Java Portlet API V3.0 framework with other Java class libraries
Java Portlet API V3.0 framework with other Java class libraries
Overview:
Java Portlet API V3.0 is a Java framework for building reuse components.It provides a standard API and specifications for developing, deploying, and scalable web applications in J2EE containers.The collaboration with other Java libraries is to enhance the function and performance of the Portlet application.
Collaborative method:
Java Portlet API V3.0 can collaborate with other Java class libraries and frameworks to meet complex business needs.The following are several common ways of collaboration:
1. Database access class library:
The Java Portlet application may need to obtain data from the database.To achieve this function, you can use a database to access the class library, such as Hibernate or MyBatis.By using these class libraries, you can connect, query and operate databases more conveniently.
Example code:
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class HibernateUtil {
private static final SessionFactory sessionFactory;
static {
try {
// Load the hibernate configuration file
Configuration configuration = new Configuration().configure();
// Create sessionFactory
sessionFactory = configuration.buildSessionFactory();
} catch (Throwable ex) {
throw new ExceptionInInitializerError(ex);
}
}
public static Session getSession() {
return sessionFactory.openSession();
}
}
public class MyPortlet extends GenericPortlet {
public void doView(RenderRequest request, RenderResponse response) throws PortletException, IOException {
Session session = HibernateUtil.getSession();
// Use Session to query data and render the Portlet view
// ...
session.close();
}
}
2. Template engine library:
Portlet view usually needs to render dynamic content.To achieve this, the template engine library can be used, such as FreeMarker or Velocity.The template engine can combine the template and the data to generate the final HTML output.
Example code:
import freemarker.template.Configuration;
import freemarker.template.Template;
import freemarker.template.TemplateException;
public class MyPortlet extends GenericPortlet {
public void doView(RenderRequest request, RenderResponse response) throws PortletException, IOException {
Configuration cfg = new Configuration(Configuration.VERSION_2_3_30);
cfg.setClassForTemplateLoading(this.getClass(), "/templates");
Template template = cfg.getTemplate("view.ftl");
// Set template variable
Map<String, Object> model = new HashMap<>();
model.put("name", "World");
StringWriter writer = new StringWriter();
try {
template.process(model, writer);
} catch (TemplateException e) {
throw new PortletException("Failed to process template.", e);
}
// Output the generated HTML to the Portlet view
response.getWriter().write(writer.toString());
}
}
3. Safety library:
Portlet applications may need to process user identity verification and authorization.To achieve this, safety libraries, such as Spring Security or Apache Shiro.These class libraries provide a complete set of security functions, including user certification, role authorization and authority management.
Example code:
import org.springframework.security.core.Authentication;
import org.springframework.security.core.context.SecurityContextHolder;
public class MyPortlet extends GenericPortlet {
public void doView(RenderRequest request, RenderResponse response) throws PortletException, IOException {
// Get the current user information
Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
String username = authentication.getName();
// Obtain relevant data according to user information and render the Portlet view
// ...
}
}
Summarize:
The Java Portlet API V3.0 framework can collaborate with other Java class libraries to enhance the function and performance of the Portlet application.The database access class library can help obtain data from the database; the template engine class library can realize the rendering of dynamic content; the security class library can handle user certification and authorization.By collaboration with these libraries, developers can more efficiently build reusable Portlet components.
