/**
* Reads an integer from the user via getInt. Continues prompting the user until they enter an
* integer within the specified range.
*
* @param prompt prompt for getInt()
* @param lower lower bound for input (inclusive)
* @param upper upper bound for input (inclusive)
* @return an integer between lower and upper inclusive
* <p>NOTE: behavior when lower is larger than upper is undefined, but will probably result in
* a non-terminating loop... so don't do that.
*/
public static int getIntInRange(String prompt, int lower, int upper) {
int userInput = getInt(prompt);
Logger.log(
Loglevel.PEDANTIC,
"Getting int from user in range " + lower + "-" + upper + " (inclusive)");
while (userInput < lower || userInput > upper) {
Logger.log(
Loglevel.WARNING, "Error, input is not in range " + lower + "-" + upper + " (inclusive)");
userInput = getInt(prompt);
}
return userInput;
}
/**
* Read the lines from a file, returning them as a list of Strings, one line per index.
*
* @param filepath absolute or relative path to file
* @return the lines from the file
*/
public static LinkedList<String> readLines(String filepath) {
Logger.log(Loglevel.PEDANTIC, "reading lines from file " + filepath);
LinkedList<String> lines = new LinkedList<String>();
try {
Scanner stream = new Scanner(new File(filepath));
while (stream.hasNextLine()) {
String next = stream.nextLine();
Logger.log(Loglevel.OVERKILL, "read line from file: " + next);
lines.append(next);
}
} catch (Exception ex) {
Logger.log(Loglevel.WARNING, "could not read file, exception: " + ex);
}
return lines;
}
/**
* Read a string form the user, displaying the prompt first. If a newline is desired after the
* prompt, it must be included in the prompt string.
*
* @param prompt the prompt to display to the user
* @return the user input as a string
*/
public static String getString(String prompt) {
Logger.log(Loglevel.PEDANTIC, "get String from user with prompt " + prompt);
String userInput;
Scanner in = new Scanner(System.in);
System.out.print(prompt);
try {
userInput = in.nextLine();
} catch (InputMismatchException e) {
Logger.log(Loglevel.WARNING, "input invalid; cannot be cast to String");
Logger.log(Loglevel.WARNING, "encountered non-fatal exception: " + e);
in.next(); // get rid of invalid value so we can try again
userInput = getString(prompt);
}
Logger.log(Loglevel.PEDANTIC, "read String from user: " + userInput);
return userInput;
}
/**
* Write lines into a file, given as a LinkedList of Strings, with one String per line.
*
* @param lines list of lines to write to the file
* @param filepath absolute or relative path to the file
*/
public static void writeLines(LinkedList<String> lines, String filepath) {
Logger.log(Loglevel.PEDANTIC, "writing lines to file " + filepath);
try {
FileOutputStream outStream = new FileOutputStream(filepath);
BufferedWriter outStreamWriter = new BufferedWriter(new OutputStreamWriter(outStream));
for (String line : lines) {
Logger.log(Loglevel.OVERKILL, "writing line: " + line);
outStreamWriter.write(line + "\n");
}
outStreamWriter.close();
outStream.close();
} catch (FileNotFoundException ex) {
Logger.log(Loglevel.WARNING, "encountered exception while " + "writing to file: " + ex);
} catch (IOException ex) {
Logger.log(Loglevel.WARNING, "encountered exception while " + "writing to file: " + ex);
}
}
/**
* Identical behavior to getString(String prompt), however, this method will continue prompting
* the user until they enter a string which matches the given regex, and will not return until the
* user enters a matching string.
*
* @param prompt the prompt to display to the user
* @param regex the regular expression to match
* @return {the user input as a string
*/
public static String getString(String prompt, String regex) {
Logger.log(Loglevel.PEDANTIC, "get String from user with prompt " + prompt);
Logger.log(Loglevel.PEDANTIC, "user input will be required to " + "match the regex: " + regex);
String userInput;
Scanner in = new Scanner(System.in);
System.out.print(prompt);
try {
userInput = in.nextLine();
} catch (InputMismatchException e) {
Logger.log(Loglevel.WARNING, "input invalid; cannot be cast to String");
Logger.log(Loglevel.WARNING, "encountered non-fatal exception: " + e);
in.next(); // get rid of invalid value so we can try again
userInput = getString(prompt);
}
if (!userInput.matches(regex)) {
Logger.log(
Loglevel.WARNING,
"invalid input; input was a valid string, but does not meet " + "required input format");
userInput = getString(prompt, regex);
}
Logger.log(Loglevel.PEDANTIC, "read String from user: " + userInput);
return userInput;
}
/**
* Asks the user a yes/no or true/false question. Will accept yes, y, true, or t as positive
* input, and will accept no, n, f, or false as negative input. Any other input will result in a
* repetition of the prompt. Use input is case insensitive.
*
* @param prompt The prompt to display to the user
* @return true if positive input, false otherwise
*/
public static boolean getBoolean(String prompt) {
String response = getString(prompt);
if (response.equalsIgnoreCase("yes")
|| response.equalsIgnoreCase("y")
|| response.equalsIgnoreCase("true")
|| response.equalsIgnoreCase("t")) {
return true;
} else if (response.equalsIgnoreCase("no")
|| response.equalsIgnoreCase("n")
|| response.equalsIgnoreCase("false")
|| response.equalsIgnoreCase("f")) {
return false;
} else {
Logger.log(Loglevel.WARNING, "invalid input; expected yes or no");
return getBoolean(prompt);
}
}