Openejb :: container :: Core framework in the Java library use tutorial
Openejb :: container :: Core framework in the Java library use tutorial
OpenEjb is an open source framework for constructing scalable and container -based enterprise Java applications.It is part of the Apache Tomee project, providing a lightweight, full -featured EJB (Enterprise JavaBeans) container, which is suitable for various Java applications.
This tutorial is designed to introduce how to use OpenEjb's Container Core framework in the Java library.We will explore how to configure and initialize the OpenEjb container, and use it to deploy and execute the EJB component.
1. Add OpenEjb dependencies
First, we need to add OpenEjb's related dependence to our Java project.You can use Maven or manually download jar files and introduce it to the project.
Maven dependencies:
<dependency>
<groupId>org.apache.openejb</groupId>
<artifactId>openejb-core</artifactId>
<version>${openejb.version}</version>
</dependency>
2. Configure OpenEJB container
Before using OpenEjb, we need to configure containers to define the deployment and operating parameters of EJB.You can use the attribute file or programming method provided by OpenEjb for configuration.
For example, you can create a attribute file called "openjb.xml" and define the required EJB in it.
<?xml version="1.0" encoding="UTF-8"?>
<openejb>
<ejb-deployment>
<ejb>
<ejb-name>MyEJB</ejb-name>
<ejb-class>com.example.MyEJB</ejb-class>
</ejb>
</ejb-deployment>
</openejb>
3. Initialize and start the OpenEjb container
Before using the OpenEjb container, initialization and startup are required.You can use the `EjbContainer` class to complete these operations.
import javax.ejb.embeddable.EJBContainer;
public class Main {
public static void main(String[] args) {
EJBContainer container = EJBContainer.createEJBContainer();
// The container initialization and startup
// ...
container.close();
// Close the container
}
}
4. Get and use EJB components
Once the container has been started and the EJB component has been successfully deployed, we can use the `EjbContainer` class to obtain and use these components.
import javax.ejb.embeddable.EJBContainer;
import javax.naming.Context;
import com.example.MyEJB;
public class Main {
public static void main(String[] args) {
EJBContainer container = EJBContainer.createEJBContainer();
Context context = container.getContext();
// Get EJB instance
MyEJB myEjb = (MyEJB) context.lookup("java:global/MyEJB");
// Use the EJB method
myEjb.doSomething();
container.close();
}
}
In the above example, we first obtain the `context` object of the container, and then use the` Lookup` method to obtain the corresponding EJB instance through the EJB JNDI name.Finally, we can call the EJB method to perform related operations.
Summarize
This tutorial introduces how to use OpenJB's Container Core framework in the Java library.We have learned how to configure and initialize the OpenEjb container and use it to deploy and execute the EJB component.I hope that this tutorial will be helpful to you and can lead you to further explore the powerful function and flexibility of the OpenEjb framework.
