Java tutorial
/* * Copyright (c) 2005-2013, WSO2 Inc. (http://www.wso2.org) All Rights Reserved. * * WSO2 Inc. 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.wso2.carbon.apimgt.everywhere.interceptor.utils; import java.io.ByteArrayInputStream; import java.io.IOException; import javax.xml.stream.XMLInputFactory; import javax.xml.stream.XMLStreamException; import javax.xml.stream.XMLStreamReader; import org.apache.axiom.om.OMAbstractFactory; import org.apache.axiom.om.OMException; import org.apache.axiom.om.OMNode; import org.apache.axiom.om.impl.builder.StAXOMBuilder; import org.apache.axiom.om.impl.llom.OMDocumentImpl; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.wso2.carbon.apimgt.everywhere.interceptor.valve.internal.DataHolder; import org.wso2.carbon.apimgt.core.APIManagerConstants; import org.wso2.carbon.base.MultitenantConstants; import org.wso2.carbon.registry.core.Collection; import org.wso2.carbon.registry.core.Registry; import org.wso2.carbon.registry.core.RegistryConstants; import org.wso2.carbon.registry.core.Resource; import org.wso2.carbon.registry.core.exceptions.RegistryException; import org.wso2.carbon.registry.core.service.RegistryService; public class ThrottleUtils { private static final Log log = LogFactory.getLog(ThrottleUtils.class); public static OMNode lookup(String key) { try { Resource resource = getResource(key); if (resource instanceof Collection || resource == null) { return null; } ByteArrayInputStream inputStream = null; Object content = resource.getContent(); if (content instanceof String) { inputStream = new ByteArrayInputStream(content.toString().getBytes()); } else if (content instanceof byte[]) { inputStream = new ByteArrayInputStream((byte[]) content); } OMNode result = null; try { XMLStreamReader parser = XMLInputFactory.newInstance().createXMLStreamReader(inputStream); StAXOMBuilder builder = new StAXOMBuilder(parser); result = builder.getDocumentElement(); } catch (OMException ignored) { // result = readNonXML(resource); } catch (XMLStreamException ignored) { //result = readNonXML(resource); } catch (Exception e) { // a more general exception(e.g. a Runtime exception if the XML doc has an // external DTD deceleration and if not connected to internet) which in case // just log for debugging log.error("Error while reading the resource '" + key + "'", e); } finally { try { resource.discard(); if (result != null && result.getParent() != null) { result.detach(); OMDocumentImpl parent = new OMDocumentImpl(OMAbstractFactory.getOMFactory()); parent.addChild(result); } if (inputStream != null) { inputStream.close(); } } catch (IOException e) { log.error("Error while closing the input stream", e); } } return result; } catch (RegistryException e) { handleException("Error while fetching the resource " + key, e); } return null; } private static void handleException(String string, RegistryException e) { // TODO Auto-generated method stub } private static Resource getResource(String path) { RegistryService registryService = DataHolder.getRegistryService(); Registry registry = null; try { registry = registryService.getGovernanceSystemRegistry(MultitenantConstants.SUPER_TENANT_ID); } catch (RegistryException e) { log.error("Error while fetching Governance Registry of Super Tenant"); return null; } String key = resolvePath(path); try { if (registry.resourceExists(key)) { return registry.get(key); } } catch (RegistryException e) { handleException("Error while fetching the resource " + path, e); } return null; } private static String resolvePath(String path) { if (path == null || "".equals(path)) { path = RegistryConstants.ROOT_PATH; } path = path.substring(APIManagerConstants.GOVERNANCE_REGISTRY_PREFIX.length()); if (path.startsWith(RegistryConstants.PATH_SEPARATOR)) { path = path.substring(1); } path = RegistryConstants.ROOT_PATH + path; return path; } }