source: MDService2/trunk/MDService2/src/eu/clarin/cmdi/mdservice/action/Helpers.java

package eu.clarin.cmdi.mdservice.action;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintStream;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.FactoryConfigurationError;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;

import org.w3c.dom.Document;
import org.xml.sax.SAXException;

public class Helpers {

        private static PrintStream log;
        
        public static Document readFSLS(String infile)
        {
                Document document = null;
                try {
                    DocumentBuilderFactory factory = 
                    DocumentBuilderFactory.newInstance();
                    DocumentBuilder builder = factory.newDocumentBuilder();
                    document = builder.parse(infile);               
                }
                catch (FactoryConfigurationError e) {
                    // unable to get a document builder factory
                        notifyUser(e.getClass() + ": " + e.getLocalizedMessage());
                } 
                catch (ParserConfigurationException e) {
                    // parser was unable to be configured
                        notifyUser(e.getClass() + ": " + e.getLocalizedMessage());                      
                }
                catch (IOException e) {
                    // i/o error
                        notifyUser(e.getClass() + ": io-error " + e.getLocalizedMessage());                     
                } catch (SAXException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                }
                
                return document;
        }
        
        public static void notifyUser (String msg) {
                if (log== null) { log = System.err; }
                log.println(msg);
                
        }

        public static void copy (InputStream in, OutputStream out) throws IOException, InterruptedException {           
                
                byte[] buffer = new byte[1024];
                int len = in.read(buffer);
                while (len != -1) {
                    out.write(buffer, 0, len);
                    len = in.read(buffer);
                    if (Thread.interrupted()) {
                        throw new InterruptedException();
                    }
                }
        }
        

        public static Document getDocument(InputStream is){
                Document doc = null;
                DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder docBuilder;
                try {
                        docBuilder = docFactory.newDocumentBuilder();
                        doc = docBuilder.parse(is);
                } catch (ParserConfigurationException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                } catch (SAXException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                }       
                return doc;
        }
        
        public static String getDocumentData(InputStream is, String expression){
                String data = "";
        
                XPathFactory factory = XPathFactory.newInstance(); 
            XPath xpath = factory.newXPath(); 
            XPathExpression expr;
                try {
                        expr = xpath.compile(expression);
                        data = (String) expr.evaluate(getDocument(is), XPathConstants.STRING);
                } catch (XPathExpressionException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                }
                        
                return data;
                
        }
        /*
         * TODO: this should go to Utilities!
         */
        public  static String convertStreamToString(InputStream is) {  
                
                BufferedReader reader = new BufferedReader(new InputStreamReader(is));  
                StringBuilder sb = new StringBuilder();  
                String line = null;  
                
                try {
                        while ((line = reader.readLine()) != null) {  
                                         sb.append(line + "\n");  
                        }
                } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                }  finally {
                        try {
                                is.close();
                        } catch (IOException e) {
                                // TODO Auto-generated catch block
                                e.printStackTrace();
                        }
                        try {
                                is.reset();
                        } catch (IOException e) {
                                // TODO Auto-generated catch block
                                e.printStackTrace();
                        }
                }
                  
                
                return sb.toString();  
        }


}