001    //$HeadURL: svn+ssh://jwilden@svn.wald.intevation.org/deegree/base/branches/2.5_testing/src/org/deegree/portal/owswatch/validator/AbstractValidator.java $
002    /*----------------------------------------------------------------------------
003     This file is part of deegree, http://deegree.org/
004     Copyright (C) 2001-2009 by:
005       Department of Geography, University of Bonn
006     and
007       lat/lon GmbH
008    
009     This library is free software; you can redistribute it and/or modify it under
010     the terms of the GNU Lesser General Public License as published by the Free
011     Software Foundation; either version 2.1 of the License, or (at your option)
012     any later version.
013     This library is distributed in the hope that it will be useful, but WITHOUT
014     ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
015     FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
016     details.
017     You should have received a copy of the GNU Lesser General Public License
018     along with this library; if not, write to the Free Software Foundation, Inc.,
019     59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
020    
021     Contact information:
022    
023     lat/lon GmbH
024     Aennchenstr. 19, 53177 Bonn
025     Germany
026     http://lat-lon.de/
027    
028     Department of Geography, University of Bonn
029     Prof. Dr. Klaus Greve
030     Postfach 1147, 53001 Bonn
031     Germany
032     http://www.geographie.uni-bonn.de/deegree/
033    
034     e-mail: info@deegree.org
035    ----------------------------------------------------------------------------*/
036    
037    package org.deegree.portal.owswatch.validator;
038    
039    import java.io.BufferedReader;
040    import java.io.ByteArrayInputStream;
041    import java.io.ByteArrayOutputStream;
042    import java.io.IOException;
043    import java.io.InputStream;
044    import java.io.InputStreamReader;
045    
046    import javax.servlet.http.HttpServletResponse;
047    import javax.xml.parsers.DocumentBuilder;
048    import javax.xml.parsers.DocumentBuilderFactory;
049    import javax.xml.parsers.ParserConfigurationException;
050    
051    import org.apache.commons.httpclient.HttpMethodBase;
052    import org.deegree.framework.log.ILogger;
053    import org.deegree.framework.log.LoggerFactory;
054    import org.deegree.framework.util.StringTools;
055    import org.deegree.framework.xml.XMLParsingException;
056    import org.deegree.framework.xml.XMLTools;
057    import org.w3c.dom.Document;
058    
059    import org.deegree.portal.owswatch.Status;
060    import org.deegree.portal.owswatch.ValidatorResponse;
061    
062    /**
063     * Abstract class implementing the method validate.
064     *
065     * @author <a href="mailto:elmasry@lat-lon.de">Moataz Elmasry</a>
066     * @author last edited by: $Author: jmays $
067     *
068     * @version $Revision: 20271 $, $Date: 2009-10-21 13:07:15 +0200 (Mi, 21 Okt 2009) $
069     */
070    public abstract class AbstractValidator implements Validator {
071    
072        private static final ILogger LOG = LoggerFactory.getLogger( AbstractValidator.class );
073    
074        /*
075         * (non-Javadoc)
076         *
077         * @see org.deegree.portal.owswatch.validator.Validator#validateAnswer(org.apache.commons.httpclient.HttpMethodBase, int,
078         *      int)
079         */
080        public ValidatorResponse validateAnswer( HttpMethodBase method, int statusCode ) {
081            if ( isValidHttpResponse( statusCode ) ) {
082                return validateXml( method );
083            } else {
084                return validateErrorHttpResponse( statusCode );
085            }
086        }
087    
088        /**
089         * Validates the HttpMethodBase and checks if the execution was successful or not
090         *
091         * @param method
092         *            the httpmethod after executing it
093         * @return an instance of ValidatorResponse with the necessary information after validation
094         */
095        protected ValidatorResponse validateXml( HttpMethodBase method ) {
096    
097            String lastMessage = null;
098            Status status = null;
099    
100            String contentType = method.getResponseHeader( "Content-Type" ).getValue();
101            if ( !contentType.contains( "xml" ) ) {
102                status = Status.RESULT_STATE_UNEXPECTED_CONTENT;
103                lastMessage = StringTools.concat( 100, "Error: Response Content is ", contentType, " not xml" );
104                return new ValidatorResponse( lastMessage, status );
105            }
106    
107            String xml = null;
108            try {
109                InputStream stream = copyStream( method.getResponseBodyAsStream() );
110                stream.reset();
111                xml = parseStream( stream );
112            } catch ( IOException e ) {
113                status = Status.RESULT_STATE_BAD_RESPONSE;
114                lastMessage = status.getStatusMessage();
115                return new ValidatorResponse( lastMessage, status );
116            }
117    
118            if ( xml.length() == 0 ) {
119                status = Status.RESULT_STATE_BAD_RESPONSE;
120                lastMessage = "Error: XML Response is empty";
121                return new ValidatorResponse( lastMessage, status );
122            }
123            if ( xml.contains( "ServiceException" ) ) {
124                return validateXmlServiceException( method );
125            }
126            // If its an xml, and there's no service exception, then don't really parse the xml,
127            // we assume that its well formed, since there might be huge xmls, which would take time to be parsed
128            status = Status.RESULT_STATE_AVAILABLE;
129            lastMessage = status.getStatusMessage();
130            return new ValidatorResponse( lastMessage, status );
131        }
132    
133        /**
134         * This method is called To read the ServiceExceptionReport from the xml file
135         *
136         * @param method
137         *            the httpmethod after executing it
138         * @return an instance of ValidatorResponse with the necessary information after validation
139         */
140        protected ValidatorResponse validateXmlServiceException( HttpMethodBase method ) {
141    
142            Document doc = null;
143            String lastMessage = null;
144            Status status = null;
145            try {
146                InputStream stream = method.getResponseBodyAsStream();
147                stream.reset();
148                doc = instantiateParser().parse( stream );
149            } catch ( Exception e ) {
150                status = Status.RESULT_STATE_INVALID_XML;
151                lastMessage = "Error: MalFormed XML Response";
152                return new ValidatorResponse( lastMessage, status );
153            }
154            try {
155                status = Status.RESULT_STATE_SERVICE_UNAVAILABLE;
156                lastMessage = XMLTools.getNodeAsString( doc.getDocumentElement(), "./ServiceException", null,
157                                                        "Service Unavailable. Unknown error" );
158                return new ValidatorResponse( lastMessage, status );
159            } catch ( XMLParsingException e ) {
160                status = Status.RESULT_STATE_SERVICE_UNAVAILABLE;
161                lastMessage = status.getStatusMessage();
162                return new ValidatorResponse( lastMessage, status );
163            }
164        }
165    
166        /**
167         * Makes sure that the HttpResponse is not a critical error
168         *
169         * @param statusCode
170         */
171        protected boolean isValidHttpResponse( int statusCode ) {
172    
173            if ( statusCode >= 100 && statusCode < 400 ) {
174                return true;
175            }
176            return false;
177        }
178    
179        /**
180         * @param statusCode
181         * @return instance of the validatorresponse with the error
182         */
183        protected ValidatorResponse validateErrorHttpResponse( int statusCode ) {
184    
185            String lastMessage = null;
186            Status status = null;
187    
188            if ( statusCode == HttpServletResponse.SC_REQUEST_TIMEOUT ) {
189                status = Status.RESULT_STATE_TIMEOUT;
190                lastMessage = status.getStatusMessage();
191            } else {
192                status = Status.RESULT_STATE_PAGE_UNAVAILABLE;
193                lastMessage = status.getStatusMessage();
194            }
195    
196            return new ValidatorResponse( lastMessage, status );
197        }
198    
199        /**
200         * Parses a given InputStream to a String
201         *
202         * @param stream
203         * @return String
204         * @throws IOException
205         */
206        protected String parseStream( InputStream stream )
207                                throws IOException {
208            stream.reset();
209            InputStreamReader reader = new InputStreamReader( stream );
210            BufferedReader bufReader = new BufferedReader( reader );
211            StringBuilder builder = new StringBuilder();
212            String line = null;
213    
214            line = bufReader.readLine();
215            while ( line != null ) {
216                builder.append( line );
217                line = bufReader.readLine();
218            }
219    
220            String answer = builder.toString();
221            return answer;
222        }
223    
224        /**
225         * Creates a new instance of DocumentBuilder
226         *
227         * @return DocumentBuilder
228         * @throws IOException
229         */
230        protected DocumentBuilder instantiateParser()
231                                throws IOException {
232    
233            DocumentBuilder parser = null;
234    
235            try {
236                DocumentBuilderFactory fac = DocumentBuilderFactory.newInstance();
237                fac.setNamespaceAware( true );
238                fac.setValidating( false );
239                fac.setIgnoringElementContentWhitespace( false );
240                parser = fac.newDocumentBuilder();
241                return parser;
242            } catch ( ParserConfigurationException e ) {
243                throw new IOException( "Unable to initialize DocumentBuilder: " + e.getMessage() );
244            }
245        }
246    
247        protected boolean closeStream( InputStream stream ) {
248            try {
249                stream.close();
250            } catch ( IOException e ) {
251                LOG.logError( e.getLocalizedMessage() );
252                return false;
253            }
254            return true;
255        }
256    
257        /**
258         * Creates a new copy of the given InputStream
259         *
260         * @param stream
261         * @return InputStream
262         * @throws IOException
263         */
264        protected InputStream copyStream( InputStream stream )
265                                throws IOException {
266            ByteArrayOutputStream out = new ByteArrayOutputStream();
267            int read;
268            byte[] bs = new byte[16384];
269            while ( ( read = stream.read( bs ) ) != -1 ) {
270                out.write( bs, 0, read );
271            }
272            return new ByteArrayInputStream( out.toByteArray() );
273        }
274    }