Java tutorial
/* * Copyright (c) 2016, WSO2 Inc. (http://www.wso2.org) All Rights Reserved. * * 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.wso2.carbon.greg.migration.client; import org.apache.axiom.om.OMElement; import org.apache.axiom.om.util.AXIOMUtil; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.NodeList; import org.wso2.carbon.base.MultitenantConstants; import org.wso2.carbon.context.PrivilegedCarbonContext; import org.wso2.carbon.greg.migration.GRegMigrationException; import org.wso2.carbon.greg.migration.client.internal.ServiceHolder; import org.wso2.carbon.greg.migration.util.Constants; import org.wso2.carbon.registry.core.Collection; import org.wso2.carbon.registry.core.Registry; import org.wso2.carbon.registry.core.Resource; import org.wso2.carbon.registry.core.exceptions.RegistryException; import org.wso2.carbon.registry.core.utils.RegistryUtils; import org.wso2.carbon.user.api.Tenant; import org.wso2.carbon.user.api.UserStoreException; import org.wso2.carbon.user.core.tenant.TenantManager; import org.xml.sax.InputSource; import org.xml.sax.SAXException; import java.io.IOException; import java.io.StringReader; import java.io.StringWriter; import java.util.ArrayList; import java.util.Arrays; import java.util.Iterator; import java.util.List; import javax.xml.namespace.QName; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.parsers.ParserConfigurationException; import javax.xml.stream.XMLStreamException; import javax.xml.transform.OutputKeys; import javax.xml.transform.Transformer; import javax.xml.transform.TransformerException; import javax.xml.transform.TransformerFactory; import javax.xml.transform.dom.DOMSource; import javax.xml.transform.stream.StreamResult; /* * This class perform a migration process to remove "provider" child from the resource content */ public class ProviderMigrationClient { private static final Log log = LogFactory.getLog(ProviderMigrationClient.class); /* * This method is used to handle the migration process */ public void providerMigration() throws GRegMigrationException { long startTimeMillis = System.currentTimeMillis(); log.info("Provider migration client started"); try { List<Tenant> tenantsArray = getTenantsArray(); for (Tenant tenant : tenantsArray) { migrate(tenant); } log.info( "Migration Completed Successfully in " + (System.currentTimeMillis() - startTimeMillis) + "ms"); } catch (IOException e) { String msg = "Error occurred while performing operations on input source. "; log.error(msg, e); throw new GRegMigrationException(msg, e); } catch (UserStoreException e) { String msg = "Error occurred while searching for tenant admin. "; log.error(msg, e); throw new GRegMigrationException(msg, e); } catch (RegistryException e) { String msg = "Error occurred while performing registry operation. "; log.error(msg, e); throw new GRegMigrationException(msg, e); } catch (TransformerException e) { String msg = "Error occurred while converting DOM objects into xml string. "; log.error(msg, e); throw new GRegMigrationException(msg, e); } catch (SAXException e) { String msg = "Error occurred while parsing the xml content into DOM objects. "; log.error(msg, e); throw new GRegMigrationException(msg, e); } catch (ParserConfigurationException e) { String msg = "Error occurred while defining document builder. "; log.error(msg, e); throw new GRegMigrationException(msg, e); } catch (XMLStreamException e) { String msg = "Error while processing string to xml"; log.error(msg, e); throw new GRegMigrationException(msg, e); } } /* * This method is used to get all tenants as a tenant array */ private List<Tenant> getTenantsArray() throws UserStoreException { TenantManager tenantManager = ServiceHolder.getRealmService().getTenantManager(); List<Tenant> tenantsArray = new ArrayList<Tenant>(Arrays.asList(tenantManager.getAllTenants())); Tenant superTenant = new Tenant(); superTenant.setDomain(MultitenantConstants.SUPER_TENANT_DOMAIN_NAME); superTenant.setId(MultitenantConstants.SUPER_TENANT_ID); tenantsArray.add(superTenant); return tenantsArray; } /* * This method is used to handle the migration process */ private void migrate(Tenant tenant) throws UserStoreException, RegistryException, SAXException, TransformerException, ParserConfigurationException, IOException, XMLStreamException { int tenantId = tenant.getId(); try { PrivilegedCarbonContext.startTenantFlow(); PrivilegedCarbonContext.getThreadLocalCarbonContext().setTenantDomain(tenant.getDomain(), true); PrivilegedCarbonContext.getThreadLocalCarbonContext().setTenantId(tenantId); String adminName = ServiceHolder.getRealmService().getTenantUserRealm(tenantId).getRealmConfiguration() .getAdminUserName(); PrivilegedCarbonContext.getThreadLocalCarbonContext().setUsername(adminName); ServiceHolder.getTenantRegLoader().loadTenantRegistry(tenantId); Registry registry = ServiceHolder.getRegistryService().getRegistry(adminName, tenantId); Collection resourceTypes = (Collection) registry.get(Constants.RESOURCETYPES_RXT_PATH); String[] resourceTypesRxtPaths = resourceTypes.getChildren(); for (String resourceTypeRxtPath : resourceTypesRxtPaths) { if (!isContentArtifact(resourceTypeRxtPath, registry)) { ServiceHolder.getRXTStoragePathService().addStoragePath( getMediaType(resourceTypeRxtPath, registry), getStoragePath(resourceTypeRxtPath, registry)); if (!(getStoragePath(resourceTypeRxtPath, registry).contains("@{overview_provider}")) || !hasOverviewProviderElement(resourceTypeRxtPath, registry)) { String[] storagePathElements = getStoragePath(resourceTypeRxtPath, registry).split("/"); String storagePath = Constants.GOV_PATH; for (String storagePathElement : storagePathElements) { if (storagePathElement.startsWith("@")) { break; } if (!storagePathElement.isEmpty()) { storagePath += ("/" + storagePathElement); } } if (registry.resourceExists(storagePath)) { Collection storageCollection = (Collection) registry.get(storagePath); migrateProvider(storageCollection, registry); } } } } } finally { PrivilegedCarbonContext.endTenantFlow(); } } /* * This method is used to check whether the artifact at the given rxt path is a content artifact */ private boolean isContentArtifact(String rxtPath, Registry registry) throws RegistryException, IOException, SAXException, ParserConfigurationException { Resource artifactRxt = registry.get(rxtPath); byte[] rxtContent = (byte[]) artifactRxt.getContent(); String rxtContentString = RegistryUtils.decodeBytes(rxtContent); Document dom = stringToDocument(rxtContentString); Element domElement = (Element) dom.getElementsByTagName(Constants.ARTIFACT_TYPE).item(0); return domElement.hasAttribute(Constants.FILE_EXTENSION); } /* * This method is used to get the media type of the artifact at the given rxt path */ private String getMediaType(String rxtPath, Registry registry) throws RegistryException, IOException, SAXException, ParserConfigurationException { Resource artifactRxt = registry.get(rxtPath); byte[] rxtContent = (byte[]) artifactRxt.getContent(); String rxtContentString = RegistryUtils.decodeBytes(rxtContent); Document dom = stringToDocument(rxtContentString); Element domElement = (Element) dom.getElementsByTagName(Constants.ARTIFACT_TYPE).item(0); return domElement.getAttribute(Constants.TYPE); } /* * This method is used to get the storage path of the artifact at the given rxt path */ private String getStoragePath(String rxtPath, Registry registry) throws RegistryException, IOException, SAXException, ParserConfigurationException { Resource artifactRxt = registry.get(rxtPath); byte[] rxtContent = (byte[]) artifactRxt.getContent(); String rxtContentString = RegistryUtils.decodeBytes(rxtContent); Document dom = stringToDocument(rxtContentString); Node storagePath = dom.getElementsByTagName(Constants.STORAGE_PATH).item(0); return storagePath.getFirstChild().getNodeValue(); } /** * This method checks whether there is a provider in the overview table. * @param rxtPath * @param registry * @return boolean * @throws RegistryException * @throws IOException * @throws SAXException * @throws ParserConfigurationException * @throws XMLStreamException */ private boolean hasOverviewProviderElement(String rxtPath, Registry registry) throws RegistryException, IOException, SAXException, ParserConfigurationException, XMLStreamException { Resource artifactRxt = registry.get(rxtPath); byte[] rxtContent = (byte[]) artifactRxt.getContent(); String rxtContentString = RegistryUtils.decodeBytes(rxtContent); OMElement rxtContentOM = AXIOMUtil.stringToOM(rxtContentString); OMElement contentElement = rxtContentOM.getFirstChildWithName(new QName(Constants.CONTENT)); Iterator tableNodes = contentElement.getChildrenWithLocalName(Constants.TABLE); while (tableNodes.hasNext()) { OMElement tableOMElement = (OMElement) tableNodes.next(); if ("Overview".equals(tableOMElement.getAttributeValue(new QName(Constants.NAME)))) { Iterator fieldNodes = tableOMElement.getChildrenWithLocalName(Constants.FIELD); while (fieldNodes.hasNext()) { OMElement fieldElement = (OMElement) fieldNodes.next(); OMElement nameElement = fieldElement.getFirstChildWithName(new QName(Constants.NAME)); if (nameElement != null) { if ("Provider".equals(nameElement.getText())) { return true; } } } } } return false; } /* * This method is used to remove the 'provider' child of 'overview' from the xml content */ private void migrateProvider(Collection root, Registry registry) throws RegistryException, SAXException, TransformerException, ParserConfigurationException, IOException { String[] childrenPaths = root.getChildren(); for (String child : childrenPaths) { Resource childResource = registry.get(child); if (childResource instanceof Collection) { migrateProvider((Collection) childResource, registry); } else { String path = childResource.getPath(); byte[] configContent = (byte[]) childResource.getContent(); String contentString = RegistryUtils.decodeBytes(configContent); Document dom = stringToDocument(contentString); if (dom.getElementsByTagName(Constants.OVERVIEW).getLength() > 0) { Node overview = dom.getElementsByTagName(Constants.OVERVIEW).item(0); NodeList childrenList = overview.getChildNodes(); for (int j = 0; j < childrenList.getLength(); j++) { Node node = childrenList.item(j); if (Constants.PROVIDER.equals(node.getNodeName())) { overview.removeChild(node); String newContentString = documentToString(dom); byte[] newContentObject = RegistryUtils.encodeString(newContentString); childResource.setContent(newContentObject); registry.put(path, childResource); } } } } } } /* * This method is used to convert given xml string to Document type */ private Document stringToDocument(String strXml) throws ParserConfigurationException, SAXException, IOException { DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); DocumentBuilder builder = factory.newDocumentBuilder(); InputSource is = new InputSource(); is.setCharacterStream(new StringReader(strXml)); return builder.parse(is); } /* * This method is used to convert given xml Document to String type */ private String documentToString(Document doc) throws TransformerException { TransformerFactory tf = TransformerFactory.newInstance(); Transformer transformer = tf.newTransformer(); transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes"); StringWriter writer = new StringWriter(); transformer.transform(new DOMSource(doc), new StreamResult(writer)); return writer.getBuffer().toString(); } }