Parser.java

import java.io.*;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ConcurrentHashMap;

//This class is used to read common.cfg and peerinfo.cfg and pass the parameters to commoncfg and peerinfo.
public class Parser {
    BufferedReader br;

    // File path of configuration(Can be any one of Common.cfg and PeerInfo.cfg)
    public Parser(String filePath) throws FileNotFoundException {
        br = new BufferedReader(new InputStreamReader(new FileInputStream(filePath)));
    }

    List<String> commonTokens = new ArrayList<String>();
    List<String> peerTokens = new ArrayList<String>();
    ConcurrentHashMap<Integer, PeerInfo> peers = new ConcurrentHashMap<Integer, PeerInfo>();

    /*
     * Method used to parse Common.cfg
     */
    public Commoncfg parseCommon() throws IOException {
        Commoncfg commoncfg = new Commoncfg();
        String Line = br.readLine();
        while (Line != null) {
            String[] LineTokens = Line.split(" ");
            commonTokens.add(LineTokens[1]);
            Line = br.readLine();
        }
        commoncfg.setNum_Of_PreferredNeighbors(Integer.parseInt(commonTokens.get(0)));
        commoncfg.setUnchoking_Interval(Integer.parseInt(commonTokens.get(1)));
        commoncfg.setOptimistic_Unchoking_Interval(Integer.parseInt(commonTokens.get(2)));
        commoncfg.setFileName(commonTokens.get(3));
        commoncfg.setFileSize(Integer.parseInt(commonTokens.get(4)));
        commoncfg.setPieceSize(Integer.parseInt(commonTokens.get(5)));
        return commoncfg;
    }

    /*
     * Method used to parse PeerInfo.cfg, return the map of each peer and its information
     */
    public ConcurrentHashMap<Integer, PeerInfo> parsePeerInfo() throws IOException {

        String Line = br.readLine();
        while (Line != null) {
            PeerInfo peerInfo = new PeerInfo();
            String[] LineTokens = Line.split(" ");

            peerInfo.setPeerID(Integer.parseInt(LineTokens[0]));
            peerInfo.setHostName(LineTokens[1]);
            peerInfo.setPort(Integer.parseInt(LineTokens[2]));

            if (LineTokens[3].equals("1")) {
                peerInfo.setFileStatus(true);
            } else {
                peerInfo.setFileStatus(false);
            }

            peers.put(peerInfo.getPeerID(), peerInfo);
            Line = br.readLine();
        }
        return peers;
    }
}