com.aspectran.shell.command.option.OptionUtils Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2023 The Aspectran Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.aspectran.shell.command.option;
import java.util.Arrays;
/**
* Contains useful helper methods for classes within this package.
*/
public final class OptionUtils {
/**
* Validates whether {@code opt} is a permissible Option
* shortOpt. The rules that specify if the {@code opt}
* is valid are:
*
*
* - a single character {@code opt} that is either
* ' '(special case), '?', '@' or a letter
* - a multi character {@code opt} that only contains
* letters.
*
*
* In case {@code opt} is {@code null} no further validation is performed.
*
* @param opt the option string to validate, may be null
* @throws IllegalArgumentException if the Option is not valid
*/
static void validateOption(String opt) throws IllegalArgumentException {
// if opt is NULL do not check further
if (opt == null) {
return;
}
// handle the single character opt
if (opt.length() == 1) {
char ch = opt.charAt(0);
if (!isValidOpt(ch)) {
throw new IllegalArgumentException("Illegal option name '" + ch + "'");
}
}
// handle the multi character opt
else {
for (char ch : opt.toCharArray()) {
if (!isValidChar(ch)) {
throw new IllegalArgumentException("The option '" + opt + "' contains an illegal "
+ "character : '" + ch + "'");
}
}
}
}
/**
* Returns whether the specified character is a valid Option.
* @param c the option to validate
* @return true if {@code c} is a letter, '?' or '@', otherwise false
*/
private static boolean isValidOpt(char c) {
return (isValidChar(c) || c == '?' || c == '@');
}
/**
* Returns whether the specified character is a valid character.
* @param c the character to validate
* @return true if {@code c} is a letter
*/
private static boolean isValidChar(final char c) {
return Character.isJavaIdentifierPart(c);
}
/**
* Remove the hyphens from the beginning of str and
* return the new String.
* @param str the string from which the hyphens should be removed
* @return the new String
*/
static String stripLeadingHyphens(String str) {
if (str == null) {
return null;
}
if (str.startsWith("--")) {
return str.substring(2);
} else if (str.startsWith("-")) {
return str.substring(1);
}
return str;
}
/**
* Remove the leading and trailing quotes from str.
* E.g. if str is '"one two"', then 'one two' is returned.
* @param str the string from which the leading and trailing quotes
* should be removed
* @return the string without the leading and trailing quotes
*/
static String stripLeadingAndTrailingQuotes(String str) {
int length = str.length();
if (length > 1 && str.startsWith("\"") && str.endsWith("\"") &&
str.substring(1, length - 1).indexOf('"') == -1) {
str = str.substring(1, length - 1);
}
return str;
}
/**
* Return a String of padding of length {@code len}.
* @param len the length of the String of padding to create
* @return the String of padding
*/
public static String createPadding(int len) {
char[] padding = new char[len];
Arrays.fill(padding, ' ');
return new String(padding);
}
/**
* Remove the trailing whitespace from the specified String.
* @param s the String to remove the trailing padding from
* @return the String of without the trailing padding
*/
public static String rtrim(String s) {
if (s == null || s.length() == 0) {
return s;
}
int pos = s.length();
while (pos > 0 && Character.isWhitespace(s.charAt(pos - 1))) {
--pos;
}
return s.substring(0, pos);
}
/**
* Finds the next text wrap position after {@code startPos} for the
* text in {@code text} with the column width {@code width}.
* The wrap point is the last position before startPos+width having a
* whitespace character (space, \n, \r). If there is no whitespace character
* before startPos+width, it will return startPos+width.
* @param text the text being searched for the wrap position
* @param width width of the wrapped text
* @param startPos position from which to start the lookup whitespace character
* @return position on which the text must be wrapped or -1 if the wrap
* position is at the end of the text
*/
public static int findWrapPos(String text, int width, int startPos) {
// the line ends before the max wrap pos or a new line char found
int pos = text.indexOf('\n', startPos);
if (pos != -1 && pos <= width) {
return pos + 1;
}
pos = text.indexOf('\t', startPos);
if (pos != -1 && pos <= width) {
return pos + 1;
}
if (startPos + width >= text.length()) {
return -1;
}
for (pos = startPos + width; pos >= startPos; --pos) {
char c = text.charAt(pos);
if (c == '[' || c == '\n' || c == '\r') {
break;
} else if (c == ']') {
pos = startPos - 1;
break;
}
}
if (pos < startPos) {
// look for the last whitespace character before startPos+width
for (pos = startPos + width; pos >= startPos; --pos) {
char c = text.charAt(pos);
if (c == ' ') {
break;
}
}
}
// if we found it - just return
if (pos > startPos) {
return pos;
}
// if we didn't find one, simply chop at startPos+width
pos = startPos + width;
return (pos == text.length() ? -1 : pos);
}
}