source: MDService2/branches/MDService_simple3/src/eu/clarin/cmdi/mdservice/proxy/BasicProxy.java @ 1613

package eu.clarin.cmdi.mdservice.proxy;

import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.util.Map;

import org.apache.log4j.Logger;
import eu.clarin.cmdi.mdservice.action.GenericAction;
import eu.clarin.cmdi.mdservice.internal.CQLParseException;
import eu.clarin.cmdi.mdservice.internal.NoStylesheetException;
import eu.clarin.cmdi.mdservice.internal.Utils;


/**
 * Base class for implementation of proxies to target systems.
 * This is now (after rework 2011-09) decoupled from the called Action. 
 * 
 * Defines the methods used for retrieving the data 
 * and provides basic implementation where possible.
 *
 * Tries to get the base_uri from Config (mdservice.properties) based on action_key
 *  
 * @author vronk
 *
 */
public class BasicProxy implements ProxyInterface{

        private static final long serialVersionUID = 1L;
        private static Logger log = Logger.getLogger("BasicProxy");
 
        private String proxy_key = "basic";
        
        private GenericAction source_action;
        
        public GenericAction getSourceAction() {
                        return source_action;
        }
        
        @Override
        public void setSourceAction(GenericAction action) {             
                source_action = action;
                
        }
        
        public Map<String,String[]> getParams() {
                return getSourceAction().getParams();
        }
        
        /**
         * Convenience function to access the request-parameters in the Action  
         * @param key
         * @return
         */
        public String getParam(String key) {
                return getSourceAction().getParam(key);
        }
        
        public void checkParams() {
                // required Params      
        }
        
        /**
         * identification of the target-proxy (type)
         * base for finding the right base_url in the props
         * subclass has to override with its specific proxykey
         * @return
         */
        public String getProxyKey() {                           
                        return proxy_key;               
        }

        /**
         * Get the base_uri based on the action-key
         */
                
        public String getBaseURI() {            
                String uri =Utils.getConfig().getProperty(getSourceAction().getActionkey() + ".uri");   
                //String uri = Termset.getTermsetAttr(getSourceAction().getActionkey(), "url");
                return uri;
        }

        /**
         * Provides the base-URL specific to given target repository or registry 
         * @return 
         * @throws MalformedURLException
         */     
        public URL getBaseURL() throws MalformedURLException {          
                URL base_url = new URL(getBaseURI());           
                return base_url;
        }
        
        
        /**
         * uses base_url + url_pattern (parametrized by actionkey) to form a url
         * @return the full target-request URL to be sent to the target repository
         * @throws CQLParseException 
         * @throws Exception 
         */     
        public URL getTargetRequest() throws IOException, CQLParseException {
                 
                URL targetURL =new URL(getBaseURI() + this.getSourceAction().getTargetRequestParams());
                
                log.debug("getTargetRequest().targetURL:" + targetURL);
            return targetURL;
                
        }

        public InputStream getSourceStream() throws IOException, NoStylesheetException, CQLParseException {
                URLConnection urlConnection = getTargetRequest().openConnection();
                getSourceAction().setRequestProperties(urlConnection);
                return urlConnection.getInputStream();//.openStream();          
        }

        

}