org.argeo.api.acr/src/org/argeo/api/acr/RuntimeNamespaceContext.java

   1 package org.argeo.api.acr;
   2
   3 import java.util.Collections;
   4 import java.util.Iterator;
   5 import java.util.Map;
   6 import java.util.NavigableMap;
   7 import java.util.TreeMap;
   8
   9 import javax.xml.XMLConstants;
  10 import javax.xml.namespace.NamespaceContext;
  11
  12 /**
  13  * Programmatically defined {@link NamespaceContext}, which is valid at runtime
  14  * (when the software is running). Code contributing namespaces MUST register
  15  * here with a single default prefix, nad MUST make sure that stored data
  16  * contains the fully qualified namespace URI.
  17  */
  18 public class RuntimeNamespaceContext implements NamespaceContext {
  19         public final static String XSD_DEFAULT_PREFIX = "xs";
  20         public final static String XSD_INSTANCE_DEFAULT_PREFIX = "xsi";
  21
  22         private NavigableMap<String, String> prefixes = new TreeMap<>();
  23         private NavigableMap<String, String> namespaces = new TreeMap<>();
  24
  25         /*
  26          * NAMESPACE CONTEXT IMPLEMENTATION
  27          */
  28
  29         @Override
  30         public String getPrefix(String namespaceURI) throws IllegalArgumentException {
  31                 return NamespaceUtils.getPrefix((ns) -> {
  32                         String prefix = namespaces.get(ns);
  33                         if (prefix == null)
  34                                 throw new IllegalArgumentException("Namespace " + ns + " is not registered.");
  35                         return prefix;
  36                 }, namespaceURI);
  37         }
  38
  39         @Override
  40         public String getNamespaceURI(String prefix) throws IllegalArgumentException {
  41                 return NamespaceUtils.getNamespaceURI((p) -> {
  42                         String ns = prefixes.get(p);
  43                         if (ns == null)
  44                                 throw new IllegalArgumentException("Prefix " + p + " is not registered.");
  45                         return ns;
  46                 }, prefix);
  47         }
  48
  49         @Override
  50         public Iterator<String> getPrefixes(String namespaceURI) throws IllegalArgumentException {
  51                 return Collections.singleton(getPrefix(namespaceURI)).iterator();
  52         }
  53
  54         /*
  55          * STATIC
  56          */
  57         private final static RuntimeNamespaceContext INSTANCE = new RuntimeNamespaceContext();
  58
  59         static {
  60                 // Standard
  61                 register(XMLConstants.XML_NS_URI, XMLConstants.XML_NS_PREFIX);
  62                 register(XMLConstants.XMLNS_ATTRIBUTE_NS_URI, XMLConstants.XMLNS_ATTRIBUTE);
  63
  64                 // Common
  65                 register(XMLConstants.W3C_XML_SCHEMA_NS_URI, XSD_DEFAULT_PREFIX);
  66                 register(XMLConstants.W3C_XML_SCHEMA_INSTANCE_NS_URI, XSD_INSTANCE_DEFAULT_PREFIX);
  67
  68                 // Argeo specific
  69                 register(ArgeoNamespace.CR_NAMESPACE_URI, ArgeoNamespace.CR_DEFAULT_PREFIX);
  70                 register(ArgeoNamespace.LDAP_NAMESPACE_URI, ArgeoNamespace.LDAP_DEFAULT_PREFIX);
  71                 register(ArgeoNamespace.ROLE_NAMESPACE_URI, ArgeoNamespace.ROLE_DEFAULT_PREFIX);
  72         }
  73
  74         /** The runtime namespace context instance. */
  75         public static NamespaceContext getNamespaceContext() {
  76                 return INSTANCE;
  77         }
  78
  79         /** The registered prefixes. */
  80         public static Map<String, String> getPrefixes() {
  81                 return Collections.unmodifiableNavigableMap(INSTANCE.prefixes);
  82         }
  83
  84         /** Registers a namespace URI / default prefix mapping. */
  85         public synchronized static void register(String namespaceURI, String defaultPrefix) {
  86                 NavigableMap<String, String> prefixes = INSTANCE.prefixes;
  87                 NavigableMap<String, String> namespaces = INSTANCE.namespaces;
  88                 if (prefixes.containsKey(defaultPrefix)) {
  89                         String ns = prefixes.get(defaultPrefix);
  90                         if (ns.equals(namespaceURI))
  91                                 return; // ignore silently
  92                         throw new IllegalStateException(
  93                                         "Prefix " + defaultPrefix + " is already registered with namespace URI " + ns);
  94                 }
  95                 if (namespaces.containsKey(namespaceURI)) {
  96                         String p = namespaces.get(namespaceURI);
  97                         if (p.equals(defaultPrefix))
  98                                 return; // ignore silently
  99                         throw new IllegalStateException("Namespace " + namespaceURI + " is already registered with prefix " + p);
 100                 }
 101                 prefixes.put(defaultPrefix, namespaceURI);
 102                 namespaces.put(namespaceURI, defaultPrefix);
 103         }
 104 }