The Stock Class

The Stock class encapsulates the idea of an investment that represents a share of ownership in a corporation.

A Stock object has several attributes such as a:

• name: the name of the corporation corresponding to the stock
• symbol: a 3-character textual code that uniquely identifies the stock
• price: the monetary value of the stock

Other attributes can be found in the API.

Creating a Stock Object

The Stock class has two constructors that allow a client to create an instance of a Stock.

The default constructor creates a Stock object with no name, no symbol, and a price of 0.0

import type.lib.Stock;
import java.io.PrintStream;

public class Stock1
{
   public static void main(String[] args)
   {
      PrintStream output = System.out;
      
      Stock s = new Stock();
      output.println("Name   : " + s.getName());
      output.println("Symbol : " + s.getSymbol());
      output.println("Price  : " + s.getPrice());
   }
}

Notice the use of new to create the Stock object.

Notice that the client can use the accessor methods getName, getSymbol, and getPrice to get the values of the name, symbol, and price, respectively.

Creating a Stock Object

The one-argument constructor creates a Stock object given its symbol. Look at the API for a description of valid symbols.

import type.lib.Stock;
import java.io.PrintStream;

public class Stock2
{
   public static void main(String[] args)
   {
      PrintStream output = System.out;
      
      Stock s1 = new Stock("HR.A");
      output.println("Name   : " + s1.getName());
      output.println("Symbol : " + s1.getSymbol());
      output.println("Price  : " + s1.getPrice());
      output.println();
      
      Stock s2 = new Stock(".MN");
      output.println("Name   : " + s2.getName());
      output.println("Symbol : " + s2.getSymbol());
      output.println("Price  : " + s2.getPrice());
   }
}

Using Scanner to Read a String

A Scanner object has two methods to scan for an arbitrary String.

One method is named next. It behaves like nextInt and nextDouble in that it skips over whitespace trying to find a String (a sequence of characters without whitespace) to return.

import type.lib.Stock;
import java.io.PrintStream;
import java.util.Scanner;

public class Stock3
{
   public static void main(String[] args)
   {
      PrintStream output = System.out;
      Scanner input = new Scanner(System.in);
           
      output.print("Enter a stock symbol : ");
      String symbol = input.next();

      Stock s = new Stock(symbol);
      output.println("Name   : " + s.getName());
      output.println("Symbol : " + s.getSymbol());
      output.println("Price  : " + s.getPrice());
      output.println();
   }
}

Note that next (and most of the other next-like methods in Scanner) does not consume the newline character at the end of the input. This means that the newline character the user inputs by pressing the Enter key remains to be processed by the Scanner. This is important to remember when using nextLine!

Using Scanner to Read a String

A second method is named nextLine. Unlike the other next-like methods, this method does not ignore newlines. It skips past the current line (i.e. it skips past the first newline character that if finds) and returns what it skipped over. If there is a newline character at the beginning of the input, nextLine skips over it and returns what was skipped (i.e. it returns an empty String).

import type.lib.Stock;
import java.io.PrintStream;
import java.util.Scanner;

public class Stock4
{
   public static void main(String[] args)
   {
      PrintStream output = System.out;
      Scanner input = new Scanner(System.in);

      output.print("Enter an integer : ");
      int anInt = input.nextInt();     
           
      output.print("Enter a stock symbol : ");
      String symbol = input.nextLine();

      Stock s = new Stock(symbol);
      output.println("Name   : " + s.getName());
      output.println("Symbol : " + s.getSymbol());
      output.println("Price  : " + s.getPrice());
      output.println();
   }
}

Notice that nextInt leaves the newline character on the input to the Scanner object. Can you fix the example above so that it actually allows the user to input a symbol?

Getting the Current Time

A java.util.Date (API) object can be used to get the time at which it was created. If you create a Date object and then immediately ask it for the time it will return the approximate current time.

import java.io.PrintStream;
import java.util.Date;

public class DateExample
{
   public static void main(String[] args)
   {
      PrintStream output = System.out;
      
      Date d = new Date();
      String dString = d.toString();
      output.println(dString);
   }
}

Complete eCheck04B

You should now have enough information to complete eCheck04B.