How can I test method that gets input and create method

[must Janik]

How can I test method that gets input and create method, I've got method that takes input from keyboard and create object.

I thought about assertNotNull, but don't know how to use it.

public RentingACar rentACar(Scanner input) {
    RentingACar rentingACar = new RentingACar();

    System.out.print("Brand: ");
    rentingACar.setBrand(input.next());
    System.out.print("Name: ");
    rentingACar.setName(input.next());
    System.out.print("Surname: ");
    rentingACar.setSurname(input.next());
    System.out.print("Rent Date: ");
    rentingACar.setRentDate(input.next());
    System.out.print("Client number: ");
    rentingACar.setClientNumber(input.nextInt());

    return rentingACar;
}

[Norm Radder]

How can I test method that gets input and create method,

You can automate the providing of input by using the Scanner class's constructor that takes a String as argument.  Build a String with all the required values that the method will read.
You can validate the contents of the created object by adding a toString method to the class that returns a String with the values of its fields and then processing that value.

[must Janik]

Norm Radder wrote:

How can I test method that gets input and create method,

You can automate the providing of input by using the Scanner class's constructor that takes a String as argument.  Build a String with all the required values that the method will read.
You can validate the contents of the created object by adding a toString method to the class that returns a String with the values of its fields and then processing that value.

I don't understand. Can you give me some example?

[Norm Radder]

give me some example

Define a Scanner to provide input:

   Scanner aScnr =  new Scanner("data1 1233 More 4444"); // provides a String, int, String, int
   String str1 = aScnr.next();  // returns data1
   int nbr1 = aScnr.nextInt(); // returns 1233

[must Janik]

Norm Radder wrote:

give me some example

There is mistake in name topic, it should be: ....and create object.
Nevermind.


Define a Scanner to provide input:

   Scanner aScnr =  new Scanner("data1 1233 More 4444"); // provides a String, int, String, int
   String str1 = aScnr.next();  // returns data1
   int nbr1 = aScnr.nextInt(); // returns 1233

How can it help me with testing?

[Campbell Ritchie]

Welcome to the Ranch

Please start by explaining what sort of input you require. It is very easy to use the methods of a Scanner to verify that its next token will match an int for example, which will return false before line 2 and true before line 3. It is much harder to verify that the next token has a particular text format; hasNext() only shows that you have not yet reached the end of the input. Which means, by the way, that a Scanner reading from System.in should always return true from hasNext().
You can try reading the next token and using its matches/match() method with a regular expression (=regex), or something similar, but that depends on knowing what your specification for the required input is. Beware: regexes need special care because they can be difficult to set up correctly.

Don't create multiple Scanners to read from System.in. Use a utility class that does all your keyboard input; you can set up the methods with a loop, like that shown here which will reject input in the incorrect format. As I said above, that would require special upgrading for next() to return something matching a particular regex.

[Norm Radder]

How can it help me with testing?

It would provide all the needed input for a call to the method so that the tester does not need to enter any input manually.

[must Janik]

Nah, really don't understand what is wrong with my method and why you are talking about Scanner's. Don't know what I should change in this.

[Norm Radder]

what is wrong with my method

Why do you think there is something wrong with the method?

what I should change in this.

Nothing need be changed unless testing finds a problem.

What do you mean by "test method"?
I assume that means to pass some data to the method and check the output from the method that it is what is expected.
If you mean something else, please explain.

My suggestion was a way to pass data to the method and a way to look at the contents of the object that the method built.

[must Janik]

Norm Radder wrote:

what is wrong with my method

Why do you think there is something wrong with the method?

what I should change in this.

Nothing need be changed unless testing finds a problem.

What do you mean by "test method"?
I assume that means to pass some data to the method and check the output from the method that it is what is expected.
If you mean something else, please explain.

My suggestion was a way to pass data to the method and a way to look at the contents of the object that the method built.

Ohh... I thought about unit tests.