Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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.apache.nifi.web; import com.sun.jersey.api.client.ClientResponse; import com.sun.jersey.api.client.ClientResponse.Status; import com.sun.jersey.core.util.MultivaluedMapImpl; import java.net.URI; import java.net.URISyntaxException; import java.util.Collections; import java.util.HashMap; import java.util.Map; import java.util.Set; import java.util.regex.Matcher; import java.util.regex.Pattern; import javax.ws.rs.HttpMethod; import javax.ws.rs.core.MultivaluedMap; import org.apache.commons.lang3.StringUtils; import org.apache.nifi.authorization.AccessDeniedException; import org.apache.nifi.cluster.coordination.ClusterCoordinator; import org.apache.nifi.cluster.coordination.http.replication.RequestReplicator; import org.apache.nifi.cluster.exception.NoClusterCoordinatorException; import org.apache.nifi.cluster.manager.NodeResponse; import org.apache.nifi.cluster.manager.exception.IllegalClusterStateException; import org.apache.nifi.cluster.protocol.NodeIdentifier; import org.apache.nifi.controller.repository.claim.ContentDirection; import org.apache.nifi.util.NiFiProperties; /** * */ public class StandardNiFiContentAccess implements ContentAccess { public static final String CLIENT_ID_PARAM = "clientId"; private static final Pattern FLOWFILE_CONTENT_URI_PATTERN = Pattern .compile("/flowfile-queues/([a-f0-9\\-]{36})/flowfiles/([a-f0-9\\-]{36})/content.*"); private static final Pattern PROVENANCE_CONTENT_URI_PATTERN = Pattern .compile("/provenance-events/([0-9]+)/content/((?:input)|(?:output)).*"); private NiFiProperties properties; private NiFiServiceFacade serviceFacade; private ClusterCoordinator clusterCoordinator; private RequestReplicator requestReplicator; @Override public DownloadableContent getContent(final ContentRequestContext request) { // if clustered, send request to cluster manager if (properties.isClustered() && clusterCoordinator != null && clusterCoordinator.isConnected()) { // get the URI URI dataUri; try { dataUri = new URI(request.getDataUri()); } catch (final URISyntaxException use) { throw new ClusterRequestException(use); } // set the request parameters final MultivaluedMap<String, String> parameters = new MultivaluedMapImpl(); parameters.add(CLIENT_ID_PARAM, request.getClientId()); // set the headers final Map<String, String> headers = new HashMap<>(); // ensure we were able to detect the cluster node id if (request.getClusterNodeId() == null) { throw new IllegalArgumentException("Unable to determine the which node has the content."); } // get the target node and ensure it exists final NodeIdentifier nodeId = clusterCoordinator.getNodeIdentifier(request.getClusterNodeId()); // replicate the request to the cluster coordinator, indicating the target node NodeResponse nodeResponse; try { headers.put(RequestReplicator.REPLICATION_TARGET_NODE_UUID_HEADER, nodeId.getId()); final NodeIdentifier coordinatorNode = clusterCoordinator.getElectedActiveCoordinatorNode(); if (coordinatorNode == null) { throw new NoClusterCoordinatorException(); } final Set<NodeIdentifier> coordinatorNodes = Collections.singleton(coordinatorNode); nodeResponse = requestReplicator .replicate(coordinatorNodes, HttpMethod.GET, dataUri, parameters, headers, false, true) .awaitMergedResponse(); } catch (InterruptedException e) { throw new IllegalClusterStateException("Interrupted while waiting for a response from node"); } final ClientResponse clientResponse = nodeResponse.getClientResponse(); final MultivaluedMap<String, String> responseHeaders = clientResponse.getHeaders(); // ensure an appropriate response if (Status.NOT_FOUND.getStatusCode() == clientResponse.getStatusInfo().getStatusCode()) { throw new ResourceNotFoundException(clientResponse.getEntity(String.class)); } else if (Status.FORBIDDEN.getStatusCode() == clientResponse.getStatusInfo().getStatusCode() || Status.UNAUTHORIZED.getStatusCode() == clientResponse.getStatusInfo().getStatusCode()) { throw new AccessDeniedException(clientResponse.getEntity(String.class)); } else if (Status.OK.getStatusCode() != clientResponse.getStatusInfo().getStatusCode()) { throw new IllegalStateException(clientResponse.getEntity(String.class)); } // get the file name final String contentDisposition = responseHeaders.getFirst("Content-Disposition"); final String filename = StringUtils.substringBetween(contentDisposition, "filename=\"", "\""); // get the content type final String contentType = responseHeaders.getFirst("Content-Type"); // create the downloadable content return new DownloadableContent(filename, contentType, clientResponse.getEntityInputStream()); } else { // example URIs: // http://localhost:8080/nifi-api/provenance/events/{id}/content/{input|output} // http://localhost:8080/nifi-api/flowfile-queues/{uuid}/flowfiles/{uuid}/content // get just the context path for comparison final String dataUri = StringUtils.substringAfter(request.getDataUri(), "/nifi-api"); if (StringUtils.isBlank(dataUri)) { throw new IllegalArgumentException("The specified data reference URI is not valid."); } // flowfile listing content final Matcher flowFileMatcher = FLOWFILE_CONTENT_URI_PATTERN.matcher(dataUri); if (flowFileMatcher.matches()) { final String connectionId = flowFileMatcher.group(1); final String flowfileId = flowFileMatcher.group(2); return getFlowFileContent(connectionId, flowfileId, dataUri); } // provenance event content final Matcher provenanceMatcher = PROVENANCE_CONTENT_URI_PATTERN.matcher(dataUri); if (provenanceMatcher.matches()) { try { final Long eventId = Long.parseLong(provenanceMatcher.group(1)); final ContentDirection direction = ContentDirection .valueOf(provenanceMatcher.group(2).toUpperCase()); return getProvenanceEventContent(eventId, dataUri, direction); } catch (final IllegalArgumentException iae) { throw new IllegalArgumentException("The specified data reference URI is not valid."); } } // invalid uri throw new IllegalArgumentException("The specified data reference URI is not valid."); } } private DownloadableContent getFlowFileContent(final String connectionId, final String flowfileId, final String dataUri) { // user authorization is handled once we have the actual content so we can utilize the flow file attributes in the resource context return serviceFacade.getContent(connectionId, flowfileId, dataUri); } private DownloadableContent getProvenanceEventContent(final Long eventId, final String dataUri, final ContentDirection direction) { // user authorization is handled once we have the actual prov event so we can utilize the event attributes in the resource context return serviceFacade.getContent(eventId, dataUri, direction); } public void setProperties(NiFiProperties properties) { this.properties = properties; } public void setServiceFacade(NiFiServiceFacade serviceFacade) { this.serviceFacade = serviceFacade; } public void setRequestReplicator(RequestReplicator requestReplicator) { this.requestReplicator = requestReplicator; } public void setClusterCoordinator(ClusterCoordinator clusterCoordinator) { this.clusterCoordinator = clusterCoordinator; } }