Java tutorial
/* * Copyright (c) 2008, 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.governance.api.schema; import org.apache.axiom.om.OMAttribute; import org.apache.axiom.om.OMElement; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.jaxen.JaxenException; import org.wso2.carbon.governance.api.common.dataobjects.GovernanceArtifact; import org.wso2.carbon.governance.api.exception.GovernanceException; import org.wso2.carbon.governance.api.schema.dataobjects.Schema; import org.wso2.carbon.governance.api.schema.dataobjects.SchemaImpl; import org.wso2.carbon.governance.api.util.GovernanceConstants; import org.wso2.carbon.governance.api.util.GovernanceUtils; 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 javax.xml.namespace.QName; import java.net.MalformedURLException; import java.net.URL; import java.util.*; /** * This provides the management functionality for schema artifacts stored on the * registry. */ public class SchemaManager { private static final Log log = LogFactory.getLog(SchemaManager.class); private Registry registry; /** * Constructor accepting an instance of the registry to use. * * @param registry the instance of the registry. */ public SchemaManager(Registry registry) { this.registry = registry; } /** * Creates a new schema artifact from the given URL. * * @param url the given URL. * * @return the artifact added. * @throws GovernanceException if the operation failed. */ public Schema newSchema(String url) throws GovernanceException { String schemaId = UUID.randomUUID().toString(); SchemaImpl schema = new SchemaImpl(schemaId, url); schema.associateRegistry(registry); return schema; } /** * Create a new Schema based on content either embedded or passed to a service. * * @param content the schema content * * @return the artifact added. * @throws GovernanceException if the operation failed. */ public Schema newSchema(byte[] content) throws RegistryException { return newSchema(content, null); } /** * Create a new Schema based on content either embedded or passed to a service. * * @param content the schema content * @param name the schema name * * @return the artifact added. * @throws GovernanceException if the operation failed. */ public Schema newSchema(byte[] content, String name) throws RegistryException { String schemaId = UUID.randomUUID().toString(); SchemaImpl schema = new SchemaImpl(schemaId, name != null ? "name://" + name : null); schema.associateRegistry(registry); schema.setSchemaElement(GovernanceUtils.buildOMElement(content)); return schema; } /** * Adds the given schema artifact to the registry. Please do not use this method to update an * existing artifact use the update method instead. If this method is used to update an existing * artifact, all existing properties (such as lifecycle details) will be removed from the * existing artifact. * * @param schema the schema artifact. * * @throws GovernanceException if the operation failed. */ public void addSchema(Schema schema) throws GovernanceException { boolean succeeded = false; try { registry.beginTransaction(); String url = ((SchemaImpl) schema).getUrl(); Resource schemaResource = registry.newResource(); schemaResource.setMediaType(GovernanceConstants.SCHEMA_MEDIA_TYPE); schemaResource.setUUID(schema.getId()); // setting the schema content setContent(schema, schemaResource); String tmpPath; if (schema.getQName() != null) { tmpPath = "/" + schema.getQName().getLocalPart(); } else if (url != null && !url.startsWith("name://")) { tmpPath = RegistryUtils.getResourceName(new URL(url).getFile().replace("~", "")); } else if (url != null) { tmpPath = url.substring("name://".length()); } else { tmpPath = schema.getId() + ".xsd"; } // OK this is a hack to get the UUID of the newly added artifact. This needs to be fixed // properly with the fix for UUID support at Kernel-level - Janaka. // Resource resource; if (url == null || url.startsWith("name://")) { // resource = registry.get(registry.put("/" + tmpPath, schemaResource)); registry.put("/" + tmpPath, schemaResource); } else { // resource = registry.get(registry.importResource(tmpPath, url, schemaResource)); registry.importResource(tmpPath, url, schemaResource); } // schema.setId(schemaResource.getUUID()); ((SchemaImpl) schema).updatePath(); ((SchemaImpl) schema).loadSchemaDetails(); succeeded = true; } catch (RegistryException e) { String msg = "Error in adding the Schema. schema id: " + schema.getId() + "."; log.error(msg, e); throw new GovernanceException(msg, e); } catch (MalformedURLException e) { String msg = "Malformed schema url provided. url: " + ((SchemaImpl) schema).getUrl() + "."; log.error(msg, e); throw new GovernanceException(msg, e); } finally { if (succeeded) { try { registry.commitTransaction(); } catch (RegistryException e) { String msg = "Error in committing transactions. Add schema failed: schema id: " + schema.getId() + ", path: " + schema.getPath() + "."; log.error(msg, e); } } else { try { registry.rollbackTransaction(); } catch (RegistryException e) { String msg = "Error in rolling back transactions. Add schema failed: schema id: " + schema.getId() + ", path: " + schema.getPath() + "."; log.error(msg, e); } } } } /** * Updates the given schema artifact on the registry. * * @param schema the schema artifact. * * @throws GovernanceException if the operation failed. */ public void updateSchema(Schema schema) throws GovernanceException { if (schema.getSchemaElement() == null) { // there won't be any updates String msg = "Updates are only accepted if the schemeElement is available. " + "So no updates will be done. " + "schema id: " + schema.getId() + ", schema path: " + schema.getPath() + "."; log.error(msg); throw new GovernanceException(msg); } boolean succeeded = false; try { registry.beginTransaction(); // getting the old schema. Schema oldSchema = getSchema(schema.getId()); if (oldSchema == null) { addSchema(schema); return; } // we are expecting only the OMElement to be different. Resource schemaResource = registry.newResource(); schemaResource.setMediaType(GovernanceConstants.SCHEMA_MEDIA_TYPE); // setting the schema content setContent(schema, schemaResource); schemaResource.setUUID(schema.getId()); registry.put(oldSchema.getPath(), schemaResource); schema.setId(schemaResource.getUUID()); ((SchemaImpl) schema).updatePath(); //schema.loadSchemaDetails(); succeeded = true; } catch (RegistryException e) { String msg = "Error in updating the schema, schema id: " + schema.getId() + ", schema path: " + schema.getPath() + "."; log.error(msg, e); throw new GovernanceException(msg, e); } finally { if (succeeded) { try { registry.commitTransaction(); } catch (RegistryException e) { String msg = "Error in committing transactions. Update schema failed: " + "schema id: " + schema.getId() + ", path: " + schema.getPath() + "."; log.error(msg, e); } } else { try { registry.rollbackTransaction(); } catch (RegistryException e) { String msg = "Error in rolling back transactions. Update schema failed: " + "schema id: " + schema.getId() + ", path: " + schema.getPath() + "."; log.error(msg, e); } } } } /** * Fetches the given schema artifact on the registry. * * @param schemaId the identifier of the schema artifact. * * @return the schema artifact. * @throws GovernanceException if the operation failed. */ public Schema getSchema(String schemaId) throws GovernanceException { GovernanceArtifact artifact = GovernanceUtils.retrieveGovernanceArtifactById(registry, schemaId); if (artifact != null && !(artifact instanceof Schema)) { String msg = "The artifact request is not a Schema. id: " + schemaId + "."; log.error(msg); throw new GovernanceException(msg); } return (Schema) artifact; } /** * Removes the given schema artifact from the registry. * * @param schemaId the identifier of the schema artifact. * * @throws GovernanceException if the operation failed. */ public void removeSchema(String schemaId) throws GovernanceException { GovernanceUtils.removeArtifact(registry, schemaId); } /** * Sets content of the given schema artifact to the given resource on the * registry. * * @param schema the schema artifact. * @param schemaResource the content resource. * * @throws GovernanceException if the operation failed. */ protected void setContent(Schema schema, Resource schemaResource) throws GovernanceException { if (schema.getSchemaElement() != null) { OMElement contentElement = schema.getSchemaElement().cloneOMElement(); try { for (String importType : new String[] { "import", "include", "redefine" }) { List<OMElement> schemaImports = GovernanceUtils.evaluateXPathToElements("//xsd:" + importType, contentElement); for (OMElement schemaImport : schemaImports) { OMAttribute location = schemaImport.getAttribute(new QName("schemaLocation")); if (location != null) { String path = location.getAttributeValue(); if (path.indexOf(";version:") > 0) { location.setAttributeValue(path.substring(0, path.lastIndexOf(";version:"))); } } } } } catch (JaxenException ignore) { } String schemaContent = contentElement.toString(); try { schemaResource.setContent(schemaContent); } catch (RegistryException e) { String msg = "Error in setting the content from schema, schema id: " + schema.getId() + ", schema path: " + schema.getPath() + "."; log.error(msg, e); throw new GovernanceException(msg, e); } } // and set all the attributes as properties. String[] attributeKeys = schema.getAttributeKeys(); if (attributeKeys != null) { Properties properties = new Properties(); for (String attributeKey : attributeKeys) { String[] attributeValues = schema.getAttributes(attributeKey); if (attributeValues != null) { // The list obtained from the Arrays#asList method is // immutable. Therefore, // we create a mutable object out of it before adding it as // a property. properties.put(attributeKey, new ArrayList<String>(Arrays.asList(attributeValues))); } } schemaResource.setProperties(properties); } schemaResource.setUUID(schema.getId()); } /** * Finds all schema artifacts matching the given filter criteria. * * @param criteria the filter criteria to be matched. * * @return the schema artifacts that match. * @throws GovernanceException if the operation failed. */ public Schema[] findSchemas(SchemaFilter criteria) throws GovernanceException { List<Schema> schemas = new ArrayList<Schema>(); for (Schema schema : getAllSchemas()) { if (schema != null) { if (criteria.matches(schema)) { schemas.add(schema); } } } return schemas.toArray(new Schema[schemas.size()]); } /** * Finds all schema artifacts on the registry. * * @return all schema artifacts on the registry. * @throws GovernanceException if the operation failed. */ public Schema[] getAllSchemas() throws GovernanceException { List<String> schemaPaths = Arrays .asList(GovernanceUtils.getResultPaths(registry, GovernanceConstants.SCHEMA_MEDIA_TYPE)); Collections.sort(schemaPaths, new Comparator<String>() { public int compare(String o1, String o2) { // First order by name int result = RegistryUtils.getResourceName(o1) .compareToIgnoreCase(RegistryUtils.getResourceName(o2)); if (result != 0) { return result; } // Then order by namespace return o1.compareToIgnoreCase(o2); } }); List<Schema> schemas = new ArrayList<Schema>(); for (String schemaPath : schemaPaths) { GovernanceArtifact artifact = GovernanceUtils.retrieveGovernanceArtifactByPath(registry, schemaPath); schemas.add((Schema) artifact); } return schemas.toArray(new Schema[schemas.size()]); } }