001/*
002 * Licensed to DuraSpace under one or more contributor license agreements.
003 * See the NOTICE file distributed with this work for additional information
004 * regarding copyright ownership.
005 *
006 * DuraSpace licenses this file to you under the Apache License,
007 * Version 2.0 (the "License"); you may not use this file except in
008 * compliance with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.fcrepo.http.commons.exceptionhandlers;
019
020import static org.fcrepo.kernel.api.RdfLexicon.CONSTRAINED_BY;
021
022import javax.ws.rs.core.Link;
023import javax.ws.rs.core.UriInfo;
024import javax.ws.rs.ext.ExceptionMapper;
025
026import org.fcrepo.kernel.api.exception.ConstraintViolationException;
027
028/**
029 * Abstract class for constraint violation subclasses
030 *
031 * @author whikloj
032 * @since 2015-06-24
033 * @param <T> Throwable subclass of ConstraintViolationException
034 */
035public abstract class ConstraintExceptionMapper<T extends ConstraintViolationException> implements ExceptionMapper<T> {
036
037    /**
038     * Where the RDF exception files sit.
039     */
040    private static final String CONSTRAINT_DIR = "/static/constraints/";
041
042    /**
043     * Creates a constrainedBy link header with the appropriate RDF URL for the exception.
044     *
045     * @param e ConstraintViolationException Exception which implements the buildContraintUri method.
046     * @param uriInfo UriInfo UriInfo from the ExceptionMapper.
047     * @return Link A http://www.w3.org/ns/ldp#constrainedBy link header
048     */
049    public static Link buildConstraintLink(final ConstraintViolationException e, final UriInfo uriInfo) {
050        final String constraintURI = uriInfo == null ? "" : String.format("%s://%s%s%s.rdf",
051                uriInfo.getBaseUri().getScheme(), uriInfo.getBaseUri().getAuthority(),
052                CONSTRAINT_DIR, e.getClass().toString().substring(e.getClass().toString().lastIndexOf('.') + 1));
053        return Link.fromUri(constraintURI).rel(CONSTRAINED_BY.getURI()).build();
054    }
055
056}