/*
* Copyright 2014 the original author or authors.
*
* 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 org.springframework.data.rest.webmvc.alps;
import static org.springframework.web.bind.annotation.RequestMethod.*;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.repository.support.Repositories;
import org.springframework.data.rest.core.config.RepositoryRestConfiguration;
import org.springframework.data.rest.core.mapping.ResourceMappings;
import org.springframework.data.rest.core.mapping.ResourceMetadata;
import org.springframework.data.rest.webmvc.BaseUriAwareController;
import org.springframework.data.rest.webmvc.BaseUri;
import org.springframework.data.rest.webmvc.ResourceNotFoundException;
import org.springframework.data.rest.webmvc.RootResourceInformation;
import org.springframework.hateoas.alps.Alps;
import org.springframework.hateoas.alps.Descriptor;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.util.Assert;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.util.UriComponentsBuilder;
/**
* Controller exposing semantic documentation for the resources exposed using the Application Level Profile Semantics
* format.
*
* @author Oliver Gierke
* @see http://alps.io
*/
@BaseUriAwareController
public class AlpsController {
static final String ALPS_ROOT_MAPPING = "/alps";
static final String ALPS_RESOURCE_MAPPING = ALPS_ROOT_MAPPING + "/{repository}";
private final Repositories repositories;
private final ResourceMappings mappings;
private final RepositoryRestConfiguration configuration;
/**
* Creates a new {@link AlpsController} for the given {@link Repositories},
* {@link RootResourceInformationToAlpsDescriptorConverter} and {@link ResourceMappings}.
*
* @param repositories must not be {@literal null}.
* @param mappings must not be {@literal null}.
* @param configuration must not be {@literal null}.
*/
@Autowired
public AlpsController(Repositories repositories, ResourceMappings mappings, RepositoryRestConfiguration configuration) {
Assert.notNull(repositories, "Repositories must not be null!");
Assert.notNull(mappings, "ResourceMappings must not be null!");
Assert.notNull(configuration, "MetadataConfiguration must not be null!");
this.repositories = repositories;
this.mappings = mappings;
this.configuration = configuration;
}
/**
* Exposes the allowed HTTP methods for the ALPS resources.
*
* @return
*/
@RequestMapping(value = { ALPS_ROOT_MAPPING, ALPS_RESOURCE_MAPPING }, method = OPTIONS)
HttpEntity<?> alpsOptions() {
verifyAlpsEnabled();
HttpHeaders headers = new HttpHeaders();
headers.setAllow(Collections.singleton(HttpMethod.GET));
return new ResponseEntity<Object>(headers, HttpStatus.OK);
}
/**
* Exposes a resource to contain descriptors pointing to the discriptors for individual resources.
*
* @return
*/
@RequestMapping(value = ALPS_ROOT_MAPPING, method = GET)
HttpEntity<Alps> alps() {
verifyAlpsEnabled();
List<Descriptor> descriptors = new ArrayList<Descriptor>();
for (Class<?> domainType : repositories) {
ResourceMetadata mapping = mappings.getMappingFor(domainType);
if (mapping.isExported()) {
BaseUri baseUri = new BaseUri(configuration.getBaseUri());
UriComponentsBuilder builder = baseUri.getUriComponentsBuilder().path(ALPS_ROOT_MAPPING);
String href = builder.path(mapping.getPath().toString()).build().toUriString();
descriptors.add(Alps.descriptor().name(mapping.getRel()).href(href).build());
}
}
Alps alps = Alps.alps().//
descriptors(descriptors).//
build();
return new ResponseEntity<Alps>(alps, HttpStatus.OK);
}
/**
* Exposes an ALPS resource to describe an individual repository resource.
*
* @param information
* @return
*/
@RequestMapping(value = ALPS_RESOURCE_MAPPING, method = GET)
HttpEntity<RootResourceInformation> descriptor(RootResourceInformation information) {
verifyAlpsEnabled();
return new ResponseEntity<RootResourceInformation>(information, HttpStatus.OK);
}
private void verifyAlpsEnabled() {
if (!configuration.metadataConfiguration().alpsEnabled()) {
throw new ResourceNotFoundException();
}
}
}