WPSConnector.java

/**
 * Copyright (C) 2008 - 2014 52°North Initiative for Geospatial Open Source
 * Software GmbH
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation.
 *
 * If the program is linked with libraries which are licensed under one of
 * the following licenses, the combination of the program with the linked
 * library is not considered a "derivative work" of the program:
 *
 *     - Apache License, version 2.0
 *     - Apache Software License, version 1.0
 *     - GNU Lesser General Public License, version 3
 *     - Mozilla Public License, versions 1.0, 1.1 and 2.0
 *     - Common Development and Distribution License (CDDL), version 1.0
 *
 * Therefore the distribution of the program linked with libraries licensed
 * under the aforementioned licenses, is permitted by the copyright holders
 * if the distribution is compliant with both the GNU General Public
 * icense version 2 and the aforementioned licenses.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
 * Public License for more details.
 */
package org.n52.ses.services.wps;

import java.net.URL;
import java.util.HashMap;
import java.util.Map;

import net.opengis.wps.x100.ExecuteResponseDocument;
import net.opengis.wps.x100.ExecuteResponseDocument.ExecuteResponse;
import net.opengis.wps.x100.ExecuteResponseDocument.ExecuteResponse.ProcessOutputs;

import org.apache.http.entity.ContentType;
import org.apache.xmlbeans.XmlObject;
import org.apache.xmlbeans.XmlOptions;
import org.n52.ses.util.http.BasicAuthenticator;
import org.n52.ses.util.http.SESHttpClient;
import org.n52.ses.util.http.SESHttpClient.SESHttpResponse;

/**
 * Provides methods to access and execute processes from a WPS. 
 * 
 * @author Matthes Rieke
 *
 */
public class WPSConnector {
	
	public final static String USER_KEY = "user";
	public final static String PASSWORD_KEY = "pw";
	
	private String wpsURL;
	
	private Map<String, String> userNamePW;
	private SESHttpClient client;
	
	public static XmlOptions requestOptions;
	
	static {
		requestOptions = new XmlOptions();
		requestOptions.setSavePrettyPrint();

		Map<String, String> suggestedPrefixes = new HashMap<String, String>();
		suggestedPrefixes.put("http://www.opengis.net/wps/1.0.0", "wps");
		suggestedPrefixes.put("http://www.aixm.aero/schema/5.1", "aixm");
		suggestedPrefixes.put("http://www.opengis.net/gml/3.2", "gml");
		requestOptions.setSaveSuggestedPrefixes(suggestedPrefixes);
		
	}
	
	/**
	 * Standard constructor
	 * 
	 * @param wfsURL
	 * @param usesSOAP
	 */
	public WPSConnector(String wpsURL) {
		this.wpsURL = wpsURL;
		client = new SESHttpClient();
	}

	/**
	 * Standard constructor using http-Authentication.
	 * 
	 * @param wfsURL
	 * @param usesSOAP
	 * @param userNamePW
	 */
	public WPSConnector(String wpsURL,
			Map<String, String> userNamePW) {
		this(wpsURL);
		this.userNamePW = userNamePW;
	}
	
	public ProcessOutputs executeRequest(XmlObject execute) throws Exception {
		XmlObject result = sendHttpPost(execute);
		
		if (result != null && result instanceof ExecuteResponseDocument) {
			ExecuteResponse response = ((ExecuteResponseDocument) result).getExecuteResponse();
			if (response != null && response.isSetProcessOutputs()) {
				return response.getProcessOutputs();
			}
		}
		
		throw new Exception("Could not retrieve result from WPS.");
	}
	
	/**
	 * Sends a request to a web service. Can deal with SOAP messages and http-authentification.
	 * 
	 * @param xmlRequest
	 * 		the request
	 * @return
	 * 		the response from the web service
	 * @throws Exception 
	 */
	private XmlObject sendHttpPost(XmlObject xmlRequest) throws Exception{
		String request = xmlRequest.xmlText(requestOptions);
		
		// authentication
		if (userNamePW != null){
			String username = userNamePW.get(USER_KEY);
			String password = userNamePW.get(PASSWORD_KEY);
			client.setAuthentication(new BasicAuthenticator(username, password));
		}

		SESHttpResponse resp = client.sendPost(new URL(wpsURL), request, ContentType.create("text/xml", "utf-8"));
		if (resp.getContentType().contains("xml")) {
			return XmlObject.Factory.parse(resp.getContent());
		}
		return null;
	}

	
	public String getURL() {
		return wpsURL;
	}

	
}