/*
* Copyright 2002-2011 the original author or authors.
*
* 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 com.mcxiaoke.minicat.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;
/**
* Miscellaneous {@link String} utility methods.
* <p/>
* <p/>
* Mainly for internal use within the framework; consider <a
* href="http://jakarta.apache.org/commons/lang/">Jakarta's Commons Lang</a> for
* a more comprehensive suite of String utilities.
* <p/>
* <p/>
* This class delivers some simple functionality that should really be provided
* by the core Java <code>String</code> and {@link StringBuilder} classes, such
* as the ability to {@link #replace} all occurrences of a given substring in a
* target string. It also provides easy-to-use methods to convert between
* delimited strings, such as CSV strings, and collections and arrays.
*
* @author Rod Johnson
* @author Juergen Hoeller
* @author Keith Donald
* @author Rob Harrop
* @author Rick Evans
* @author Arjen Poutsma
* @since 1.0
*/
public abstract class StringUtils {
private static final String FOLDER_SEPARATOR = "/";
private static final char EXTENSION_SEPARATOR = '.';
// ---------------------------------------------------------------------
// General convenience methods for working with Strings
// ---------------------------------------------------------------------
/**
* Check that the given CharSequence is neither <code>null</code> nor of
* length 0. Note: Will return <code>true</code> for a CharSequence that
* purely consists of whitespace.
* <p/>
* <p/>
* <pre>
* StringUtils.hasLength(null) = false
* StringUtils.hasLength("") = false
* StringUtils.hasLength(" ") = true
* StringUtils.hasLength("Hello") = true
* </pre>
*
* @param str the CharSequence to check (may be <code>null</code>)
* @return <code>true</code> if the CharSequence is not null and has length
* @see #hasText(String)
*/
public static boolean hasLength(CharSequence str) {
return (str != null && str.length() > 0);
}
/**
* Check that the given String is neither <code>null</code> nor of length 0.
* Note: Will return <code>true</code> for a String that purely consists of
* whitespace.
*
* @param str the String to check (may be <code>null</code>)
* @return <code>true</code> if the String is not null and has length
* @see #hasLength(CharSequence)
*/
public static boolean hasLength(String str) {
return hasLength((CharSequence) str);
}
/**
* Check whether the given CharSequence has actual text. More specifically,
* returns <code>true</code> if the string not <code>null</code>, its length
* is greater than 0, and it contains at least one non-whitespace character.
* <p/>
* <p/>
* <pre>
* StringUtils.hasText(null) = false
* StringUtils.hasText("") = false
* StringUtils.hasText(" ") = false
* StringUtils.hasText("12345") = true
* StringUtils.hasText(" 12345 ") = true
* </pre>
*
* @param str the CharSequence to check (may be <code>null</code>)
* @return <code>true</code> if the CharSequence is not <code>null</code>,
* its length is greater than 0, and it does not contain whitespace
* only
* @see java.lang.Character#isWhitespace
*/
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;
}
/**
* Check whether the given String has actual text. More specifically,
* returns <code>true</code> if the string not <code>null</code>, its length
* is greater than 0, and it contains at least one non-whitespace character.
*
* @param str the String to check (may be <code>null</code>)
* @return <code>true</code> if the String is not <code>null</code>, its
* length is greater than 0, and it does not contain whitespace only
* @see #hasText(CharSequence)
*/
public static boolean hasText(String str) {
return hasText((CharSequence) str);
}
/**
* Check whether the given CharSequence contains any whitespace characters.
*
* @param str the CharSequence to check (may be <code>null</code>)
* @return <code>true</code> if the CharSequence is not empty and contains
* at least 1 whitespace character
* @see java.lang.Character#isWhitespace
*/
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;
}
/**
* Check whether the given String contains any whitespace characters.
*
* @param str the String to check (may be <code>null</code>)
* @return <code>true</code> if the String is not empty and contains at
* least 1 whitespace character
* @see #containsWhitespace(CharSequence)
*/
public static boolean containsWhitespace(String str) {
return containsWhitespace((CharSequence) str);
}
/**
* Trim leading and trailing whitespace from the given String.
*
* @param str the String to check
* @return the trimmed String
* @see java.lang.Character#isWhitespace
*/
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();
}
/**
* Trim <i>all</i> whitespace from the given String: leading, trailing, and
* inbetween characters.
*
* @param str the String to check
* @return the trimmed String
* @see java.lang.Character#isWhitespace
*/
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();
}
/**
* Trim leading whitespace from the given String.
*
* @param str the String to check
* @return the trimmed String
* @see java.lang.Character#isWhitespace
*/
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();
}
/**
* Trim trailing whitespace from the given String.
*
* @param str the String to check
* @return the trimmed String
* @see java.lang.Character#isWhitespace
*/
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();
}
/**
* Trim all occurences of the supplied leading character from the given
* String.
*
* @param str the String to check
* @param leadingCharacter the leading character to be trimmed
* @return the trimmed String
*/
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();
}
/**
* Trim all occurences of the supplied trailing character from the given
* String.
*
* @param str the String to check
* @param trailingCharacter the trailing character to be trimmed
* @return the trimmed String
*/
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();
}
/**
* Test if the given String starts with the specified prefix, ignoring
* upper/lower case.
*
* @param str the String to check
* @param prefix the prefix to look for
* @see java.lang.String#startsWith
*/
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);
}
/**
* Test if the given String ends with the specified suffix, ignoring
* upper/lower case.
*
* @param str the String to check
* @param suffix the suffix to look for
* @see java.lang.String#endsWith
*/
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);
}
/**
* Test whether the given string matches the given substring at the given
* index.
*
* @param str the original string (or StringBuilder)
* @param index the index in the original string to check matching against
* @param substring the substring to match at the given index
*/
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;
}
/**
* Count the occurrences of the substring in string s.
*
* @param str string to search in. Return 0 if this is null.
* @param sub string to search for. Return 0 if this is null.
*/
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;
}
/**
* Replace all occurences of a substring within a string with another
* string.
*
* @param inString String to examine
* @param oldPattern String to replace
* @param newPattern String to insert
* @return a String with the replacements
*/
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; // our position in the old string
int index = inString.indexOf(oldPattern);
// the index of an occurrence we've found, or -1
int patLen = oldPattern.length();
while (index >= 0) {
sb.append(inString.substring(pos, index));
sb.append(newPattern);
pos = index + patLen;
index = inString.indexOf(oldPattern, pos);
}
sb.append(inString.substring(pos));
// remember to append any characters to the right of a match
return sb.toString();
}
/**
* Delete all occurrences of the given substring.
*
* @param inString the original String
* @param pattern the pattern to delete all occurrences of
* @return the resulting String
*/
public static String delete(String inString, String pattern) {
return replace(inString, pattern, "");
}
/**
* Delete any character in a given String.
*
* @param inString the original String
* @param charsToDelete a set of characters to delete. E.g. "az\n" will delete 'a's,
* 'z's and new lines.
* @return the resulting String
*/
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();
}
// ---------------------------------------------------------------------
// 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;
}
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();
}
/**
* 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 extIndex = path.lastIndexOf(EXTENSION_SEPARATOR);
if (extIndex == -1) {
return null;
}
int folderIndex = path.lastIndexOf(FOLDER_SEPARATOR);
if (folderIndex > extIndex) {
return null;
}
return path.substring(extIndex + 1);
}
/**
* 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 extIndex = path.lastIndexOf(EXTENSION_SEPARATOR);
if (extIndex == -1) {
return path;
}
int folderIndex = path.lastIndexOf(FOLDER_SEPARATOR);
if (folderIndex > extIndex) {
return path;
}
return path.substring(0, extIndex);
}
/**
* Apply the given relative path to the given path, assuming standard Java
* folder separation (i.e. "/" separators).
*
* @param path the path to check 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;
}
}
/**
* Parse the given <code>localeString</code> value into a {@link Locale}.
* <p/>
* This is the inverse operation of {@link Locale#toString Locale's
* toString}.
*
* @param localeString the locale string, following <code>Locale's</code>
* <code>toString()</code> format ("en", "en_UK", etc); also
* accepts spaces as separators, as an alternative to underscores
* @return a corresponding <code>Locale</code> instance
*/
public static Locale parseLocaleString(String localeString) {
for (int i = 0; i < localeString.length(); i++) {
char ch = localeString.charAt(i);
if (ch != '_' && ch != ' ' && !Character.isLetterOrDigit(ch)) {
throw new IllegalArgumentException("Locale value \""
+ localeString + "\" contains invalid characters");
}
}
String[] parts = tokenizeToStringArray(localeString, "_ ", false, false);
String language = (parts.length > 0 ? parts[0] : "");
String country = (parts.length > 1 ? parts[1] : "");
String variant = "";
if (parts.length >= 2) {
// There is definitely a variant, and it is everything after the
// country
// code sans the separator between the country code and the variant.
int endIndexOfCountryCode = localeString.indexOf(country)
+ country.length();
// Strip off any leading '_' and whitespace, what's left is the
// variant.
variant = trimLeadingWhitespace(localeString
.substring(endIndexOfCountryCode));
if (variant.startsWith("_")) {
variant = trimLeadingCharacter(variant, '_');
}
}
return (language.length() > 0 ? new Locale(language, country, variant)
: null);
}
/**
* Determine the RFC 3066 compliant language tag, as used for the HTTP
* "Accept-Language" header.
*
* @param locale the Locale to transform to a language tag
* @return the RFC 3066 compliant language tag as String
*/
public static String toLanguageTag(Locale locale) {
return locale.getLanguage()
+ (hasText(locale.getCountry()) ? "-" + locale.getCountry()
: "");
}
/**
* Copy the given Collection into a String array. The Collection must
* contain String elements only.
*
* @param collection the Collection to copy
* @return the String array (<code>null</code> if the passed-in Collection
* was <code>null</code>)
*/
public static String[] toStringArray(Collection<String> collection) {
if (collection == null) {
return null;
}
return collection.toArray(new String[collection.size()]);
}
/**
* Copy the given Enumeration into a String array. The Enumeration must
* contain String elements only.
*
* @param enumeration the Enumeration to copy
* @return the String array (<code>null</code> if the passed-in Enumeration
* was <code>null</code>)
*/
public static String[] toStringArray(Enumeration<String> enumeration) {
if (enumeration == null) {
return null;
}
List<String> list = Collections.list(enumeration);
return list.toArray(new String[list.size()]);
}
/**
* Split a String at the first occurrence of the delimiter. Does not include
* the delimiter in the result.
*
* @param toSplit the string to split
* @param delimiter to split the string up with
* @return a two element array with index 0 being before the delimiter, and
* index 1 being after the delimiter (neither element includes the
* delimiter); or <code>null</code> if the delimiter wasn't found in
* the given input String
*/
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};
}
/**
* Tokenize the given String into a String array via a StringTokenizer.
* Trims tokens and omits empty tokens.
* <p/>
* The given delimiters string is supposed to consist of any number of
* delimiter characters. Each of those characters can be used to separate
* tokens. A delimiter is always a single character; for multi-character
* delimiters, consider using <code>delimitedListToStringArray</code>
*
* @param str the String to tokenize
* @param delimiters the delimiter characters, assembled as String (each of those
* characters is individually considered as delimiter).
* @return an array of the tokens
* @see java.util.StringTokenizer
* @see java.lang.String#trim()
* @see #delimitedListToStringArray
*/
public static String[] tokenizeToStringArray(String str, String delimiters) {
return tokenizeToStringArray(str, delimiters, true, true);
}
/**
* Tokenize the given String into a String array via a StringTokenizer.
* <p/>
* The given delimiters string is supposed to consist of any number of
* delimiter characters. Each of those characters can be used to separate
* tokens. A delimiter is always a single character; for multi-character
* delimiters, consider using <code>delimitedListToStringArray</code>
*
* @param str the String to tokenize
* @param delimiters the delimiter characters, assembled as String (each of those
* characters is individually considered as delimiter)
* @param trimTokens trim the tokens via String's <code>trim</code>
* @param ignoreEmptyTokens omit empty tokens from the result array (only applies to
* tokens that are empty after trimming; StringTokenizer will not
* consider subsequent delimiters as token in the first place).
* @return an array of the tokens (<code>null</code> if the input String was
* <code>null</code>)
* @see java.util.StringTokenizer
* @see java.lang.String#trim()
* @see #delimitedListToStringArray
*/
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);
}
/**
* Take a String which is a delimited list and convert it to a String array.
* <p/>
* A single delimiter can consists of more than one character: It will still
* be considered as single delimiter string, rather than as bunch of
* potential delimiter characters - in contrast to
* <code>tokenizeToStringArray</code>.
*
* @param str the input String
* @param delimiter the delimiter between elements (this is a single delimiter,
* rather than a bunch individual delimiter characters)
* @return an array of the tokens in the list
* @see #tokenizeToStringArray
*/
public static String[] delimitedListToStringArray(String str,
String delimiter) {
return delimitedListToStringArray(str, delimiter, null);
}
/**
* Take a String which is a delimited list and convert it to a String array.
* <p/>
* A single delimiter can consists of more than one character: It will still
* be considered as single delimiter string, rather than as bunch of
* potential delimiter characters - in contrast to
* <code>tokenizeToStringArray</code>.
*
* @param str the input String
* @param delimiter the delimiter between elements (this is a single delimiter,
* rather than a bunch individual delimiter characters)
* @param charsToDelete a set of characters to delete. Useful for deleting unwanted
* line breaks: e.g. "\r\n\f" will delete all new lines and line
* feeds in a String.
* @return an array of the tokens in the list
* @see #tokenizeToStringArray
*/
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()) {
// Add rest of String, but not in case of empty input.
result.add(deleteAny(str.substring(pos), charsToDelete));
}
}
return toStringArray(result);
}
/**
* Convert a CSV list into an array of Strings.
*
* @param str the input String
* @return an array of Strings, or the empty array in case of empty input
*/
public static String[] commaDelimitedListToStringArray(String str) {
return delimitedListToStringArray(str, ",");
}
/**
* Convenience method to convert a CSV string list to a set. Note that this
* will suppress duplicates.
*
* @param str the input String
* @return a Set of String entries in the list
*/
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;
}
}