Java tutorial
/** * Licensed to Apereo under one or more contributor license * agreements. See the NOTICE file distributed with this work * for additional information regarding copyright ownership. * Apereo 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 the following location: * * 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.apereo.portal.io.xml; import java.io.IOException; import java.io.InputStream; import java.util.Iterator; import java.util.Map; import java.util.Queue; import java.util.Set; import java.util.concurrent.ConcurrentHashMap; import java.util.concurrent.ConcurrentLinkedQueue; import java.util.concurrent.ConcurrentMap; import java.util.concurrent.atomic.AtomicLong; import javax.xml.stream.XMLInputFactory; import javax.xml.stream.events.StartElement; import org.apache.commons.io.IOUtils; import org.codehaus.stax2.XMLInputFactory2; import org.apereo.portal.utils.ConcurrentMapUtils; import org.apereo.portal.utils.ResourceUtils; import org.apereo.portal.xml.StaxUtils; import org.apereo.portal.xml.stream.BufferedXMLEventReader; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.core.io.Resource; import com.ctc.wstx.api.WstxInputProperties; import com.google.common.base.Function; public final class PortalDataKeyFileProcessor implements Function<Resource, Object> { protected final Logger logger = LoggerFactory.getLogger(getClass()); private final AtomicLong count = new AtomicLong(); private final ConcurrentMap<PortalDataKey, Queue<Resource>> dataToImport = new ConcurrentHashMap<PortalDataKey, Queue<Resource>>(); private final Map<PortalDataKey, IPortalDataType> dataKeyTypes; private final XMLInputFactory xmlInputFactory; private final IPortalDataHandlerService.BatchImportOptions options; PortalDataKeyFileProcessor(Map<PortalDataKey, IPortalDataType> dataKeyTypes, IPortalDataHandlerService.BatchImportOptions options) { this.dataKeyTypes = dataKeyTypes; this.options = options; this.xmlInputFactory = XMLInputFactory.newFactory(); //Set the input buffer to 2k bytes. This appears to work for reading just enough to get the start element event for //all of the data files in a single read operation. this.xmlInputFactory.setProperty(WstxInputProperties.P_INPUT_BUFFER_LENGTH, 2000); this.xmlInputFactory.setProperty(XMLInputFactory2.P_LAZY_PARSING, true); //Do as little parsing as possible, just want basic info this.xmlInputFactory.setProperty(XMLInputFactory.IS_VALIDATING, false); //Don't do any validation here this.xmlInputFactory.setProperty(XMLInputFactory.SUPPORT_DTD, false); //Don't load referenced DTDs here } /** * @return total number of resources to import */ public long getResourceCount() { return count.get(); } /** * @return Map of the data to import */ public ConcurrentMap<PortalDataKey, Queue<Resource>> getDataToImport() { return dataToImport; } @Override public Object apply(Resource input) { final InputStream fis; try { fis = input.getInputStream(); } catch (IOException e) { if (this.options == null || this.options.isFailOnError()) { throw new RuntimeException("Failed to create InputStream for: " + input, e); } logger.warn("Failed to create InputStream, resource will be ignored: {}", input); return null; } final PortalDataKey portalDataKey; final BufferedXMLEventReader xmlEventReader; try { xmlEventReader = new BufferedXMLEventReader(this.xmlInputFactory.createXMLEventReader(fis), -1); final StartElement rootElement = StaxUtils.getRootElement(xmlEventReader); portalDataKey = new PortalDataKey(rootElement); } catch (Exception e) { if (this.options != null && !this.options.isIngoreNonDataFiles()) { throw new RuntimeException("Failed to parse: " + input, e); } logger.warn("Failed to parse resource, it will be ignored: {}", input); return null; } finally { IOUtils.closeQuietly(fis); } xmlEventReader.reset(); final IPortalDataType portalDataType = this.dataKeyTypes.get(portalDataKey); if (portalDataType == null) { Iterator<PortalDataKey> iter = dataKeyTypes.keySet().iterator(); StringBuffer potentialKeys = new StringBuffer(); potentialKeys.append("---------------- Potential Keys To Match -------------------"); while (iter.hasNext()) { PortalDataKey key = iter.next(); potentialKeys.append(key + "\n"); } logger.warn("{}No IPortalDataType configured for {}, the resource will be ignored: {}", potentialKeys, portalDataKey, input); return null; } //Allow the PortalDataType to do any necessary post-processing of the input, needed as some types require extra work final String resourceUri = ResourceUtils.getResourceUri(input); final Set<PortalDataKey> processedPortalDataKeys = portalDataType.postProcessPortalDataKey(resourceUri, portalDataKey, xmlEventReader); xmlEventReader.reset(); for (final PortalDataKey processedPortalDataKey : processedPortalDataKeys) { //Add the PortalDataKey and File into the map Queue<Resource> queue = this.dataToImport.get(processedPortalDataKey); if (queue == null) { queue = ConcurrentMapUtils.putIfAbsent(this.dataToImport, processedPortalDataKey, new ConcurrentLinkedQueue<Resource>()); } queue.offer(input); count.incrementAndGet(); } return null; } }