stringutils.java

一些简要的公爵类一些简要的公爵类一些简要的公爵类

	/**
	 * Delete any character in a given string.
	 * @param charsToDelete a set of characters to delete.
	 * E.g. "az\n" will delete 'a's, 'z's and new lines.
	 */
	public static String deleteAny(String inString, String charsToDelete) {
		if (inString == null || charsToDelete == null) {
			return inString;
		}
		StringBuffer out = new StringBuffer();
		for (int i = 0; i < inString.length(); i++) {
			char c = inString.charAt(i);
			if (charsToDelete.indexOf(c) == -1) {
				out.append(c);
			}
		}
		return out.toString();
	}


	//---------------------------------------------------------------------
	// Convenience methods for working with formatted Strings
	//---------------------------------------------------------------------

	/**
	 * Quote the given String with single quotes.
	 * @param str the input String (e.g. "myString")
	 * @return the quoted String (e.g. "'myString'"),
	 * or <code>null<code> if the input was <code>null</code>
	 */
	public static String quote(String str) {
		return (str != null ? "'" + str + "'" : null);
	}

	/**
	 * Turn the given Object into a String with single quotes
	 * if it is a String; keeping the Object as-is else.
	 * @param obj the input Object (e.g. "myString")
	 * @return the quoted String (e.g. "'myString'"),
	 * or the input object as-is if not a String
	 */
	public static Object quoteIfString(Object obj) {
		return (obj instanceof String ? quote((String) obj) : obj);
	}

	/**
	 * Unqualify a string qualified by a '.' dot character. For example,
	 * "this.name.is.qualified", returns "qualified".
	 * @param qualifiedName the qualified name
	 */
	public static String unqualify(String qualifiedName) {
		return unqualify(qualifiedName, '.');
	}

	/**
	 * Unqualify a string qualified by a separator character. For example,
	 * "this:name:is:qualified" returns "qualified" if using a ':' separator.
	 * @param qualifiedName the qualified name
	 * @param separator the separator
	 */
	public static String unqualify(String qualifiedName, char separator) {
		return qualifiedName.substring(qualifiedName.lastIndexOf(separator) + 1);
	}

	/**
	 * Capitalize a <code>String</code>, changing the first letter to
	 * upper case as per {@link Character#toUpperCase(char)}.
	 * No other letters are changed.
	 * @param str the String to capitalize, may be <code>null</code>
	 * @return the capitalized String, <code>null</code> if null
	 */
	public static String capitalize(String str) {
		return changeFirstCharacterCase(str, true);
	}

	/**
	 * Uncapitalize a <code>String</code>, changing the first letter to
	 * lower case as per {@link Character#toLowerCase(char)}.
	 * No other letters are changed.
	 * @param str the String to uncapitalize, may be <code>null</code>
	 * @return the uncapitalized String, <code>null</code> if null
	 */
	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;
		}
		StringBuffer buf = new StringBuffer(str.length());
		if (capitalize) {
			buf.append(Character.toUpperCase(str.charAt(0)));
		}
		else {
			buf.append(Character.toLowerCase(str.charAt(0)));
		}
		buf.append(str.substring(1));
		return buf.toString();
	}

	/**
	 * Extract the filename from the given path,
	 * e.g. "mypath/myfile.txt" -> "myfile.txt".
	 * @param path the file path (may be <code>null</code>)
	 * @return the extracted filename, or <code>null</code> if none
	 */
	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);
	}

	/**
	 * Extract the filename extension from the given path,
	 * e.g. "mypath/myfile.txt" -> "txt".
	 * @param path the file path (may be <code>null</code>)
	 * @return the extracted filename extension, or <code>null</code> if none
	 */
	public static String getFilenameExtension(String path) {
		if (path == null) {
			return null;
		}
		int sepIndex = path.lastIndexOf(EXTENSION_SEPARATOR);
		return (sepIndex != -1 ? path.substring(sepIndex + 1) : null);
	}

	/**
	 * Strip the filename extension from the given path,
	 * e.g. "mypath/myfile.txt" -> "mypath/myfile".
	 * @param path the file path (may be <code>null</code>)
	 * @return the path with stripped filename extension,
	 * or <code>null</code> if none
	 */
	public static String stripFilenameExtension(String path) {
		if (path == null) {
			return null;
		}
		int sepIndex = path.lastIndexOf(EXTENSION_SEPARATOR);
		return (sepIndex != -1 ? path.substring(0, sepIndex) : path);
	}

	/**
	 * Apply the given relative path to the given path,
	 * assuming standard Java folder separation (i.e. "/" separators);
	 * @param path the path to start from (usually a full file path)
	 * @param relativePath the relative path to apply
	 * (relative to the full file path above)
	 * @return the full file path that results from applying the relative path
	 */
	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 += FOLDER_SEPARATOR;
			}
			return newPath + relativePath;
		}
		else {
			return relativePath;
		}
	}

	/**
	 * Normalize the path by suppressing sequences like "path/.." and
	 * inner simple dots.
	 * <p>The result is convenient for path comparison. For other uses,
	 * notice that Windows separators ("\") are replaced by simple slashes.
	 * @param path the original path
	 * @return the normalized path
	 */
	public static String cleanPath(String path) {
		String pathToUse = replace(path, WINDOWS_FOLDER_SEPARATOR, FOLDER_SEPARATOR);

		// Strip prefix from path to analyze, to not treat it as part of the
		// first path element. This is necessary to correctly parse paths like
		// "file:core/../core/io/Resource.class", where the ".." should just
		// strip the first "core" directory while keeping the "file:" prefix.
		int prefixIndex = pathToUse.indexOf(":");
		String prefix = "";
		if (prefixIndex != -1) {
			prefix = pathToUse.substring(0, prefixIndex + 1);
			pathToUse = pathToUse.substring(prefixIndex + 1);
		}

		String[] pathArray = delimitedListToStringArray(pathToUse, FOLDER_SEPARATOR);
		List pathElements = new LinkedList();
		int tops = 0;

		for (int i = pathArray.length - 1; i >= 0; i--) {
			if (CURRENT_PATH.equals(pathArray[i])) {
				// Points to current directory - drop it.
			}
			else if (TOP_PATH.equals(pathArray[i])) {
				// Registering top path found.
				tops++;
			}
			else {
				if (tops > 0) {
					// Merging path element with corresponding to top path.
					tops--;
				}
				else {
					// Normal path element found.
					pathElements.add(0, pathArray[i]);
				}
			}
		}

		// Remaining top paths need to be retained.
		for (int i = 0; i < tops; i++) {
			pathElements.add(0, TOP_PATH);
		}

		return prefix + collectionToDelimitedString(pathElements, FOLDER_SEPARATOR);
	}

	/**
	 * Compare two paths after normalization of them.
	 * @param path1 First path for comparizon
	 * @param path2 Second path for comparizon
	 * @return whether the two paths are equivalent after normalization
	 */
	public static boolean pathEquals(String path1, String path2) {
		return cleanPath(path1).equals(cleanPath(path2));
	}

	/**
	 * Parse the given locale string into a <code>java.util.Locale</code>.
	 * This is the inverse operation of Locale's <code>toString</code>.
	 * @param localeString the locale string, following
	 * <code>java.util.Locale</code>'s toString format ("en", "en_UK", etc).
	 * Also accepts spaces as separators, as alternative to underscores.
	 * @return a corresponding Locale instance
	 */
	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] : "");
		String variant = (parts.length > 2 ? parts[2] : "");
		return (language.length() > 0 ? new Locale(language, country, variant) : null);
	}


	//---------------------------------------------------------------------
	// Convenience methods for working with String arrays
	//---------------------------------------------------------------------

	/**
	 * Append the given String to the given String array, returning a new array
	 * consisting of the input array contents plus the given String.
	 * @param array the array to append to (can be <code>null</code>)
	 * @param str the String to append
	 * @return the new array (never <code>null</code>)
	 */
	public static String[] addStringToArray(String[] array, String str) {
		if (ObjectUtils.isEmpty(array)) {
			return new String[] {str};
		}
		String[] newArr = new String[array.length + 1];
		System.arraycopy(array, 0, newArr, 0, array.length);
		newArr[array.length] = str;
		return newArr;
	}

	/**
	 * Concatenate the given String arrays into one,
	 * with overlapping array elements included twice.
	 * <p>The order of elements in the original arrays is preserved.
	 * @param array1 the first array (can be <code>null</code>)
	 * @param array2 the second array (can be <code>null</code>)
	 * @return the new array (<code>null</code> if both given arrays were <code>null</code>)
	 */
	public static String[] concatenateStringArrays(String[] array1, String[] array2) {
		if (ObjectUtils.isEmpty(array1)) {
			return array2;
		}
		if (ObjectUtils.isEmpty(array2)) {
			return array1;
		}
		String[] newArr = new String[array1.length + array2.length];
		System.arraycopy(array1, 0, newArr, 0, array1.length);
		System.arraycopy(array2, 0, newArr, array1.length, array2.length);
		return newArr;
	}

	/**
	 * Merge the given String arrays into one, with overlapping
	 * array elements only included once.
	 * <p>The order of elements in the original arrays is preserved
	 * (with the exception of overlapping elements, which are only
	 * included on their first occurence).
	 * @param array1 the first array (can be <code>null</code>)
	 * @param array2 the second array (can be <code>null</code>)
	 * @return the new array (<code>null</code> if both given arrays were <code>null</code>)
	 */
	public static String[] mergeStringArrays(String[] array1, String[] array2) {
		if (ObjectUtils.isEmpty(array1)) {
			return array2;
		}
		if (ObjectUtils.isEmpty(array2)) {
			return array1;
		}
		List result = new ArrayList();
		result.addAll(Arrays.asList(array1));
		for (int i = 0; i < array2.length; i++) {
			String str = array2[i];
			if (!result.contains(str)) {
				result.add(str);
			}
		}