Need help with a java project I need to do. Here is the project specifications :
"""Create a console calculator applicaion that:
* Takes one command line argument: your name and surname. When the
program starts, display the date and time with a welcome message for the
user.
* Display all the available options to the user. Your calculator must include
the arithmetic operations as well as at least five scientific operations of the
Math class.
-Your program must also have the ability to round a number and
truncate it.
-When you multiply by 2, you should not use the '*' operator to perform the
operation.
-Your program must also be able to reverse the sign of a number.
* Include sufficient error checking in your program to ensure that the user
only enters valid input. Make use of the String; Character, and other
wrapper classes to help you.
* Your program must be able to do conversions between decimal, octal and
hex numbers.
* Make use of a menu. You should give the user the option to end the
program when entering a certain option.
* When the program exits, display a message for the user, stating the
current time, and calculate and display how long the user used your
program.
* Make use of helper classes where possible.
* Use the SDK to run your program."""
I am stuck at the moment and don't know how to correct this problem.
I have created a method ' hexadecimalEquivalent(); ' (among others...) which if the user chooses, it converts the numbers he/she provided as input to the hexadecimal equivalent, my ' octalEquivalent(); ' method works but I get an error message with my ' hexadecimalEquivalent(); ' method and it states
" Exception in thread "main" java.lang.NumberFormatException: For input string: "b"
at java.lang.NumberFormatException.forInputString(Unknown Source)
at java.lang.Long.parseLong(Unknown Source)
at java.lang.Long.parseLong(Unknown Source)
at org.Java.Instructor.Project.hexadecimalEquivalent1(Project.java:86)
at org.Java.Instructor.Project.Calculator(Project.java:271)
at org.Java.Instructor.Project.main(Project.java:329)
"
Can anyone please help me.
Here is the code that I have done so far for my Project.class:
import java.io.*;
import java.util.*;
import java.text.*;
public class Project {
private static String nameSurname = "";
private static String num1 = null;
private static String num2 = null;
private static String choice1 = null;
private static double answer = 0;
private static char more;
public double Add() {
answer = (Double.parseDouble(num1) + Double.parseDouble(num2));
return answer;
}
public double Subtract() {
answer = (Double.parseDouble(num1) - Double.parseDouble(num2));
return answer;
}
public double Multiply() {
answer = (Double.parseDouble(num1) * Double.parseDouble(num2));
return answer;
}
public double Divide() {
answer = (Double.parseDouble(num1) / Double.parseDouble(num2));
return answer;
}
public double Modulus() {
answer = (Double.parseDouble(num1) % Double.parseDouble(num2));
return answer;
}
public double maximumValue() {
answer = (Math.max(Double.parseDouble(num1), Double.parseDouble(num2)));
return answer;
}
public double minimumValue() {
answer = (Math.min(Double.parseDouble(num1), Double.parseDouble(num2)));
return answer;
}
public double absoluteNumber1() {
answer = (Math.abs(Double.parseDouble(num1)));
return answer;
}
public double absoluteNumber2() {
answer = (Math.abs(Double.parseDouble(num2)));
return answer;
}
public double Squareroot1() {
answer = (Math.sqrt(Double.parseDouble(num1)));
return answer;
}
public double Squareroot2() {
answer = (Math.sqrt(Double.parseDouble(num2)));
return answer;
}
public double octalEquivalent1() {
long n1 = Long.parseLong(num1);
answer = Long.parseLong(Long.toOctalString(n1));
return answer;
}
public double octalEquivalent2() {
long n2 = Long.parseLong(num2);
answer = Long.parseLong(Long.toHexString(n2));
return answer;
}
public double hexadecimalEquivalent1() {
long n1 = Long.parseLong(num1);
answer = Long.parseLong(Long.toHexString(n1));
return answer;
}
public double hexadecimalEquivalent2() {
long n2 = Long.parseLong(num2);
answer = Long.parseLong(Long.toHexString(n2));
return answer;
}
public double Round1() {
answer = Math.round(Double.parseDouble(num1));
return answer;
}
public double Round2() {
answer = Math.round(Double.parseDouble(num2));
return answer;
}
SimpleDateFormat format1 = new SimpleDateFormat("EEEE, dd MMMM yyyy");
Date now = new Date();
SimpleDateFormat format2 = new SimpleDateFormat("hh:mm a");
Date now2 = new Date();
DecimalFormat decimals = new DecimalFormat("#0.00");
public String insertNameAndSurname() throws IOException{
boolean inputCorrect = false;
while (inputCorrect == false) {
while (nameSurname == null || nameSurname.length() == 0) {
for (int i = 0; i < nameSurname.length(); i++) {
if ((nameSurname.charAt(i) > 'a') && (nameSurname.charAt(i) < 'Z')){
inputCorrect = true;
}
else{
inputCorrect = false;
break;
}
}
try {
BufferedReader inStream = new BufferedReader (new InputStreamReader(System.in));
System.out.print("Please enter your name and surname: ");
nameSurname = inStream.readLine();
inputCorrect = true;
}catch (IOException ex) {
System.out.println("You did not enter your name and surname, " + nameSurname + " is not a name, please enter your name and surname :");
inputCorrect = false;
}
}
System.out.println("\nA warm welcome " + nameSurname + " ,todays date is: " + format1.format(now));
System.out.println("and the time is now exactly " + format2.format(now2) + ".");
}
return nameSurname;
}
public String inputNumber1() throws IOException {
boolean inputCorrect = false;
while (inputCorrect == false) {
try {
BufferedReader br = new BufferedReader (new InputStreamReader(System.in));
System.out.print("\nPlease enter a number you want to do a calculation with and hit <ENTER>: ");
num1 = br.readLine();
double number1 = Double.parseDouble(num1);
System.out.println("\nThe number you have entered is: " + number1);
inputCorrect = true;
} catch (NumberFormatException nfe) {
System.out.println("\nYou did not enter a valid number: " + "\""+ num1 + "\" is not a number!!");
inputCorrect = false;
}
}
return num1;
}
public String calculatorChoice() throws IOException {
System.out.println("Please select an option of what you would like to do with this number from the menu below and hit <ENTER>: ");
System.out.println("\n*********************************************");
System.out.println("---------------------------------------------");
System.out.println("Please select an option from the list below: ");
System.out.println("---------------------------------------------");
System.out.println("1 - Add");
System.out.println("2 - Subtract");
System.out.println("3 - Multiply");
System.out.println("4 - Divide (remainder included)");
System.out.println("5 - Maximum and minimum value of two numbers");
System.out.println("6 - Squareroot");
System.out.println("7 - Absolute value of numbers");
System.out.println("8 - Octal and Hexadecimal equivalent of numbers");
System.out.println("9 - Round numbers");
System.out.println("0 - Exit program");
System.out.println("**********************************************");
boolean inputCorrect = false;
while (inputCorrect == false) {
try {
BufferedReader inStream = new BufferedReader (new InputStreamReader(System.in));
System.out.print("Please enter your option and hit <ENTER>: ");
choice1 = inStream.readLine();
int c1 = Integer.parseInt(choice1);
System.out.println("\nYou have entered choice number: " + c1);
inputCorrect = true;
} catch (NumberFormatException nfe) {
System.out.println("You did not enter a valid choice number: " + "\""+ choice1 + "\" is not in the list!!");
inputCorrect = false;
}
}
return choice1;
}
public String inputNumber2() throws IOException {
boolean inputCorrect = false;
while (inputCorrect == false) {
try {
BufferedReader br2 = new BufferedReader (new InputStreamReader(System.in));
System.out.print("\nPlease enter another number you want to do the calculation with and hit <ENTER>: ");
num2 = br2.readLine();
double n2 = Double.parseDouble(num2);
System.out.println("\nThe second number you have entered is: " + n2);
System.out.println("\nYour numbers are: " + num1 + " and " + num2);
inputCorrect = true;
} catch (NumberFormatException nfe) {
System.out.println("You did not enter a valid number: " + "\""+ num2 + "\" is not a number!!");
inputCorrect = false;
}
}
return num2;
}
public int Calculator() {
int choice2 = (int) Double.parseDouble(choice1);
switch (choice2) {
case 1 :
Add();
System.out.print("The answer of " + num1 + " + " + num2 + " is: " + decimals.format(answer));
break;
case 2 :
Subtract();
System.out.print("The answer of " + num1 + " - " + num2 + " is: " + decimals.format(answer));
break;
case 3 :
Multiply();
System.out.print("The answer of " + num1 + " * " + num2 + " is: " + decimals.format(answer));
break;
case 4 :
Divide();
System.out.print("The answer of " + num1 + " / " + num2 + " is: " + decimals.format(answer));
Modulus();
System.out.print(" and the remainder is " + decimals.format(answer));
break;
case 5 :
maximumValue();
System.out.println("The maximum number between the numbers " + num1 + " and " + num2 + " is: " + decimals.format(answer));
minimumValue();
System.out.println("The minimum number between the numbers " + num1 + " and " + num2 + " is: " + decimals.format(answer));
break;
case 6 :
Squareroot1();
System.out.println("The squareroot of value " + num1 + " is: " + decimals.format(answer));
Squareroot2();
System.out.println("The squareroot of value " + num2 + " is: " + decimals.format(answer));
break;
case 7 :
absoluteNumber1();
System.out.println("The absolute number of " + num1 + " is: " + decimals.format(answer));
absoluteNumber2();
System.out.println("The absolute number of " + num2 + " is: " + decimals.format(answer));
break;
case 8 :
octalEquivalent1();
System.out.println("The octal equivalent of " + num1 + " is: " + decimals.format(answer));
hexadecimalEquivalent1();
System.out.println("The hexadecimal equivalent of " + num1 + " is: " + decimals.format(answer));
octalEquivalent2();
System.out.println("\nThe octal equivalent of " + num2 + " is: " + decimals.format(answer));
hexadecimalEquivalent2();
System.out.println("The hexadecimal equivalent of " + num2 + " is: " + decimals.format(answer));
break;
case 9 :
Round1();
System.out.println("The rounded number of " + num1 + " is: " + decimals.format(answer));
Round2();
System.out.println("The rounded number of " + num2 + " is: " + decimals.format(answer));
break;
case 0 :
if (choice2 == 0) {
System.exit(1);
}
break;
}
return choice2;
}
public char anotherCalculation() throws IOException {
try {
System.out.print("\nWould you like to do another calculation? Y/N");
more = (char) System.in.read();
do {
inputNumber1();
System.out.println("");
calculatorChoice();
System.out.println("");
inputNumber2();
System.out.println("");
Calculator();
System.out.println("");
anotherCalculation();
System.out.println("");
} while((more == 'y') | (more == 'Y'));
System.exit(0);
} catch (IOException ex){
System.exit(0);
}
return more;
}
public static void main(String[] args) throws IOException {
Project p1 = new Project();
p1.insertNameAndSurname();
System.out.println("");
p1.inputNumber1();
System.out.println("");
p1.calculatorChoice();
System.out.println("");
p1.inputNumber2();
System.out.println("");
p1.Calculator();
System.out.println("");
p1.anotherCalculation();
System.out.println("");
}
}Your help will be much appreciated.
Thanks