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Diffstat (limited to 'app-c/appc/appc-common/src/main/java/org/openecomp/appc/util/StringHelper.java')
| -rw-r--r-- | app-c/appc/appc-common/src/main/java/org/openecomp/appc/util/StringHelper.java | 592 |
1 files changed, 592 insertions, 0 deletions
diff --git a/app-c/appc/appc-common/src/main/java/org/openecomp/appc/util/StringHelper.java b/app-c/appc/appc-common/src/main/java/org/openecomp/appc/util/StringHelper.java new file mode 100644 index 000000000..0f9188694 --- /dev/null +++ b/app-c/appc/appc-common/src/main/java/org/openecomp/appc/util/StringHelper.java @@ -0,0 +1,592 @@ +/*- + * ============LICENSE_START======================================================= + * openECOMP : APP-C + * ================================================================================ + * Copyright (C) 2017 AT&T Intellectual Property. All rights + * reserved. + * ================================================================================ + * 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. + * ============LICENSE_END========================================================= + */ + + + +package org.openecomp.appc.util; + +import java.util.Date; +import java.util.List; +import java.util.Map; +import java.util.Properties; +import java.util.Set; +import java.util.regex.Matcher; +import java.util.regex.Pattern; + +/** + * This class contains several static helper methods that can be used to perform string manipulation algorithms. + * + */ + +public final class StringHelper { + + public static final String DASH = "-"; + public static final String DOT = "."; + public static final String ELLIPSES = "..."; + public static final String LINE_FEED = "\n"; + public static final String SLASH = "/"; + public static final String COMMA = ","; + + /** + * Converts the specified string pattern to a regular expression string. If the supplied string is null or empty, + * then a regular expression that matches all strings (.*) is returned. + * <p> + * The expression passed to this method should not already be a regular expression. If it contains problematic + * meta-characters for this routine (such as period, asterisk, and plus), they will be escaped and matched literally + * in the resulting regular expression returned. + * </p> + * + * @param value + * The pattern that we need to convert to a regular expression + * @return The regular expression that is equivalent to the pattern + */ + public static String convertToRegex(String value) { + if (value == null || value.trim().length() == 0) { + return ".*"; + } + boolean appendEOL = false; + StringBuffer buffer = new StringBuffer(value.trim()); + + /* + * If there are any period characters, we need to escape them so that they are exactly matched + */ + Pattern pattern = Pattern.compile("\\."); + Matcher matcher = pattern.matcher(buffer); + int position = 0; + while (matcher.find(position)) { + buffer.replace(matcher.start(), matcher.end(), "\\."); + position = matcher.end() + 1; + } + + /* + * If there are any asterisks or pluses, which we need to interpret as wildcard characters, we need to convert + * them into .* or . + */ + pattern = Pattern.compile("\\*|\\+"); + matcher = pattern.matcher(buffer); + position = 0; + while (matcher.find(position)) { + String metachar = buffer.substring(matcher.start(), matcher.end()); + if (metachar.equals("*")) { + buffer.replace(matcher.start(), matcher.end(), ".*"); + position = matcher.end() + 1; + if (matcher.end() < buffer.length() - 1) { + appendEOL = true; + } + } else if (metachar.equals("+")) { + buffer.replace(matcher.start(), matcher.end(), "."); + position = matcher.end(); + if (matcher.end() == buffer.length()) { + appendEOL = true; + } + } + } + + /* + * If the string contains a .* meta-character sequence anywhere in the middle of the string (i.e., there are + * other characters following the .* meta-characters), OR the string ends with the .+ sequence, then we need to + * append the "end-of-line" boundary condition to the end of the string to get predictable results. + */ + if (appendEOL) { + buffer.append("$"); + } + return buffer.toString(); + } + + /** + * Takes a string that may possibly be very long and return a string that is at most maxLength. If the string is + * longer than maxLength, the last three characters will be the ellipses (...) to indicate that the string was + * shortened. + * + * @param possiblyLongString + * @param maxLength + * must be at least 4 (one character plus ellipses) + * @return possibly shortened string + */ + public static String getShortenedString(String possiblyLongString, int maxLength) { + if ((possiblyLongString != null) && (maxLength > ELLIPSES.length()) + && (possiblyLongString.length() > maxLength)) { + return possiblyLongString.substring(0, maxLength - ELLIPSES.length()) + ELLIPSES; + + } + return possiblyLongString; + } + + /** + * Determines that a provided string is not null and not empty (length = 0 after trimming) + * + * @param theString + * The string to be tested + * @return true if the string IS NOT null and is NOT empty + */ + public static boolean isNotNullNotEmpty(String theString) { + return ((theString != null) && (!theString.trim().isEmpty())); + } + + /** + * Determines that a provided string IS null or an empty string (length = 0 after trimming) + * + * @param theString + * The string to be tested + * @return true if the string IS null OR is empty + */ + public static boolean isNullOrEmpty(String theString) { + return ((theString == null) || (theString.trim().isEmpty())); + } + + /** + * Returns an indication if the first string is equal to the second string, allowing for either or both strings to + * be null. + * + * @param a + * The first string to be compared + * @param b + * The second string to be compared + * @return True if both strings are null, or both strings are non-null AND they are equal. False otherwise. + */ + public static boolean equals(String a, String b) { + return equals(a, b, false); + } + + /** + * Returns an indication if the first string is equal to the second string, allowing for either or both strings to + * be null, and ignoring case. + * + * @param a + * The first string to be compared + * @param b + * The second string to be compared + * @return True if both strings are null, or both strings are non-null AND they are equal (without regard to case). + * False otherwise. + */ + public static boolean equalsIgnoreCase(String a, String b) { + return equals(a, b, true); + } + + /** + * Compares two strings (allowing either or both to be null), and allowing for optional case sensitive or + * insensitive comparison. + * + * @param a + * The first string to be compared + * @param b + * The second string to be compared + * @param caseInsensitive + * True if the comparison is to be case in-sensitive. + * @return True if both strings are null, or both strings are non-null and they are equal + */ + private static boolean equals(String a, String b, boolean caseInsensitive) { + if (a == null && b == null) { + return true; + } + if (a != null && b != null) { + if (caseInsensitive) { + return a.equalsIgnoreCase(b); + } else { + return a.equals(b); + } + } + + return false; + } + + /** + * This method is used to mangle a name. + * <p> + * This method will first remove all unacceptable characters from the name and translate all characters to lower + * case. This is done to eliminate any potentially troublesome characters. If the resulting string is empty, then a + * random string of characters for the minimum desired length is returned. If the string is too short to meet the + * minimum length requirement, it is padded with random characters. + * </p> + * <p> + * Once the string has been scrubbed and possibly padded, it may be truncated (if longer than the maximum value) and + * the result is returned. To make the string as unique as possible, the algorithm removes excess letters from the + * center of the string, concatenating the first nad last parts of the name together. The assumption is that users + * tend to start the names of multiple things in similar ways, and get more descriptive as the name progresses. If + * for example, several objects were named "A test Object", "A test Object1", and "A test Object2", shortening the + * name only from the left does not generate a unique name. + * </p> + * + * @param name + * The name to be mangled + * @param minLen + * minimum number of characters for the name + * @param maxLen + * maximum number of characters for the name + * @return The mangled name, or an empty string if the value is null or an empty string. + */ + public static String mangleName(String name, int minLen, int maxLen) { + StringBuffer buffer = new StringBuffer(name == null ? "" : name); + Pattern pattern = Pattern.compile("[^a-z0-9]+", Pattern.CASE_INSENSITIVE); + Matcher matcher = pattern.matcher(buffer); + int position = 0; + while (matcher.find(position)) { + buffer.delete(matcher.start(), matcher.end()); + position = matcher.start(); + } + + if (buffer.length() < minLen) { + for (int i = buffer.length(); i <= minLen; i++) { + buffer.append("A"); + } + } + + /* + * Remove out of the center of the name to preserve start and end and result in a string of max len + */ + if (buffer.length() > maxLen) { + int excess = buffer.length() - maxLen; + int left = maxLen / 2; + + buffer.delete(left, excess + left); + } + + return buffer.toString().toLowerCase(); + } + + /** + * This method is used to normalize a string value. + * <p> + * This method will ensure that the string value is trimmed of all leading and trailing whitespace if not null. If + * it is null or an empty string, then it will return null. + * </p> + * + * @param value + * The value to be normalized + * @return The normalized (no leading or trailing whitespace) value, or null if the string was null or an empty + * string (or all whitespace). This method will never return an empty string. + */ + public static String normalizeString(String value) { + if (value != null) { + String temp = value.trim(); + if (temp.length() > 0) { + return temp; + } + } + return null; + } + + /** + * This method is used to strip all carriage returns and line feed characters from a string + * + * @param value + * @return The original value less all carriage returns and line feeds + */ + public static String stripCRLF(String value) { + + if (value == null) { + return null; + } + String[] tokens = value.split("\r\n|\n\r|\r|\n"); + StringBuffer buffer = new StringBuffer(); + for (String token : tokens) { + buffer.append(token.trim()); + } + return buffer.toString(); + } + + /** + * Converts UNIX-style line endings to DOS-style. Replaces LF with CR+LF as long as the LF does not already exist + * paired with a CR. + * + * @param content + * The content to be converted + * @return The converted content. + */ + public static String toDOSLines(String content) { + if (content == null) { + return null; + } + + StringBuffer buffer = new StringBuffer(content); + Pattern pattern = Pattern.compile("^(\n)[^\r]|[^\r](\n)[^\r]|[^\r](\n)$"); + Matcher matcher = pattern.matcher(buffer); + int position = 0; + while (matcher.find(position)) { + int index = matcher.start(1); + if (index == -1) { + index = matcher.start(2); + } + if (index == -1) { + index = matcher.start(3); + } + + buffer.replace(index, index + 1, "\r\n"); + position = index + 1; + } + + return buffer.toString(); + } + + /** + * This method will convert a string contents to use the UNIX-style line endings. That is, all occurrences of CR + * (Carriage Return) and LF (Line Feed) are reduced to just use LF. + * + * @param content + * The buffer to be processed + * @return The converted contents + */ + public static String toUnixLines(String content) { + if (content == null) { + return null; + } + + StringBuffer buffer = new StringBuffer(content); + Pattern pattern = Pattern.compile("\r\n|\n\r"); + Matcher matcher = pattern.matcher(buffer); + int position = 0; + while (matcher.find(position)) { + buffer.replace(matcher.start(), matcher.end(), "\n"); + position = matcher.start(); + } + + return buffer.toString(); + } + + /** + * This method is used to translate characters in the input sequence that match the characters in the match list to + * the corresponding character in the replacement list. If the replacement list is shorter than the match list, then + * the character from the replacement list is taken as the modulo of the match character position and the length of + * the replacement list. + * + * @param sequence + * The input sequence to be processed + * @param match + * The list of matching characters to be searched + * @param replacement + * The list of replacement characters, positional coincident with the match list. If shorter than the + * match list, then the position "wraps" around on the replacement list. + * @return The translated string contents. + */ + public static Object translate(String sequence, String match, String replacement) { + + if (sequence == null) { + return sequence; + } + + StringBuffer buffer = new StringBuffer(sequence); + + for (int index = 0; index < buffer.length(); index++) { + char ch = buffer.charAt(index); + + int position = match.indexOf(ch); + if (position == -1) { + continue; + } + + if (position >= replacement.length()) { + position %= replacement.length(); + } + buffer.setCharAt(index, replacement.charAt(position)); + } + + return buffer.toString(); + } + + /** + * Ensures that the name provided is a valid identifier. This means that no spaces are allowed as well as special + * characters. This method translates all spaces and illegal characters to underscores (_). + * + * @param name + * The name to be checked and converted to an identifier if needed + * @return The valid identifier from the name + */ + public static String validIdentifier(String name) { + if (name == null || name.length() == 0) { + return name; + } + + StringBuffer buffer = new StringBuffer(name); + for (int index = 0; index < buffer.length(); index++) { + char ch = buffer.charAt(index); + + if ((index == 0 && !Character.isJavaIdentifierStart(ch)) || (!Character.isJavaIdentifierPart(ch))) { + buffer.setCharAt(index, '_'); + } + } + return buffer.toString(); + } + + /** + * This method verifies that the provided string only contains characters from the legal set, and replaces any + * character not in the legal set with the specified replacement character. + * + * @param sequence + * The sequence to be verified + * @param legal + * The set of all legal characters + * @param replacement + * The replacement character if a character is not in the legal set + * @return The verified *and possibly updated) string + */ + public static String verify(String sequence, String legal, char replacement) { + if (sequence == null) { + return sequence; + } + + StringBuffer buffer = new StringBuffer(sequence); + for (int index = 0; index < buffer.length(); index++) { + char ch = buffer.charAt(index); + if (legal.indexOf(ch) == -1) { + buffer.setCharAt(index, replacement); + } + } + return buffer.toString(); + } + + /** + * Private constructor to prevent instantiation of this class - All methods are static! + */ + private StringHelper() { + + } + + /** + * @param list + * The list of elements + * @return The list of elements formatted as a comma-delimited list + */ + public static String asList(List<String> list) { + StringBuffer buffer = new StringBuffer(); + if (list != null) { + if (list.size() == 1) { + buffer.append(list.get(0)); + } else { + for (String element : list) { + buffer.append(element); + buffer.append(", "); + } + + if (buffer.length() > 2) { + buffer.delete(buffer.length() - 2, buffer.length()); + } + } + } + return buffer.toString(); + } + + /** + * @param map + * A map of strings + * @return A map expressed as a comma-delimited list of name=value tuples + */ + public static String asList(Map<String, String> map) { + StringBuffer buffer = new StringBuffer(); + if (map != null) { + Set<String> keys = map.keySet(); + for (String key : keys) { + buffer.append(String.format("%s=%s, ", key, map.get(key))); + } + + if (buffer.length() > 2) { + buffer.delete(buffer.length() - 2, buffer.length()); + } + } + return buffer.toString(); + } + + /** + * @param values + * An array or varargs of Strings to be concatenated into a comma-separated list + * @return The comma-seprated list of values + */ + public static String asList(String... values) { + StringBuilder builder = new StringBuilder(); + builder.append('['); + if (values != null && values.length > 0) { + int count = values.length; + for (int index = 0; index < count - 1; index++) { + builder.append(values[index]); + builder.append(','); + } + builder.append(values[count - 1]); + } + builder.append(']'); + return builder.toString(); + } + + public static Object resolveToType(String input) { + String intRegex = "^(\\-)?[0-9]+$"; + String doubleRegex = "^(\\-)?[0-9\\.]+$"; + String boolRegex = "(^(?i)((true)|(false))$)"; + + // Check for null + if (input == null) { + return null; + } + + // Check int first + if (input.matches(intRegex)) { + try { + return Integer.parseInt(input); + } catch (NumberFormatException nfe) { + // Should not happen + nfe.printStackTrace(); + } + } + + // Check double (int + decimal point) + if (input.matches(doubleRegex)) { + try { + return Double.parseDouble(input); + } catch (NumberFormatException | NullPointerException e) { + // NPE won't happen bc of regex check + } + } + + // Check boolean + if (input.matches(boolRegex)) { + return Boolean.parseBoolean(input); + } + + // Try to parse a date + Date date = Time.utcParse(input); + if (date != null) { + return date; + } + + // No special type, return string + return input; + } + + /** + * Converts a properties object to a string in the format of <pre>[ key=value, key=value, ... ]</pre> + * + * @param props + * The properties object to format + * @return A string in the format <pre>[ key=value, ... ]</pre> or null if the input was null + */ + public static String propertiesToString(Properties props) { + if (props == null) { + return null; + } + StringBuilder out = new StringBuilder(); + out.append("["); + for (Object key : props.keySet()) { + out.append(String.format(" %s = %s,", key.toString(), props.getProperty(key.toString()))); + } + if (props.size() > 0) { + out.deleteCharAt(out.lastIndexOf(",")); + } + out.append(" ]"); + return out.toString(); + } +} |