textutil.java

来自「我想下载一个东西」· Java 代码 · 共 463 行

/* 
    JSPWiki - a JSP-based WikiWiki clone.

    Copyright (C) 2001-2002 Janne Jalkanen ([e-mail])

    This program is free software; you can redistribute it and/or modify
    it 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.

    This program 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 program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
package com.ecyrd.jspwiki;

import java.io.UnsupportedEncodingException;
import java.util.Properties;


/**
 *  Contains a number of static utility methods.
 */
public class TextUtil
{
    static final String   HEX_DIGITS = "0123456789ABCDEF";

    /**
     *  java.net.URLEncoder.encode() method in JDK < 1.4 is buggy.  This duplicates
     *  its functionality.
     */
    protected static String urlEncode( byte[] rs )
    {
        StringBuffer result = new StringBuffer();

        // Does the URLEncoding.  We could use the java.net one, but
        // it does not eat byte[]s.

        for( int i = 0; i < rs.length; i++ )
        {
            char c = (char) rs[i];

            switch( c )
            {
              case '_':
              case '.':
              case '*':
              case '-':
                result.append( c );
                break;

              case ' ':
                result.append( '+' );
                break;

              default:
                if( (c >= 'a' && c <= 'z') ||
                    (c >= 'A' && c <= 'Z') ||
                    (c >= '0' && c <= '9') )
                {                    
                    result.append( c );
                }
                else
                {
                    result.append( '%' );
                    result.append( HEX_DIGITS.charAt( (c & 0xF0) >> 4 ) );
                    result.append( HEX_DIGITS.charAt( c & 0x0F ) );
                }
            }

        } // for

        return result.toString();
    }

    /**
     *  URL encoder does not handle all characters correctly.
     *  See <A HREF="http://developer.java.sun.com/developer/bugParade/bugs/4257115.html">
     *  Bug parade, bug #4257115</A> for more information.
     *  <P>
     *  Thanks to CJB for this fix.
     */ 
    protected static String urlDecode( byte[] bytes )
        throws UnsupportedEncodingException,
               IllegalArgumentException
    {
        if(bytes == null) 
        {
            return null;
        }

        byte[] decodeBytes   = new byte[bytes.length];
        int decodedByteCount = 0;

        try 
        {
            for( int count = 0; count < bytes.length; count++ ) 
            {
                switch( bytes[count] ) 
                {
                  case '+':
                    decodeBytes[decodedByteCount++] = (byte) ' ';
                    break ;

                  case '%':
                    decodeBytes[decodedByteCount++] = (byte)((HEX_DIGITS.indexOf(bytes[++count]) << 4) +
                                                             (HEX_DIGITS.indexOf(bytes[++count])) );

                    break ;

                  default:
                    decodeBytes[decodedByteCount++] = bytes[count] ;
                }
            }

        }
        catch (IndexOutOfBoundsException ae) 
        {
            throw new IllegalArgumentException( "Malformed UTF-8 string?" );
        }

        String processedPageName = null ;

        try 
        {
            processedPageName = new String(decodeBytes, 0, decodedByteCount, "UTF-8") ;
        } 
        catch (UnsupportedEncodingException e) 
        {
            throw new UnsupportedEncodingException( "UTF-8 encoding not supported on this platform" );
        }

        return(processedPageName.toString());
    }

    /**
     *  As java.net.URLEncoder class, but this does it in UTF8 character set.
     */
    public static String urlEncodeUTF8( String text )
    {
        byte[] rs = {};

        try
        {
            rs = text.getBytes("UTF-8");
            return urlEncode( rs );
        }
        catch( UnsupportedEncodingException e )
        {
            return java.net.URLEncoder.encode( text );
        }

    }

    /**
     *  As java.net.URLDecoder class, but for UTF-8 strings.
     */
    public static String urlDecodeUTF8( String utf8 )
    {
        String rs = null;

        try
        {
            rs = urlDecode( utf8.getBytes("ISO-8859-1") );
        }
        catch( UnsupportedEncodingException e )
        {
            rs = java.net.URLDecoder.decode( utf8 );
        }

        return rs;
    }

    /**
     * Provides encoded version of string depending on encoding.
     * Encoding may be UTF-8 or ISO-8859-1 (default).
     *
     * <p>This implementation is the same as in 
     * FileSystemProvider.mangleName().
     */
    public static String urlEncode( String data, String encoding )
    {
        // Presumably, the same caveats apply as in FileSystemProvider.
        // Don't see why it would be horribly kludgy, though. 
        if( "UTF-8".equals( encoding ) )
            return( TextUtil.urlEncodeUTF8( data ) );
        else
            return( TextUtil.urlEncode( data.getBytes() ) );
    }

    /**
     * Provides decoded version of string depending on encoding.
     * Encoding may be UTF-8 or ISO-8859-1 (default).
     *
     * <p>This implementation is the same as in 
     * FileSystemProvider.unmangleName().
     */
    public static String urlDecode( String data, String encoding )
        throws UnsupportedEncodingException,
               IllegalArgumentException
    {
        // Presumably, the same caveats apply as in FileSystemProvider.
        // Don't see why it would be horribly kludgy, though. 
        if( "UTF-8".equals( encoding ) )
            return( TextUtil.urlDecodeUTF8( data ) );
        else
            return( TextUtil.urlDecode( data.getBytes() ) );
    }

    /**
     *  Replaces the relevant entities inside the String.
     *  All &gt;, &lt; and &quot; are replaced by their
     *  respective names.
     *
     *  @since 1.6.1
     */
    public static String replaceEntities( String src )
    {
        src = replaceString( src, "<", "&lt;" );
        src = replaceString( src, ">", "&gt;" );
        src = replaceString( src, "\"", "&quot;" );

        return src;
    }

    /**
     *  Replaces a string with an other string.
     *
     *  @param orig Original string.  Null is safe.
     *  @param src  The string to find.
     *  @param dest The string to replace <I>src</I> with.
     */

    public static String replaceString( String orig, String src, String dest )
    {
        if( orig == null ) return null;

        StringBuffer res = new StringBuffer();
        int start, end = 0, last = 0;

        while( (start = orig.indexOf(src,end)) != -1 )
        {
            res.append( orig.substring( last, start ) );
            res.append( dest );
            end  = start+src.length();
            last = start+src.length();
        }

        res.append( orig.substring( end ) );

        return res.toString();
    }

    /**
     *  Replaces a part of a string with a new String.
     *
     *  @param start Where in the original string the replacing should start.
     *  @param end Where the replacing should end.
     *  @param orig Original string.  Null is safe.
     *  @param text The new text to insert into the string.
     */
    public static String replaceString( String orig, int start, int end, String text )
    {
        if( orig == null ) return null;

        StringBuffer buf = new StringBuffer(orig);

        buf.replace( start, end, text );

        return buf.toString();
    }

    /**
     *  Parses an integer parameter, returning a default value
     *  if the value is null or a non-number.
     */

    public static int parseIntParameter( String value, int defvalue )
    {
        int val = defvalue;
        
        try
        {
            val = Integer.parseInt( value );
        }
        catch( Exception e ) {}
            
        return val;
    }

    /**
     *  Gets a boolean property from a standard Properties list.
     *  Returns the default value, in case the key has not been set.
     *  <P>
     *  The possible values for the property are "true"/"false", "yes"/"no", or
     *  "on"/"off".  Any value not recognized is always defined as "false".
     *
     *  @param props   A list of properties to search.
     *  @param key     The property key.
     *  @param defval  The default value to return.
     *
     *  @return True, if the property "key" was set to "true", "on", or "yes".
     *
     *  @since 2.0.11
     */
    public static boolean getBooleanProperty( Properties props, 
                                              String key, 
                                              boolean defval )
    {
        String val = props.getProperty( key );

        if( val == null ) return defval;

        return isPositive( val );
    }

    /**
     *  Returns true, if the string "val" denotes a positive string.  Allowed
     *  values are "yes", "on", and "true".  Comparison is case-insignificant.
     *  Null values are safe.
     *
     *  @param val Value to check.
     *  @return True, if val is "true", "on", or "yes"; otherwise false.
     *
     *  @since 2.0.26
     */
    public static boolean isPositive( String val )
    {
        if( val == null ) return false;

        return ( val.equalsIgnoreCase("true") || val.equalsIgnoreCase("on") ||
                 val.equalsIgnoreCase("yes") );
    }

    /**
     *  Makes sure that the POSTed data is conforms to certain rules.  These
     *  rules are:
     *  <UL>
     *  <LI>The data always ends with a newline (some browsers, such
     *      as NS4.x series, does not send a newline at the end, which makes
     *      the diffs a bit strange sometimes.
     *  <LI>The CR/LF/CRLF mess is normalized to plain CRLF.
     *  </UL>
     *
     *  The reason why we're using CRLF is that most browser already
     *  return CRLF since that is the closest thing to a HTTP standard.
     */
    public static String normalizePostData( String postData )
    {
        StringBuffer sb = new StringBuffer();

        for( int i = 0; i < postData.length(); i++ )
        {
            switch( postData.charAt(i) )
            {
              case 0x0a: // LF, UNIX
                sb.append( "\r\n" );
                break;

              case 0x0d: // CR, either Mac or MSDOS
                sb.append( "\r\n" );
                // If it's MSDOS, skip the LF so that we don't add it again.
                if( i < postData.length()-1 && postData.charAt(i+1) == 0x0a )
                {
                    i++;
                }
                break;

              default:
                sb.append( postData.charAt(i) );
                break;
            }
        }

        if( sb.length() < 2 || !sb.substring( sb.length()-2 ).equals("\r\n") )
        {
            sb.append( "\r\n" );
        }

        return sb.toString();
    }

    private static final int EOI   = 0;
    private static final int LOWER = 1;
    private static final int UPPER = 2;
    private static final int DIGIT = 3;
    private static final int OTHER = 4;

    private static int getCharKind(int c)
    {
        if (c==-1)
        {
            return EOI;
        }

        char ch = (char) c;

        if (Character.isLowerCase(ch))
            return LOWER;
        else if (Character.isUpperCase(ch))
            return UPPER;
        else if (Character.isDigit(ch))
            return DIGIT;
        else
            return OTHER;
    }

    /**
     *  Adds spaces in suitable locations of the input string.  This is
     *  used to transform a WikiName into a more readable format.
     *
     *  @param s String to be beautified.
     *  @return A beautified string.
     */
    public static String beautifyString( String s )
    {
        StringBuffer result = new StringBuffer();

        if( s == null || s.length() == 0 ) return "";

        int cur     = s.charAt(0);
        int curKind = getCharKind(cur);

        int prevKind = LOWER;
        int nextKind = -1;

        int next = -1;
        int nextPos = 1;

        while( curKind != EOI )
        {
            next = (nextPos < s.length()) ? s.charAt(nextPos++) : -1;
            nextKind = getCharKind( next );

            if( (prevKind == UPPER) && (curKind == UPPER) && (nextKind == LOWER) )
            {
                result.append(' ');
                result.append((char) cur);
            }
            else
            {
                result.append((char) cur);
                if( ( (curKind == UPPER) && (nextKind == DIGIT) )
                    || ( (curKind == LOWER) && ((nextKind == DIGIT) || (nextKind == UPPER)) )
                    || ( (curKind == DIGIT) && ((nextKind == UPPER) || (nextKind == LOWER)) ))
                {
                    result.append(' ');
                }
            }
            prevKind = curKind;
            cur      = next;
            curKind  = nextKind;
        }

        return result.toString();
    }
}