected Java Web app rather than the "Spring" type. Not sure why that would make the CloudEnvironment properties not be available (I was under the impression that approach was the common method to inject the details in non-Spring apps) - but re-deploying it to the server as a Spring app resolved the probs!