net.sf.saxon.functions.EscapeURI Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of saxon9 Show documentation
Provides a basic XSLT 2.0 and XQuery 1.0 processor (W3C Recommendations, January 2007). Command line interfaces and implementations of several Java APIs (DOM, XPath, s9api) are also included.
The newest version!
package net.sf.saxon.functions;
import net.sf.saxon.Err;
import net.sf.saxon.charcode.UnicodeCharacterSet;
import net.sf.saxon.event.HTMLURIEscaper;
import net.sf.saxon.expr.XPathContext;
import net.sf.saxon.om.FastStringBuffer;
import net.sf.saxon.om.Item;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.value.StringValue;

import java.util.Arrays;

/**
 * This class supports the functions encode-for-uri() and iri-to-uri()
 */

public class EscapeURI extends SystemFunction {

    public static final int ENCODE_FOR_URI = 1;
    public static final int IRI_TO_URI = 2;
    public static final int HTML_URI = 3;

    public static boolean[] allowedASCII = new boolean[128];

    static {
        Arrays.fill(allowedASCII, 0, 32, false);
        Arrays.fill(allowedASCII, 33, 127, true);
        allowedASCII[(int)'"'] = false;
        allowedASCII[(int)'<'] = false;
        allowedASCII[(int)'>'] = false;
        allowedASCII[(int)'\\'] = false;
        allowedASCII[(int)'^'] = false;
        allowedASCII[(int)'`'] = false;
        allowedASCII[(int)'{'] = false;
        allowedASCII[(int)'|'] = false;
        allowedASCII[(int)'}'] = false;
    }

    /**
    * Evaluate the function
    */

    public Item evaluateItem(XPathContext c) throws XPathException {
        Item item = argument[0].evaluateItem(c);
        if (item == null) {
            return StringValue.EMPTY_STRING;
        }
        final CharSequence s = item.getStringValueCS();
        switch (operation) {
            case ENCODE_FOR_URI:
                return StringValue.makeStringValue(escape(s, "-_.~"));
            case IRI_TO_URI:
                return StringValue.makeStringValue(iriToUri(s));
            case HTML_URI:
                return StringValue.makeStringValue(HTMLURIEscaper.escapeURL(s, false));
            default:
                throw new UnsupportedOperationException("Unknown escape operation");
        }
    }

    /**
     * Escape special characters in a URI. The characters that are %HH-encoded are
     * all non-ASCII characters
     * @param s the URI to be escaped
     * @return the %HH-encoded string
     */

    public static CharSequence iriToUri(CharSequence s) {
        // NOTE: implements a late spec change which says that characters that are illegal in an IRI,
        // for example "\", must be %-encoded.
        if (allAllowedAscii(s)) {
            // it's worth doing a prescan to avoid the cost of copying in the common all-ASCII case
            return s;
        }
        FastStringBuffer sb = new FastStringBuffer(s.length()+20);
        for (int i=0; i=0x7f || !allowedASCII[(int)c]) {
                escapeChar(c, ((i+1)=0x7f || !allowedASCII[(int)c]) {
                return false;
            }
        }
        return true;
    }


    /**
     * Escape special characters in a URI. The characters that are %HH-encoded are
     * all non-ASCII characters, plus all ASCII characters except (a) letter A-Z
     * and a-z, (b) digits 0-9, and (c) characters listed in the allowedPunctuation
     * argument
     * @param s the URI to be escaped
     * @param allowedPunctuation ASCII characters other than letters and digits that
     * should NOT be %HH-encoded
     * @return the %HH-encoded string
     */

    public static CharSequence escape(CharSequence s, String allowedPunctuation) {
        FastStringBuffer sb = new FastStringBuffer(s.length());
        for (int i=0; i='a' && c<='z') || (c>='A' && c<='Z') || (c>='0' && c<='9')) {
                sb.append(c);
            } else if (c<=0x20 || c>=0x7f) {
                escapeChar(c, ((i+1)= 0) {
                sb.append(c);
            } else {
                escapeChar(c, ' ', sb);
            }

        }
        return sb;
    }

    private static final String hex = "0123456789ABCDEF";

    /**
     * Escape a single character in %HH representation, or a pair of two chars representing
     * a surrogate pair
     * @param c the character to be escaped, or the first character of a surrogate pair
     * @param c2 the second character of a surrogate pair
     * @param sb the buffer to contain the escaped result
     */

    private static void escapeChar(char c, char c2, FastStringBuffer sb) {
        byte[] array = new byte[4];
        int used = UnicodeCharacterSet.getUTF8Encoding(c, c2, array);
        for (int b=0; b= uri.length()) {
                    throw new XPathException("% sign in URI must be followed by two hex digits" +
                                    Err.wrap(uri));
                }
                int h1 = hexDigits.indexOf(uri.charAt(i+1));
                if (h1 > 15) {
                    h1 -= 6;
                }

                int h2 = hexDigits.indexOf(uri.charAt(i+2));
                if (h2 > 15) {
                    h2 -= 6;
                }
                if (h1 >= 0 && h2 >= 0) {
                    int b = h1<<4 | h2;
                    expectedOctets = UTF8RepresentationLength[h1];
                    if (expectedOctets == -1) {
                        throw new XPathException("First %-encoded octet in URI is not valid as the start of a UTF-8 " +
                                "character: first two bits must not be '10'" +
                                    Err.wrap(uri));
                    }
                    bytes = new byte[expectedOctets];
                    bytes[0] = (byte)b;
                    i+=3;
                    for (int q=1; q uri.length() || uri.charAt(i) != '%') {
                            throw new XPathException("Incomplete %-encoded UTF-8 octet sequence in URI " +
                                    Err.wrap(uri));
                        }
                        h1 = hexDigits.indexOf(uri.charAt(i+1));
                        if (h1 > 15) {
                            h1 -= 6;
                        }

                        h2 = hexDigits.indexOf(uri.charAt(i+2));
                        if (h2 > 15) {
                            h2 -= 6;
                        }
                        if (h1 < 0 || h2 < 0) {
                            throw new XPathException("Invalid %-encoded UTF-8 octet sequence in URI" +
                                    Err.wrap(uri));
                        }
                        if (UTF8RepresentationLength[h1] != -1) {
                            throw new XPathException("In a URI, a %-encoded UTF-8 octet after the first " +
                                    "must have '10' as the first two bits" +
                                    Err.wrap(uri));
                        }
                        b = h1<<4 | h2;
                        bytes[q] = (byte)b;
                        i += 3;
                    }
                } else {
                    throw new XPathException("% sign in URI must be followed by two hex digits" +
                                    Err.wrap(uri));
                }
            } else {
                i++;
            }

        }

    }

    private static String hexDigits = "0123456789abcdefABCDEF";

    // Length of a UTF8 byte sequence, as a function of the first nibble
    private static int[] UTF8RepresentationLength = {1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, 2, 2, 3, 4};
}



//
// The contents of this file are subject to the Mozilla Public License Version 1.0 (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.mozilla.org/MPL/
//
// Software distributed under the License is distributed on an "AS IS" basis,
// WITHOUT WARRANTY OF ANY KIND, either express or implied.
// See the License for the specific language governing rights and limitations under the License.
//
// The Original Code is: all this file.
//
// The Initial Developer of the Original Code is Michael H. Kay
//
// Portions created by (your name) are Copyright (C) (your legal entity). All Rights Reserved.
//
// Contributor(s): none.
//