pattern.java

一个简单好用的java语言实现的个人日志管理系统

/*
 * @(#)Pattern.java	1.97 04/01/13
 *
 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package java.util.regex;

import java.security.AccessController;
import java.security.PrivilegedAction;
import java.text.CharacterIterator;
import sun.text.Normalizer;
import java.util.ArrayList;
import java.util.HashMap;


/**
 * A compiled representation of a regular expression.
 *
 * <p> A regular expression, specified as a string, must first be compiled into
 * an instance of this class.  The resulting pattern can then be used to create
 * a {@link Matcher} object that can match arbitrary {@link
 * java.lang.CharSequence </code>character sequences<code>} against the regular
 * expression.  All of the state involved in performing a match resides in the
 * matcher, so many matchers can share the same pattern.
 *
 * <p> A typical invocation sequence is thus
 *
 * <blockquote><pre>
 * Pattern p = Pattern.{@link #compile compile}("a*b");
 * Matcher m = p.{@link #matcher matcher}("aaaaab");
 * boolean b = m.{@link Matcher#matches matches}();</pre></blockquote>
 *
 * <p> A {@link #matches matches} method is defined by this class as a
 * convenience for when a regular expression is used just once.  This method
 * compiles an expression and matches an input sequence against it in a single
 * invocation.  The statement
 *
 * <blockquote><pre>
 * boolean b = Pattern.matches("a*b", "aaaaab");</pre></blockquote>
 *
 * is equivalent to the three statements above, though for repeated matches it
 * is less efficient since it does not allow the compiled pattern to be reused.
 *
 * <p> Instances of this class are immutable and are safe for use by multiple
 * concurrent threads.  Instances of the {@link Matcher} class are not safe for
 * such use.
 *
 *
 * <a name="sum">
 * <h4> Summary of regular-expression constructs </h4>
 *
 * <table border="0" cellpadding="1" cellspacing="0" 
 *  summary="Regular expression constructs, and what they match">
 *
 * <tr align="left">
 * <th bgcolor="#CCCCFF" align="left" id="construct">Construct</th>
 * <th bgcolor="#CCCCFF" align="left" id="matches">Matches</th>
 * </tr>
 *
 * <tr><th>&nbsp;</th></tr>
 * <tr align="left"><th colspan="2" id="characters">Characters</th></tr>
 *
 * <tr><td valign="top" headers="construct characters"><i>x</i></td>
 *     <td headers="matches">The character <i>x</i></td></tr>
 * <tr><td valign="top" headers="construct characters"><tt>\\</tt></td>
 *     <td headers="matches">The backslash character</td></tr>
 * <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>n</i></td>
 *     <td headers="matches">The character with octal value <tt>0</tt><i>n</i>
 *         (0&nbsp;<tt>&lt;=</tt>&nbsp;<i>n</i>&nbsp;<tt>&lt;=</tt>&nbsp;7)</td></tr>
 * <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>nn</i></td>
 *     <td headers="matches">The character with octal value <tt>0</tt><i>nn</i>
 *         (0&nbsp;<tt>&lt;=</tt>&nbsp;<i>n</i>&nbsp;<tt>&lt;=</tt>&nbsp;7)</td></tr>
 * <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>mnn</i></td>
 *     <td headers="matches">The character with octal value <tt>0</tt><i>mnn</i>
 *         (0&nbsp;<tt>&lt;=</tt>&nbsp;<i>m</i>&nbsp;<tt>&lt;=</tt>&nbsp;3,
 *         0&nbsp;<tt>&lt;=</tt>&nbsp;<i>n</i>&nbsp;<tt>&lt;=</tt>&nbsp;7)</td></tr>
 * <tr><td valign="top" headers="construct characters"><tt>\x</tt><i>hh</i></td>
 *     <td headers="matches">The character with hexadecimal&nbsp;value&nbsp;<tt>0x</tt><i>hh</i></td></tr>
 * <tr><td valign="top" headers="construct characters"><tt>&#92;u</tt><i>hhhh</i></td>
 *     <td headers="matches">The character with hexadecimal&nbsp;value&nbsp;<tt>0x</tt><i>hhhh</i></td></tr>
 * <tr><td valign="top" headers="matches"><tt>\t</tt></td>
 *     <td headers="matches">The tab character (<tt>'&#92;u0009'</tt>)</td></tr>
 * <tr><td valign="top" headers="construct characters"><tt>\n</tt></td>
 *     <td headers="matches">The newline (line feed) character (<tt>'&#92;u000A'</tt>)</td></tr>
 * <tr><td valign="top" headers="construct characters"><tt>\r</tt></td>
 *     <td headers="matches">The carriage-return character (<tt>'&#92;u000D'</tt>)</td></tr>
 * <tr><td valign="top" headers="construct characters"><tt>\f</tt></td>
 *     <td headers="matches">The form-feed character (<tt>'&#92;u000C'</tt>)</td></tr>
 * <tr><td valign="top" headers="construct characters"><tt>\a</tt></td>
 *     <td headers="matches">The alert (bell) character (<tt>'&#92;u0007'</tt>)</td></tr>
 * <tr><td valign="top" headers="construct characters"><tt>\e</tt></td>
 *     <td headers="matches">The escape character (<tt>'&#92;u001B'</tt>)</td></tr>
 * <tr><td valign="top" headers="construct characters"><tt>\c</tt><i>x</i></td>
 *     <td headers="matches">The control character corresponding to <i>x</i></td></tr>
 *
 * <tr><th>&nbsp;</th></tr>
 * <tr align="left"><th colspan="2" id="classes">Character classes</th></tr>
 *
 * <tr><td valign="top" headers="construct classes"><tt>[abc]</tt></td>
 *     <td headers="matches"><tt>a</tt>, <tt>b</tt>, or <tt>c</tt> (simple class)</td></tr>
 * <tr><td valign="top" headers="construct classes"><tt>[^abc]</tt></td>
 *     <td headers="matches">Any character except <tt>a</tt>, <tt>b</tt>, or <tt>c</tt> (negation)</td></tr>
 * <tr><td valign="top" headers="construct classes"><tt>[a-zA-Z]</tt></td>
 *     <td headers="matches"><tt>a</tt> through <tt>z</tt>
 *         or <tt>A</tt> through <tt>Z</tt>, inclusive (range)</td></tr>
 * <tr><td valign="top" headers="construct classes"><tt>[a-d[m-p]]</tt></td>
 *     <td headers="matches"><tt>a</tt> through <tt>d</tt>,
 *      or <tt>m</tt> through <tt>p</tt>: <tt>[a-dm-p]</tt> (union)</td></tr>
 * <tr><td valign="top" headers="construct classes"><tt>[a-z&&[def]]</tt></td>
 *     <td headers="matches"><tt>d</tt>, <tt>e</tt>, or <tt>f</tt> (intersection)</tr>
 * <tr><td valign="top" headers="construct classes"><tt>[a-z&&[^bc]]</tt></td>
 *     <td headers="matches"><tt>a</tt> through <tt>z</tt>,
 *         except for <tt>b</tt> and <tt>c</tt>: <tt>[ad-z]</tt> (subtraction)</td></tr>
 * <tr><td valign="top" headers="construct classes"><tt>[a-z&&[^m-p]]</tt></td>
 *     <td headers="matches"><tt>a</tt> through <tt>z</tt>,
 *          and not <tt>m</tt> through <tt>p</tt>: <tt>[a-lq-z]</tt>(subtraction)</td></tr>
 * <tr><th>&nbsp;</th></tr>
 *
 * <tr align="left"><th colspan="2" id="predef">Predefined character classes</th></tr>
 *
 * <tr><td valign="top" headers="construct predef"><tt>.</tt></td>
 *     <td headers="matches">Any character (may or may not match <a href="#lt">line terminators</a>)</td></tr>
 * <tr><td valign="top" headers="construct predef"><tt>\d</tt></td>
 *     <td headers="matches">A digit: <tt>[0-9]</tt></td></tr>
 * <tr><td valign="top" headers="construct predef"><tt>\D</tt></td>
 *     <td headers="matches">A non-digit: <tt>[^0-9]</tt></td></tr>
 * <tr><td valign="top" headers="construct predef"><tt>\s</tt></td>
 *     <td headers="matches">A whitespace character: <tt>[ \t\n\x0B\f\r]</tt></td></tr>
 * <tr><td valign="top" headers="construct predef"><tt>\S</tt></td>
 *     <td headers="matches">A non-whitespace character: <tt>[^\s]</tt></td></tr>
 * <tr><td valign="top" headers="construct predef"><tt>\w</tt></td>
 *     <td headers="matches">A word character: <tt>[a-zA-Z_0-9]</tt></td></tr>
 * <tr><td valign="top" headers="construct predef"><tt>\W</tt></td>
 *     <td headers="matches">A non-word character: <tt>[^\w]</tt></td></tr>
 *
 * <tr><th>&nbsp;</th></tr>
 * <tr align="left"><th colspan="2" id="posix">POSIX character classes</b> (US-ASCII only)<b></th></tr>
 *
 * <tr><td valign="top" headers="construct posix"><tt>\p{Lower}</tt></td>
 *     <td headers="matches">A lower-case alphabetic character: <tt>[a-z]</tt></td></tr>
 * <tr><td valign="top" headers="construct posix"><tt>\p{Upper}</tt></td>
 *     <td headers="matches">An upper-case alphabetic character:<tt>[A-Z]</tt></td></tr>
 * <tr><td valign="top" headers="construct posix"><tt>\p{ASCII}</tt></td>
 *     <td headers="matches">All ASCII:<tt>[\x00-\x7F]</tt></td></tr>
 * <tr><td valign="top" headers="construct posix"><tt>\p{Alpha}</tt></td>
 *     <td headers="matches">An alphabetic character:<tt>[\p{Lower}\p{Upper}]</tt></td></tr>
 * <tr><td valign="top" headers="construct posix"><tt>\p{Digit}</tt></td>
 *     <td headers="matches">A decimal digit: <tt>[0-9]</tt></td></tr>
 * <tr><td valign="top" headers="construct posix"><tt>\p{Alnum}</tt></td>
 *     <td headers="matches">An alphanumeric character:<tt>[\p{Alpha}\p{Digit}]</tt></td></tr>
 * <tr><td valign="top" headers="construct posix"><tt>\p{Punct}</tt></td>
 *     <td headers="matches">Punctuation: One of <tt>!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~</tt></td></tr>
 *     <!-- <tt>[\!"#\$%&'\(\)\*\+,\-\./:;\<=\>\?@\[\\\]\^_`\{\|\}~]</tt>
 *          <tt>[\X21-\X2F\X31-\X40\X5B-\X60\X7B-\X7E]</tt> -->
 * <tr><td valign="top" headers="construct posix"><tt>\p{Graph}</tt></td>
 *     <td headers="matches">A visible character: <tt>[\p{Alnum}\p{Punct}]</tt></td></tr>
 * <tr><td valign="top" headers="construct posix"><tt>\p{Print}</tt></td>
 *     <td headers="matches">A printable character: <tt>[\p{Graph}]</tt></td></tr>
 * <tr><td valign="top" headers="construct posix"><tt>\p{Blank}</tt></td>
 *     <td headers="matches">A space or a tab: <tt>[ \t]</tt></td></tr>
 * <tr><td valign="top" headers="construct posix"><tt>\p{Cntrl}</tt></td>
 *     <td headers="matches">A control character: <tt>[\x00-\x1F\x7F]</td></tr>
 * <tr><td valign="top" headers="construct posix"><tt>\p{XDigit}</tt></td>
 *     <td headers="matches">A hexadecimal digit: <tt>[0-9a-fA-F]</tt></td></tr>
 * <tr><td valign="top" headers="construct posix"><tt>\p{Space}</tt></td>
 *     <td headers="matches">A whitespace character: <tt>[ \t\n\x0B\f\r]</tt></td></tr>
 *
 * <tr><th>&nbsp;</th></tr>
 * <tr align="left"><th colspan="2" id="unicode">Classes for Unicode blocks and categories</th></tr>
 *
 * <tr><td valign="top" headers="construct unicode"><tt>\p{InGreek}</tt></td>
 *     <td headers="matches">A character in the Greek&nbsp;block (simple <a href="#ubc">block</a>)</td></tr>
 * <tr><td valign="top" headers="construct unicode"><tt>\p{Lu}</tt></td>
 *     <td headers="matches">An uppercase letter (simple <a href="#ubc">category</a>)</td></tr>
 * <tr><td valign="top" headers="construct unicode"><tt>\p{Sc}</tt></td>
 *     <td headers="matches">A currency symbol</td></tr>
 * <tr><td valign="top" headers="construct unicode"><tt>\P{InGreek}</tt></td>
 *     <td headers="matches">Any character except one in the Greek block (negation)</td></tr>
 * <tr><td valign="top" headers="construct unicode"><tt>[\p{L}&&[^\p{Lu}]]&nbsp;</tt></td>
 *     <td headers="matches">Any letter except an uppercase letter (subtraction)</td></tr>
 *
 * <tr><th>&nbsp;</th></tr>
 * <tr align="left"><th colspan="2" id="bounds">Boundary matchers</th></tr>
 *
 * <tr><td valign="top" headers="construct bounds"><tt>^</tt></td>
 *     <td headers="matches">The beginning of a line</td></tr>
 * <tr><td valign="top" headers="construct bounds"><tt>$</tt></td>
 *     <td headers="matches">The end of a line</td></tr>
 * <tr><td valign="top" headers="construct bounds"><tt>\b</tt></td>
 *     <td headers="matches">A word boundary</td></tr>
 * <tr><td valign="top" headers="construct bounds"><tt>\B</tt></td>
 *     <td headers="matches">A non-word boundary</td></tr>
 * <tr><td valign="top" headers="construct bounds"><tt>\A</tt></td>
 *     <td headers="matches">The beginning of the input</td></tr>
 * <tr><td valign="top" headers="construct bounds"><tt>\G</tt></td>
 *     <td headers="matches">The end of the previous match</td></tr>
 * <tr><td valign="top" headers="construct bounds"><tt>\Z</tt></td>
 *     <td headers="matches">The end of the input but for the final
 *         <a href="#lt">terminator</a>, if&nbsp;any</td></tr>
 * <tr><td valign="top" headers="construct bounds"><tt>\z</tt></td>
 *     <td headers="matches">The end of the input</td></tr>
 *
 * <tr><th>&nbsp;</th></tr>
 * <tr align="left"><th colspan="2" id="greedy">Greedy quantifiers</th></tr>
 *
 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>?</tt></td>
 *     <td headers="matches"><i>X</i>, once or not at all</td></tr>
 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>*</tt></td>
 *     <td headers="matches"><i>X</i>, zero or more times</td></tr>
 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>+</tt></td>
 *     <td headers="matches"><i>X</i>, one or more times</td></tr>
 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>}</tt></td>
 *     <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr>
 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>,}</tt></td>
 *     <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr>
 * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}</tt></td>
 *     <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
 *
 * <tr><th>&nbsp;</th></tr>
 * <tr align="left"><th colspan="2" id="reluc">Reluctant quantifiers</th></tr>
 *
 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>??</tt></td>
 *     <td headers="matches"><i>X</i>, once or not at all</td></tr>
 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>*?</tt></td>
 *     <td headers="matches"><i>X</i>, zero or more times</td></tr>
 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>+?</tt></td>
 *     <td headers="matches"><i>X</i>, one or more times</td></tr>
 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>}?</tt></td>
 *     <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr>
 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>,}?</tt></td>
 *     <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr>
 * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}?</tt></td>
 *     <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
 *
 * <tr><th>&nbsp;</th></tr>
 * <tr align="left"><th colspan="2" id="poss">Possessive quantifiers</th></tr>
 *
 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>?+</tt></td>
 *     <td headers="matches"><i>X</i>, once or not at all</td></tr>
 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>*+</tt></td>
 *     <td headers="matches"><i>X</i>, zero or more times</td></tr>
 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>++</tt></td>
 *     <td headers="matches"><i>X</i>, one or more times</td></tr>
 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>}+</tt></td>
 *     <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr>
 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>,}+</tt></td>
 *     <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr>
 * <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}+</tt></td>
 *     <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
 *
 * <tr><th>&nbsp;</th></tr>
 * <tr align="left"><th colspan="2" id="logical">Logical operators</th></tr>
 *
 * <tr><td valign="top" headers="construct logical"><i>XY</i></td>
 *     <td headers="matches"><i>X</i> followed by <i>Y</i></td></tr>
 * <tr><td valign="top" headers="construct logical"><i>X</i><tt>|</tt><i>Y</i></td>
 *     <td headers="matches">Either <i>X</i> or <i>Y</i></td></tr>
 * <tr><td valign="top" headers="construct logical"><tt>(</tt><i>X</i><tt>)</tt></td>
 *     <td headers="matches">X, as a <a href="#cg">capturing group</a></td></tr>
 *
 * <tr><th>&nbsp;</th></tr>
 * <tr align="left"><th colspan="2" id="backref">Back references</th></tr>
 *
 * <tr><td valign="bottom" headers="construct backref"><tt>\</tt><i>n</i></td>
 *     <td valign="bottom" headers="matches">Whatever the <i>n</i><sup>th</sup>
 *     <a href="#cg">capturing group</a> matched</td></tr>
 *
 * <tr><th>&nbsp;</th></tr>
 * <tr align="left"><th colspan="2" id="quot">Quotation</th></tr>
 *
 * <tr><td valign="top" headers="construct quot"><tt>\</tt></td>
 *     <td headers="matches">Nothing, but quotes the following character</tt></td></tr>
 * <tr><td valign="top" headers="construct quot"><tt>\Q</tt></td>
 *     <td headers="matches">Nothing, but quotes all characters until <tt>\E</tt></td></tr>
 * <tr><td valign="top" headers="construct quot"><tt>\E</tt></td>
 *     <td headers="matches">Nothing, but ends quoting started by <tt>\Q</tt></td></tr>
 *     <!-- Metachars: !$()*+.<>?[\]^{|} -->
 *
 * <tr><th>&nbsp;</th></tr>
 * <tr align="left"><th colspan="2" id="special">Special constructs (non-capturing)</th></tr>
 *
 * <tr><td valign="top" headers="construct special"><tt>(?:</tt><i>X</i><tt>)</tt></td>
 *     <td headers="matches"><i>X</i>, as a non-capturing group</td></tr>
 * <tr><td valign="top" headers="construct special"><tt>(?idmsux-idmsux)&nbsp;</tt></td>
 *     <td headers="matches">Nothing, but turns match flags on - off</td></tr>
 * <tr><td valign="top" headers="construct special"><tt>(?idmsux-idmsux:</tt><i>X</i><tt>)</tt>&nbsp;&nbsp;</td>
 *     <td headers="matches"><i>X</i>, as a <a href="#cg">non-capturing group</a> with the
 *         given flags on - off</td></tr>
 * <tr><td valign="top" headers="construct special"><tt>(?=</tt><i>X</i><tt>)</tt></td>
 *     <td headers="matches"><i>X</i>, via zero-width positive lookahead</td></tr>
 * <tr><td valign="top" headers="construct special"><tt>(?!</tt><i>X</i><tt>)</tt></td>
 *     <td headers="matches"><i>X</i>, via zero-width negative lookahead</td></tr>
 * <tr><td valign="top" headers="construct special"><tt>(?&lt;=</tt><i>X</i><tt>)</tt></td>
 *     <td headers="matches"><i>X</i>, via zero-width positive lookbehind</td></tr>
 * <tr><td valign="top" headers="construct special"><tt>(?&lt;!</tt><i>X</i><tt>)</tt></td>
 *     <td headers="matches"><i>X</i>, via zero-width negative lookbehind</td></tr>
 * <tr><td valign="top" headers="construct special"><tt>(?&gt;</tt><i>X</i><tt>)</tt></td>
 *     <td headers="matches"><i>X</i>, as an independent, non-capturing group</td></tr>
 *
 * </table>
 *
 * <hr>
 *
 *
 * <a name="bs">
 * <h4> Backslashes, escapes, and quoting </h4>
 *
 * <p> The backslash character (<tt>'\'</tt>) serves to introduce escaped
 * constructs, as defined in the table above, as well as to quote characters
 * that otherwise would be interpreted as unescaped constructs.  Thus the
 * expression <tt>\\</tt> matches a single backslash and <tt>\{</tt> matches a
 * left brace.
 *
 * <p> It is an error to use a backslash prior to any alphabetic character that
 * does not denote an escaped construct; these are reserved for future
 * extensions to the regular-expression language.  A backslash may be used
 * prior to a non-alphabetic character regardless of whether that character is
 * part of an unescaped construct.
 *
 * <p> Backslashes within string literals in Java source code are interpreted
 * as required by the <a
 * href="http://java.sun.com/docs/books/jls/second_edition/html/">Java Language
 * Specification</a> as either <a
 * href="http://java.sun.com/docs/books/jls/second_edition/html/lexical.doc.html#100850">Unicode
 * escapes</a> or other <a
 * href="http://java.sun.com/docs/books/jls/second_edition/html/lexical.doc.html#101089">character
 * escapes</a>.  It is therefore necessary to double backslashes in string