done: load/save database from/to file system, done: client/server design pattern, wip: validation

import javax.swing.*;

import java.io.*;

import java.net.*;

public class Main {

  public static void main(String[] args) {

    System.out.println("hello world");

  static MoleculeDatabase moleculeDb;

  public static void dbLoad() throws IOException, ClassNotFoundException {

    FileInputStream fileInStream = new FileInputStream("molecule.db");

    ObjectInputStream objInStream = new ObjectInputStream(fileInStream);

    moleculeDb = (MoleculeDatabase) objInStream.readObject();

    objInStream.close();

    fileInStream.close();

  }

  public static void dbSave() throws IOException {

    FileOutputStream fileOutStream = new FileOutputStream("molecule.db");

    ObjectOutputStream objOutStream = new ObjectOutputStream(fileOutStream);

    objOutStream.writeObject(moleculeDb);

    objOutStream.close();

    fileOutStream.close();

  }

  public static void runClient(Socket clientSocket, String argument)

      throws IOException {

    OutputStream outStream = clientSocket.getOutputStream();

    PrintWriter writer = new PrintWriter(outStream);

    writer.println(argument);

    writer.flush();

    writer.close();

    outStream.close();

  }

  public static void runServer(ServerSocket serverSocket)

      throws IOException {

    try {

      dbLoad();

    } catch (IOException e) {

      moleculeDb = new MoleculeDatabase();

    } catch (ClassNotFoundException e) {

      throw new RuntimeException(e);

    }

    Socket clientSocket = serverSocket.accept();

    InputStream inStream = clientSocket.getInputStream();

    BufferedReader reader = new BufferedReader(new InputStreamReader(inStream));

    String[] arguments = reader.readLine().split(" ");

    String command = arguments[0];

    while (!command.equals("quit")) {

      String filePath = arguments[1];

      if (command.equals("--addMolecule")) {

      } else if (command.equals("--findMolecule")) {

      }

      clientSocket = serverSocket.accept();

      inStream = clientSocket.getInputStream();

      reader = new BufferedReader(new InputStreamReader(inStream));

      arguments = reader.readLine().split(" ");

      command = arguments[0];

    }

    reader.close();

    inStream.close();

    clientSocket.close();

  }

  public static void main(String[] args) throws IOException {

    final int PORT_NUMBER = Integer.parseInt(args[0]);

    String command = "";

    String filePath = "";

    if (args.length == 2) {

      command = args[1];

    } else if (args.length == 3) {

      command = args[1];

      filePath = args[2];

    } else {

      System.out.println("invalid number of arguments");

    }

    try (Socket clientSocket = new Socket("localhost", PORT_NUMBER)) {

      runClient(clientSocket, command + " " + filePath);

//      clientSocket.close();

    } catch (ConnectException e) {

      ServerSocket serverSocket = new ServerSocket(PORT_NUMBER);

      serverSocket.setSoTimeout(60 * 1000);

      runServer(serverSocket);

      serverSocket.close();

      dbSave();

      System.out.println("goodbye");

    }

  }

}

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