ca.ualberta.cmput301w13t11.FoodBook.model.ClientHelper.java Source code

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Here is the source code for ca.ualberta.cmput301w13t11.FoodBook.model.ClientHelper.java

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package ca.ualberta.cmput301w13t11.FoodBook.model;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.lang.reflect.Type;
import java.util.ArrayList;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.entity.StringEntity;

import com.google.gson.Gson;
import com.google.gson.JsonSyntaxException;
import com.google.gson.reflect.TypeToken;
import java.util.Collection;

/**
 *  Helper class -- responsible for transforming HTTP response into Java Objects
 *  and vice-versa in service of the ServerClient.
 * 
 * Code inspired by:
 * ESDemo with HTTP Client and GSON
 * 
 * LICENSE:
 * 
 * CC0 http://creativecommons.org/choose/zero/
 * 
 * To the extent possible under law, Abram Hindle and Chenlei Zhang has waived all copyright 
 * and related or neighboring rights to this work. This work is published from: Canada.
 *
 * @author Abram Hindle, Chenlei Zhang, Marko Babic
 *
 */
public class ClientHelper {

    static private Gson gson = new Gson();

    /**
     * Empty constructor.
     */
    public ClientHelper() {
    }

    /**
     * Converts the given recipe to a JSON object (this includes re-encoding photos).
     * @param recipe The recipe to be converted.
     * @return A JSON version of the given recipe.
     */
    public StringEntity recipeToJSON(Recipe recipe) {
        StringEntity se = null;
        ServerRecipe sr = new ServerRecipe(recipe);

        try {
            se = new StringEntity(gson.toJson(sr));
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }

        return se;

    }

    /**
     * Transforms the given ServerPhoto to a JSON-style string suitable for uploading.
     * @param sp The ServerPhoto to be converted.
     * @return A JSON-style string representing the given ServerPhoto.
     */
    public String serverPhotoToJSON(ServerPhoto sp) {
        String ret = gson.toJson(sp);
        return ret;
    }

    /**
     * Converts the given HTTP response to a string.
     * @param (HttpResponse) http_response The response to be converted to a string.
     * @return A string version of the HttpResponse passed.
     * @throws IOException 
     */
    public String responseToString(HttpResponse http_response) throws IOException {
        String ret = "";
        BufferedReader br = new BufferedReader(new InputStreamReader((http_response.getEntity().getContent())));
        String out;

        while ((out = br.readLine()) != null) {
            ret += out;
        }
        return ret;
    }

    /**
     * After executing a search on the server, this method is called to 
     * transform the search results into a list of recipes.
     * @param response
     * @return 
     * @throws IOException
     */
    public ArrayList<Recipe> toRecipeList(String json) throws IOException {

        ServerSearchResponse<ServerRecipe> search_response;
        ArrayList<Recipe> search_results = new ArrayList<Recipe>();

        Type serverSearchResponseType = new TypeToken<ServerSearchResponse<ServerRecipe>>() {
        }.getType();
        try {
            search_response = gson.fromJson(json, serverSearchResponseType);
        } catch (JsonSyntaxException jse) {
            return search_results;
        }

        for (ServerResponse<ServerRecipe> sr : search_response.getHits()) {
            ServerRecipe server_recipe = sr.getSource();
            search_results.add(ServerRecipe.toRecipe(server_recipe));
        }
        return search_results;

    }

    /** 
     * @uml.property name="serverRecipe"
     * @uml.associationEnd multiplicity="(0 -1)" aggregation="shared" inverse="clientHelper:ca.ualberta.cmput301w13t11.FoodBook.model.ServerRecipe"
     * @uml.association name="creates from Recipes"
     */
    private Collection serverRecipe;

    /** 
     * Getter of the property <tt>serverRecipe</tt>
     * @return  Returns the serverRecipe.
     * @uml.property  name="serverRecipe"
     */
    public Collection getServerRecipe() {
        return serverRecipe;
    }

    /** 
     * Setter of the property <tt>serverRecipe</tt>
     * @param serverRecipe  The serverRecipe to set.
     * @uml.property  name="serverRecipe"
     */
    public void setServerRecipe(Collection serverRecipe) {
        this.serverRecipe = serverRecipe;
    }

}