source: VirtualCollectionRegistry/trunk/VirtualCollectionRegistry/src/main/java/eu/clarin/cmdi/virtualcollectionregistry/model/PersistentIdentifierProvider.java @ 278

package eu.clarin.cmdi.virtualcollectionregistry.model;

import java.lang.reflect.Constructor;
import java.net.URI;
import java.util.Map;

import eu.clarin.cmdi.virtualcollectionregistry.VirtualCollectionRegistryException;

public abstract class PersistentIdentifierProvider {
        public static final String BASE_URI      = "pid_provider.base_uri";
        public static final String PROVIDER_CLASS= "pid_provider.class";
        
        protected PersistentIdentifierProvider(Map<String, String> config)
                        throws VirtualCollectionRegistryException {
                super();
        }

        public abstract PersistentIdentifier createIdentifier(VirtualCollection vc)
                        throws VirtualCollectionRegistryException;

        public abstract void updateIdentifier(String pid, URI target)
                        throws VirtualCollectionRegistryException;

        public abstract void deleteIdentifier(String pid)
                        throws VirtualCollectionRegistryException;

        protected PersistentIdentifier doCreate(VirtualCollection vc,
                                                                                        PersistentIdentifier.Type type,
                                                                                        String identifier) {
                return new PersistentIdentifier(vc, type, identifier);
        }

        protected static String getConfigParameter(Map<String, String> config,
                        String parameter) throws VirtualCollectionRegistryException {
                String value = config.get(parameter);
                if (value == null) {
                        throw new VirtualCollectionRegistryException("configuration "
                                        + "parameter \"" + parameter + "\" is not set");
                }
                value = value.trim();
                if (value.isEmpty()) {
                        throw new VirtualCollectionRegistryException("configuration "
                                        + "parameter \"" + parameter + "\" is invalid");
                }
                return value;
        }

        public static PersistentIdentifierProvider
                createProvider(Map<String, String> config)
                throws VirtualCollectionRegistryException {
                /*
                 * XXX: instantiating the pid provider should probably done in a
                 *      different and less complicated way. 
                 */
                String clazzName = getConfigParameter(config, PROVIDER_CLASS);
                try {
                        Class<?> clazz = Class.forName(clazzName);
                        if (PersistentIdentifierProvider.class.isAssignableFrom(clazz)) {
                                Constructor<?> c = clazz.getConstructor(Map.class);
                                return (PersistentIdentifierProvider) c.newInstance(config);
                        }
                } catch (Exception e) {
                        throw new VirtualCollectionRegistryException("error initalizing " +
                                        "persistent identifier provider", e);
                }
                throw new VirtualCollectionRegistryException("invalid persistent " +
                                "identifier provider (" + clazzName + ")" );
        }

} // abstract class PersistentIdentifierProvider