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, and MUST make sure that stored data
  16  * contains the fully qualified namespace URI.</br>
  17  * </br>
  18  * All environments sharing the classloader of this class MUST use strictly the
  19  * same default prefix / namespace mappings, as a static reference to the
  20  * mapping is kept.
  21  */
  22 public class RuntimeNamespaceContext implements NamespaceContext {
  23         public final static String XSD_DEFAULT_PREFIX = "xs";
  24         public final static String XSD_INSTANCE_DEFAULT_PREFIX = "xsi";
  25
  26         private final static RuntimeNamespaceContext INSTANCE = new RuntimeNamespaceContext();
  27
  28         private NavigableMap<String, String> prefixes = new TreeMap<>();
  29         private NavigableMap<String, String> namespaces = new TreeMap<>();
  30
  31         /*
  32          * NAMESPACE CONTEXT IMPLEMENTATION
  33          */
  34
  35         @Override
  36         public String getPrefix(String namespaceURI) throws IllegalArgumentException {
  37                 return NamespaceUtils.getPrefix((ns) -> {
  38                         String prefix = namespaces.get(ns);
  39                         if (prefix == null)
  40                                 throw new IllegalArgumentException("Namespace " + ns + " is not registered.");
  41                         return prefix;
  42                 }, namespaceURI);
  43         }
  44
  45         @Override
  46         public String getNamespaceURI(String prefix) throws IllegalArgumentException {
  47                 return NamespaceUtils.getNamespaceURI((p) -> {
  48                         String ns = prefixes.get(p);
  49                         if (ns == null)
  50                                 throw new IllegalArgumentException("Prefix " + p + " is not registered.");
  51                         return ns;
  52                 }, prefix);
  53         }
  54
  55         @Override
  56         public Iterator<String> getPrefixes(String namespaceURI) throws IllegalArgumentException {
  57                 return Collections.singleton(getPrefix(namespaceURI)).iterator();
  58         }
  59
  60         /*
  61          * STATIC
  62          */
  63
  64         static {
  65                 // Standard
  66                 register(XMLConstants.XML_NS_URI, XMLConstants.XML_NS_PREFIX);
  67                 register(XMLConstants.XMLNS_ATTRIBUTE_NS_URI, XMLConstants.XMLNS_ATTRIBUTE);
  68
  69                 // Common
  70                 // FIXME shouldn't it be registered externally?
  71                 register(XMLConstants.W3C_XML_SCHEMA_NS_URI, XSD_DEFAULT_PREFIX);
  72                 register(XMLConstants.W3C_XML_SCHEMA_INSTANCE_NS_URI, XSD_INSTANCE_DEFAULT_PREFIX);
  73
  74                 // Argeo specific
  75                 register(ArgeoNamespace.CR_NAMESPACE_URI, ArgeoNamespace.CR_DEFAULT_PREFIX);
  76                 register(ArgeoNamespace.LDAP_NAMESPACE_URI, ArgeoNamespace.LDAP_DEFAULT_PREFIX);
  77                 register(ArgeoNamespace.ROLE_NAMESPACE_URI, ArgeoNamespace.ROLE_DEFAULT_PREFIX);
  78         }
  79
  80         /** The runtime namespace context instance. */
  81         public static NamespaceContext getNamespaceContext() {
  82                 return INSTANCE;
  83         }
  84
  85         /** The registered prefixes. */
  86         public static Map<String, String> getPrefixes() {
  87                 return Collections.unmodifiableNavigableMap(INSTANCE.prefixes);
  88         }
  89
  90         /** Registers a namespace URI / default prefix mapping. */
  91         public synchronized static void register(String namespaceURI, String defaultPrefix) {
  92                 NavigableMap<String, String> prefixes = INSTANCE.prefixes;
  93                 NavigableMap<String, String> namespaces = INSTANCE.namespaces;
  94                 if (prefixes.containsKey(defaultPrefix)) {
  95                         String ns = prefixes.get(defaultPrefix);
  96                         if (ns.equals(namespaceURI))
  97                                 return; // ignore silently
  98                         throw new IllegalStateException(
  99                                         "Prefix " + defaultPrefix + " is already registered with namespace URI " + ns);
 100                 }
 101                 if (namespaces.containsKey(namespaceURI)) {
 102                         String p = namespaces.get(namespaceURI);
 103                         if (p.equals(defaultPrefix))
 104                                 return; // ignore silently
 105                         throw new IllegalStateException("Namespace " + namespaceURI + " is already registered with prefix " + p);
 106                 }
 107                 prefixes.put(defaultPrefix, namespaceURI);
 108                 namespaces.put(namespaceURI, defaultPrefix);
 109         }
 110 }