org.xchain.framework.digester.DigesterNamespaceContext.java Source code

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Here is the source code for org.xchain.framework.digester.DigesterNamespaceContext.java

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/**
 *    Copyright 2011 meltmedia
 *
 *    Licensed 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.
 */
package org.xchain.framework.digester;

import javax.xml.namespace.NamespaceContext;
import org.apache.commons.digester.Digester;
import java.util.Collections;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import static javax.xml.XMLConstants.*;
import javax.xml.namespace.NamespaceContext;

/**
 * @author Christian Trimble
 */
public class DigesterNamespaceContext implements NamespaceContext {
    private Map<String, String> xmlns = null;

    public DigesterNamespaceContext(Digester digester) {
        this.xmlns = digester.getCurrentNamespaces();
    }

    public String getNamespaceURI(String prefix) {
        if (prefix == null) {
            throw new IllegalArgumentException("A null prefix cannot be used with a NamespaceContext object.");
        } else if (!xmlns.containsKey(prefix)) {
            return NULL_NS_URI;
        } else if (XML_NS_PREFIX.equals(prefix)) {
            return XML_NS_URI;
        } else if (XMLNS_ATTRIBUTE.equals(prefix)) {
            return XMLNS_ATTRIBUTE_NS_URI;
        } else {
            return xmlns.get(prefix);
        }
    }

    public String getPrefix(String namespaceUri) {
        if (namespaceUri == null) {
            throw new IllegalArgumentException(
                    "A null namespace URI cannot be used with a NamespaceContext object.");
        } else if (XML_NS_URI.equals(namespaceUri)) {
            return XML_NS_PREFIX;
        } else if (XMLNS_ATTRIBUTE_NS_URI.equals(namespaceUri)) {
            return XMLNS_ATTRIBUTE;
        } else {
            for (Map.Entry<String, String> entry : xmlns.entrySet()) {
                if (namespaceUri.equals(entry.getValue())) {
                    return entry.getKey();
                }
            }
            return null;
        }
    }

    public Iterator<String> getPrefixes(String namespaceUri) {
        if (namespaceUri == null) {
            throw new IllegalArgumentException(
                    "A null namespace URI cannot be used with a NamespaceContext object.");
        } else if (XML_NS_URI.equals(namespaceUri)) {
            return Collections.singleton(XML_NS_PREFIX).iterator();
        } else if (XMLNS_ATTRIBUTE_NS_URI.equals(namespaceUri)) {
            return Collections.singleton(XMLNS_ATTRIBUTE).iterator();
        } else {
            ArrayList<String> prefixes = new ArrayList<String>();
            for (Map.Entry<String, String> entry : xmlns.entrySet()) {
                if (namespaceUri.equals(entry.getValue())) {
                    prefixes.add(entry.getKey());
                }
            }
            return Collections.unmodifiableList(prefixes).iterator();
        }
    }
}