1. Input Characters from the Keyboard tMyn1 Input Characters from the Keyboard We have been using console output, but not console (keyboard) input. The main reason for this is that Java’s input system relies upon a rather complex system of classes, the use of which requires an understanding of various features, such as exception handling and classes, that are not discussed until later. There is no direct parallel to the very convenient println() method, for example, that allows you to read various types of data entered by the user.

2. Input Characters from the Keyboard tMyn2 Java’s approach to console input is not as easy to use as one might like. Also, most real-world Java programs and applets will be graphical and window based, not console based. However, there is one type of console input that is easy to use: reading a character from the keyboard. The easiest way to read a character from the keyboard is to call System.in.read(). System.in is the compliment to System.out. System.in is the input object attached to the keyboard.

3. Input Characters from the Keyboard tMyn3 The read() method waits until the user presses a key and then returns the result. The character is returned as an integer, so it must be cast into a char to assign it to a char variable. By default, console input is line buffered, so you must press ENTER before any character that you type will be sent to your program. The fact that System.in is line buffered is a source of annoyance at times. When you press ENTER, a carriage return, line feed sequence is entered into the input stream.

4. Input Characters from the Keyboard tMyn4 Furthermore, these characters are left pending in the input buffer until you read them. Thus, for some applications, you may need to remove them (by reading them) before the next input operation.

5. Input Characters from the Keyboard tMyn5 package inputchar; public class Main { public static void main(String[] args) throws java.io.IOException { char ch; System.out.println("Input a character followed by ENTER: "); ch=(char)System.in.read(); System.out.println("You entered "+ch); } run: Input a character followed by ENTER: T You entered T BUILD SUCCESSFUL (total time: 20 seconds)

6. Input Characters from the Keyboard tMyn6 Because System.in.read() is being used, the program must specify the throws java.io.IOException clause. This line is necessary to handle input errors.