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

package eu.clarin.cmdi.mdservice.action;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.StringReader;
import java.io.StringWriter;
import java.net.MalformedURLException;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.HashMap;
import java.io.ByteArrayInputStream;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;

import eu.clarin.cmdi.mdservice.model.Query;
import eu.clarin.cmdi.mdservice.model.WorkspaceProfile;

/**
 * Proxy to the Metadata Repository.  
 * Responds to requests (collections, model, recordset) 
 * by dispatching the requests to appropriate internal methods and filling the inputStream with the result
 * 
 * It is possible to switch target-repository dynamically  (on every request). I.e. the client explicitly selects one of the repositories.
 *  
 * @author vronk
 *
 */
public class MDRepoProxyAction extends GenericProxyAction {

        private static final long serialVersionUID = 1L;

        private String proxy_key = "mdrepository";
        
        /**
         * Override of the basic method provided by the super-class 
         */     
        @Override       
        public String getBaseURI() {            
                String uri = WorkspaceProfile.getRepositoryPath(getRepository());               
                return uri;
        }
        
        @Override
        public void setFormat(String format) {
                super.setFormat(format);                
        }
        
        @Override
        public String getProxyKey() {
                return proxy_key;
        }
        
        /**
         * A mapping between the actionkeys in the request and the operation-parameter expected by the MDRepository 
         */
        private final static HashMap<String,String> urls = new HashMap<String,String>();
         static
         {       urls.put("collection", "?operation=getCollections&collection=");
                 urls.put("model", "?operation=queryModel&q=");
                 urls.put("values", "?operation=scanIndex&q=");
                 urls.put("recordset", "?operation=searchRetrieve&query=");
                 urls.put("record", "?operation=searchRetrieve&query=");
         } 
 
         public String fullQueryString(){
                String full_query_string= this.getQ();
                        
                if (!getSquery().equals("") && !this.getQ().equals("")){
                                full_query_string = "(" + this.getSquery() + " ) and (" + this.getQ() + ")";
                        } else if (!this.getSquery().equals("")) {
                                full_query_string = this.getSquery();
                        } else if (!this.getQ().equals("")){
                                full_query_string = this.getQ();
                        } else {
                                full_query_string = "";
                        }
                
                return full_query_string;
         }
         
        /**
         * uses base_url + url_pattern (parametrized by actionkey) to form a url
         * @return the URL to the component-file
         * @throws Exception 
         */
         @Override
        public URL getTargetRequest() throws IOException {
        // URL targetURL =new URL( base_url, compname + ".xml");
                
                Admin.notifyUser("MDRPA.getQ:" + getSquery() + " and (" +  getQ() + ")");
                Admin.notifyUser("MDRPA.getActionkey:" + getActionkey());               
                
                Query query = new Query(getSquery(), getQ(),getActionkey());

        // check if the query could get parsed
                if (query.isStatus(Query.PARSEERROR)) {
                        Admin.notifyUser("MDRPA.query.PARSEERROR:" + query.getMsg());
                        // pass this bad news to the client
                        setUserMsg(query.getMsg());
                        return null;
                } else {
                        query.setMaxdepth(getMaxdepth());               
                        query.setCollection(getCollection());
                        query.setColumns(getColumns());
                        query.setMaximumItems(getMaximumItems());
                        query.setStartItem(getStartItem());
                        query.setOptions(getOptions());
                        query.setSort(getSort());
                
                        URL targetURL = null;
                        targetURL =new URL( getBaseURL(), urls.get(getActionkey()) + query.toURLParam() );
                        Admin.notifyUser("MDRPA.targetURL.query.toURLParam:" + query.toURLParam());
                        Admin.notifyUser("MDRPA.targetURL:" + targetURL);
                return targetURL;
                }
        }


        @Override
        public InputStream getSourceStream() throws IOException, NoStylesheetException {
                
                /*if (getCommand() == null){
                        try {
                                return getSourcePz2();
                        } catch (Exception e) {
                                // TODO Auto-generated catch block
                                e.printStackTrace();
                        }
                } 
                        */
                return super.getSourceStream();
        }
        
        @Override
        public void prepare() throws Exception{
                super.prepare();
                
        }
}