primefind.java

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package net.jxta.impl.shell.bin.primefind;

import net.jxta.impl.shell.ShellApp;
import net.jxta.impl.shell.ShellEnv;
import net.jxta.impl.shell.ShellObject;
import net.jxta.peergroup.PeerGroup;
import net.jxta.id.ID;
import net.jxta.document.Advertisement;
import net.jxta.document.MimeMediaType;
import net.jxta.document.StructuredTextDocument;
import net.jxta.document.StructuredDocumentFactory;
import net.jxta.pipe.OutputPipe;
import net.jxta.endpoint.Message;
import net.jxta.endpoint.MessageElement;
import primecruncher.Dispatcher;
import primecruncher.ResultListener;
import primecruncher.ServiceConstants;

import java.util.Map;
import java.io.IOException;
import java.io.ByteArrayInputStream;

public class primefind extends ShellApp implements ResultListener {


    ShellEnv environment;
    Dispatcher dispatcher = null;
    String result;

    public primefind() {

    }


    /**
     * Called when the shell command is started.
     */
    public int startApp(String[] argv) {
        environment = getEnv();

        if (argv.length != 2) {
            return ShellApp.appParamError;
        }

        int low;
        int high;
        try {
            low = Integer.parseInt(argv[0]);
            high = Integer.parseInt(argv[1]);
        } catch (NumberFormatException e) {
            return ShellApp.appParamError;
        }

        dispatcher = new Dispatcher(getGroup());

        dispatcher.processPrimes(low, high, this);
            synchronized(this) {
            try {
                    wait();
                } catch (InterruptedException me) {
                }
            }

        Message mes = getGroup().getPipeService().createMessage();
        MessageElement el = mes.newMessageElement("results", new MimeMediaType("text/plain"),
                result.getBytes());
        mes.addElement(el);
        try {
            outputPipe.send(mes);
            StructuredTextDocument doc = (StructuredTextDocument)StructuredDocumentFactory.newStructuredDocument(
                    new MimeMediaType("text/xml"), "result", result);

            ShellObject so = new ShellObject("results", doc);
            environment.add("results", so);
        } catch (IOException e) {
            e.printStackTrace();
        }

        return ShellApp.appNoError;
    }


    public void stopApp() {
        super.stopApp();
    }


    public void help() {
        println("NAME");
        println("     primefind -- find prime numbers between two integers");
        println(" ");
        println("SYNOPSYS");
        println(" ");
        println("     primefind X Y");
        println(" ");
        println("DESCRIPTION");
        println("'primefind' utilizes peers offering a prime number finding ");
        println("service to search prime numbers in a distributed manner.");
        println("When invoked, 'primefind' discovers peers offering that ");
        println("service, distributes the list of numbers between the two");
        println("parameters among those peers, and waits for the peers to");
        println("respond with their results. Once all results are obtained,");
        println("'primefind' produces a comma-separated list of prime numbers");
        println("on its standard output. Note that this command relies on ");
        println("other peers to search prime numbers; If no peer offering");
        println("that service is available, 'primefind' will block until ");
        println("at least one such peer is discovered.");
        println(" ");
        println("EXAMPLE");
        println(" ");
        println("    JXTA>primefind 10 100");
        println(" ");
        println("This command produces a list of all prime numbers between");
        println("10 and 100 on its standard ouput.");
        println(" ");
    }


    public String getDescription() {
        return "Search for prime numbers";
    }

    public void resultEvent (Map resultMap) {
        synchronized(this) {
        result = (String)resultMap.get(ServiceConstants.RESULTSTRING);
        if (result != null)
            System.out.println("Result is not null");
        System.out.println("result even called");
        notifyAll();
        }
    }

}