Basic Gridify Example

This example contains HelloWorld example that is using Gridify ^Javadoc annotation. GridGain will detect that a method is annotated with this annotation, it will execute this method on remote node.

String 'Hello World' is passed as an argument to GridifyHelloWorldBasicExample.sayIt(String) method. Since this method is annotated with @Gridify ^Javadoc annotation it is automatically grid-enabled and will be executed on remote node. Note, that the only thing user had to do is annotate method sayIt(String) with @Gridify ^Javadoc annotation, everything else is taken care of by the system automatically.

Package:
org.gridgain.examples.helloworld.gridify.basic

There is one class implemented for this example:

• GridifyHelloWorldBasicExample.java

AspectJ AOP Configuration

We will use AspectJ AOP for this example. To use other AOP implementations (such as JBoss AOP, or Spring AOP), refer to AOP Configuration documentation.

The following configuration needs to be applied to enable AspectJ byte code weaving.

• JVM configuration should include: -javaagent:[GRIDGAIN_HOME]/libs/aspectjweaver-1.5.3.jar
• Classpath should contain the [GRIDGAIN_HOME]/config/aop/aspectj folder.

Running Grid Node

This example will need one remote node to be running. Note that you don't need another machine for it - you can start remote node on the same machine you are running example on.

To start a remote node open the terminal window on Linux/Mac OS X or Command Prompt on Windows, change directory to ${GRIDGAIN_HOME}/bin and run the gridgain.{sh|bat} script. It takes 2-3 seconds for grid node to start and if everything worked fine you should see starting log ending with successful start acknowledgment.

GridifyHelloWorldBasicExample.java

1. Import GridGain classes.

import org.gridgain.grid.*;
import org.gridgain.grid.gridify.*;

2. Add Grid Start and Stop.

GridFactory.start();
        
try {
    ...
}
finally {
    GridFactory.stop(true);
}

finally clause allows for graceful grid shutdown in case of the exceptions.

3. Add @Gridify Annotation.

In order to grid-enable helloWorld method, we add @Gridify ^Javadoc annotation to it.

@Gridify
private static int sayIt(String phrase) {
    // Simply print out the argument.
    System.out.println(">>>");
    System.out.println(">>> Printing '" + phrase + "' on this node from grid-enabled method.");
    System.out.println(">>>");

    return phrase.length();
}

Source Code (edited)

package org.gridgain.examples.helloworld.gridify.basic;

import org.gridgain.grid.*;
import org.gridgain.grid.gridify.*;
import org.gridgain.grid.gridify.aop.spring.*;

public final class GridifyHelloWorldBasicExample {
    @Gridify
    private static int sayIt(String phrase) {
        // Simply print out the argument.
        System.out.println(">>>");
        System.out.println(">>> Printing '" + phrase + "' on this node from grid-enabled method.");
        System.out.println(">>>");

        return phrase.length();
    }

    public static void main(String[] args) throws GridException {
        if (args.length == 0) {
            GridFactory.start();
        }
        else {
            GridFactory.start(args[0]);
        }

        try {
            // This method will be executed on a remote grid node.
            int phraseLen = sayIt("Hello World");

            System.out.println(">>>");
            System.out.println(">>> Finished executing Gridify \"Hello World\" example with all defaults.");
            System.out.println(">>> Total number of characters in the phrase is '" + phraseLen + "'.");
            System.out.println(">>> You should see print out of 'Hello World' on one of the remote nodes.");
            System.out.println(">>> Check all nodes for output (this node is also part of the grid).");
            System.out.println(">>>");
        }
        finally {
            GridFactory.stop(true);
        }
    }
}