Java tutorial
// // Licensed to the Apache Software Foundation (ASF) under one // or more contributor license agreements. See the NOTICE file // distributed with this work for additional information // regarding copyright ownership. The ASF licenses this file // to you 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.cloud.utils; import java.nio.charset.Charset; import java.util.ArrayList; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.regex.Matcher; import java.util.regex.Pattern; import org.owasp.esapi.StringUtilities; public class StringUtils { private static final char[] hexChar = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' }; private static Charset preferredACSCharset; private static final String UTF8 = "UTF-8"; static { if (isUtf8Supported()) { preferredACSCharset = Charset.forName(UTF8); } else { preferredACSCharset = Charset.defaultCharset(); } } public static Charset getPreferredCharset() { return preferredACSCharset; } public static boolean isUtf8Supported() { return Charset.isSupported(UTF8); } protected static Charset getDefaultCharset() { return Charset.defaultCharset(); } public static String join(final Iterable<? extends Object> iterable, final String delim) { final StringBuilder sb = new StringBuilder(); if (iterable != null) { final Iterator<? extends Object> iter = iterable.iterator(); if (iter.hasNext()) { final Object next = iter.next(); sb.append(next.toString()); } while (iter.hasNext()) { final Object next = iter.next(); sb.append(delim + next.toString()); } } return sb.toString(); } public static String join(final String delimiter, final Object... components) { return org.apache.commons.lang.StringUtils.join(components, delimiter); } public static boolean isNotBlank(final String str) { if (str != null && str.trim().length() > 0) { return true; } return false; } public static String cleanupTags(String tags) { if (tags != null) { final String[] tokens = tags.split(","); final StringBuilder t = new StringBuilder(); for (int i = 0; i < tokens.length; i++) { t.append(tokens[i].trim()).append(","); } t.delete(t.length() - 1, t.length()); tags = t.toString(); } return tags; } /** * @param tags * @return List of tags */ public static List<String> csvTagsToList(final String tags) { final List<String> tagsList = new ArrayList<String>(); if (tags != null) { final String[] tokens = tags.split(","); for (int i = 0; i < tokens.length; i++) { tagsList.add(tokens[i].trim()); } } return tagsList; } /** * Converts a List of tags to a comma separated list * @param tags * @return String containing a comma separated list of tags */ public static String listToCsvTags(final List<String> tagsList) { final StringBuilder tags = new StringBuilder(); if (tagsList.size() > 0) { for (int i = 0; i < tagsList.size(); i++) { tags.append(tagsList.get(i)); if (i != tagsList.size() - 1) { tags.append(','); } } } return tags.toString(); } public static String getExceptionStackInfo(final Throwable e) { final StringBuffer sb = new StringBuffer(); sb.append(e.toString()).append("\n"); final StackTraceElement[] elemnents = e.getStackTrace(); for (final StackTraceElement element : elemnents) { sb.append(element.getClassName()).append("."); sb.append(element.getMethodName()).append("("); sb.append(element.getFileName()).append(":"); sb.append(element.getLineNumber()).append(")"); sb.append("\n"); } return sb.toString(); } public static String unicodeEscape(final String s) { final StringBuilder sb = new StringBuilder(); for (int i = 0; i < s.length(); i++) { final char c = s.charAt(i); if (c >> 7 > 0) { sb.append("\\u"); sb.append(hexChar[c >> 12 & 0xF]); // append the hex character for the left-most 4-bits sb.append(hexChar[c >> 8 & 0xF]); // hex for the second group of 4-bits from the left sb.append(hexChar[c >> 4 & 0xF]); // hex for the third group sb.append(hexChar[c & 0xF]); // hex for the last group, e.g., the right most 4-bits } else { sb.append(c); } } return sb.toString(); } public static String getMaskedPasswordForDisplay(final String password) { if (password == null || password.isEmpty()) { return "*"; } final StringBuffer sb = new StringBuffer(); sb.append(password.charAt(0)); for (int i = 1; i < password.length(); i++) { sb.append("*"); } return sb.toString(); } // removes a password request param and it's value, also considering password is in query parameter value which has been url encoded private static final Pattern REGEX_PASSWORD_QUERYSTRING = Pattern .compile("(&|%26)?[^(&|%26)]*((p|P)assword|accesskey|secretkey)(=|%3D).*?(?=(%26|[&'\"]|$))"); // removes a password/accesskey/ property from a response json object private static final Pattern REGEX_PASSWORD_JSON = Pattern .compile("\"((p|P)assword|privatekey|accesskey|secretkey)\":\\s?\".*?\",?"); private static final Pattern REGEX_PASSWORD_DETAILS = Pattern.compile( "(&|%26)?details(\\[|%5B)\\d*(\\]|%5D)\\.key(=|%3D)((p|P)assword|accesskey|secretkey)(?=(%26|[&'\"]))"); private static final Pattern REGEX_PASSWORD_DETAILS_INDEX = Pattern.compile("details(\\[|%5B)\\d*(\\]|%5D)"); private static final Pattern REGEX_REDUNDANT_AND = Pattern.compile("(&|%26)(&|%26)+"); // Responsible for stripping sensitive content from request and response strings public static String cleanString(final String stringToClean) { String cleanResult = ""; if (stringToClean != null) { cleanResult = REGEX_PASSWORD_QUERYSTRING.matcher(stringToClean).replaceAll(""); cleanResult = REGEX_PASSWORD_JSON.matcher(cleanResult).replaceAll(""); final Matcher detailsMatcher = REGEX_PASSWORD_DETAILS.matcher(cleanResult); while (detailsMatcher.find()) { final Matcher detailsIndexMatcher = REGEX_PASSWORD_DETAILS_INDEX.matcher(detailsMatcher.group()); if (detailsIndexMatcher.find()) { cleanResult = cleanDetails(cleanResult, detailsIndexMatcher.group()); } } } return cleanResult; } public static String cleanDetails(final String stringToClean, final String detailsIndexSting) { String cleanResult = stringToClean; for (final String log : stringToClean.split("&|%26")) { if (log.contains(detailsIndexSting)) { cleanResult = cleanResult.replace(log, ""); } } cleanResult = REGEX_REDUNDANT_AND.matcher(cleanResult).replaceAll("&"); return cleanResult; } public static boolean areTagsEqual(final String tags1, final String tags2) { if (tags1 == null && tags2 == null) { return true; } if (tags1 != null && tags2 == null) { return false; } if (tags1 == null && tags2 != null) { return false; } final String delimiter = ","; final List<String> lstTags1 = new ArrayList<String>(); final String[] aTags1 = tags1.split(delimiter); for (final String tag1 : aTags1) { lstTags1.add(tag1.toLowerCase()); } final List<String> lstTags2 = new ArrayList<String>(); final String[] aTags2 = tags2.split(delimiter); for (final String tag2 : aTags2) { lstTags2.add(tag2.toLowerCase()); } return lstTags1.containsAll(lstTags2) && lstTags2.containsAll(lstTags1); } public static String stripControlCharacters(final String s) { return StringUtilities.stripControls(s); } public static int formatForOutput(final String text, final int start, final int columns, final char separator) { if (start >= text.length()) { return -1; } int end = start + columns; if (end > text.length()) { end = text.length(); } final String searchable = text.substring(start, end); final int found = searchable.lastIndexOf(separator); return found > 0 ? found : end - start; } public static Map<String, String> stringToMap(final String s) { final Map<String, String> map = new HashMap<String, String>(); final String[] elements = s.split(";"); for (final String parts : elements) { final String[] keyValue = parts.split(":"); map.put(keyValue[0], keyValue[1]); } return map; } public static String mapToString(final Map<String, String> map) { String s = ""; for (final Map.Entry<String, String> entry : map.entrySet()) { s += entry.getKey() + ":" + entry.getValue() + ";"; } if (s.length() > 0) { s = s.substring(0, s.length() - 1); } return s; } public static <T> List<T> applyPagination(final List<T> originalList, final Long startIndex, final Long pageSizeVal) { // Most likely pageSize will never exceed int value, and we need integer to partition the listToReturn final boolean applyPagination = startIndex != null && pageSizeVal != null && startIndex <= Integer.MAX_VALUE && startIndex >= Integer.MIN_VALUE && pageSizeVal <= Integer.MAX_VALUE && pageSizeVal >= Integer.MIN_VALUE; List<T> listWPagination = null; if (applyPagination) { listWPagination = new ArrayList<>(); final int index = startIndex.intValue() == 0 ? 0 : startIndex.intValue() / pageSizeVal.intValue(); final List<List<T>> partitions = StringUtils.partitionList(originalList, pageSizeVal.intValue()); if (index < partitions.size()) { listWPagination = partitions.get(index); } } return listWPagination; } private static <T> List<List<T>> partitionList(final List<T> originalList, final int chunkSize) { final List<List<T>> listOfChunks = new ArrayList<List<T>>(); for (int i = 0; i < originalList.size() / chunkSize; i++) { listOfChunks.add(originalList.subList(i * chunkSize, i * chunkSize + chunkSize)); } if (originalList.size() % chunkSize != 0) { listOfChunks.add(originalList.subList(originalList.size() - originalList.size() % chunkSize, originalList.size())); } return listOfChunks; } }