Java tutorial
/* * JBoss DNA (http://www.jboss.org/dna) * See the COPYRIGHT.txt file distributed with this work for information * regarding copyright ownership. Some portions may be licensed * to Red Hat, Inc. under one or more contributor license agreements. * See the AUTHORS.txt file in the distribution for a full listing of * individual contributors. * * Unless otherwise indicated, all code in JBoss DNA is licensed * to you under the terms of the GNU Lesser General Public License as * published by the Free Software Foundation; either version 2.1 of * the License, or (at your option) any later version. * * JBoss DNA is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this software; if not, write to the Free * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA, or see the FSF site: http://www.fsf.org. */ import java.text.CharacterIterator; import java.text.StringCharacterIterator; /** * A utility class for determining the validity of various XML names, per the * <a href="http://www.w3.org/TR/REC-xml/">XML 1.0 Specification</a>. */ public class XmlCharacters { private static final int NUMBER_OF_CHARACTERS = 1 << 16; // 65536 or 0x10000 /** * This implementation uses an array that captures for each character the XML classifications. * An array is used because it is a fast way of looking up each character. */ private static final char[] MASKS = new char[NUMBER_OF_CHARACTERS]; private static final int VALID_CHARACTER = 1; private static final int CONTENT_CHARACTER = 1 << 1; private static final int SPACE_CHARACTER = 1 << 2; private static final int NAME_START_CHARACTER = 1 << 3; private static final int NAME_CHARACTER = 1 << 4; private static final int NCNAME_START_CHARACTER = 1 << 5; private static final int NCNAME_CHARACTER = 1 << 6; private static final int PUBID_CHARACTER = 1 << 7; static { // ---------------- // Valid Characters // ---------------- // [2] Char ::= #x9 | #xA | #xD | [#x20-#xD7FF] | [#xE000-#xFFFD] | [#x10000-#x10FFFF] // See http://www.w3.org/TR/REC-xml/#charsets MASKS[0x9] |= VALID_CHARACTER | CONTENT_CHARACTER; MASKS[0xA] |= VALID_CHARACTER | CONTENT_CHARACTER; MASKS[0xD] |= VALID_CHARACTER | CONTENT_CHARACTER; for (int i = 0x20; i <= 0xD7FF; ++i) MASKS[i] |= VALID_CHARACTER | CONTENT_CHARACTER; for (int i = 0xE000; i <= 0xFFFD; ++i) MASKS[i] |= VALID_CHARACTER | CONTENT_CHARACTER; // Last range is bigger than our character array, so we'll handle in the 'isValid' method ... // for ( int i=0x10000; i<=0x10FFFF; ++i ) MASKS[i] = VALID_CHARACTER_MASK | CONTENT_CHARACTER; // Remove the other characters that are not allowed in XML content: // '<', '&', '\n', '\r', ']' MASKS['<'] &= ~(CONTENT_CHARACTER); MASKS['&'] &= ~(CONTENT_CHARACTER); MASKS['\n'] &= ~(CONTENT_CHARACTER); MASKS['\r'] &= ~(CONTENT_CHARACTER); MASKS[']'] &= ~(CONTENT_CHARACTER); // --------------------- // Whitespace Characters // --------------------- // [3] S ::= (#x20 | #x9 | #xD | #xA)+ // See http://www.w3.org/TR/REC-xml/#sec-common-syn MASKS[0x20] |= SPACE_CHARACTER; MASKS[0x9] |= SPACE_CHARACTER; MASKS[0xA] |= SPACE_CHARACTER; MASKS[0xD] |= SPACE_CHARACTER; // --------------------- // Name Start Characters // --------------------- // [4] NameStartChar ::= ":" | [A-Z] | "_" | [a-z] | [#xC0-#xD6] | [#xD8-#xF6] | [#xF8-#x2FF] | // [#x370-#x37D] | [#x37F-#x1FFF] | [#x200C-#x200D] | [#x2070-#x218F] | // [#x2C00-#x2FEF] | [#x3001-#xD7FF] | [#xF900-#xFDCF] | [#xFDF0-#xFFFD] | // [#x10000-#xEFFFF] // See http://www.w3.org/TR/REC-xml/#sec-common-syn // // Note that all these start characters AND characters are valid for NAME and NCNAME int nameStartMask = NAME_START_CHARACTER | NCNAME_START_CHARACTER | NAME_CHARACTER | NCNAME_CHARACTER; MASKS[':'] |= nameStartMask; MASKS['_'] |= nameStartMask; for (int i = 'A'; i <= 'Z'; ++i) MASKS[i] |= nameStartMask; for (int i = 'a'; i <= 'z'; ++i) MASKS[i] |= nameStartMask; for (int i = 0xC0; i <= 0xD6; ++i) MASKS[i] |= nameStartMask; for (int i = 0xD8; i <= 0xF6; ++i) MASKS[i] |= nameStartMask; for (int i = 0xF8; i <= 0x2FF; ++i) MASKS[i] |= nameStartMask; for (int i = 0x370; i <= 0x37D; ++i) MASKS[i] |= nameStartMask; for (int i = 0x37F; i <= 0x1FFF; ++i) MASKS[i] |= nameStartMask; for (int i = 0x200C; i <= 0x200D; ++i) MASKS[i] |= nameStartMask; for (int i = 0x2070; i <= 0x218F; ++i) MASKS[i] |= nameStartMask; for (int i = 0x2C00; i <= 0x2FEF; ++i) MASKS[i] |= nameStartMask; for (int i = 0x3001; i <= 0xD7FF; ++i) MASKS[i] |= nameStartMask; for (int i = 0xF900; i <= 0xFDCF; ++i) MASKS[i] |= nameStartMask; for (int i = 0xFDF0; i <= 0xFFFD; ++i) MASKS[i] |= nameStartMask; // Last range is bigger than our character array ... //for (int i = 0x10000; i <= 0xEFFFF; ++i) MASKS[i] |= nameStartMask; // --------------- // Name Characters // --------------- // [4a] NameChar ::= NameStartChar | "-" | "." | [0-9] | #xB7 | [#x0300-#x036F] | [#x203F-#x2040] // See http://www.w3.org/TR/REC-xml/#sec-common-syn // // Note that all these characters are valid for NAME and NCNAME int nameMask = NAME_CHARACTER | NCNAME_CHARACTER; MASKS['-'] |= nameMask; MASKS['.'] |= nameMask; MASKS[0xB7] |= nameMask; for (int i = '0'; i <= '9'; ++i) MASKS[i] |= nameMask; for (int i = 0x0300; i <= 0x036F; ++i) MASKS[i] |= nameStartMask; for (int i = 0x203F; i <= 0x2040; ++i) MASKS[i] |= nameStartMask; // -------- // NC Names // -------- // [4] NCName ::= NCNameStartChar NCNameChar* // which is just an XML Name, minus the ":" // See http://www.w3.org/TR/REC-xml-names/#ns-decl // So, remove the NCNAME_CHARACTER and NCNAME_START_CHARACTER masks from ':' ... MASKS[':'] &= ~(NCNAME_START_CHARACTER | NCNAME_CHARACTER); // -------------------- // Public ID characters // -------------------- // [13] PubidChar ::= #x20 | #xD | #xA | [a-zA-Z0-9] | [-'()+,./:=?;!*#@$_%] MASKS[0x20] |= PUBID_CHARACTER; MASKS[0xA] |= PUBID_CHARACTER; MASKS[0xD] |= PUBID_CHARACTER; for (int i = 'A'; i <= 'Z'; ++i) MASKS[i] |= PUBID_CHARACTER; for (int i = 'a'; i <= 'z'; ++i) MASKS[i] |= PUBID_CHARACTER; for (int i = '0'; i <= '9'; ++i) MASKS[i] |= PUBID_CHARACTER; MASKS['-'] |= PUBID_CHARACTER; MASKS['\''] |= PUBID_CHARACTER; MASKS['('] |= PUBID_CHARACTER; MASKS[')'] |= PUBID_CHARACTER; MASKS['+'] |= PUBID_CHARACTER; MASKS[','] |= PUBID_CHARACTER; MASKS['.'] |= PUBID_CHARACTER; MASKS['/'] |= PUBID_CHARACTER; MASKS[':'] |= PUBID_CHARACTER; MASKS['='] |= PUBID_CHARACTER; MASKS['?'] |= PUBID_CHARACTER; MASKS[';'] |= PUBID_CHARACTER; MASKS['!'] |= PUBID_CHARACTER; MASKS['*'] |= PUBID_CHARACTER; MASKS['#'] |= PUBID_CHARACTER; MASKS['@'] |= PUBID_CHARACTER; MASKS['$'] |= PUBID_CHARACTER; MASKS['_'] |= PUBID_CHARACTER; MASKS['%'] |= PUBID_CHARACTER; } private XmlCharacters() { } /** * Determine whether the supplied character is a valid first character in an XML Name. * The first character in an XML name is more restrictive than the {@link #isValidName(int) remaining characters}. * * @param c the character * @return true if the character is valid for an XML Name's first character */ public static boolean isValidNameStart(int c) { return c < NUMBER_OF_CHARACTERS && (MASKS[c] & NAME_START_CHARACTER) != 0; } /** * Determine whether the supplied character is a valid first character in an XML NCName. * The first character in an XML NCName is more restrictive than the {@link #isValidName(int) remaining characters}. * * @param c the character * @return true if the character is valid for an XML NCName's first character */ public static boolean isValidNcNameStart(int c) { return c < NUMBER_OF_CHARACTERS && (MASKS[c] & NCNAME_START_CHARACTER) != 0; } /** * Determine whether the supplied character is a valid non-first character in an XML Name. * The {@link #isValidNameStart(int) first character} in an XML name is more restrictive than the remaining characters. * * @param c the character * @return true if the character is valid character in an XML Name */ public static boolean isValidName(int c) { return c < NUMBER_OF_CHARACTERS && (MASKS[c] & NAME_CHARACTER) != 0; } /** * Determine whether the supplied character is a valid non-first character in an XML NCName. * The {@link #isValidNcNameStart(int) first character} in an XML NCName is more restrictive than the remaining characters. * * @param c the character * @return true if the character is valid character in an XML NCName */ public static boolean isValidNcName(int c) { return c < NUMBER_OF_CHARACTERS && (MASKS[c] & NCNAME_CHARACTER) != 0; } /** * Determine whether the supplied character is a valid character in an XML Pubid. * * @param c the character * @return true if the character is valid character in an XML Pubid */ public static boolean isValidPubid(int c) { return c < NUMBER_OF_CHARACTERS && (MASKS[c] & PUBID_CHARACTER) != 0; } /** * Determine whether the supplied character is a valid character in XML. * * @param c the character * @return true if the character is valid character in XML */ public static boolean isValid(int c) { return (c < NUMBER_OF_CHARACTERS && (MASKS[c] & VALID_CHARACTER) != 0) || (0x10000 <= c && c <= 0x10FFFF); } /** * Determine whether the supplied character is a valid character in XML content * * @param c the character * @return true if the character is valid character in XML content */ public static boolean isValidContent(int c) { return (c < NUMBER_OF_CHARACTERS && (MASKS[c] & CONTENT_CHARACTER) != 0) || (0x10000 <= c && c <= 0x10FFFF); } /** * Determine whether the supplied character is a valid whitespace character in XML * * @param c the character * @return true if the character is valid whitespace character in XML */ public static boolean isValidSpace(int c) { return c <= 0x20 && (MASKS[c] & SPACE_CHARACTER) != 0; } /** * Determine if the supplied name is a valid XML Name. * * @param name the string being checked * @return true if the supplied name is indeed a valid XML Name, or false otherwise */ public static boolean isValidName(String name) { if (name == null || name.length() == 0) return false; CharacterIterator iter = new StringCharacterIterator(name); char c = iter.first(); if (!isValidNameStart(c)) return false; while (c != CharacterIterator.DONE) { if (!isValidName(c)) return false; c = iter.next(); } return true; } /** * Determine if the supplied name is a valid XML NCName. * * @param name the string being checked * @return true if the supplied name is indeed a valid XML NCName, or false otherwise */ public static boolean isValidNcName(String name) { if (name == null || name.length() == 0) return false; CharacterIterator iter = new StringCharacterIterator(name); char c = iter.first(); if (!isValidNcNameStart(c)) return false; while (c != CharacterIterator.DONE) { if (!isValidNcName(c)) return false; c = iter.next(); } return true; } }