/*
***************************************************************************************
* Copyright (C) 2006 EsperTech, Inc. All rights reserved. *
* http://www.espertech.com/esper *
* http://www.espertech.com *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the GPL license *
* a copy of which has been included with this distribution in the license.txt file. *
***************************************************************************************
*/
package com.espertech.esperio.http.config;
import com.espertech.esper.client.ConfigurationException;
import com.espertech.esper.util.DOMElementIterator;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.xml.sax.SAXException;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import java.io.IOException;
import java.io.InputStream;
public class ConfigurationHTTPAdapterParser {
/**
* Use the configuration specified in the given input stream.
*
* @param configuration is the configuration object to populate
* @param stream Inputstream to be read from
* @param resourceName The name to use in warning/error messages
* @throws RuntimeException is thrown when the configuration could not be parsed
*/
protected static void doConfigure(ConfigurationHTTPAdapter configuration, InputStream stream, String resourceName) throws RuntimeException {
Document document = getDocument(stream, resourceName);
doConfigure(configuration, document);
}
/**
* Returns the document.
*
* @param stream to read
* @param resourceName resource in stream
* @return document
* @throws RuntimeException if the document could not be loaded or parsed
*/
protected static Document getDocument(InputStream stream, String resourceName) throws RuntimeException {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder;
Document document = null;
try {
builder = factory.newDocumentBuilder();
document = builder.parse(stream);
} catch (ParserConfigurationException ex) {
throw new RuntimeException("Could not get a DOM parser configuration: " + resourceName, ex);
} catch (SAXException ex) {
throw new RuntimeException("Could not parse configuration: " + resourceName, ex);
} catch (IOException ex) {
throw new RuntimeException("Could not read configuration: " + resourceName, ex);
} finally {
try {
stream.close();
} catch (IOException ioe) {
log.warn("could not close input stream for: " + resourceName, ioe);
}
}
return document;
}
/**
* Parse the W3C DOM document.
*
* @param configuration is the configuration object to populate
* @param doc to parse
* @throws RuntimeException to indicate parse errors
*/
protected static void doConfigure(ConfigurationHTTPAdapter configuration, Document doc) throws RuntimeException {
Element root = doc.getDocumentElement();
DOMElementIterator eventTypeNodeIterator = new DOMElementIterator(root.getChildNodes());
while (eventTypeNodeIterator.hasNext()) {
Element element = eventTypeNodeIterator.next();
String nodeName = element.getNodeName();
if (nodeName.equals("service")) {
handleService(configuration, element);
} else if (nodeName.equals("service")) {
handleGet(configuration, element);
} else if (nodeName.equals("get")) {
handleGet(configuration, element);
} else if (nodeName.equals("request")) {
handleRequest(configuration, element);
}
}
}
private static void handleService(ConfigurationHTTPAdapter configuration, Node node) {
String name = getRequiredAttribute(node, "name");
String port = getRequiredAttribute(node, "port");
String nio = getRequiredAttribute(node, "nio");
Service service = new Service();
configuration.getServices().put(name, service);
service.setPort(Integer.parseInt(port));
service.setNio(Boolean.parseBoolean(nio));
}
private static void handleGet(ConfigurationHTTPAdapter configuration, Node node) {
String service = getRequiredAttribute(node, "service");
String pattern = getRequiredAttribute(node, "pattern");
GetHandler get = new GetHandler();
configuration.getGetHandlers().add(get);
get.setService(service);
get.setPattern(pattern);
}
private static void handleRequest(ConfigurationHTTPAdapter configuration, Node node) {
String stream = getRequiredAttribute(node, "stream");
String uri = getRequiredAttribute(node, "uri");
Request request = new Request();
request.setStream(stream);
request.setUri(uri);
configuration.getRequests().add(request);
}
/**
* Returns an input stream from an application resource in the classpath.
*
* @param resource to get input stream for
* @return input stream for resource
*/
protected static InputStream getResourceAsStream(String resource) {
String stripped = resource.startsWith("/") ?
resource.substring(1) : resource;
InputStream stream = null;
ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
if (classLoader != null) {
stream = classLoader.getResourceAsStream(stripped);
}
if (stream == null) {
ConfigurationHTTPAdapterParser.class.getResourceAsStream(resource);
}
if (stream == null) {
stream = ConfigurationHTTPAdapterParser.class.getClassLoader().getResourceAsStream(stripped);
}
if (stream == null) {
throw new RuntimeException(resource + " not found");
}
return stream;
}
private static String getOptionalAttribute(Node node, String key) {
Node valueNode = node.getAttributes().getNamedItem(key);
if (valueNode != null) {
return valueNode.getTextContent();
}
return null;
}
private static String getRequiredAttribute(Node node, String key) {
Node valueNode = node.getAttributes().getNamedItem(key);
if (valueNode == null) {
throw new ConfigurationException("Required attribute by name '" + key + "' not found");
}
return valueNode.getTextContent();
}
private static Logger log = LoggerFactory.getLogger(ConfigurationHTTPAdapterParser.class);
}