Can someone do it for me please I am totally lost :(

Question

Write a simple application class with only a main method. It should convert the single command line argument into an integer and print the result. When converting the integer, catch any exceptions that might be thrown and print the exception object caught along with the
stack trace. >java NumberConvert
java.lang.ArrayIndexOutOfBoundsException: 0
at NumberConvert.main(NumberConvert.java:15)
java NumberConvert abc java.lang.NumberFormatException: For input string: "abc"
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48 )
at java.lang.Integer.parseInt(Integer.java:426)
at java.lang.Integer.parseInt(Integer.java:476)
at NumberConvert.main(NumberConvert.java:15)
java NumberConvert 99 Your argument was 99
Write a class called "Temp" that stores a temperature. Write four methods for accessing the object, one called Celsius() that returns the temperature in degrees Celsius, one called Fahrenheit() that returns the temperature in degrees Fahrenheit, one called Rankine() that returns the temperature in degrees Rankine, and one called Kelvin() that returns the temperature in degrees Kelvin. Also write four accessing methods to set the temperature (setCelsius(), setKelvin(), setFahrenheit() and setRankine()) using any temperature scale. These methods should throw an unchecked exception (RuntimeException) if a temperature argument is supplied that is below absolute zero (273.15�C). The relationship between temperatures are F=1.8*C+32, K=C+273.15, R=F+459.67. Use the following main() method in your class as a unit test.
public static void main (String[] args)
Temp t = new Temp();
t.setCelsius(Double.parseDouble(args[0]));
System.out.println("Celsius: " + t.Celsius());
System.out.println("Kelvin: " + t.Kelvin());
System.out.println("Fahrenheit: " + t.Fahrenheit());
System.out.println("Rankine: " + t.Rankine());
java Temp 100 Celsius: 100
Kelvin: 373.15
Fahrenheit: 212
Rankine: 671.67
java Temp -300 Exception in thread "main" java.lang.RuntimeException: Temperature below absoute zero!
at Temp.setCelsius(Temp.java:18 )
at Temp.main(Temp.java:30)
Modify the solution from the previous problem so that the main method also catches the exception thrown by the accessing methods, prints a message and then exits gracefully. Also modify the temperature class so that the exception thrown on error is a checked exception (Exception). Also specifically check for the ArrayIndexOutOfBoundsException that might be thrown if the user does not supply a command line argument and the NumberFormatException that might be thrown if the argument is not a number and supply appropriate diagnostic messages.
java Temp 100 Celsius: 100
Kelvin: 373.15
Fahrenheit: 212
Rankine: 671.67
java Temp You must supply the temperature on the command line.
java Temp abc Your command line argument could not be formatted as a number.
java Temp -300 Temperature is too low. Must be above -273C.
Modify the solution from the previous problem so that the temperature class throws a checked exception derived from Exception called TempTooLowException. This exception should have a constructor that takes the temperature value that was attempted to be used as a string (with the temperature scale abbreviation included) and then composes a message like "-300C is below absolute zero!". Make sure that the main method checks for this exception and then displays the message to the user if this error occurs (do not just print the exception object, only print the internal message). Main should still catch Exception as a last resort and simply print out the object thrown before exiting.
java Temp 100 Celsius: 100
Kelvin: 373.15
Fahrenheit: 212
Rankine: 671.67
java Temp You must supply the temperature on the command line.
java Temp abc Your command line argument could not be formatted as a number.
java Temp -300 -300.0C is below absolute zero!

Answer 1

How come you don't know how to do this? Wasn't there a textbook which came with the course? Lectures? Did you ask your teacher?
If you have no idea where to start, you cannot be helped here, I'm afraid.
Try this:
http://java.sun.com/docs/books/tutorial/getStarted/index.html
and then:
http://java.sun.com/docs/books/tutorial/java/index.html