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.dao.impl; import org.apache.commons.lang3.StringUtils; import org.apache.nifi.controller.FlowController; import org.apache.nifi.controller.Template; import org.apache.nifi.controller.TemplateUtils; import org.apache.nifi.controller.exception.ProcessorInstantiationException; import org.apache.nifi.controller.serialization.FlowEncodingVersion; import org.apache.nifi.groups.ProcessGroup; import org.apache.nifi.web.NiFiCoreException; import org.apache.nifi.web.ResourceNotFoundException; import org.apache.nifi.web.api.dto.FlowSnippetDTO; import org.apache.nifi.web.api.dto.ProcessGroupDTO; import org.apache.nifi.web.api.dto.TemplateDTO; import org.apache.nifi.web.dao.TemplateDAO; import org.apache.nifi.web.util.SnippetUtils; import java.util.HashSet; import java.util.List; import java.util.Set; /** * */ public class StandardTemplateDAO extends ComponentDAO implements TemplateDAO { private FlowController flowController; private SnippetUtils snippetUtils; private Template locateTemplate(String templateId) { // get the template Template template = flowController.getGroup(flowController.getRootGroupId()).findTemplate(templateId); // ensure the template exists if (template == null) { throw new ResourceNotFoundException( String.format("Unable to locate template with id '%s'.", templateId)); } return template; } @Override public void verifyCanAddTemplate(String name, String groupId) { final ProcessGroup processGroup = flowController.getGroup(groupId); if (processGroup == null) { throw new ResourceNotFoundException("Could not find Process Group with ID " + groupId); } verifyAdd(name, processGroup); } private void verifyAdd(final String name, final ProcessGroup processGroup) { processGroup.verifyCanAddTemplate(name); } @Override public void verifyComponentTypes(FlowSnippetDTO snippet) { flowController.verifyComponentTypesInSnippet(snippet); } @Override public Template createTemplate(TemplateDTO templateDTO, String groupId) { final ProcessGroup processGroup = flowController.getGroup(groupId); if (processGroup == null) { throw new ResourceNotFoundException("Could not find Process Group with ID " + groupId); } verifyAdd(templateDTO.getName(), processGroup); TemplateUtils.scrubTemplate(templateDTO); final Template template = new Template(templateDTO); processGroup.addTemplate(template); return template; } @Override public Template importTemplate(TemplateDTO templateDTO, String groupId) { return createTemplate(templateDTO, groupId); } @Override public FlowSnippetDTO instantiateTemplate(String groupId, Double originX, Double originY, String templateId, String idGenerationSeed) { ProcessGroup group = locateProcessGroup(flowController, groupId); // get the template id and find the template Template template = getTemplate(templateId); // ensure the template could be found if (template == null) { throw new ResourceNotFoundException( String.format("Unable to locate template with id '%s'.", templateId)); } try { // copy the template which pre-processes all ids TemplateDTO templateDetails = template.getDetails(); FlowSnippetDTO snippet = snippetUtils.copy(templateDetails.getSnippet(), group, idGenerationSeed, false); // calculate scaling factors based on the template encoding version // attempt to parse the encoding version final FlowEncodingVersion templateEncodingVersion = FlowEncodingVersion .parse(templateDetails.getEncodingVersion()); // get the major version, or 0 if no version could be parsed int templateEncodingMajorVersion = templateEncodingVersion != null ? templateEncodingVersion.getMajorVersion() : 0; // based on the major version < 1, use the default scaling factors. Otherwise, don't scale (use factor of 1.0) double factorX = templateEncodingMajorVersion < 1 ? FlowController.DEFAULT_POSITION_SCALE_FACTOR_X : 1.0; double factorY = templateEncodingMajorVersion < 1 ? FlowController.DEFAULT_POSITION_SCALE_FACTOR_Y : 1.0; // reposition and scale the template contents org.apache.nifi.util.SnippetUtils.moveAndScaleSnippet(snippet, originX, originY, factorX, factorY); // find all the child process groups in each process group in the top level of this snippet final List<ProcessGroupDTO> childProcessGroups = org.apache.nifi.util.SnippetUtils .findAllProcessGroups(snippet); // scale (but don't reposition) child process groups childProcessGroups.stream().forEach(processGroup -> org.apache.nifi.util.SnippetUtils .scaleSnippet(processGroup.getContents(), factorX, factorY)); // instantiate the template into this group flowController.instantiateSnippet(group, snippet); return snippet; } catch (ProcessorInstantiationException pie) { throw new NiFiCoreException(String.format( "Unable to instantiate template because processor type '%s' is unknown to this NiFi.", StringUtils.substringAfterLast(pie.getMessage(), "."))); } } @Override public void deleteTemplate(String templateId) { // ensure the template exists final Template template = locateTemplate(templateId); // remove the specified template template.getProcessGroup().removeTemplate(template); } @Override public Template getTemplate(String templateId) { return locateTemplate(templateId); } @Override public Set<Template> getTemplates() { final Set<Template> templates = new HashSet<>(); for (final Template template : flowController.getGroup(flowController.getRootGroupId()) .findAllTemplates()) { templates.add(template); } return templates; } /* * setters */ public void setFlowController(FlowController flowController) { this.flowController = flowController; } public void setSnippetUtils(SnippetUtils snippetUtils) { this.snippetUtils = snippetUtils; } }