replicatedstackjgroups.ReplStack.java Source code

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Here is the source code for replicatedstackjgroups.ReplStack.java

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/*
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package replicatedstackjgroups;

import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Map;
import java.util.Scanner;
import org.jgroups.JChannel;
import org.jgroups.Message;
import org.jgroups.ReceiverAdapter;
import org.jgroups.View;
import org.jgroups.util.Util;
import org.json.simple.JSONObject;

/**
 *
 * @author Andarias Silvanus & Rita Sarah
 */
public class ReplStack<T> extends ReceiverAdapter {
    JChannel channel;
    ArrayList container;
    String user_name = System.getProperty("user.name", "n/a");

    public ReplStack() throws Exception {
        container = new ArrayList<T>();
        start();
    }

    public void push(T obj) {
        container.add(obj);
    }

    public T pop() {
        if (container.isEmpty()) {
            return null;
        } else {
            T x = (T) container.get(container.size() - 1);
            container.remove(container.size() - 1);
            return x;
        }
    }

    public T top() {
        if (container.isEmpty()) {
            return null;
        } else {
            T x = (T) container.get(container.size() - 1);
            return x;
        }
    }

    public ArrayList getContainer() {
        return container;
    }

    private void start() throws Exception {
        channel = new JChannel(); // use the default config, udp.xml
        channel.setReceiver(this);
        channel.connect("ChatCluster");
        channel.getState(null, 10000);
        eventLoop();
        channel.close();
    }

    @Override
    public void viewAccepted(View new_view) {
        //        System.out.println("** view: " + new_view);
    }

    @Override
    public void receive(Message msg) {
        JSONObject obj = (JSONObject) msg.getObject();
        String mode = obj.get("mode").toString();

        if (mode.equals("stack_push")) {
            T param = (T) obj.get("body");
            push(param);
            System.out.println(param + " pushed");
        } else if (mode.equals("stack_pop")) {
            T x = pop();
            System.out.println(x + " popped");
        } else if (mode.equals("stack_top")) {
            T x = top();
            System.out.println(x + " is top");
        }

    }

    private void eventLoop() {
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        Scanner input = new Scanner(System.in);
        JSONObject json_obj = new JSONObject();
        while (true) {
            try {
                System.out.print("> ");
                System.out.flush();
                //                String line = in.readLine().toLowerCase();
                String line = input.next().toLowerCase();

                if (line.startsWith("quit") || line.startsWith("exit"))
                    break;
                else if (line.startsWith("stack_push")) {
                    T object = (T) input.nextLine();
                    json_obj.put("mode", "stack_push");
                    json_obj.put("body", object);
                } else if (line.startsWith("stack_pop")) {
                    json_obj.put("mode", "stack_pop");
                    json_obj.put("body", "");
                } else if (line.startsWith("stack_top")) {
                    json_obj.put("mode", "stack_top");
                    json_obj.put("body", "");
                }

                Message msg = new Message(null, null, json_obj);
                channel.send(msg);
                json_obj.clear();
            } catch (Exception e) {
            }
        }
    }

    public void getState(OutputStream output) throws Exception {
        synchronized (container) {
            Util.objectToStream(container, new DataOutputStream(output));
        }
    }

    @SuppressWarnings("unchecked")
    public void setState(InputStream input) throws Exception {
        ArrayList<T> remoteSet = (ArrayList<T>) Util.objectFromStream(new DataInputStream(input));

        synchronized (container) {
            container.clear();
            container.addAll(remoteSet);
        }

        //        System.out.println(remoteSet.size() + " messages in chat history):");
        //        for(int i = 0; i<remoteSet.size(); i++)
        //            System.out.println(remoteSet.get(i));
    }

    public static void main(String[] args) throws Exception {
        ReplStack RS = new ReplStack<String>();
    }

}