Java XML Attribute Get getAttributeAsURIString(XMLStreamReader reader, String name)

Description

TUSCANY-242 Returns the URI value of an attribute as a string and first applies the URI whitespace processing as defined in section 4.3.6 of XML Schema Part2: Datatypes [http://www.w3.org/TR/xmlschema-2/#rf-facets].

License

Apache License

Parameter

Parameter	Description
reader	a parameter
name	a parameter

Declaration

public static String getAttributeAsURIString(XMLStreamReader reader, String name)

Method Source Code

//package com.java2s;
/*/* w  w w.  ja  v  a  2s.c  o  m*/
 * 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.    
 */

import javax.xml.stream.XMLStreamReader;

public class Main {
    /**
     * TUSCANY-242
     * 
     * Returns the URI value of an attribute as a string and first applies the 
     * URI whitespace processing as defined in section 4.3.6 of XML Schema Part2: Datatypes
     * [http://www.w3.org/TR/xmlschema-2/#rf-facets]. anyURI is defined with the following 
     * XSD:
     *   <xs:simpleType name="anyURI" id="anyURI">
     *        <xs:restriction base="xs:anySimpleType">
     *          <xs:whiteSpace value="collapse" fixed="true" id="anyURI.whiteSpace"/>
     *        </xs:restriction>
     *   </xs:simpleType>
     *   
     * The <xs:whiteSpace value="collapse"/> constraining facet is defined as follows
     * 
     *   replace
     *      All occurrences of #x9 (tab), #xA (line feed) and #xD (carriage return) are replaced with #x20 (space) 
     *   collapse
     *      After the processing implied by replace, contiguous sequences of #x20's are collapsed to a single #x20, 
     *      and leading and trailing #x20's are removed
     *      
     * It seems that the StAX parser does apply this rule so we do it here. 
     * 
     * @param reader
     * @param name
     * @return
     */
    public static String getAttributeAsURIString(XMLStreamReader reader, String name) {
        // get the basic string value
        String uri = reader.getAttributeValue(null, name);

        // apply the "collapse" rule
        if (uri != null) {
            // turn tabs, line feeds and carriage returns into spaces
            uri = uri.replace('\t', ' ');
            uri = uri.replace('\n', ' ');
            uri = uri.replace('\r', ' ');

            // remote leading and trailing spaces. Other whitespace
            // has already been converted to spaces above
            uri = uri.trim();

            // collapse any contiguous spaces into a single space
            StringBuilder sb = new StringBuilder(uri.length());
            boolean spaceFound = false;
            for (int i = 0; i < uri.length(); ++i) {
                char c = uri.charAt(i);
                if (c == ' ') {
                    if (!spaceFound) {
                        sb.append(c);
                        spaceFound = true;
                    } else {
                        // collapse the space by ignoring it
                    }
                } else {
                    sb.append(c);
                    spaceFound = false;
                }
            }
            uri = sb.toString();
        }

        return uri;
    }
}