Easiest example I can think of would be a method that sends some content to a JMS server. If you are in the context of a transaction, you want the message to be coupled to the transaction scope. But if there isn’t already a transaction running, why bother calling the transaction server also and starting … Read more
I would go for Stateless – the server can generate many instances of the bean and process incoming requests in parallel. Singleton sounds like a potential bottleneck – the default @Lock value is @Lock(WRITE) but may be changed to @Lock(READ) for the bean or individual methods.
I solved my problem placing the insertable=false, updatable=false in the @JoinColumn annotation in both classes, Person and Company.
This working on Wildfly 8.1: <datasource jta=”true” jndi-name=”java:jboss/datasources/xxxdb” pool-name=”xxxxDB” enabled=”true” use-ccm=”false”> <connection-url>jdbc:mysql://localhost:3306/xxxdb?autoReconnect=true&amp;useUnicode=true&amp;characterEncoding=UTF-8</connection-url> <driver-class>com.mysql.jdbc.Driver</driver-class> <driver>mysql-connector-java-5.1.26-bin.jar</driver> <security> <user-name>xxxuser</user-name> <password>xxxpassword</password> </security> <validation> <check-valid-connection-sql>select 1</check-valid-connection-sql> <validate-on-match>false</validate-on-match> <background-validation>true</background-validation> <background-validation-millis>10000</background-validation-millis> </validation> <statement> <share-prepared-statements>false</share-prepared-statements> </statement> </datasource>
providedCompile is shipped with war plugin. So you need to add: plugins { // … id ‘war’ }
As per the Javadoc for the @Schedule annotation, the default values are: * for all fields except hour, minute, and second; and 0 for hour, minute, and second, by default. By specifying minute=”*” and leaving hour at its default of 0, it requests that the timer run every minute after midnight for one hour (i.e., … Read more
A detached entity is an entity whose state must not be reflected by the JPA provider. In other words, if you change its state (i.e. through setters methods) these changes will not be saved to the underlying database, as the JPA provider doesn’t have to “observe” such entities. If entity E1 is a managed entity … Read more
I found a plausible explanation here: By default, javax.ejb.Singleton session beans are transactional (section 13.3.7 of the EJB 3.1 specification) and require acquisition of an exclusive lock for every business method invocation (sections 4.8.5.4 and 4.8.5.5). In contrast, a javax.inject.Singleton is not transactional and does not support container-managed concurrency (the major consequence being that no … Read more
As you can see, I have declared the annotation “@Local” on the service implementation without defining the local interface. Is it correct? With EJB 3.1, the requirement for local interfaces was dropped. No need to write them unless you explicitly need them. What is the best way to inject one EJB into another one? Couple … Read more
Similar to an MDB the transaction is started by the container just before your @Asynchronous, @Schedule or @Timeout method (and applicable interceptors) is actually invoked and committed just after the method (and interceptors) completes. As per usual, the transaction propagates to all beans called in said method and all beans those beans call, recursively. Of … Read more