Add string utils to core

bundles/org.openhab.core/src/main/java/org/openhab/core/util/StringUtils.java

@@ -0,0 +1,305 @@
+/**
+ * Copyright (c) 2010-2023 Contributors to the openHAB project
+ *
+ * See the NOTICE file(s) distributed with this work for additional
+ * information.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package org.openhab.core.util;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.eclipse.jdt.annotation.Nullable;
+
+/**
+ * Static utility methods that are helpful when dealing with strings.
+ *
+ * @author Leo Siepel - Initial contribution
+ */
+
+@NonNullByDefault
+public class StringUtils {
+
+ /**
+ * If a newline char exists at the end of the line, it is removed
+ *
+ * <pre>
+ * Util.chomp(null) = null
+ * Util.chomp("") = ""
+ * Util.chomp("abc \r") = "abc "
+ * Util.chomp("abc\n") = "abc"
+ * Util.chomp("abc\r\n") = "abc"
+ * Util.chomp("abc\r\n\r\n") = "abc\r\n"
+ * Util.chomp("abc\n\r") = "abc\n"
+ * Util.chomp("abc\n\rabc") = "abc\n\rabc"
+ * Util.chomp("\r") = ""
+ * Util.chomp("\n") = ""
+ * Util.chomp("\r\n") = ""
+ * </pre>
+ *
+ * @param str the input String to escape, may be null
+ * @return the chomped string, may be null
+ */
+ public static @Nullable String chomp(final @Nullable String str) {
+ if (str == null || str.isEmpty()) {
+ return str;
+ }
+ if (str.endsWith("\r\n")) {
+ return str.substring(0, str.length() - 2);
+ } else if (str.endsWith("\r") || str.endsWith("\n")) {
+ return str.substring(0, str.length() - 1);
+ } else {
+ return str;
+ }
+ }
+
+ /**
+ * Simple method to escape XML special characters in String.
+ * There are five XML Special characters which needs to be escaped:
+ * 
+ * <pre>
+ * & - &amp;
+ * < - &lt;
+ * > - &gt;
+ * " - &quot;
+ * ' - &apos;
+ * </pre>
+ *
+ * @param xml the input xml as String to escape, may not be null
+ * @return the escaped xml as String
+ */
+ public static String escapeXml(String xml) {
+ xml = xml.replaceAll("&", "&amp;");
+ xml = xml.replaceAll("<", "&lt;");
+ xml = xml.replaceAll(">", "&gt;");
+ xml = xml.replaceAll("\"", "&quot;");
+ xml = xml.replaceAll("'", "&apos;");
+ return xml;
+ }
+
+ /**
+ * Capitalizes a String changing the first character to title case.
+ * No other characters are changed.
+ *
+ * <pre>
+ * "" => ""
+ * "cat" => "Cat"
+ * "cAt" => "CAt"
+ * "'cat'" => "'cat'"
+ * </pre>
+ *
+ * @param val the String to capitalize, may not be null
+ * @return the capitalized String
+ */
+ public static String capitalize(String val) {
+ if (val.length() == 0) {
+ return val;
+ }
+ return val.substring(0, 1).toUpperCase() + val.substring(1);
+ }
+
+ /**
+ * Capitalizes words in the string. Only the first char of every word is capitalized, other are set to lowercasing.
+ * Words are recognized by an underscore delimiter
+ *
+ * <pre>
+ * "openHAB_is_cool" => "Openhab Is Cool"
+ * "foobar_Example" => "Foobar Example"
+ * </pre>
+ * 
+ * @param input the String to capitalize, may not be null
+ * @return the capitalized String
+ */
+ public static String capitalizeFully(String input) {
+ final String delimiter = "_";
+ String capitalizedFully = "";
+ for (String str : input.split(delimiter)) {
+ String properlyCapitalized = "";
+ if (str.length() > 0) {
+ properlyCapitalized = str.substring(0, 1).toUpperCase();
+ }
+ if (str.length() > 1) {
+ properlyCapitalized += str.substring(1).toLowerCase();
+ }
+ capitalizedFully = capitalizedFully + properlyCapitalized;
+ }
+
+ return capitalizedFully;
+ }
+
+ /**
+ * Capitalizes words in the string. Only the first char of every word is capitalized, the rest is left as is.
+ * Words are recognized by any whitespace.
+ *
+ * <pre>
+ * "openHAB is cool" => "OpenHAB Is Cool"
+ * "foobar Example" => "Foobar Example"
+ * </pre>
+ * 
+ * @param input the String to capitalize, may be null
+ * @return the capitalized String
+ */
+ public static String capitalizeWords(@Nullable String input) {
+ String output = "";
+ if (input != null) {
+ String[] splitted = input.split("\\s+");
+ String[] processed = new String[splitted.length];
+ for (int wordIndex = 0; wordIndex < splitted.length; wordIndex++) {
+ if (splitted[wordIndex].length() > 1) {
+ processed[wordIndex] = splitted[wordIndex].substring(0, 1).toUpperCase()
+ + splitted[wordIndex].substring(1);
+ } else {
+ processed[wordIndex] = splitted[wordIndex].toUpperCase();
+ }
+ }
+ output = String.join(" ", processed);
+ }
+ return output;
+ }
+
+ /**
+ * Pads the string from the left
+ * 
+ * <pre>
+ * padLeft("9", 4, "0") => "0009"
+ * padLeft("3112", 12, "*") => "********3112"
+ * padLeft("openHAB", 4, "*") => "openHAB"
+ * </pre>
+ * 
+ * @param input the String to pad, may be null
+ * @param minSize the minimum String size to return
+ * @param padString the String to add when padding
+ * @return the padded String
+ */
+ public static String padLeft(@Nullable String input, int minSize, String padString) {
+ if (input == null) {
+ input = "";
+ }
+ return String.format("%" + minSize + "s", input).replace(" ", padString);
+ }
+
+ /**
+ * Creates a random string
+ * 
+ * @param length the length of the String to return
+ * @param charset the characters to use to create the String
+ * @return the random String
+ */
+ public static String randomString(int length, String charset) {
+ StringBuilder sb = new StringBuilder(length);
+ for (int i = 0; i < length; i++) {
+ int index = (int) (charset.length() * Math.random());
+ sb.append(charset.charAt(index));
+ }
+
+ return sb.toString();
+ }
+
+ /**
+ * Creates a random string with [A-Zaz] characters
+ * 
+ * @param length the length of the String to return
+ * @return the random String
+ */
+ public static String randomAlphabetic(int length) {
+ return StringUtils.randomString(length, "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvxyz");
+ }
+
+ /**
+ * Creates a random string with only hex characters
+ * 
+ * @param length the length of the String to return
+ * @return the random String
+ */
+ public static String randomHex(int length) {
+ return StringUtils.randomString(length, "0123456789ABCDEF");
+ }
+
+ /**
+ * Creates a random string with [A-Za-z0-9] characters
+ * 
+ * @param length the length of the String to return
+ * @return the random String
+ */
+ public static String randomAlphanummeric(int length) {
+ return StringUtils.randomString(length, "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvxyz");
+ }
+
+ /**
+ * Splits the string by character type into an array
+ * 
+ * <pre>
+ * "ab de fg" => "ab", " ", "de", " ", "fg";
+ * "ab de fg" => "ab", " ", "de", " ", "fg";
+ * "ab:cd:ef" => "ab", ":", "cd", ":", "ef";
+ * "number5" => "number", "5"
+ * "fooBar" => "foo", "Bar"
+ * "OHRules" => "OH", "Rules"
+ * </pre>
+ * 
+ * @param input the input String to split, may be null
+ * @return the splitted String
+ */
+ public static String[] splitByCharacterType(@Nullable String input) {
+ if (input == null) {
+ return new String[0];
+ }
+ if (input.isBlank()) {
+ return new String[0];
+ }
+ List<String> cache = new ArrayList<>();
+ char[] inputAsCharArray = input.toCharArray();
+ int prevType = Character.getType(inputAsCharArray[0]);
+ int prevTypeStart = 0;
+ for (int i = prevTypeStart + 1; i < inputAsCharArray.length; i++) {
+ int curType = Character.getType(inputAsCharArray[i]);
+ if (prevType == curType) {
+ continue;
+ }
+ if (curType == Character.LOWERCASE_LETTER && prevType == Character.UPPERCASE_LETTER) {
+ int tmpStart = i - 1;
+ if (tmpStart != prevTypeStart) {
+ cache.add(new String(inputAsCharArray, prevTypeStart, tmpStart - prevTypeStart));
+ prevTypeStart = tmpStart;
+ }
+ } else {
+ cache.add(new String(inputAsCharArray, prevTypeStart, i - prevTypeStart));
+ prevTypeStart = i;
+ }
+ prevType = curType;
+ }
+ cache.add(new String(inputAsCharArray, prevTypeStart, inputAsCharArray.length - prevTypeStart));
+ return cache.toArray(String[]::new);
+ }
+
+ /**
+ * Simple method to un escape XML special characters in String.
+ * There are five XML Special characters which needs to be escaped:
+ * 
+ * <pre>
+ * & => &amp;
+ * < => &lt;
+ * > => &gt;
+ * " => &quot;
+ * ' => &apos;
+ * </pre>
+ * 
+ * @param input the input xml as String to unescape, may not be null
+ * @return the unescaped xml as String
+ */
+ public static String unEscapeXml(String xml) {
+ xml = xml.replaceAll("&amp;", "&");
+ xml = xml.replaceAll("&lt;", "<");
+ xml = xml.replaceAll("&gt;", ">");
+ xml = xml.replaceAll("&quot;", "\"");
+ xml = xml.replaceAll("&apos;", "'");
+ return xml;
+ }
+}