Generally fairly stuck with classes and methods

[Ben1]

Hey all,

I haven't properly touched Java in a while and I'm pretty stuck getting back into the basics - classes and method calling etc etc.

I want to make a program that captures msn packets (done) and compares aspects of them against predefined information - so sender, receiver and message content.

I have so far:

Main class:

/*
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 * and open the template in the editor.
 */
package msgmonitor;

import java.io.IOException;
import jpcap.JpcapCaptor;
import jpcap.NetworkInterface;
import jpcap.packet.Packet;
import msgMonitor.CapturePackets;
import java.util.Scanner;

/**
 *
 * @author Ben
 */
public class IMsafe {

    public static void main(String[] args) throws IOException {
        NetworkInterface[] devices = JpcapCaptor.getDeviceList();

//for each network interface
        for (int i = 0; i < devices.length; i++) {
            //print out its name and description
            System.out.println(i + ": " + devices[i].name + "("
                    + devices[i].description + ")");
            //print out its datalink name and description
            System.out.println(" datalink: "
                    + devices[i].datalink_name + "(" + devices[i].datalink_description
                    + ")");

        }

        //What NIC to capture from. - Allows for multiple NIC's or VM NIC's
            System.out.println("Please select the Network Inface you would like to capture from: ");
            Scanner scan = new Scanner(System.in);
            String NICtemp = scan.next();

            int NIC = Integer.parseInt(NICtemp);
            int index = NIC;

//        //sets which NIC to capture from
        JpcapCaptor captor = JpcapCaptor.openDevice(devices[index], -1, false, 20);

        System.out.println("Now monitoring...");
        System.out.println("______________________");


        Packet tempPacket = captor.getPacket();
        for (index = 0; index < 10; index++) {
            if (tempPacket != null) {
                new Thread(new CapturePackets(captor, tempPacket)).start();
                tempPacket = captor.getPacket();
                index = 0;
            } else {
                tempPacket = captor.getPacket();
                index = 0;
            }
        }
    }
}

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package msgMonitor;

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import jpcap.JpcapCaptor;
import jpcap.packet.Packet;
import msgmonitor.KnownSender;

//captor.close();
/**
 *
 * @author Ben
 */
public class CapturePackets implements Runnable {

    private JpcapCaptor captor;
    private Packet tempPacket;
    public String payload;

    public CapturePackets(JpcapCaptor captor, Packet tempPacket) {
        this.captor = captor;
        this.tempPacket = tempPacket;
    }

    public void run() {

        //tempPacket = the variable used to hold the raw data straight off the NIC
        //packetString = the byte array used to hold the converted "data" from tempPacket
        //payload = the data as a string - final var for this stage.

        byte[] packetString = tempPacket.data;
        String payloadTemp = new String(packetString);

        //For Windows Live Messenger 2009
        if (payloadTemp.contains("MSG")
                && payloadTemp.contains("Content-Type: text/plain")) {
            payload = payloadTemp;

            System.out.println(payload);
            System.out.println("______________________");

            System.out.println(payloadTemp);
        }

        //For Windows Live Messenger 2009
        if (payloadTemp.contains("Message-Type: Text")
                && payloadTemp.contains("Content-Type: text/plain")) {
            payload = payloadTemp;

            //System.out.println(payload);
            //System.out.println("______________________");
        }

        if (payload == null) {
            return;
        } else {
        }
        //}
        //Breaking up the payload

        //public void splitPacket(String to, String from, String message) {

        //Get the message destination
        String to, from, message;
        int start = payload.indexOf("To: 1:");
        if (start == -1) {
            try {
                BufferedWriter out = new BufferedWriter(new FileWriter("Error File.txt", true));
                out.write("There was an error processing the data. The packet data is... \r\n");
                out.write(payload + "\r\n");
                out.write("______________________ \r\n");
                out.close();
            } catch (IOException e) {
            }
        }

        int end = payload.indexOf("\r\n", start);
        if (start == -1) {
            try {
                BufferedWriter out = new BufferedWriter(new FileWriter("Error File.txt", true));
                out.write("There was an error processing the data. The packet data is... \r\n");
                out.write(payload + "\r\n");
                out.write("______________________ \r\n");
                out.close();
            } catch (IOException e) {
            }
        }
        to = payload.substring(start + 6, end);
        System.out.println("To: " + to);


        //Get the message source
        start = payload.indexOf("From: 1:");
        if (start == -1) {
            try {
                BufferedWriter out = new BufferedWriter(new FileWriter("Error File.txt", true));
                out.write("There was an error processing the data. The packet data is... \r\n");
                out.write(payload + "\r\n");
                out.write("______________________ \r\n");
                out.close();
            } catch (IOException e) {
            }
        }
        end = payload.indexOf(";", start);
        if (start == -1) {
            try {
                BufferedWriter out = new BufferedWriter(new FileWriter("Error File.txt", true));
                out.write("There was an error processing the data. The packet data is... \r\n");
                out.write(payload + "\r\n");
                out.write("______________________ \r\n");
                out.close();
            } catch (IOException e) {
            }
        }
        from = payload.substring(start + 8, end);
        System.out.println("From: " + from);

        //Get the message
        start = payload.indexOf("X-MMS-IM-Format");
        if (start == -1) {
            try {
                BufferedWriter out = new BufferedWriter(new FileWriter("Error File.txt", true));
                out.write("There was an error processing the data. The packet data is... \r\n");
                out.write(payload + "\r\n");
                out.write("______________________ \r\n");
                out.close();
            } catch (IOException e) {
            }
        }

        start = payload.indexOf("\r\n\r\n", start);
        if (start == -1) {
            try {
                BufferedWriter out = new BufferedWriter(new FileWriter("Error File.txt", true));
                out.write("There was an error processing the data. The packet data is... \r\n");
                out.write(payload + "\r\n");
                out.write("______________________ \r\n");
                out.close();
            } catch (IOException e) {
            }
        }
        start += 4;
        message = payload.substring(start);
        System.out.println("Message: " + message);
        System.out.println("______________________");


        //***
        //set setters
        KnownSender knownSender = new KnownSender();

//        knownSender.setTo(to);
        knownSender.setFrom(from);
        
        KnownSender knownsenderObject = new KnownSender();
        KnownSender.test();

    }
}

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package msgmonitor;

public class KnownSender {

    String fromTemp;
    //get From

    public String getFrom() {
        return fromTemp;
    }

    public void setFrom(String from) {
        this.fromTemp = from;
    }
    //set getters
    String from = getFrom();

    public void test() {
        System.out.println("The sender of this message is: " + fromTemp);
    }
}

I have the program capturing packets and printing them out in formatted way. But I want to pass the "to" and "from" into the last class detailed for analysis. But at the moment I'm getting "non-static method test() cannot be referenced from a static context".

Any help getting me out of this confusion would be greatly appreciated. If I've confused anyone let me know and I'll try and clarify.

Thanks
Ben

[KevinWorkman]

Honestly, you might want to start quite a bit smaller. Here's a good beginner tutorial, give it a read-through: Trail: Learning the Java Language (The Java™ Tutorials)

[Ben1]

Ok please ignore this whole thread. I was being an idiot. Got it working :-)

[KevinWorkman]

Cool, glad you got it working. Don't worry, being an idiot sometimes is part of being a programmer. You might consider posting your solution (or part of it, or a description of it) so people with similar problems in the future can benefit from what you did.