StringUtils.java

/*
 * Copyright (C) 2015
 *            heaven7(donshine723@gmail.com)
 *
 * 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 org.heaven7.scrap.util;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Enumeration;
import java.util.List;
import java.util.Locale;
import java.util.Set;
import java.util.StringTokenizer;
import java.util.TreeSet;

/**
 * comes from spring
 */
public abstract class StringUtils {
	private static final String FOLDER_SEPARATOR = "/";
	private static final String WINDOWS_FOLDER_SEPARATOR = "\\";
	private static final String TOP_PATH = "..";
	private static final String CURRENT_PATH = ".";
	private static final char EXTENSION_SEPARATOR = '.';

	public static boolean hasLength(CharSequence str) {
		return (str != null) && (str.length() > 0);
	}

	public static boolean hasLength(String str) {
		return (str != null) && (str.length() > 0);
	}

	public static boolean hasText(CharSequence str) {
		if (!hasLength(str)) {
			return false;
		}
		int strLen = str.length();
		for (int i = 0; i < strLen; i++) {
			if (!Character.isWhitespace(str.charAt(i))) {
				return true;
			}
		}
		return false;
	}

	public static boolean hasText(String str) {
		return hasText(str);
	}

	public static boolean containsWhitespace(CharSequence str) {
		if (!hasLength(str)) {
			return false;
		}
		int strLen = str.length();
		for (int i = 0; i < strLen; i++) {
			if (Character.isWhitespace(str.charAt(i))) {
				return true;
			}
		}
		return false;
	}

	public static String trimWhitespace(String str) {
		if (!hasLength(str)) {
			return str;
		}
		StringBuilder sb = new StringBuilder(str);
		while ((sb.length() > 0) && (Character.isWhitespace(sb.charAt(0)))) {
			sb.deleteCharAt(0);
		}
		while ((sb.length() > 0)
				&& (Character.isWhitespace(sb.charAt(sb.length() - 1)))) {
			sb.deleteCharAt(sb.length() - 1);
		}
		return sb.toString();
	}

	public static String trimAllWhitespace(String str) {
		if (!hasLength(str)) {
			return str;
		}
		StringBuilder sb = new StringBuilder(str);
		int index = 0;
		while (sb.length() > index) {
			if (Character.isWhitespace(sb.charAt(index))) {
				sb.deleteCharAt(index);
			} else {
				index++;
			}
		}
		return sb.toString();
	}

	public static String trimLeadingWhitespace(String str) {
		if (!hasLength(str)) {
			return str;
		}
		StringBuilder sb = new StringBuilder(str);
		while ((sb.length() > 0) && (Character.isWhitespace(sb.charAt(0)))) {
			sb.deleteCharAt(0);
		}
		return sb.toString();
	}

	public static String trimTrailingWhitespace(String str) {
		if (!hasLength(str)) {
			return str;
		}
		StringBuilder sb = new StringBuilder(str);
		while ((sb.length() > 0)
				&& (Character.isWhitespace(sb.charAt(sb.length() - 1)))) {
			sb.deleteCharAt(sb.length() - 1);
		}
		return sb.toString();
	}

	public static String trimLeadingCharacter(String str, char leadingCharacter) {
		if (!hasLength(str)) {
			return str;
		}
		StringBuilder sb = new StringBuilder(str);
		while ((sb.length() > 0) && (sb.charAt(0) == leadingCharacter)) {
			sb.deleteCharAt(0);
		}
		return sb.toString();
	}

	public static String trimTrailingCharacter(String str,
			char trailingCharacter) {
		if (!hasLength(str)) {
			return str;
		}
		StringBuilder sb = new StringBuilder(str);
		while ((sb.length() > 0)
				&& (sb.charAt(sb.length() - 1) == trailingCharacter)) {
			sb.deleteCharAt(sb.length() - 1);
		}
		return sb.toString();
	}

	public static boolean startsWithIgnoreCase(String str, String prefix) {
		if ((str == null) || (prefix == null)) {
			return false;
		}
		if (str.startsWith(prefix)) {
			return true;
		}
		if (str.length() < prefix.length()) {
			return false;
		}
		String lcStr = str.substring(0, prefix.length()).toLowerCase();
		String lcPrefix = prefix.toLowerCase();
		return lcStr.equals(lcPrefix);
	}

	public static boolean endsWithIgnoreCase(String str, String suffix) {
		if ((str == null) || (suffix == null)) {
			return false;
		}
		if (str.endsWith(suffix)) {
			return true;
		}
		if (str.length() < suffix.length()) {
			return false;
		}

		String lcStr = str.substring(str.length() - suffix.length())
				.toLowerCase();
		String lcSuffix = suffix.toLowerCase();
		return lcStr.equals(lcSuffix);
	}

	public static boolean substringMatch(CharSequence str, int index,
			CharSequence substring) {
		for (int j = 0; j < substring.length(); j++) {
			int i = index + j;
			if ((i >= str.length()) || (str.charAt(i) != substring.charAt(j))) {
				return false;
			}
		}
		return true;
	}

	public static int countOccurrencesOf(String str, String sub) {
		if ((str == null) || (sub == null) || (str.length() == 0)
				|| (sub.length() == 0)) {
			return 0;
		}
		int count = 0;
		int pos = 0;
		int idx;
		while ((idx = str.indexOf(sub, pos)) != -1) {
			count++;
			pos = idx + sub.length();
		}
		return count;
	}

	public static String replace(String inString, String oldPattern,
			String newPattern) {
		if ((!hasLength(inString)) || (!hasLength(oldPattern))
				|| (newPattern == null)) {
			return inString;
		}
		StringBuilder sb = new StringBuilder();
		int pos = 0;
		int index = inString.indexOf(oldPattern);

		int oldPatternLen = oldPattern.length();
		while (index >= 0) {
			sb.append(inString.substring(pos, index));
			sb.append(newPattern);
			pos = index + oldPatternLen;
			index = inString.indexOf(oldPattern, pos);
		}
		sb.append(inString.substring(pos));

		return sb.toString();
	}

	public static String delete(String inString, String pattern) {
		return replace(inString, pattern, "");
	}

	public static String deleteAny(String inString, String charsToDelete) {
		if ((!hasLength(inString)) || (!hasLength(charsToDelete))) {
			return inString;
		}
		StringBuilder sb = new StringBuilder();
		for (int i = 0; i < inString.length(); i++) {
			char c = inString.charAt(i);
			if (charsToDelete.indexOf(c) == -1) {
				sb.append(c);
			}
		}
		return sb.toString();
	}

	public static String quote(String str) {
		return str != null ? new StringBuilder().append("'").append(str)
				.append("'").toString() : null;
	}

	public static Object quoteIfString(Object obj) {
		return (obj instanceof String) ? quote((String) obj) : obj;
	}
	public static String unqualify(String qualifiedName) {
		return unqualify(qualifiedName, EXTENSION_SEPARATOR);
	}

	public static String unqualify(String qualifiedName, char separator) {
		return qualifiedName
				.substring(qualifiedName.lastIndexOf(separator) + 1);
	}

	public static String capitalize(String str) {
		return changeFirstCharacterCase(str, true);
	}
	public static String uncapitalize(String str) {
		return changeFirstCharacterCase(str, false);
	}

	private static String changeFirstCharacterCase(String str,
			boolean capitalize) {
		if ((str == null) || (str.length() == 0)) {
			return str;
		}
		StringBuilder sb = new StringBuilder(str.length());
		if (capitalize) {
			sb.append(Character.toUpperCase(str.charAt(0)));
		} else {
			sb.append(Character.toLowerCase(str.charAt(0)));
		}
		sb.append(str.substring(1));
		return sb.toString();
	}

	public static String getFilename(String path) {
		if (path == null) {
			return null;
		}
		int separatorIndex = path.lastIndexOf(FOLDER_SEPARATOR);
		return separatorIndex != -1 ? path.substring(separatorIndex + 1) : path;
	}

	public static String getFilenameExtension(String path) {
		if (path == null) {
			return null;
		}
		int extIndex = path.lastIndexOf(46);
		if (extIndex == -1) {
			return null;
		}
		int folderIndex = path.lastIndexOf(FOLDER_SEPARATOR);
		if (folderIndex > extIndex) {
			return null;
		}
		return path.substring(extIndex + 1);
	}

	public static String stripFilenameExtension(String path) {
		if (path == null) {
			return null;
		}
		int extIndex = path.lastIndexOf(46);
		if (extIndex == -1) {
			return path;
		}
		int folderIndex = path.lastIndexOf(FOLDER_SEPARATOR);
		if (folderIndex > extIndex) {
			return path;
		}
		return path.substring(0, extIndex);
	}

	public static String applyRelativePath(String path, String relativePath) {
		int separatorIndex = path.lastIndexOf(FOLDER_SEPARATOR);
		if (separatorIndex != -1) {
			String newPath = path.substring(0, separatorIndex);
			if (!relativePath.startsWith(FOLDER_SEPARATOR)) {
				newPath = new StringBuilder().append(newPath)
						.append(FOLDER_SEPARATOR).toString();
			}
			return new StringBuilder().append(newPath).append(relativePath)
					.toString();
		}

		return relativePath;
	}

	public static Locale parseLocaleString(String localeString) {
		String[] parts = tokenizeToStringArray(localeString, "_ ", false, false);
		String language = parts.length > 0 ? parts[0] : "";
		String country = parts.length > 1 ? parts[1] : "";
		validateLocalePart(language);
		validateLocalePart(country);
		String variant = "";
		if (parts.length >= 2) {
			int endIndexOfCountryCode = localeString.indexOf(country)
					+ country.length();

			variant = trimLeadingWhitespace(localeString
					.substring(endIndexOfCountryCode));
			if (variant.startsWith("_")) {
				variant = trimLeadingCharacter(variant, '_');
			}
		}
		return language.length() > 0 ? new Locale(language, country, variant)
				: null;
	}

	private static void validateLocalePart(String localePart) {
		for (int i = 0; i < localePart.length(); i++) {
			char ch = localePart.charAt(i);
			if ((ch != '_') && (ch != ' ') && (!Character.isLetterOrDigit(ch)))
				throw new IllegalArgumentException(new StringBuilder()
						.append("Locale part \"").append(localePart)
						.append("\" contains invalid characters").toString());
		}
	}

	public static String toLanguageTag(Locale locale) {
		return new StringBuilder()
				.append(locale.getLanguage())
				.append(hasText(locale.getCountry()) ? new StringBuilder()
						.append("-").append(locale.getCountry()).toString()
						: "").toString();
	}

	public static String[] toStringArray(Collection<String> collection) {
		if (collection == null) {
			return null;
		}
		return (String[]) collection.toArray(new String[collection.size()]);
	}

	public static String[] toStringArray(Enumeration<String> enumeration) {
		if (enumeration == null) {
			return null;
		}
		List<String> list = Collections.list(enumeration);
		return (String[]) list.toArray(new String[list.size()]);
	}

	public static String[] split(String toSplit, String delimiter) {
		if ((!hasLength(toSplit)) || (!hasLength(delimiter))) {
			return null;
		}
		int offset = toSplit.indexOf(delimiter);
		if (offset < 0) {
			return null;
		}
		String beforeDelimiter = toSplit.substring(0, offset);
		String afterDelimiter = toSplit.substring(offset + delimiter.length());
		return new String[] { beforeDelimiter, afterDelimiter };
	}

	public static String[] tokenizeToStringArray(String str, String delimiters) {
		return tokenizeToStringArray(str, delimiters, true, true);
	}
	public static String[] tokenizeToStringArray(String str, String delimiters,
			boolean trimTokens, boolean ignoreEmptyTokens) {
		if (str == null) {
			return null;
		}
		StringTokenizer st = new StringTokenizer(str, delimiters);
		List<String> tokens = new ArrayList<String>();
		while (st.hasMoreTokens()) {
			String token = st.nextToken();
			if (trimTokens) {
				token = token.trim();
			}
			if ((!ignoreEmptyTokens) || (token.length() > 0)) {
				tokens.add(token);
			}
		}
		return toStringArray(tokens);
	}

	public static String[] delimitedListToStringArray(String str,
			String delimiter) {
		return delimitedListToStringArray(str, delimiter, null);
	}

	public static String[] delimitedListToStringArray(String str,
			String delimiter, String charsToDelete) {
		if (str == null) {
			return new String[0];
		}
		if (delimiter == null) {
			return new String[] { str };
		}
		List<String> result = new ArrayList<String>();
		if ("".equals(delimiter)) {
			for (int i = 0; i < str.length(); i++)
				result.add(deleteAny(str.substring(i, i + 1), charsToDelete));
		} else {
			int pos = 0;
			int delPos;
			while ((delPos = str.indexOf(delimiter, pos)) != -1) {
				result.add(deleteAny(str.substring(pos, delPos), charsToDelete));
				pos = delPos + delimiter.length();
			}
			if ((str.length() > 0) && (pos <= str.length())) {
				result.add(deleteAny(str.substring(pos), charsToDelete));
			}
		}
		return toStringArray(result);
	}

	public static String[] commaDelimitedListToStringArray(String str) {
		return delimitedListToStringArray(str, ",");
	}

	public static Set<String> commaDelimitedListToSet(String str) {
		Set<String> set = new TreeSet<String>();
		String[] tokens = commaDelimitedListToStringArray(str);
		for (String token : tokens) {
			set.add(token);
		}
		return set;
	}

}