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.synapse.registry.url; import org.apache.axiom.om.*; import org.apache.axiom.om.impl.builder.StAXOMBuilder; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.synapse.SynapseConstants; import org.apache.synapse.SynapseException; import org.apache.synapse.config.Entry; import org.apache.synapse.config.SynapseConfigUtils; import org.apache.synapse.registry.AbstractRegistry; import org.apache.synapse.registry.Registry; import org.apache.synapse.registry.RegistryEntry; import org.apache.synapse.registry.RegistryEntryImpl; import javax.xml.stream.XMLInputFactory; import javax.xml.stream.XMLStreamException; import javax.xml.stream.XMLStreamReader; import java.io.*; import java.net.MalformedURLException; import java.net.URL; import java.net.URLConnection; import java.util.ArrayList; import java.util.Properties; /** * A Simple HTTP GET based registry which will work with a Web Server / WebDAV * <p/> * This saves the root server URL, and appends the a given key to construct the * full URL to locate resources */ public class SimpleURLRegistry extends AbstractRegistry implements Registry { private static final Log log = LogFactory.getLog(SimpleURLRegistry.class); private static final int MAX_KEYS = 200; private String root = ""; private final OMFactory omFactory = OMAbstractFactory.getOMFactory(); public OMNode lookup(String key) { if (log.isDebugEnabled()) { log.debug("==> Repository fetch of resource with key : " + key); } URL url = SynapseConfigUtils.getURLFromPath(root + key, properties.get(SynapseConstants.SYNAPSE_HOME) != null ? properties.get(SynapseConstants.SYNAPSE_HOME).toString() : ""); if (url == null) { return null; } BufferedInputStream inputStream; try { URLConnection connection = SynapseConfigUtils.getURLConnection(url); if (connection == null) { if (log.isDebugEnabled()) { log.debug("Cannot create a URLConnection for given URL : " + url); } return null; } connection.connect(); inputStream = new BufferedInputStream(connection.getInputStream()); } catch (IOException e) { return null; } OMNode result = null; if (inputStream != null) { try { XMLStreamReader parser = XMLInputFactory.newInstance().createXMLStreamReader(inputStream); StAXOMBuilder builder = new StAXOMBuilder(parser); result = builder.getDocumentElement(); } catch (OMException ignored) { if (log.isDebugEnabled()) { log.debug("The resource at the provided URL isn't " + "well-formed XML,So,takes it as a text"); } try { inputStream.close(); } catch (IOException e) { log.error("Error in closing the input stream. ", e); } result = SynapseConfigUtils.readNonXML(url); } catch (XMLStreamException ignored) { if (log.isDebugEnabled()) { log.debug("The resource at the provided URL isn't " + "well-formed XML,So,takes it as a text"); } try { inputStream.close(); } catch (IOException e) { log.error("Error in closing the input stream. ", e); } result = SynapseConfigUtils.readNonXML(url); } finally { try { if (result != null && result.getParent() != null) { //TODO Replace following code with the correct code when synapse is moving to AXIOM 1.2.9 result.detach(); OMDocument omDocument = omFactory.createOMDocument(); omDocument.addChild(result); } inputStream.close(); } catch (IOException e) { log.error("Error in closing the input stream.", e); } } } return result; } public RegistryEntry getRegistryEntry(String key) { if (log.isDebugEnabled()) { log.debug("Perform RegistryEntry lookup for key : " + key); } URL url = SynapseConfigUtils.getURLFromPath(root + key, properties.get(SynapseConstants.SYNAPSE_HOME) != null ? properties.get(SynapseConstants.SYNAPSE_HOME).toString() : ""); if (url == null) { return null; } URLConnection connection = SynapseConfigUtils.getURLConnection(url); if (connection == null) { if (log.isDebugEnabled()) { log.debug("Cannot create a URLConnection for given URL : " + url); } return null; } RegistryEntryImpl wre = new RegistryEntryImpl(); wre.setKey(key); wre.setName(url.getFile()); wre.setType(connection.getContentType()); wre.setDescription("Resource at : " + url.toString()); wre.setLastModified(connection.getLastModified()); wre.setVersion(connection.getLastModified()); if (connection.getExpiration() > 0) { wre.setCachableDuration(connection.getExpiration() - System.currentTimeMillis()); } else { wre.setCachableDuration(getCachableDuration()); } return wre; } public OMElement getFormat(Entry entry) { return null; //To change body of implemented methods use File | Settings | File Templates. } public OMNode lookupFormat(String key) { return null; //To change body of implemented methods use File | Settings | File Templates. } public void init(Properties properties) { super.init(properties); String value = properties.getProperty("root"); if (value != null) { // if the root is folder, it should always end with '/' // therefore, property keys do not have to begin with '/', which could be misleading try { new URL(value); if (!value.endsWith("/")) { value = value + "/"; } } catch (MalformedURLException e) { // don't do any thing if this is not a valid URL } root = value; } else { handleException("Parameter root is null"); } } public void delete(String path) { //TODO } public void newResource(String path, boolean isDirectory) { //TODO } public void updateResource(String path, Object value) { //TODO } public void updateRegistryEntry(RegistryEntry entry) { //TODO } private long getCachableDuration() { String cachableDuration = (String) properties.get("cachableDuration"); return cachableDuration == null ? 1500 : Long.parseLong(cachableDuration); } public RegistryEntry[] getChildren(RegistryEntry entry) { URL url; if (entry == null) { RegistryEntryImpl entryImpl = new RegistryEntryImpl(); entryImpl.setKey(""); entry = entryImpl; } url = SynapseConfigUtils.getURLFromPath(root + entry.getKey(), properties.get(SynapseConstants.SYNAPSE_HOME) != null ? properties.get(SynapseConstants.SYNAPSE_HOME).toString() : ""); if (url == null) { return null; } if (url.getProtocol().equals("file")) { File file = new File(url.getFile()); if (!file.isDirectory()) { return null; } BufferedReader reader = null; try { reader = new BufferedReader(new InputStreamReader((InputStream) url.getContent())); ArrayList<RegistryEntry> entryList = new ArrayList<RegistryEntry>(); String key; while ((key = reader.readLine()) != null) { RegistryEntryImpl registryEntryImpl = new RegistryEntryImpl(); if (entry.getKey().equals("")) { registryEntryImpl.setKey(key); } else { if (entry.getKey().endsWith("/")) { registryEntryImpl.setKey(entry.getKey() + key); } else { registryEntryImpl.setKey(entry.getKey() + "/" + key); } } entryList.add(registryEntryImpl); } RegistryEntry[] entries = new RegistryEntry[entryList.size()]; for (int i = 0; i < entryList.size(); i++) { entries[i] = entryList.get(i); } return entries; } catch (Exception e) { throw new SynapseException("Error in reading the URL."); } finally { if (reader != null) { try { reader.close(); } catch (IOException ignored) { } } } } else { throw new SynapseException("Invalid protocol."); } } public RegistryEntry[] getDescendants(RegistryEntry entry) { ArrayList<RegistryEntry> list = new ArrayList<RegistryEntry>(); fillDescendants(entry, list); RegistryEntry[] descendants = new RegistryEntry[list.size()]; for (int i = 0; i < list.size(); i++) { descendants[i] = list.get(i); } return descendants; } private void fillDescendants(RegistryEntry parent, ArrayList<RegistryEntry> list) { RegistryEntry[] children = getChildren(parent); if (children != null) { for (RegistryEntry child : children) { if (child == null) { continue; } if (list.size() > MAX_KEYS) { break; } fillDescendants(child, list); } } else { list.add(parent); } } private void handleException(String msg) { log.error(msg); throw new SynapseException(msg); } }