applicationhandler.java

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/**
 * 
 */
package com.pjaol.ifodder.application;

import java.util.Map;
import java.util.StringTokenizer;
import java.util.Vector;

import org.apache.log4j.Logger;

import com.pjaol.ifodder.storage.IRetrival;
import com.pjaol.ifodder.storage.IStorage;
import com.pjaol.ifodder.storage.ListItem;
import com.pjaol.ifodder.storage.StorageException;




/**
 * @author pjaol
 *
 */
public class ApplicationHandler {
	
	private enum actions {addListItem, addTag, getListItem, getListItemsByUser} ;

	private static IStorage store;
	private static IRetrival retrive;
	
	private Logger _log = Logger.getLogger(getClass());
	
	public String handle(String action, Map arguments) throws StorageException{
	
		switch (actions.valueOf(action)) {
		case addListItem:
			addListItem(arguments);
			return "ok";
		case addTag:
			addTag(arguments);
			return "ok";
		case getListItem:
			return getListItem(arguments);
		case getListItemsByUser:
			return getListItemsByUser(arguments);
		}
		
		return errorString("handler: no valid action");
	}
	
	private void addListItem (Map arguments) throws StorageException {
		
		String url = (String)arguments.get("url");
		int user_id = ((Integer) arguments.get("user_id")).intValue();
		String description = (String) arguments.get("description");
		String tags = (String) arguments.get("tags");
		int datum_id = -1; 
		
		try {
			datum_id = store.getDatumId(url);	
		} catch (StorageException e) {
			throw new StorageException(2,getClass().getName(),"addListItem", "get a datum",  e);
		}
		
		if (datum_id < 0) {
			try {
				store.addDatum(url);
				datum_id = store.getDatumId(url);
			} catch (StorageException e) {
				throw new StorageException(2,getClass().getName(),"addListItem", "Failed to store datum",  e);
			}
		}

		_log.debug("getDatumId returned "+ datum_id);
		store.addListItem(user_id, datum_id, description);
		addTag(user_id, datum_id, tags);
		
	}
	
	private void addTag (Map arguments) throws StorageException{
		int user_id = ((Integer)arguments.get("user_id")).intValue();
		String tags = (String) arguments.get("tags");
		int datum_id = ((Integer) arguments.get("datum_id")).intValue();
		addTag(user_id, datum_id, tags);
	}
	
	private void addTag (int user_id, int datum_id, String tags) throws StorageException {
		
		if (tags == null)
			return;
		
		int li_id;
		li_id = store.getListId(user_id, datum_id);
		
		StringTokenizer tokenizer = new StringTokenizer(tags, ",\"", true);
		while (tokenizer.hasMoreTokens()) {
		  String token = com.pjaol.ifodder.storage.StringUtils.getNextToken(tokenizer);
		  store.addTag(user_id, li_id, token);
		}
	}
	private String getListItem(Map arguments) throws StorageException{
		int user_id= ((Integer) arguments.get("user_id")).intValue();
		int li_id = ((Integer) arguments.get("li_id")).intValue();
		return getListItem(user_id, li_id);
	}
	
	private String getListItem( int user_id, int li_id) throws StorageException {
		ListItem listItem = retrive.getListItem(user_id, li_id);
		if (listItem == null)
			return  errorString("getListItem: no such list item");
		
		return listItem.asXML();
	}
	
	private String getListItemsByUser (Map arguments) throws StorageException{
		int user_id= ((Integer) arguments.get("user_id")).intValue();
		return getListItemsByUser(user_id);
	}
	private String getListItemsByUser (int user_id) throws StorageException{
		Vector listItems = retrive.getListItemsByUser(user_id);
		String result = new String();
		int size = listItems.size();
		for (int x = 0 ; x < size; x++){
			ListItem li = (ListItem) listItems.get(x);
			result+= li.asXML();
		}
		return result;
	}

	private String errorString(String message){
		return "<error>"+message+"</error>";
	}
	public void setStorage (String storageClass) throws InstantiationException, IllegalAccessException, ClassNotFoundException {
		store = (IStorage ) Class.forName(storageClass).newInstance();
	}
	
	public void setRetrival (String retrivalClass) throws InstantiationException, IllegalAccessException, ClassNotFoundException {
		retrive = (IRetrival) Class.forName(retrivalClass).newInstance();
	}
}