Java tutorial
/* * Copyright (c) 2009-2010 Lockheed Martin Corporation * * 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.eurekastreams.server.action.validation.gallery; import java.io.IOException; import java.io.InputStream; import java.io.Serializable; import java.util.Map; import javax.xml.transform.stream.StreamSource; import javax.xml.validation.Schema; import javax.xml.validation.SchemaFactory; import javax.xml.validation.Validator; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.eurekastreams.commons.actions.ValidationStrategy; import org.eurekastreams.commons.actions.context.service.ServiceActionContext; import org.eurekastreams.commons.exceptions.ValidationException; import org.eurekastreams.server.service.actions.strategies.ResourceFetcher; /** * Implementation of GalleryItemValidator that validates XML from provided URL via provided in schema/XSD. * */ public class UrlXmlValidator implements ValidationStrategy<ServiceActionContext> { /** * url key. */ private static final String URL_KEY = "url"; /** * Logger. */ private Log log = LogFactory.getLog(UrlXmlValidator.class); /** * Schema String to use. */ private String schemaString; /** * Path to xsd file. Ex. /themes/openSocialGadget_0-9.xsd */ private String xsdPath; /** * Fetcher for the XML theme definition. */ private ResourceFetcher xmlFetcher = null; /** * Constructor. * * @param inSchema * The schema string. * @param inXsdPath * The classpath to xsd file. * @param inResourceFetcher * The ResourceFetcher implementation. */ public UrlXmlValidator(final String inSchema, final String inXsdPath, final ResourceFetcher inResourceFetcher) { schemaString = inSchema; xsdPath = inXsdPath; xmlFetcher = inResourceFetcher; } /** * Validates xml from given Url returning true if it passes validation, false otherwise. * * @param inActionContext * the action context * @throws ValidationException * on error */ @Override @SuppressWarnings("unchecked") public void validate(final ServiceActionContext inActionContext) throws ValidationException { InputStream schemaStream = null; Map<String, Serializable> fields = (Map<String, Serializable>) inActionContext.getParams(); String galleryItemUrl = (String) fields.get(URL_KEY); try { schemaStream = this.getClass().getResourceAsStream(xsdPath); log.debug("Attempt to validate xml at: " + galleryItemUrl + "with xsd at: " + xsdPath); SchemaFactory schemaFactory = SchemaFactory.newInstance(schemaString); Schema schema = schemaFactory.newSchema(new StreamSource(schemaStream)); Validator validator = schema.newValidator(); // TODO: stuff the input stream into the context for execute() InputStream galleryItemInputStream = xmlFetcher.getInputStream(galleryItemUrl); validator.validate(new StreamSource(galleryItemInputStream)); log.debug("Success validating xml at: " + galleryItemUrl); } catch (Exception e) { log.error("Validation for gadget definition failed.", e); ValidationException ve = new ValidationException(); ve.addError(URL_KEY, "Valid url is required"); throw ve; } finally { try { if (schemaStream != null) { schemaStream.close(); } } catch (IOException ex) { log.error("Error closing stream, already closed.", ex); } } } }