Web Hosting Web Hosting, web hosting, JSP, Servlets, Tomcat, website hosting, web site hosting
Web Hosting, web hosting, JSP, Servlets, Tomcat, website hosting, web site hosting
Web Hosting, web hosting, JSP, Servlets, Tomcat, website hosting, web site hosting

Alden Hosting provides professional, efficient, and reliable business-class Web hosting services to small- and medium-sized businesses.

WWW.

Call Us Toll-Free
(877) 256-0328

Outside USA
1 - (201) 505-0430

Web Hosting Welcome Web Hosting Web Hosting Plans Overview , Fund Raising, Fundraising, web hosting, website hosting, web site hosting Web Hosting Fund Raising, Fundraising, web hosting Web Hosting Resellers, web Hosting Web Hosting Web Design, web Hosting Web Hosting Extra Services,  web Hosting Web Hosting Traffic Booster, web hosting Web Hosting Traffic Booster, web hosting Web Hosting Technical Support,  web Hosting Web Hosting webmaster tips,  web Hosting Web Hosting 30 Day Money Back, web hosting Web Hosting Legal Notices for Web Hosting Web Hosting Glossary Computer Terms for web Hosting Web Hosting Contact Information - web hosting

Site Map

  Web Hosting Web Hosting Sign-Up   Web Hosting Fund Raising, Fundraising, web hosting, website hosting, web site hosting    Web Hosting Resellers web hosting, website hosting, web site hosting   Web Hosting EZ Site Control Panel for web hosting,website hosting, web site hosting
Designing a Remote Interface (The Java™ Tutorials > RMI)
Trail: RMI
Section: Writing an RMI Server
Home Page > RMI
Designing a Remote Interface
At the core of the compute engine is a protocol that enables tasks to be submitted to the compute engine, the compute engine to run those tasks, and the results of those tasks to be returned to the client. This protocol is expressed in the interfaces that are supported by the compute engine. The remote communication for this protocol is illustrated in the following figure.

Each interface contains a single method. The compute engine's remote interface, Compute, enables tasks to be submitted to the engine. The client interface, Task, defines how the compute engine executes a submitted task.

The compute.Compute interface defines the remotely accessible part, the compute engine itself. Here is the source code for the Compute interface:

package compute;

import java.rmi.Remote;
import java.rmi.RemoteException;

public interface Compute extends Remote {
    <T> T executeTask(Task<T> t) throws RemoteException;
}

By extending the interface java.rmi.Remote, the Compute interface identifies itself as an interface whose methods can be invoked from another Java virtual machine. Any object that implements this interface can be a remote object.

As a member of a remote interface, the executeTask method is a remote method. Therefore, this method must be defined as being capable of throwing a java.rmi.RemoteException. This exception is thrown by the RMI system from a remote method invocation to indicate that either a communication failure or a protocol error has occurred. A RemoteException is a checked exception, so any code invoking a remote method needs to handle this exception by either catching it or declaring it in its throws clause.

The second interface needed for the compute engine is the Task interface, which is the type of the parameter to the executeTask method in the Compute interface. The compute.Task interface defines the interface between the compute engine and the work that it needs to do, providing the way to start the work. Here is the source code for the Task interface:

package compute;

public interface Task<T> {
    T execute();
}

The Task interface defines a single method, execute, which has no parameters and throws no exceptions. Because the interface does not extend Remote, the method in this interface doesn't need to list java.rmi.RemoteException in its throws clause.

The Task interface has a type parameter, T, which represents the result type of the task's computation. This interface's execute method returns the result of the computation and thus its return type is T.

The Compute interface's executeTask method, in turn, returns the result of the execution of the Task instance passed to it. Thus, the executeTask method has its own type parameter, T, that associates its own return type with the result type of the passed Task instance.

RMI uses the Java object serialization mechanism to transport objects by value between Java virtual machines. For an object to be considered serializable, its class must implement the java.io.Serializable marker interface. Therefore, classes that implement the Task interface must also implement Serializable, as must the classes of objects used for task results.

Different kinds of tasks can be run by a Compute object as long as they are implementations of the Task type. The classes that implement this interface can contain any data needed for the computation of the task and any other methods needed for the computation.

Here is how RMI makes this simple compute engine possible. Because RMI can assume that the Task objects are written in the Java programming language, implementations of the Task object that were previously unknown to the compute engine are downloaded by RMI into the compute engine's Java virtual machine as needed. This capability enables clients of the compute engine to define new kinds of tasks to be run on the server machine without needing the code to be explicitly installed on that machine.

The compute engine, implemented by the ComputeEngine class, implements the Compute interface, enabling different tasks to be submitted to it by calls to its executeTask method. These tasks are run using the task's implementation of the execute method and the results, are returned to the remote client.

Previous page: Writing an RMI Server
Next page: Implementing a Remote Interface
Web Hosting, web hosting, JSP, Servlets, Tomcat, website hosting, web site hosting
Add to My Yahoo!

XML icon

Add to Google

 

 

 

 

 

 

 

 

 

 

 

http://alden-servlet-Hosting.com
JSP at alden-servlet-Hosting.com
Servlets at alden-servlet-Hosting.com
Servlet at alden-servlet-Hosting.com
Tomcat at alden-servlet-Hosting.com
MySQL at alden-servlet-Hosting.com
Java at alden-servlet-Hosting.com
sFTP at alden-servlet-Hosting.com
http://alden-tomcat-Hosting.com
JSP at alden-tomcat-Hosting.com
Servlets at alden-tomcat-Hosting.com
Servlet at alden-tomcat-Hosting.com
Tomcat at alden-tomcat-Hosting.com
MySQL at alden-tomcat-Hosting.com
Java at alden-tomcat-Hosting.com
sFTP at alden-tomcat-Hosting.com
http://alden-sftp-Hosting.com
JSP at alden-sftp-Hosting.com
Servlets at alden-sftp-Hosting.com
Servlet at alden-sftp-Hosting.com
Tomcat at alden-sftp-Hosting.com
MySQL at alden-sftp-Hosting.com
Java at alden-sftp-Hosting.com
sFTP at alden-sftp-Hosting.com
http://alden-jsp-Hosting.com
JSP at alden-jsp-Hosting.com
Servlets at alden-jsp-Hosting.com
Servlet at alden-jsp-Hosting.com
Tomcat at alden-jsp-Hosting.com
MySQL at alden-jsp-Hosting.com
Java at alden-jsp-Hosting.com
sFTP at alden-jsp-Hosting.com
http://alden-java-Hosting.com
JSp at alden-java-Hosting.com
Servlets at alden-java-Hosting.com
Servlet at alden-java-Hosting.com
Tomcat at alden-java-Hosting.com
MySQL at alden-java-Hosting.com
Java at alden-java-Hosting.com
sFTP at alden-java-Hosting.com
JSP Servlets Tomcat mysql Java JSP Servlets Tomcat mysql Java JSP Servlets Tomcat mysql Java JSP Servlets Tomcat mysql Java JSP at JSP.aldenWEBhosting.com Servlets at servlets.aldenWEBhosting.com Tomcat at Tomcat.aldenWEBhosting.com mysql at mysql.aldenWEBhosting.com Java at Java.aldenWEBhosting.com Web Hosts Portal Web Links Web Links Web Hosting JSP Solutions Web Links JSP Solutions Web Hosting Servlets Solutions Web Links Servlets Solutions Web Hosting Web Links Web Links . .
.
.
. .
. . . . jsp hosting servlets hosting web hosting web sites designed cheap web hosting web site hosting myspace web hosting