Java tutorial
/** * Copyright 2009, 2010 The Regents of the University of California * Licensed under the Educational Community 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.osedu.org/licenses/ECL-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.opencastproject.workflow.remote; import static org.apache.http.HttpStatus.SC_CREATED; import static org.apache.http.HttpStatus.SC_NOT_FOUND; import static org.apache.http.HttpStatus.SC_NO_CONTENT; import static org.apache.http.HttpStatus.SC_OK; import static org.apache.http.HttpStatus.SC_PRECONDITION_FAILED; import org.opencastproject.mediapackage.MediaPackage; import org.opencastproject.mediapackage.MediaPackageParser; import org.opencastproject.security.api.UnauthorizedException; import org.opencastproject.serviceregistry.api.RemoteBase; import org.opencastproject.util.NotFoundException; import org.opencastproject.util.SolrUtils; import org.opencastproject.workflow.api.WorkflowDatabaseException; import org.opencastproject.workflow.api.WorkflowDefinition; import org.opencastproject.workflow.api.WorkflowInstance; import org.opencastproject.workflow.api.WorkflowInstance.WorkflowState; import org.opencastproject.workflow.api.WorkflowListener; import org.opencastproject.workflow.api.WorkflowParser; import org.opencastproject.workflow.api.WorkflowParsingException; import org.opencastproject.workflow.api.WorkflowQuery; import org.opencastproject.workflow.api.WorkflowQuery.QueryTerm; import org.opencastproject.workflow.api.WorkflowService; import org.opencastproject.workflow.api.WorkflowSet; import org.opencastproject.workflow.api.WorkflowStatistics; import org.apache.http.HttpResponse; import org.apache.http.NameValuePair; import org.apache.http.ParseException; import org.apache.http.client.entity.UrlEncodedFormEntity; import org.apache.http.client.methods.HttpDelete; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpPost; import org.apache.http.client.methods.HttpPut; import org.apache.http.client.utils.URLEncodedUtils; import org.apache.http.message.BasicNameValuePair; import org.apache.http.util.EntityUtils; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.io.IOException; import java.io.UnsupportedEncodingException; import java.util.ArrayList; import java.util.List; import java.util.Map; import java.util.Map.Entry; /** * An implementation of the workflow service that communicates with a remote workflow service via HTTP. */ public class WorkflowServiceRemoteImpl extends RemoteBase implements WorkflowService { /** The logger */ private static final Logger logger = LoggerFactory.getLogger(WorkflowServiceRemoteImpl.class); public WorkflowServiceRemoteImpl() { super(JOB_TYPE); } /** * {@inheritDoc} * * @see org.opencastproject.workflow.api.WorkflowService#getWorkflowDefinitionById(java.lang.String) */ @Override public WorkflowDefinition getWorkflowDefinitionById(String id) throws WorkflowDatabaseException, NotFoundException { HttpGet get = new HttpGet("/definition/" + id + ".xml"); HttpResponse response = getResponse(get, SC_NOT_FOUND, SC_OK); try { if (response != null) { if (SC_NOT_FOUND == response.getStatusLine().getStatusCode()) { throw new NotFoundException("Workflow definition " + id + " does not exist."); } else { return WorkflowParser.parseWorkflowDefinition(response.getEntity().getContent()); } } } catch (NotFoundException e) { throw e; } catch (Exception e) { throw new WorkflowDatabaseException(e); } finally { closeConnection(response); } throw new WorkflowDatabaseException("Unable to connect to a remote workflow service"); } /** * {@inheritDoc} * * @see org.opencastproject.workflow.api.WorkflowService#getWorkflowById(long) */ @Override public WorkflowInstance getWorkflowById(long id) throws WorkflowDatabaseException, NotFoundException { HttpGet get = new HttpGet("/instance/" + id + ".xml"); HttpResponse response = getResponse(get, SC_NOT_FOUND, SC_OK); try { if (response != null) { if (SC_NOT_FOUND == response.getStatusLine().getStatusCode()) { throw new NotFoundException("Workflow instance " + id + " does not exist."); } else { return WorkflowParser.parseWorkflowInstance(response.getEntity().getContent()); } } } catch (NotFoundException e) { throw e; } catch (Exception e) { throw new WorkflowDatabaseException(e); } finally { closeConnection(response); } throw new WorkflowDatabaseException("Unable to connect to a remote workflow service"); } /** * {@inheritDoc} * * @see org.opencastproject.workflow.api.WorkflowService * #getWorkflowInstances(org.opencastproject.workflow.api.WorkflowQuery) */ @Override public WorkflowSet getWorkflowInstances(WorkflowQuery query) throws WorkflowDatabaseException { List<NameValuePair> queryStringParams = new ArrayList<NameValuePair>(); if (query.getText() != null) queryStringParams.add(new BasicNameValuePair("q", query.getText())); if (query.getStates() != null) { for (QueryTerm stateQueryTerm : query.getStates()) { String value = stateQueryTerm.isInclude() ? stateQueryTerm.getValue() : "-" + stateQueryTerm.getValue(); queryStringParams.add(new BasicNameValuePair("state", value)); } } if (query.getCurrentOperations() != null) { for (QueryTerm opQueryTerm : query.getCurrentOperations()) { String value = opQueryTerm.isInclude() ? opQueryTerm.getValue() : "-" + opQueryTerm.getValue(); queryStringParams.add(new BasicNameValuePair("op", value)); } } if (query.getSeriesId() != null) queryStringParams.add(new BasicNameValuePair("seriesId", query.getSeriesId())); if (query.getSeriesTitle() != null) queryStringParams.add(new BasicNameValuePair("seriesTitle", query.getSeriesTitle())); if (query.getMediaPackageId() != null) queryStringParams.add(new BasicNameValuePair("mp", query.getMediaPackageId())); if (query.getWorkflowDefinitionId() != null) queryStringParams.add(new BasicNameValuePair("workflowdefinition", query.getWorkflowDefinitionId())); if (query.getFromDate() != null) queryStringParams.add(new BasicNameValuePair("fromdate", SolrUtils.serializeDate(query.getFromDate()))); if (query.getToDate() != null) queryStringParams.add(new BasicNameValuePair("todate", SolrUtils.serializeDate(query.getToDate()))); if (query.getCreator() != null) queryStringParams.add(new BasicNameValuePair("creator", query.getCreator())); if (query.getContributor() != null) queryStringParams.add(new BasicNameValuePair("contributor", query.getContributor())); if (query.getLanguage() != null) queryStringParams.add(new BasicNameValuePair("language", query.getLanguage())); if (query.getLicense() != null) queryStringParams.add(new BasicNameValuePair("license", query.getLicense())); if (query.getTitle() != null) queryStringParams.add(new BasicNameValuePair("title", query.getTitle())); if (query.getSubject() != null) queryStringParams.add(new BasicNameValuePair("subject", query.getSubject())); if (query.getSort() != null) { String sort = query.getSort().toString(); if (!query.isSortAscending()) { sort += "_DESC"; } queryStringParams.add(new BasicNameValuePair("sort", sort)); } if (query.getStartPage() > 0) queryStringParams.add(new BasicNameValuePair("startPage", Long.toString(query.getStartPage()))); if (query.getCount() > 0) queryStringParams.add(new BasicNameValuePair("count", Long.toString(query.getCount()))); StringBuilder url = new StringBuilder(); url.append("/instances.xml"); if (queryStringParams.size() > 0) url.append("?" + URLEncodedUtils.format(queryStringParams, "UTF-8")); HttpGet get = new HttpGet(url.toString()); HttpResponse response = getResponse(get); try { if (response != null) return WorkflowParser.parseWorkflowSet(response.getEntity().getContent()); } catch (Exception e) { throw new WorkflowDatabaseException(e); } finally { closeConnection(response); } throw new WorkflowDatabaseException("Workflow instances can not be loaded from a remote workflow service"); } /** * {@inheritDoc} * * @see org.opencastproject.workflow.api.WorkflowService#getWorkflowInstancesForAdministrativeRead(org.opencastproject.workflow.api.WorkflowQuery) */ @Override public WorkflowSet getWorkflowInstancesForAdministrativeRead(WorkflowQuery q) throws WorkflowDatabaseException, UnauthorizedException { return getWorkflowInstances(q); } /** * {@inheritDoc} * * @see org.opencastproject.workflow.api.WorkflowService#getStatistics() */ @Override public WorkflowStatistics getStatistics() throws WorkflowDatabaseException { HttpGet get = new HttpGet("/statistics.xml"); HttpResponse response = getResponse(get); try { if (response != null) return WorkflowParser.parseWorkflowStatistics(response.getEntity().getContent()); } catch (Exception e) { throw new WorkflowDatabaseException("Unable to load workflow statistics", e); } finally { closeConnection(response); } throw new WorkflowDatabaseException("Unable to connect to a remote workflow service"); } /** * {@inheritDoc} * * @see org.opencastproject.workflow.api.WorkflowService#start(org.opencastproject.workflow.api.WorkflowDefinition, * org.opencastproject.mediapackage.MediaPackage, java.util.Map) */ @Override public WorkflowInstance start(WorkflowDefinition workflowDefinition, MediaPackage mediaPackage, Map<String, String> properties) throws WorkflowDatabaseException { try { return start(workflowDefinition, mediaPackage, null, properties); } catch (NotFoundException e) { throw new IllegalStateException( "A null parent workflow id should never result in a not found exception ", e); } } /** * Converts a Map<String, String> to s key=value\n string, suitable for the properties form parameter expected by the * workflow rest endpoint. * * @param props * The map of strings * @return the string representation */ private String mapToString(Map<String, String> props) { StringBuilder sb = new StringBuilder(); for (Entry<String, String> entry : props.entrySet()) { sb.append(entry.getKey()); sb.append("="); sb.append(entry.getValue()); sb.append("\n"); } return sb.toString(); } /** * {@inheritDoc} * * @see org.opencastproject.workflow.api.WorkflowService#start(org.opencastproject.workflow.api.WorkflowDefinition, * org.opencastproject.mediapackage.MediaPackage, Long, java.util.Map) */ @Override public WorkflowInstance start(WorkflowDefinition workflowDefinition, MediaPackage mediaPackage, Long parentWorkflowId, Map<String, String> properties) throws WorkflowDatabaseException, NotFoundException { HttpPost post = new HttpPost("/start"); try { List<BasicNameValuePair> params = new ArrayList<BasicNameValuePair>(); if (workflowDefinition != null) params.add(new BasicNameValuePair("definition", WorkflowParser.toXml(workflowDefinition))); params.add(new BasicNameValuePair("mediapackage", MediaPackageParser.getAsXml(mediaPackage))); if (parentWorkflowId != null) params.add(new BasicNameValuePair("parent", parentWorkflowId.toString())); if (properties != null) params.add(new BasicNameValuePair("properties", mapToString(properties))); post.setEntity(new UrlEncodedFormEntity(params)); } catch (Exception e) { throw new IllegalStateException("Unable to assemble a remote workflow request", e); } HttpResponse response = getResponse(post, SC_NOT_FOUND, SC_OK); try { if (response != null) { if (SC_NOT_FOUND == response.getStatusLine().getStatusCode()) { throw new NotFoundException("Workflow instance " + parentWorkflowId + " does not exist."); } else { return WorkflowParser.parseWorkflowInstance(response.getEntity().getContent()); } } } catch (NotFoundException e) { throw e; } catch (Exception e) { throw new WorkflowDatabaseException("Unable to build a workflow from xml", e); } finally { closeConnection(response); } throw new WorkflowDatabaseException( "Unable to start a remote workflow. The http response code was unexpected."); } /** * {@inheritDoc} * * @see org.opencastproject.workflow.api.WorkflowService#start(org.opencastproject.workflow.api.WorkflowDefinition, * org.opencastproject.mediapackage.MediaPackage) */ @Override public WorkflowInstance start(WorkflowDefinition workflowDefinition, MediaPackage mediaPackage) throws WorkflowDatabaseException { try { return start(workflowDefinition, mediaPackage, null, null); } catch (NotFoundException e) { throw new IllegalStateException( "A null parent workflow id should never result in a not found exception ", e); } } /** * {@inheritDoc} * * @see org.opencastproject.workflow.api.WorkflowService#countWorkflowInstances() */ @Override public long countWorkflowInstances() throws WorkflowDatabaseException { return countWorkflowInstances(null, null); } /** * {@inheritDoc} * * @see org.opencastproject.workflow.api.WorkflowService#countWorkflowInstances(org.opencastproject.workflow.api.WorkflowInstance.WorkflowState, * java.lang.String) */ @Override public long countWorkflowInstances(WorkflowState state, String operation) throws WorkflowDatabaseException { List<NameValuePair> queryStringParams = new ArrayList<NameValuePair>(); if (state != null) queryStringParams.add(new BasicNameValuePair("state", state.toString())); if (operation != null) queryStringParams.add(new BasicNameValuePair("operation", operation)); StringBuilder url = new StringBuilder("/count"); if (queryStringParams.size() > 0) { url.append("?"); url.append(URLEncodedUtils.format(queryStringParams, "UTF-8")); } HttpGet get = new HttpGet(url.toString()); HttpResponse response = getResponse(get); try { if (response != null) { String body = null; try { body = EntityUtils.toString(response.getEntity()); return Long.parseLong(body); } catch (NumberFormatException e) { throw new WorkflowDatabaseException("Unable to parse the response body as a long: " + body); } } } catch (ParseException e) { throw new WorkflowDatabaseException("Unable to parse the response body"); } catch (IOException e) { throw new WorkflowDatabaseException("Unable to parse the response body"); } finally { closeConnection(response); } throw new WorkflowDatabaseException("Unable to count workflow instances"); } /** * {@inheritDoc} * * @see org.opencastproject.workflow.api.WorkflowService#stop(long) */ @Override public WorkflowInstance stop(long workflowInstanceId) throws WorkflowDatabaseException, NotFoundException { HttpPost post = new HttpPost("/stop"); List<BasicNameValuePair> params = new ArrayList<BasicNameValuePair>(); params.add(new BasicNameValuePair("id", Long.toString(workflowInstanceId))); try { post.setEntity(new UrlEncodedFormEntity(params)); } catch (UnsupportedEncodingException e) { throw new IllegalStateException("Unable to assemble a remote workflow service request", e); } HttpResponse response = getResponse(post, SC_OK, SC_NOT_FOUND); try { if (response != null) { if (response.getStatusLine().getStatusCode() == SC_NOT_FOUND) { throw new NotFoundException("Workflow instance with id='" + workflowInstanceId + "' not found"); } else { logger.info("Workflow '{}' stopped", workflowInstanceId); return WorkflowParser.parseWorkflowInstance(response.getEntity().getContent()); } } } catch (NotFoundException e) { throw e; } catch (Exception e) { throw new WorkflowDatabaseException(e); } finally { closeConnection(response); } throw new WorkflowDatabaseException("Unable to stop workflow instance " + workflowInstanceId); } /** * {@inheritDoc} * * @see org.opencastproject.workflow.api.WorkflowService#suspend(long) */ @Override public WorkflowInstance suspend(long workflowInstanceId) throws WorkflowDatabaseException, NotFoundException { HttpPost post = new HttpPost("/suspend"); List<BasicNameValuePair> params = new ArrayList<BasicNameValuePair>(); params.add(new BasicNameValuePair("id", Long.toString(workflowInstanceId))); try { post.setEntity(new UrlEncodedFormEntity(params)); } catch (UnsupportedEncodingException e) { throw new IllegalStateException("Unable to assemble a remote workflow service request", e); } HttpResponse response = getResponse(post, SC_OK, SC_NOT_FOUND); try { if (response != null) { if (response.getStatusLine().getStatusCode() == SC_NOT_FOUND) { throw new NotFoundException("Workflow instance with id='" + workflowInstanceId + "' not found"); } else { logger.info("Workflow '{}' suspended", workflowInstanceId); return WorkflowParser.parseWorkflowInstance(response.getEntity().getContent()); } } } catch (NotFoundException e) { throw e; } catch (Exception e) { throw new WorkflowDatabaseException(e); } finally { closeConnection(response); } throw new WorkflowDatabaseException("Unable to suspend workflow instance " + workflowInstanceId); } /** * {@inheritDoc} * * @see org.opencastproject.workflow.api.WorkflowService#resume(long) */ @Override public WorkflowInstance resume(long workflowInstanceId) throws NotFoundException, WorkflowDatabaseException { return resume(workflowInstanceId, null); } /** * {@inheritDoc} * * @see org.opencastproject.workflow.api.WorkflowService#resume(long, java.util.Map) */ @Override public WorkflowInstance resume(long workflowInstanceId, Map<String, String> properties) throws NotFoundException, WorkflowDatabaseException { HttpPost post = new HttpPost("/resume"); List<BasicNameValuePair> params = new ArrayList<BasicNameValuePair>(); params.add(new BasicNameValuePair("id", Long.toString(workflowInstanceId))); if (properties != null) params.add(new BasicNameValuePair("properties", mapToString(properties))); try { post.setEntity(new UrlEncodedFormEntity(params)); } catch (UnsupportedEncodingException e) { throw new IllegalStateException("Unable to assemble a remote workflow service request", e); } HttpResponse response = getResponse(post, SC_OK, SC_NOT_FOUND); try { if (response != null) { if (response.getStatusLine().getStatusCode() == SC_NOT_FOUND) { throw new NotFoundException("Workflow instance with id='" + workflowInstanceId + "' not found"); } else { logger.info("Workflow '{}' resumed", workflowInstanceId); return WorkflowParser.parseWorkflowInstance(response.getEntity().getContent()); } } } catch (NotFoundException e) { throw e; } catch (Exception e) { throw new WorkflowDatabaseException(e); } finally { closeConnection(response); } throw new WorkflowDatabaseException("Unable to resume workflow instance " + workflowInstanceId); } /** * {@inheritDoc} * * @see org.opencastproject.workflow.api.WorkflowService#update(org.opencastproject.workflow.api.WorkflowInstance) */ @Override public void update(WorkflowInstance workflowInstance) throws WorkflowDatabaseException { HttpPost post = new HttpPost("/update"); try { List<BasicNameValuePair> params = new ArrayList<BasicNameValuePair>(); params.add(new BasicNameValuePair("workflow", WorkflowParser.toXml(workflowInstance))); post.setEntity(new UrlEncodedFormEntity(params)); } catch (UnsupportedEncodingException e) { throw new IllegalStateException("Unable to assemble a remote workflow service request", e); } catch (Exception e) { throw new IllegalStateException("unable to serialize workflow instance to xml"); } HttpResponse response = getResponse(post, SC_NO_CONTENT); try { if (response != null) { logger.info("Workflow '{}' updated", workflowInstance); return; } } finally { closeConnection(response); } throw new WorkflowDatabaseException("Unable to update workflow instance " + workflowInstance.getId()); } /** * {@inheritDoc} * * @see org.opencastproject.workflow.api.WorkflowService#remove(long) */ @Override public void remove(long workflowInstanceId) throws WorkflowDatabaseException, WorkflowParsingException, NotFoundException, UnauthorizedException { HttpDelete delete = new HttpDelete("/remove/" + Long.toString(workflowInstanceId)); HttpResponse response = getResponse(delete, SC_NO_CONTENT, SC_NOT_FOUND); try { if (response != null) { if (SC_NOT_FOUND == response.getStatusLine().getStatusCode()) { throw new NotFoundException("Workflow id not found: " + workflowInstanceId); } else { logger.info("Workflow '{}' removed", workflowInstanceId); return; } } } finally { closeConnection(response); } throw new WorkflowDatabaseException("Unable to remove workflow instance " + workflowInstanceId); } /** * {@inheritDoc} * * @see org.opencastproject.workflow.api.WorkflowService#listAvailableWorkflowDefinitions() */ @Override public List<WorkflowDefinition> listAvailableWorkflowDefinitions() throws WorkflowDatabaseException { HttpGet get = new HttpGet("/definitions.xml"); HttpResponse response = getResponse(get); try { if (response != null) return WorkflowParser.parseWorkflowDefinitions(response.getEntity().getContent()); } catch (Exception e) { throw new IllegalStateException("Unable to parse workflow definitions"); } finally { closeConnection(response); } throw new WorkflowDatabaseException( "Unable to read the registered workflow definitions from the remote workflow service"); } /** * {@inheritDoc} * * @see org.opencastproject.workflow.api.WorkflowService#registerWorkflowDefinition(org.opencastproject.workflow.api.WorkflowDefinition) */ @Override public void registerWorkflowDefinition(WorkflowDefinition workflow) throws WorkflowDatabaseException { HttpPut put = new HttpPut("/definition"); try { List<BasicNameValuePair> params = new ArrayList<BasicNameValuePair>(); params.add(new BasicNameValuePair("workflowDefinition", WorkflowParser.toXml(workflow))); put.setEntity(new UrlEncodedFormEntity(params)); } catch (UnsupportedEncodingException e) { throw new IllegalStateException("Unable to assemble a remote workflow service request", e); } catch (Exception e) { throw new IllegalStateException("unable to serialize workflow definition to xml"); } HttpResponse response = getResponse(put, SC_CREATED, SC_PRECONDITION_FAILED); try { if (response != null) { if (SC_PRECONDITION_FAILED == response.getStatusLine().getStatusCode()) { throw new IllegalStateException( "A workflow definition with ID '" + workflow.getId() + "' is already registered."); } else { logger.info("Workflow definition '{}' registered", workflow); return; } } } finally { closeConnection(response); } throw new WorkflowDatabaseException("Unable to register workflow definition " + workflow.getId()); } /** * {@inheritDoc} * * @see org.opencastproject.workflow.api.WorkflowService#unregisterWorkflowDefinition(java.lang.String) */ @Override public void unregisterWorkflowDefinition(String workflowDefinitionId) throws NotFoundException, WorkflowDatabaseException { HttpDelete delete = new HttpDelete("/definition/" + workflowDefinitionId); HttpResponse response = getResponse(delete, SC_NO_CONTENT, SC_NOT_FOUND); try { if (response != null) { if (SC_NOT_FOUND == response.getStatusLine().getStatusCode()) { throw new NotFoundException("Workflow definition '" + workflowDefinitionId + "' not found."); } else { logger.info("Workflow definition '{}' unregistered", workflowDefinitionId); return; } } } finally { closeConnection(response); } throw new WorkflowDatabaseException("Unable to delete workflow definition '" + workflowDefinitionId + "'"); } /** * {@inheritDoc} * * @see org.opencastproject.workflow.api.WorkflowService#addWorkflowListener(org.opencastproject.workflow.api.WorkflowListener) */ @Override public void addWorkflowListener(WorkflowListener listener) { throw new UnsupportedOperationException( "Adding workflow listeners to a remote workflow service is not supported"); } /** * {@inheritDoc} * * @see org.opencastproject.workflow.api.WorkflowService#removeWorkflowListener(org.opencastproject.workflow.api.WorkflowListener) */ @Override public void removeWorkflowListener(WorkflowListener listener) { throw new UnsupportedOperationException( "Removing workflow listeners from a remote workflow service is not supported"); } }