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| author | Gerald Barker <geraldbarker@gmail.com> | 2011-09-02 23:19:51 +0100 |
|---|---|---|
| committer | Gerald Barker <geraldbarker@gmail.com> | 2011-09-02 23:19:51 +0100 |
| commit | 53936c7ee6654a525075b03e1b4c8ddbfbcd4ef5 (patch) | |
| tree | 41154be6daecad1b4483223d72920e0a290024ef /src/org/apache/commons/lang3/CharUtils.java | |
| parent | afbe8c5164e1157e38e0f8c4b28942cbd9fe3d41 (diff) | |
| download | cgeo-53936c7ee6654a525075b03e1b4c8ddbfbcd4ef5.zip cgeo-53936c7ee6654a525075b03e1b4c8ddbfbcd4ef5.tar.gz cgeo-53936c7ee6654a525075b03e1b4c8ddbfbcd4ef5.tar.bz2 | |
First commit of Apache Commons String & Date functions and required, and
refactor of code to use them.
Diffstat (limited to 'src/org/apache/commons/lang3/CharUtils.java')
| -rw-r--r-- | src/org/apache/commons/lang3/CharUtils.java | 539 |
1 files changed, 539 insertions, 0 deletions
diff --git a/src/org/apache/commons/lang3/CharUtils.java b/src/org/apache/commons/lang3/CharUtils.java new file mode 100644 index 0000000..4a6f188 --- /dev/null +++ b/src/org/apache/commons/lang3/CharUtils.java @@ -0,0 +1,539 @@ +/*
+ * 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 org.apache.commons.lang3;
+
+/**
+ * <p>Operations on char primitives and Character objects.</p>
+ *
+ * <p>This class tries to handle {@code null} input gracefully.
+ * An exception will not be thrown for a {@code null} input.
+ * Each method documents its behaviour in more detail.</p>
+ *
+ * <p>#ThreadSafe#</p>
+ * @since 2.1
+ * @version $Id$
+ */
+public class CharUtils {
+
+ private static final String[] CHAR_STRING_ARRAY = new String[128];
+
+ /**
+ * {@code \u000a} linefeed LF ('\n').
+ *
+ * @see <a href="http://java.sun.com/docs/books/jls/third_edition/html/lexical.html#101089">JLF: Escape Sequences
+ * for Character and String Literals</a>
+ * @since 2.2
+ */
+ public static final char LF = '\n';
+
+ /**
+ * {@code \u000d} carriage return CR ('\r').
+ *
+ * @see <a href="http://java.sun.com/docs/books/jls/third_edition/html/lexical.html#101089">JLF: Escape Sequences
+ * for Character and String Literals</a>
+ * @since 2.2
+ */
+ public static final char CR = '\r';
+
+
+ static {
+ for (char c = 0; c < CHAR_STRING_ARRAY.length; c++) {
+ CHAR_STRING_ARRAY[c] = String.valueOf(c);
+ }
+ }
+
+ /**
+ * <p>{@code CharUtils} instances should NOT be constructed in standard programming.
+ * Instead, the class should be used as {@code CharUtils.toString('c');}.</p>
+ *
+ * <p>This constructor is public to permit tools that require a JavaBean instance
+ * to operate.</p>
+ */
+ public CharUtils() {
+ super();
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * <p>Converts the character to a Character.</p>
+ *
+ * <p>For ASCII 7 bit characters, this uses a cache that will return the
+ * same Character object each time.</p>
+ *
+ * <pre>
+ * CharUtils.toCharacterObject(' ') = ' '
+ * CharUtils.toCharacterObject('A') = 'A'
+ * </pre>
+ *
+ * @deprecated Java 5 introduced {@link Character#valueOf(char)} which caches chars 0 through 127.
+ * @param ch the character to convert
+ * @return a Character of the specified character
+ */
+ @Deprecated
+ public static Character toCharacterObject(char ch) {
+ return Character.valueOf(ch);
+ }
+
+ /**
+ * <p>Converts the String to a Character using the first character, returning
+ * null for empty Strings.</p>
+ *
+ * <p>For ASCII 7 bit characters, this uses a cache that will return the
+ * same Character object each time.</p>
+ *
+ * <pre>
+ * CharUtils.toCharacterObject(null) = null
+ * CharUtils.toCharacterObject("") = null
+ * CharUtils.toCharacterObject("A") = 'A'
+ * CharUtils.toCharacterObject("BA") = 'B'
+ * </pre>
+ *
+ * @param str the character to convert
+ * @return the Character value of the first letter of the String
+ */
+ public static Character toCharacterObject(String str) {
+ if (StringUtils.isEmpty(str)) {
+ return null;
+ }
+ return Character.valueOf(str.charAt(0));
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * <p>Converts the Character to a char throwing an exception for {@code null}.</p>
+ *
+ * <pre>
+ * CharUtils.toChar(' ') = ' '
+ * CharUtils.toChar('A') = 'A'
+ * CharUtils.toChar(null) throws IllegalArgumentException
+ * </pre>
+ *
+ * @param ch the character to convert
+ * @return the char value of the Character
+ * @throws IllegalArgumentException if the Character is null
+ */
+ public static char toChar(Character ch) {
+ if (ch == null) {
+ throw new IllegalArgumentException("The Character must not be null");
+ }
+ return ch.charValue();
+ }
+
+ /**
+ * <p>Converts the Character to a char handling {@code null}.</p>
+ *
+ * <pre>
+ * CharUtils.toChar(null, 'X') = 'X'
+ * CharUtils.toChar(' ', 'X') = ' '
+ * CharUtils.toChar('A', 'X') = 'A'
+ * </pre>
+ *
+ * @param ch the character to convert
+ * @param defaultValue the value to use if the Character is null
+ * @return the char value of the Character or the default if null
+ */
+ public static char toChar(Character ch, char defaultValue) {
+ if (ch == null) {
+ return defaultValue;
+ }
+ return ch.charValue();
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * <p>Converts the String to a char using the first character, throwing
+ * an exception on empty Strings.</p>
+ *
+ * <pre>
+ * CharUtils.toChar("A") = 'A'
+ * CharUtils.toChar("BA") = 'B'
+ * CharUtils.toChar(null) throws IllegalArgumentException
+ * CharUtils.toChar("") throws IllegalArgumentException
+ * </pre>
+ *
+ * @param str the character to convert
+ * @return the char value of the first letter of the String
+ * @throws IllegalArgumentException if the String is empty
+ */
+ public static char toChar(String str) {
+ if (StringUtils.isEmpty(str)) {
+ throw new IllegalArgumentException("The String must not be empty");
+ }
+ return str.charAt(0);
+ }
+
+ /**
+ * <p>Converts the String to a char using the first character, defaulting
+ * the value on empty Strings.</p>
+ *
+ * <pre>
+ * CharUtils.toChar(null, 'X') = 'X'
+ * CharUtils.toChar("", 'X') = 'X'
+ * CharUtils.toChar("A", 'X') = 'A'
+ * CharUtils.toChar("BA", 'X') = 'B'
+ * </pre>
+ *
+ * @param str the character to convert
+ * @param defaultValue the value to use if the Character is null
+ * @return the char value of the first letter of the String or the default if null
+ */
+ public static char toChar(String str, char defaultValue) {
+ if (StringUtils.isEmpty(str)) {
+ return defaultValue;
+ }
+ return str.charAt(0);
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * <p>Converts the character to the Integer it represents, throwing an
+ * exception if the character is not numeric.</p>
+ *
+ * <p>This method coverts the char '1' to the int 1 and so on.</p>
+ *
+ * <pre>
+ * CharUtils.toIntValue('3') = 3
+ * CharUtils.toIntValue('A') throws IllegalArgumentException
+ * </pre>
+ *
+ * @param ch the character to convert
+ * @return the int value of the character
+ * @throws IllegalArgumentException if the character is not ASCII numeric
+ */
+ public static int toIntValue(char ch) {
+ if (isAsciiNumeric(ch) == false) {
+ throw new IllegalArgumentException("The character " + ch + " is not in the range '0' - '9'");
+ }
+ return ch - 48;
+ }
+
+ /**
+ * <p>Converts the character to the Integer it represents, throwing an
+ * exception if the character is not numeric.</p>
+ *
+ * <p>This method coverts the char '1' to the int 1 and so on.</p>
+ *
+ * <pre>
+ * CharUtils.toIntValue('3', -1) = 3
+ * CharUtils.toIntValue('A', -1) = -1
+ * </pre>
+ *
+ * @param ch the character to convert
+ * @param defaultValue the default value to use if the character is not numeric
+ * @return the int value of the character
+ */
+ public static int toIntValue(char ch, int defaultValue) {
+ if (isAsciiNumeric(ch) == false) {
+ return defaultValue;
+ }
+ return ch - 48;
+ }
+
+ /**
+ * <p>Converts the character to the Integer it represents, throwing an
+ * exception if the character is not numeric.</p>
+ *
+ * <p>This method coverts the char '1' to the int 1 and so on.</p>
+ *
+ * <pre>
+ * CharUtils.toIntValue('3') = 3
+ * CharUtils.toIntValue(null) throws IllegalArgumentException
+ * CharUtils.toIntValue('A') throws IllegalArgumentException
+ * </pre>
+ *
+ * @param ch the character to convert, not null
+ * @return the int value of the character
+ * @throws IllegalArgumentException if the Character is not ASCII numeric or is null
+ */
+ public static int toIntValue(Character ch) {
+ if (ch == null) {
+ throw new IllegalArgumentException("The character must not be null");
+ }
+ return toIntValue(ch.charValue());
+ }
+
+ /**
+ * <p>Converts the character to the Integer it represents, throwing an
+ * exception if the character is not numeric.</p>
+ *
+ * <p>This method coverts the char '1' to the int 1 and so on.</p>
+ *
+ * <pre>
+ * CharUtils.toIntValue(null, -1) = -1
+ * CharUtils.toIntValue('3', -1) = 3
+ * CharUtils.toIntValue('A', -1) = -1
+ * </pre>
+ *
+ * @param ch the character to convert
+ * @param defaultValue the default value to use if the character is not numeric
+ * @return the int value of the character
+ */
+ public static int toIntValue(Character ch, int defaultValue) {
+ if (ch == null) {
+ return defaultValue;
+ }
+ return toIntValue(ch.charValue(), defaultValue);
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * <p>Converts the character to a String that contains the one character.</p>
+ *
+ * <p>For ASCII 7 bit characters, this uses a cache that will return the
+ * same String object each time.</p>
+ *
+ * <pre>
+ * CharUtils.toString(' ') = " "
+ * CharUtils.toString('A') = "A"
+ * </pre>
+ *
+ * @param ch the character to convert
+ * @return a String containing the one specified character
+ */
+ public static String toString(char ch) {
+ if (ch < 128) {
+ return CHAR_STRING_ARRAY[ch];
+ }
+ return new String(new char[] {ch});
+ }
+
+ /**
+ * <p>Converts the character to a String that contains the one character.</p>
+ *
+ * <p>For ASCII 7 bit characters, this uses a cache that will return the
+ * same String object each time.</p>
+ *
+ * <p>If {@code null} is passed in, {@code null} will be returned.</p>
+ *
+ * <pre>
+ * CharUtils.toString(null) = null
+ * CharUtils.toString(' ') = " "
+ * CharUtils.toString('A') = "A"
+ * </pre>
+ *
+ * @param ch the character to convert
+ * @return a String containing the one specified character
+ */
+ public static String toString(Character ch) {
+ if (ch == null) {
+ return null;
+ }
+ return toString(ch.charValue());
+ }
+
+ //--------------------------------------------------------------------------
+ /**
+ * <p>Converts the string to the Unicode format '\u0020'.</p>
+ *
+ * <p>This format is the Java source code format.</p>
+ *
+ * <pre>
+ * CharUtils.unicodeEscaped(' ') = "\u0020"
+ * CharUtils.unicodeEscaped('A') = "\u0041"
+ * </pre>
+ *
+ * @param ch the character to convert
+ * @return the escaped Unicode string
+ */
+ public static String unicodeEscaped(char ch) {
+ if (ch < 0x10) {
+ return "\\u000" + Integer.toHexString(ch);
+ } else if (ch < 0x100) {
+ return "\\u00" + Integer.toHexString(ch);
+ } else if (ch < 0x1000) {
+ return "\\u0" + Integer.toHexString(ch);
+ }
+ return "\\u" + Integer.toHexString(ch);
+ }
+
+ /**
+ * <p>Converts the string to the Unicode format '\u0020'.</p>
+ *
+ * <p>This format is the Java source code format.</p>
+ *
+ * <p>If {@code null} is passed in, {@code null} will be returned.</p>
+ *
+ * <pre>
+ * CharUtils.unicodeEscaped(null) = null
+ * CharUtils.unicodeEscaped(' ') = "\u0020"
+ * CharUtils.unicodeEscaped('A') = "\u0041"
+ * </pre>
+ *
+ * @param ch the character to convert, may be null
+ * @return the escaped Unicode string, null if null input
+ */
+ public static String unicodeEscaped(Character ch) {
+ if (ch == null) {
+ return null;
+ }
+ return unicodeEscaped(ch.charValue());
+ }
+
+ //--------------------------------------------------------------------------
+ /**
+ * <p>Checks whether the character is ASCII 7 bit.</p>
+ *
+ * <pre>
+ * CharUtils.isAscii('a') = true
+ * CharUtils.isAscii('A') = true
+ * CharUtils.isAscii('3') = true
+ * CharUtils.isAscii('-') = true
+ * CharUtils.isAscii('\n') = true
+ * CharUtils.isAscii('©') = false
+ * </pre>
+ *
+ * @param ch the character to check
+ * @return true if less than 128
+ */
+ public static boolean isAscii(char ch) {
+ return ch < 128;
+ }
+
+ /**
+ * <p>Checks whether the character is ASCII 7 bit printable.</p>
+ *
+ * <pre>
+ * CharUtils.isAsciiPrintable('a') = true
+ * CharUtils.isAsciiPrintable('A') = true
+ * CharUtils.isAsciiPrintable('3') = true
+ * CharUtils.isAsciiPrintable('-') = true
+ * CharUtils.isAsciiPrintable('\n') = false
+ * CharUtils.isAsciiPrintable('©') = false
+ * </pre>
+ *
+ * @param ch the character to check
+ * @return true if between 32 and 126 inclusive
+ */
+ public static boolean isAsciiPrintable(char ch) {
+ return ch >= 32 && ch < 127;
+ }
+
+ /**
+ * <p>Checks whether the character is ASCII 7 bit control.</p>
+ *
+ * <pre>
+ * CharUtils.isAsciiControl('a') = false
+ * CharUtils.isAsciiControl('A') = false
+ * CharUtils.isAsciiControl('3') = false
+ * CharUtils.isAsciiControl('-') = false
+ * CharUtils.isAsciiControl('\n') = true
+ * CharUtils.isAsciiControl('©') = false
+ * </pre>
+ *
+ * @param ch the character to check
+ * @return true if less than 32 or equals 127
+ */
+ public static boolean isAsciiControl(char ch) {
+ return ch < 32 || ch == 127;
+ }
+
+ /**
+ * <p>Checks whether the character is ASCII 7 bit alphabetic.</p>
+ *
+ * <pre>
+ * CharUtils.isAsciiAlpha('a') = true
+ * CharUtils.isAsciiAlpha('A') = true
+ * CharUtils.isAsciiAlpha('3') = false
+ * CharUtils.isAsciiAlpha('-') = false
+ * CharUtils.isAsciiAlpha('\n') = false
+ * CharUtils.isAsciiAlpha('©') = false
+ * </pre>
+ *
+ * @param ch the character to check
+ * @return true if between 65 and 90 or 97 and 122 inclusive
+ */
+ public static boolean isAsciiAlpha(char ch) {
+ return (ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z');
+ }
+
+ /**
+ * <p>Checks whether the character is ASCII 7 bit alphabetic upper case.</p>
+ *
+ * <pre>
+ * CharUtils.isAsciiAlphaUpper('a') = false
+ * CharUtils.isAsciiAlphaUpper('A') = true
+ * CharUtils.isAsciiAlphaUpper('3') = false
+ * CharUtils.isAsciiAlphaUpper('-') = false
+ * CharUtils.isAsciiAlphaUpper('\n') = false
+ * CharUtils.isAsciiAlphaUpper('©') = false
+ * </pre>
+ *
+ * @param ch the character to check
+ * @return true if between 65 and 90 inclusive
+ */
+ public static boolean isAsciiAlphaUpper(char ch) {
+ return ch >= 'A' && ch <= 'Z';
+ }
+
+ /**
+ * <p>Checks whether the character is ASCII 7 bit alphabetic lower case.</p>
+ *
+ * <pre>
+ * CharUtils.isAsciiAlphaLower('a') = true
+ * CharUtils.isAsciiAlphaLower('A') = false
+ * CharUtils.isAsciiAlphaLower('3') = false
+ * CharUtils.isAsciiAlphaLower('-') = false
+ * CharUtils.isAsciiAlphaLower('\n') = false
+ * CharUtils.isAsciiAlphaLower('©') = false
+ * </pre>
+ *
+ * @param ch the character to check
+ * @return true if between 97 and 122 inclusive
+ */
+ public static boolean isAsciiAlphaLower(char ch) {
+ return ch >= 'a' && ch <= 'z';
+ }
+
+ /**
+ * <p>Checks whether the character is ASCII 7 bit numeric.</p>
+ *
+ * <pre>
+ * CharUtils.isAsciiNumeric('a') = false
+ * CharUtils.isAsciiNumeric('A') = false
+ * CharUtils.isAsciiNumeric('3') = true
+ * CharUtils.isAsciiNumeric('-') = false
+ * CharUtils.isAsciiNumeric('\n') = false
+ * CharUtils.isAsciiNumeric('©') = false
+ * </pre>
+ *
+ * @param ch the character to check
+ * @return true if between 48 and 57 inclusive
+ */
+ public static boolean isAsciiNumeric(char ch) {
+ return ch >= '0' && ch <= '9';
+ }
+
+ /**
+ * <p>Checks whether the character is ASCII 7 bit numeric.</p>
+ *
+ * <pre>
+ * CharUtils.isAsciiAlphanumeric('a') = true
+ * CharUtils.isAsciiAlphanumeric('A') = true
+ * CharUtils.isAsciiAlphanumeric('3') = true
+ * CharUtils.isAsciiAlphanumeric('-') = false
+ * CharUtils.isAsciiAlphanumeric('\n') = false
+ * CharUtils.isAsciiAlphanumeric('©') = false
+ * </pre>
+ *
+ * @param ch the character to check
+ * @return true if between 48 and 57 or 65 and 90 or 97 and 122 inclusive
+ */
+ public static boolean isAsciiAlphanumeric(char ch) {
+ return (ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z') || (ch >= '0' && ch <= '9');
+ }
+
+}
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