Class ConsoleIn

java.lang.Object
  |
  +--ConsoleIn

public class ConsoleIn

extends java.lang.Object

Class for robust keyboard input. If the user enters an improper input, that is, an input of the wrong type or a blank line when the line should be nonblank, then the user is given an error message and is prompted to reenter the input

Constructor Summary

ConsoleIn()

Method Summary

static java.lang.String	readLine() Reads a line of text and returns that line as a String value.
static boolean	readLineBoolean() Input should consist of a single word on a line, possibly surrounded by whitespace.
static byte	readLineByte() The user is supposed to enter a whole number of type byte on a line by itself.
static double	readLineDouble() The user is supposed to enter a number of type double on a line by itself.
static float	readLineFloat() The user is supposed to enter a number of type float on a line by itself.
static int	readLineInt() The user is supposed to enter a whole number of type int on a line by itself.
static long	readLineLong() The user is supposed to enter a whole number of type long on a line by itself.
static char	readLineNonwhiteChar() Returns the first non-whitespace character on the input line The rest of the input line is discarded.
static short	readLineShort() The user is supposed to enter a whole number of type short on a line by itself.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ConsoleIn

public ConsoleIn()

Method Detail

readLine

public static java.lang.String readLine()

Reads a line of text and returns that line as a String value. The end of a line must be indicated either by a new-line character '\n' or by a carriage return '\r' followed by a new-line character '\n'. (Essentially all systems do this automatically. So you need not worry about this detail.) Neither the '\n', nor the '\r' if present, are part of the string returned. This will read the rest of a line if the line is already partially read.

Returns:

The line input from the keyboard.

readLineInt

public static int readLineInt()

The user is supposed to enter a whole number of type int on a line by itself. There may be whitespace before and/or after the number. Returns the number entered as a value of type int. The rest of the line is discarded.If the input is not entered correctly, then in most cases, the user will be asked to reenter the input. In particular ,incorrect number formats and blank lines result in a prompt to reenter the input.

Returns:

Returns the integer input.

readLineLong

public static long readLineLong()

The user is supposed to enter a whole number of type long on a line by itself. There may be whitespace before and/or after the number. Returns the number entered as a value of type long. The rest of the line is discarded.If the input is not entered correctly, then in most cases, the user will be asked to reenter the input. In particular, incorrect number formats and blank lines result in a prompt to reenter the input.

Returns:

Returns the integer input.

readLineByte

public static byte readLineByte()

The user is supposed to enter a whole number of type byte on a line by itself. There may be whitespace before and/or after the number. Returns the number entered as a value of type byte. The rest of the line is discarded.If the input is not entered correctly, then in most cases, the user will be asked to reenter the input. In particular, incorrect number formats and blank lines result in a prompt to reenter the input.

Returns:

Returns the integer input.

readLineShort

public static short readLineShort()

The user is supposed to enter a whole number of type short on a line by itself. There may be whitespace before and/or after the number. Returns the number entered as a value of type short. The rest of the line is discarded.If the input is not entered correctly, then in most cases, the user will be asked to reenter the input. In particular, incorrect number formats and blank lines result in a prompt to reenter the input.

Returns:

Returns the integer input.

readLineDouble

public static double readLineDouble()

The user is supposed to enter a number of type double on a line by itself. There may be whitespace before and/or after the number. Returns the number entered as a value of type double. The rest of the line is discarded.If the input is not entered correctly, then in most cases, the user will be asked to reenter the input. In particular, incorrect number formats and blank lines result in a prompt to reenter the input.

Returns:

The floating point number input.

readLineFloat

public static float readLineFloat()

The user is supposed to enter a number of type float on a line by itself. There may be whitespace before and/or after the number. Returns the number entered as a value of type float. The rest of the line is discarded.If the input is not entered correctly, then in most cases, the user will be asked to reenter the input. In particular, incorrect number formats and blank lines result in a prompt to reenter the input.

Returns:

The floating point number input.

readLineNonwhiteChar

public static char readLineNonwhiteChar()

Returns the first non-whitespace character on the input line The rest of the input line is discarded. If the line contains only whitespace, the user is asked to reenter the line.

Returns:

The first non-whitespace character on the input line.

readLineBoolean

public static boolean readLineBoolean()

Input should consist of a single word on a line, possibly surrounded by whitespace. The line is read and discarded. If the input word is "true" or "t", then true is returned. If the input word is "false" or "f", then false is returned. Uppercase and lowercase letters are considered equal. If the user enters anything else (for example, multiple words or different words), the user is asked to reenter the input.

Returns:

The boolean value entered.