com.cloudseal.client.saml2.NamespaceContextMap Maven / Gradle / Ivy

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/* Copyright 2012 Cloudseal Ltd
 *
 * 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 com.cloudseal.client.saml2;

import javax.xml.XMLConstants;
import javax.xml.namespace.NamespaceContext;
import java.util.*;

public class NamespaceContextMap implements NamespaceContext {

    private final Map prefixMap;
    private final Map> nsMap;

    public NamespaceContextMap(
            Map prefixMappings) {
        prefixMap = createPrefixMap(prefixMappings);
        nsMap = createNamespaceMap(prefixMap);
    }

    /**
     * Convenience constructor.
     *
     * @param mappingPairs
     *          pairs of prefix-namespaceURI values
     */
    public NamespaceContextMap(String... mappingPairs) {
        this(toMap(mappingPairs));
    }

    private static Map toMap(
            String... mappingPairs) {
        Map prefixMappings = new HashMap(
                mappingPairs.length / 2);
        for (int i = 0; i < mappingPairs.length; i++) {
            prefixMappings
                    .put(mappingPairs[i], mappingPairs[++i]);
        }
        return prefixMappings;
    }

    private Map createPrefixMap(
            Map prefixMappings) {
        Map prefixMap = new HashMap(
                prefixMappings);
        addConstant(prefixMap, XMLConstants.XML_NS_PREFIX,
                XMLConstants.XML_NS_URI);
        addConstant(prefixMap, XMLConstants.XMLNS_ATTRIBUTE,
                XMLConstants.XMLNS_ATTRIBUTE_NS_URI);
        return Collections.unmodifiableMap(prefixMap);
    }

    private void addConstant(Map prefixMap,
                             String prefix, String nsURI) {
        String previous = prefixMap.put(prefix, nsURI);
        if (previous != null && !previous.equals(nsURI)) {
            throw new IllegalArgumentException(prefix + " -> "
                    + previous + "; see NamespaceContext contract");
        }
    }

    private Map> createNamespaceMap(
            Map prefixMap) {
        Map> nsMap = new HashMap>();
        for (Map.Entry entry : prefixMap
                .entrySet()) {
            String nsURI = entry.getValue();
            Set prefixes = nsMap.get(nsURI);
            if (prefixes == null) {
                prefixes = new HashSet();
                nsMap.put(nsURI, prefixes);
            }
            prefixes.add(entry.getKey());
        }
        for (Map.Entry> entry : nsMap
                .entrySet()) {
            Set readOnly = Collections
                    .unmodifiableSet(entry.getValue());
            entry.setValue(readOnly);
        }
        return nsMap;
    }

    @Override
    public String getNamespaceURI(String prefix) {
        checkNotNull(prefix);
        String nsURI = prefixMap.get(prefix);
        return nsURI == null ? XMLConstants.NULL_NS_URI : nsURI;
    }

    @Override
    public String getPrefix(String namespaceURI) {
        checkNotNull(namespaceURI);
        Set set = nsMap.get(namespaceURI);
        return set == null ? null : set.iterator().next();
    }

    @Override
    public Iterator getPrefixes(String namespaceURI) {
        checkNotNull(namespaceURI);
        Set set = nsMap.get(namespaceURI);
        return set.iterator();
    }

    private void checkNotNull(String value) {
        if (value == null) {
            throw new IllegalArgumentException("null");
        }
    }

    /**
     * @return an unmodifiable map of the mappings in the form prefix-namespaceURI
     */
    public Map getMap() {
        return prefixMap;
    }

}