byte, short, int,
* long, float, double,
* char, String, and boolean.
*
*
* Each method displays an initial prompt with a suggested value, waits
* for the user's response, and validates it. If the user's response
* is invalid, the method prompts the user again using a clarification
* prompt until the user enters a valid response or selects Cancel. If
* the user selects Cancel, the input method returns the suggested value
* as a default. Thus, each input method requires an initial prompt, a
* suggested value, and a clarification prompt. Input methods for numeric
* values may also provide a range of valid values.
* (This input style was inspired by the Java Power Tools package developed
* by Richard Rasala, Jeff Raab, and Viera Proulx at Northeastern University.)
*
* @author Joel Booth
* @author Alyce Brady
* @version September 3, 2004
**/
public class ValidatedInputReader
{
/** Puts up a dialog box displaying the initialPrompt,
* waits for the user's response, and validates it (the response must
* be a valid byte).
* If the user's response is invalid, it prompts the user again
* using the clarificationPrompt until the user enters
* a valid response or selects Cancel. If the user selects Cancel,
* getByte returns the suggestedValue.
* @param initialPrompt the initial prompt to the user
* @param suggestedValue a suggested, valid value that is displayed
* to the user, and is also used as the default
* value if the user selects Cancel
* @param clarificationPrompt a follow-up prompt for input after
* the user has input invalid data
**/
public static byte getByte(String initialPrompt, byte suggestedValue,
String clarificationPrompt)
{
return getByte(initialPrompt, Byte.MIN_VALUE, Byte.MAX_VALUE,
suggestedValue, clarificationPrompt);
}
/** Puts up a dialog box displaying the initialPrompt,
* waits for the user's response, and validates it (the response must
* be a valid byte in the range provided).
* If the user's response is invalid, it prompts the user again
* using the clarificationPrompt until the user enters
* a valid response or selects Cancel. If the user selects Cancel,
* getByte returns the suggestedValue.
* @param initialPrompt the initial prompt to the user
* @param startOfRange the smallest value in the range of valid values
* @param endOfRange the largest value in the range of valid values
* @param suggestedValue a suggested, valid value that is displayed
* to the user, and is also used as the default
* value if the user selects Cancel
* @param clarificationPrompt a follow-up prompt for input after
* the user has input invalid data
**/
public static byte getByte(String initialPrompt,
byte startOfRange, byte endOfRange,
byte suggestedValue, String clarificationPrompt)
{
String suggested = "" + suggestedValue;
String response = getResponse(initialPrompt, suggested);
while (response != null)
try
{
byte userEntered = Byte.parseByte(response.trim());
if ( userEntered < startOfRange || userEntered > endOfRange )
throw new NumberFormatException();
return userEntered;
}
catch (NumberFormatException ex)
{ response = getResponse(clarificationPrompt, suggested); }
return suggestedValue;
}
/** Puts up a dialog box displaying the initialPrompt,
* waits for the user's response, and validates it (the response must
* be a valid short).
* If the user's response is invalid, it prompts the user again
* using the clarificationPrompt until the user enters
* a valid response or selects Cancel. If the user selects Cancel,
* getShort returns the suggestedValue.
* @param initialPrompt the initial prompt to the user
* @param suggestedValue a suggested, valid value that is displayed
* to the user, and is also used as the default
* value if the user selects Cancel
* @param clarificationPrompt a follow-up prompt for input after
* the user has input invalid data
**/
public static short getShort(String initialPrompt, short suggestedValue,
String clarificationPrompt)
{
return getShort(initialPrompt, Short.MIN_VALUE, Short.MAX_VALUE,
suggestedValue, clarificationPrompt);
}
/** Puts up a dialog box displaying the initialPrompt,
* waits for the user's response, and validates it (the response must
* be a valid short in the range provided).
* If the user's response is invalid, it prompts the user again
* using the clarificationPrompt until the user enters
* a valid response or selects Cancel. If the user selects Cancel,
* getShort returns the suggestedValue.
* @param initialPrompt the initial prompt to the user
* @param startOfRange the smallest value in the range of valid values
* @param endOfRange the largest value in the range of valid values
* @param suggestedValue a suggested, valid value that is displayed
* to the user, and is also used as the default
* value if the user selects Cancel
* @param clarificationPrompt a follow-up prompt for input after
* the user has input invalid data
**/
public static short getShort(String initialPrompt,
short startOfRange, short endOfRange,
short suggestedValue,
String clarificationPrompt)
{
String suggested = "" + suggestedValue;
String response = getResponse(initialPrompt, suggested);
while (response != null)
try
{
short userEntered = Short.parseShort(response.trim());
if ( userEntered < startOfRange || userEntered > endOfRange )
throw new NumberFormatException();
return userEntered;
}
catch (NumberFormatException ex)
{ response = getResponse(clarificationPrompt, suggested); }
return suggestedValue;
}
/** Puts up a dialog box displaying the initialPrompt,
* waits for the user's response, and validates it (the response must
* be a valid integer).
* If the user's response is invalid, it prompts the user again
* using the clarificationPrompt until the user enters
* a valid response or selects Cancel. If the user selects Cancel,
* getInteger returns the suggestedValue.
* @param initialPrompt the initial prompt to the user
* @param suggestedValue a suggested, valid value that is displayed
* to the user, and is also used as the default
* value if the user selects Cancel
* @param clarificationPrompt a follow-up prompt for input after
* the user has input invalid data
**/
public static int getInteger(String initialPrompt, int suggestedValue,
String clarificationPrompt)
{
return getInteger(initialPrompt, Integer.MIN_VALUE, Integer.MAX_VALUE,
suggestedValue, clarificationPrompt);
}
/** Puts up a dialog box displaying the initialPrompt,
* waits for the user's response, and validates it (the response must
* be a valid integer in the range provided).
* If the user's response is invalid, it prompts the user again
* using the clarificationPrompt until the user enters
* a valid response or selects Cancel. If the user selects Cancel,
* getInteger returns the suggestedValue.
* @param initialPrompt the initial prompt to the user
* @param startOfRange the smallest value in the range of valid values
* @param endOfRange the largest value in the range of valid values
* @param suggestedValue a suggested, valid value that is displayed
* to the user, and is also used as the default
* value if the user selects Cancel
* @param clarificationPrompt a follow-up prompt for input after
* the user has input invalid data
**/
public static int getInteger(String initialPrompt,
int startOfRange, int endOfRange,
int suggestedValue,
String clarificationPrompt)
{
String suggested = "" + suggestedValue;
String response = getResponse(initialPrompt, suggested);
while (response != null)
try
{
int userEntered = Integer.parseInt(response.trim());
if ( userEntered < startOfRange || userEntered > endOfRange )
throw new NumberFormatException();
return userEntered;
}
catch (NumberFormatException ex)
{ response = getResponse(clarificationPrompt, suggested); }
return suggestedValue;
}
/** Puts up a dialog box displaying the initialPrompt,
* waits for the user's response, and validates it (the response must
* be a valid long).
* If the user's response is invalid, it prompts the user again
* using the clarificationPrompt until the user enters
* a valid response or selects Cancel. If the user selects Cancel,
* getLong returns the suggestedValue.
* @param initialPrompt the initial prompt to the user
* @param suggestedValue a suggested, valid value that is displayed
* to the user, and is also used as the default
* value if the user selects Cancel
* @param clarificationPrompt a follow-up prompt for input after
* the user has input invalid data
**/
public static long getLong(String initialPrompt, long suggestedValue,
String clarificationPrompt)
{
return getLong(initialPrompt, Long.MIN_VALUE, Long.MAX_VALUE,
suggestedValue, clarificationPrompt);
}
/** Puts up a dialog box displaying the initialPrompt,
* waits for the user's response, and validates it (the response must
* be a valid long in the range provided).
* If the user's response is invalid, it prompts the user again
* using the clarificationPrompt until the user enters
* a valid response or selects Cancel. If the user selects Cancel,
* getLong returns the suggestedValue.
* @param initialPrompt the initial prompt to the user
* @param startOfRange the smallest value in the range of valid values
* @param endOfRange the largest value in the range of valid values
* @param suggestedValue a suggested, valid value that is displayed
* to the user, and is also used as the default
* value if the user selects Cancel
* @param clarificationPrompt a follow-up prompt for input after
* the user has input invalid data
**/
public static long getLong(String initialPrompt,
long startOfRange, long endOfRange,
long suggestedValue,
String clarificationPrompt)
{
String suggested = "" + suggestedValue;
String response = getResponse(initialPrompt, suggested);
while (response != null)
try
{
long userEntered = Long.parseLong(response.trim());
if ( userEntered < startOfRange || userEntered > endOfRange )
throw new NumberFormatException();
return userEntered;
}
catch (NumberFormatException ex)
{ response = getResponse(clarificationPrompt, suggested); }
return suggestedValue;
}
/** Puts up a dialog box displaying the initialPrompt,
* waits for the user's response, and validates it (the response must
* be a valid float).
* If the user's response is invalid, it prompts the user again
* using the clarificationPrompt until the user enters
* a valid response or selects Cancel. If the user selects Cancel,
* getFloat returns the suggestedValue.
* @param initialPrompt the initial prompt to the user
* @param suggestedValue a suggested, valid value that is displayed
* to the user, and is also used as the default
* value if the user selects Cancel
* @param clarificationPrompt a follow-up prompt for input after
* the user has input invalid data
**/
public static float getFloat(String initialPrompt, float suggestedValue,
String clarificationPrompt)
{
String suggested = "" + suggestedValue;
String response = getResponse(initialPrompt, suggested);
while (response != null)
try
{
float userEntered = Float.parseFloat(response.trim());
return userEntered;
}
catch (NumberFormatException ex)
{ response = getResponse(clarificationPrompt, suggested); }
return suggestedValue;
}
/** Puts up a dialog box displaying the initialPrompt,
* waits for the user's response, and validates it (the response must
* be a valid float in the range provided).
* If the user's response is invalid, it prompts the user again
* using the clarificationPrompt until the user enters
* a valid response or selects Cancel. If the user selects Cancel,
* getFloat returns the suggestedValue.
* @param initialPrompt the initial prompt to the user
* @param startOfRange the smallest value in the range of valid values
* @param endOfRange the largest value in the range of valid values
* @param suggestedValue a suggested, valid value that is displayed
* to the user, and is also used as the default
* value if the user selects Cancel
* @param clarificationPrompt a follow-up prompt for input after
* the user has input invalid data
**/
public static float getFloat(String initialPrompt,
float startOfRange, float endOfRange,
float suggestedValue,
String clarificationPrompt)
{
String suggested = "" + suggestedValue;
String response = getResponse(initialPrompt, suggested);
while (response != null)
try
{
float userEntered = Float.parseFloat(response.trim());
if ( userEntered < startOfRange || userEntered > endOfRange )
throw new NumberFormatException();
return userEntered;
}
catch (NumberFormatException ex)
{ response = getResponse(clarificationPrompt, suggested); }
return suggestedValue;
}
/** Puts up a dialog box displaying the initialPrompt,
* waits for the user's response, and validates it (the response must
* be a valid double).
* If the user's response is invalid, it prompts the user again
* using the clarificationPrompt until the user enters
* a valid response or selects Cancel. If the user selects Cancel,
* getDouble returns the suggestedValue.
* Any valid double value will be accepted. If the
* number is out
* of the range of a double the value will show up as the
* double representation of either positive or negative
* inifinity.
* @param initialPrompt the initial prompt to the user
* @param suggestedValue a suggested, valid value that is displayed
* to the user, and is also used as the default
* value if the user selects Cancel
* @param clarificationPrompt a follow-up prompt for input after
* the user has input invalid data
**/
public static double getDouble(String initialPrompt, double suggestedValue,
String clarificationPrompt)
{
String suggested = "" + suggestedValue;
String response = getResponse(initialPrompt, suggested);
while (response != null)
try
{
double userEntered = Double.parseDouble(response.trim());
return userEntered;
}
catch (NumberFormatException ex)
{ response = getResponse(clarificationPrompt, suggested); }
return suggestedValue;
}
/** Puts up a dialog box displaying the initialPrompt,
* waits for the user's response, and validates it (the response must
* be a valid double in the range provided).
* If the user's response is invalid, it prompts the user again
* using the clarificationPrompt until the user enters
* a valid response or selects Cancel. If the user selects Cancel,
* getDouble returns the suggestedValue.
* @param initialPrompt the initial prompt to the user
* @param startOfRange the smallest value in the range of valid values
* @param endOfRange the largest value in the range of valid values
* @param suggestedValue a suggested, valid value that is displayed
* to the user, and is also used as the default
* value if the user selects Cancel
* @param clarificationPrompt a follow-up prompt for input after
* the user has input invalid data
**/
public static double getDouble(String initialPrompt,
double startOfRange, double endOfRange,
double suggestedValue,
String clarificationPrompt)
{
String suggested = "" + suggestedValue;
String response = getResponse(initialPrompt, suggested);
while (response != null)
try
{
double userEntered = Double.parseDouble(response.trim());
if ( userEntered < startOfRange || userEntered > endOfRange )
throw new NumberFormatException();
return userEntered;
}
catch (NumberFormatException ex)
{ response = getResponse(clarificationPrompt, suggested); }
return suggestedValue;
}
/** Puts up a dialog box displaying the initialPrompt,
* waits for the user's response, and validates it (the response must
* be a valid char). Special characters are accepted. Any empty
* response will be taken as the null character.
* If the user's response is not a valid character, getChar
* prompts again using the clarificationPrompt until
* the user enters a valid response or selects Cancel. If the user
* selects Cancel, getChar returns the
* suggestedValue.
* @param initialPrompt the initial prompt to the user
* @param suggestedValue a suggested, valid value that is displayed
* to the user, and is also used as the default
* value if the user selects Cancel
* @param clarificationPrompt a follow-up prompt for input after
* the user has input invalid data
**/
public static char getChar(String initialPrompt, char suggestedValue,
String clarificationPrompt)
{
String suggested = "" + suggestedValue;
String response = getResponse(initialPrompt, suggested);
while (response != null)
try
{
String userEntered = response.trim();
if (userEntered.equals(""))
return '\u0000';
else if (userEntered.length() != 1)
throw new DataFormatException();
return userEntered.charAt(0);
}
catch (DataFormatException ex)
{ response = getResponse(clarificationPrompt, suggested); }
return suggestedValue;
}
/** Puts up a dialog box displaying the initialPrompt,
* waits for the user's response. Because it is prompting for a
* String, any response will be accepted, including
* an empty string.
* If the user selects Cancel the suggestedValue.
* will be returned.
* @param initialPrompt the initial prompt to the user
* @param suggestedValue a suggested, valid value that is displayed
* to the user, and is also used as the default
* value if the user selects Cancel
**/
public static String getString(String initialPrompt, String suggestedValue)
{
String suggested = "" + suggestedValue;
String response = getResponse(initialPrompt, suggested);
return response.trim();
}
/** Puts up a dialog box displaying the initialPrompt,
* waits for the user's response, and validates it. The response must
* be a valid boolean in the form of "true" or "false" (case-insensitive).
* If the user's response is invalid, it prompts the user again
* using the clarificationPrompt until the user enters
* a valid response or selects Cancel. If the user selects Cancel,
* getBoolean returns the suggestedValue.
* @param initialPrompt the initial prompt to the user
* @param suggestedValue a suggested, valid value that is displayed
* to the user, and is also used as the default
* value if the user selects Cancel
* @param clarificationPrompt a follow-up prompt for input after
* the user has input invalid data
**/
public static boolean getBoolean(String initialPrompt,
boolean suggestedValue,
String clarificationPrompt)
{
String suggested = "" + suggestedValue;
String response = getResponse(initialPrompt, suggested);
while (response != null)
try
{
String userEntered = (response.trim()).toUpperCase();
if (userEntered.equals("TRUE"))
return true;
else if (userEntered.equals("FALSE"))
return false;
else
throw new DataFormatException();
}
catch (DataFormatException ex)
{ response = getResponse(clarificationPrompt, suggested); }
return suggestedValue;
}
/** Displays the appropriate JOptionPane and gets the result. **/
protected static String getResponse(String prompt,
String suggestedValue)
{
return (String)JOptionPane.showInputDialog(null, prompt,
"Input", JOptionPane.QUESTION_MESSAGE, null, null,
suggestedValue);
}
}