Last edition before arraylist

package assembler;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;

public class ObjectCode {
    private int cursor;
    private int lineNumber = 0;
    private ArrayList<String> listingfile = new ArrayList<>();
    private ArrayList<String> objectProgram = new ArrayList<>();
    private static final String FILENAME = "C:\\Users\\karem\\Downloads\\SIC-Example.txt";
    private static final String FILENAME2 = "C:\\Users\\karem\\Desktop\\listingfile.txt";
    private static final String FILENAME3 = "C:\\Users\\karem\\Desktop\\objectprogram.txt";

    private void readfile() {
        BufferedReader br = null;
        FileReader fr = null;
        try {
            fr = new FileReader(FILENAME);
            br = new BufferedReader(fr);
            String CurrentLine;
            while ((CurrentLine = br.readLine()) != null) {
                // call for a function that uses the line
                lineNumber++;
                this.line(CurrentLine);
            }

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (br != null)
                    br.close();
                if (fr != null)
                    fr.close();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
    }

    private void line(String line) {
        // check if comment
        char firstChar = line.charAt(0);
        if (firstChar == '.') {
            System.out.println("hello from the other side");
        } else {
            // checking format
            this.checkFormat(line);
            // get Label From Line
            // if no Label in the line get Label will return null
            String label = getLabel(line);
            if (label != null)
                label = label.toUpperCase();
            System.out.print(label);
            // get OperationCode From Line
            String operationCode = getOperationCode(line).toUpperCase();
            System.out.print("\t" + operationCode);
            // get Operand From Line
            // if no operand in the line get operand will return null
            String operand = getOperand(line);
            if (operand != null)
                operand = operand.toUpperCase();
            System.out.print("\t" + operand);
            String objectCode = getObjectCode(operationCode, operand);
            writeListing(label, operationCode, operand, objectCode);
            writeObject(label, operationCode, objectCode);
        }
        System.out.println();
    }

    private String getObjectCode(String operationCode, String operand) {
        // search for operation Code in the mnemonic Table
        boolean found = false;
        String mnemonicValue = "00";
        String operandAddress;
        String objectCode = new String();
        if (found) {
            if (operand == null) {
                operandAddress = "0000";
                objectCode = mnemonicValue.concat(operandAddress);
            } else {
                // search for operand in the symtab
                // if found
                // operandAddress = symbol value;
                // objectCode = mnemonicValue.concat(operandAddress);
                // if not found (Un Defined Symbol)
                // operandAddress = "0000";
                // ERROR
            }
        } else if (operationCode.equals("WORD")) {
            String hex = Integer.toHexString(Integer.parseInt(operand));
            if (hex.length() == 1) {
                String concat = "00000";
                hex = concat.concat(hex);
            } else if (hex.length() == 2) {
                String concat = "0000";
                hex = concat.concat(hex);
            } else if (hex.length() == 3) {
                String concat = "000";
                hex = concat.concat(hex);
            } else if (hex.length() == 4) {
                String concat = "00";
                hex = concat.concat(hex);
            } else if (hex.length() == 5) {
                String concat = "0";
                hex = concat.concat(hex);
            }
            objectCode = hex;
        } else if (operationCode.equals("BYTE")) {
            if (operand.charAt(0) == 'X') {
                objectCode = operand.substring(2, operationCode.length());
            } else if (operand.charAt(0) == 'C') {
                for (int i = 2; i < operand.length() - 1; i++) {
                    objectCode = objectCode.concat(Integer.toHexString((int) operand.charAt(i)));
                }
            }
        }
        // if object code will not fit into the current text record
        // write text record to object program
        // intialize new text record
        // add object code to text record
        return objectCode;
    }

    private void writeListing(String label, String operationCode, String operand, String objectCode) {
        if (label == null) {
            label = "\t";
        }
        if (operand == null) {
            operand = "\t";
        }
        // while(label.length() < 9){
        // label = label;
        // }
        //
        // while(operationCode.length() < 6){
        // operationCode = operationCode.concat(" ");
        // }
        // listing file
        int line = lineNumber * 5;
        String listing;
        if (lineNumber == 1) {
            listing = "Line" + "\t" + "LOC" + "\t\t" + "Source Statement" + "\t\t" + "Object Code" + "\n";
            listingfile.add(listing);
        }
        if (operationCode.equals("START") || operationCode.equals("RESB") || operationCode.equals("RESW")) {
            listing = String.valueOf(line) + "\t" + "LOC" + "\t" + label + "\t" + operationCode + "\t" + operand + "\n";
            listingfile.add(listing);
        } else if (operationCode.equals("END")) {
            listing = String.valueOf(line) + "\t" + "LOC" + "\t" + label + "\t" + operationCode + "\t" + operand;
            listingfile.add(listing);
            writeListingFile();
        } else {
            listing = String.valueOf(line) + "\t" + "LOC" + "\t" + label + "\t" + operationCode + "\t" + operand + "\t"
                    + objectCode + "\n";
            listingfile.add(listing);
        }
        // objectProgram

    }

    private void writeObject(String label, String operationCode, String objectCode) {
        String objectLine;
        if (operationCode.equals("START")) {
            while (label.length() != 6) {
                label = label.concat(" ");
            }
            objectLine = "H" + label + "STADDR" + "LENPRO" + "\n";
            objectProgram.add(objectLine);
            writeObjectProgramFile();
        }

    }

    private void writeListingFile() {
        // Listing File
        try (BufferedWriter bw = new BufferedWriter(new FileWriter(FILENAME2))) {
            for (int i = 0; i < listingfile.size(); i++) {
                bw.write(listingfile.get(i));
            }
            bw.close();
        } catch (IOException e) {

            e.printStackTrace();
        }

    }

    private void writeObjectProgramFile() {
        // objectProgram file
        try (BufferedWriter bw = new BufferedWriter(new FileWriter(FILENAME3))) {
            for (int i = 0; i < objectProgram.size(); i++) {
                bw.write(objectProgram.get(i));
            }
            bw.close();
        } catch (IOException e) {

            e.printStackTrace();
        }
    }

    private void checkFormat(String line) {
        cursor = 8;
        int y = 0;
        if (line.charAt(0) == '\t' || line.charAt(4) == '\t') {
            cursor = 5;
            y = y + 4;
            if (line.charAt(1) == '\t') {
                cursor = 2;
                y = y + 4;
            }
        } else if (line.charAt(5) == '\t') {
            cursor = 6;
            y = y + 3;
        }
        if (line.length() > cursor && line.charAt(cursor) != ' ') {
            System.out.println("Error");
        }
        for (int i = 9; line.length() > i && i < 15; i++) {
            if (line.charAt(i) == '\t') {
                y = y + 3;
                break;
            }
        }

        if (line.length() > 15 - y && line.charAt(15 - y) != ' ' && line.charAt(15 - y) != '\t') {
            System.out.println("Error");
        }
        if (line.length() > 16 - y && line.charAt(16 - y) != ' ' && line.charAt(15 - y) != '\t') {
            System.out.println("Error");
        }

    }

    private String getLabel(String line) {
        boolean flag = false;
        int i = 0;
        char firstChar = line.charAt(0);
        if (firstChar == ' ' || firstChar == '\t') {
            flag = true;
        }
        if (!flag) {
            while (i < 8) {
                if (line.length() > i && line.charAt(i) != ' ' && line.charAt(i) != '\t') {
                } else {
                    break;
                }
                i++;
            }
            String label = line.substring(0, i);
            return label;
        } else
            return null;
    }

    private String getOperationCode(String line) {
        int i = cursor + 1;
        int end = cursor + 7;
        while (i < end) {
            if (line.length() > i && line.charAt(i) != ' ' && line.charAt(i) != '\t') {
            } else {
                break;
            }
            i++;
        }
        String opertionCode = line.substring(cursor + 1, i);
        cursor = i;
        return opertionCode;
    }

    private String getOperand(String line) {
        boolean flag = false;
        int i = cursor + 1;
        int end = cursor + 31;
        while (i < end) {
            if (line.length() > i && line.charAt(i) == ' ' && line.charAt(i) != '\t') {
            } else {
                break;
            }
            i++;
            cursor++;
        }
        while (i < end) {
            if (line.length() > i && line.charAt(i) != ' ' && line.charAt(i) != '\t') {
                flag = true;
            } else {
                break;
            }
            i++;
        }
        if (flag) {
            String operand = line.substring(cursor + 1, i);
            return operand;
        } else
            return null;
    }

    public static void main(String[] args) {
        ObjectCode g = new ObjectCode();
        g.readfile();
    }

}