com.ushahidi.java.sdk.api.tasks.BaseTask.java Source code

Introduction

Here is the source code for com.ushahidi.java.sdk.api.tasks.BaseTask.java

Source

/*****************************************************************************
 ** Copyright (c) 2010 - 2012 Ushahidi Inc
 ** All rights reserved
 ** Contact: team@ushahidi.com
 ** Website: http://www.ushahidi.com
 **
 ** GNU Lesser General Public License Usage
 ** This file may be used under the terms of the GNU Lesser
 ** General Public License version 3 as published by the Free Software
 ** Foundation and appearing in the file LICENSE.LGPL included in the
 ** packaging of this file. Please review the following information to
 ** ensure the GNU Lesser General Public License version 3 requirements
 ** will be met: http://www.gnu.org/licenses/lgpl.html.
 **
 **
 ** If you have questions regarding the use of this file, please contact
 ** Ushahidi developers at team@ushahidi.com.
 **
 *****************************************************************************/
package com.ushahidi.java.sdk.api.tasks;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.MalformedURLException;
import java.net.URL;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.stream.JsonReader;
import com.ushahidi.java.sdk.api.json.Date;
import com.ushahidi.java.sdk.api.json.DateDeserializer;
import com.ushahidi.java.sdk.net.Authentication;
import com.ushahidi.java.sdk.net.PasswordAuthentication;
import com.ushahidi.java.sdk.net.UshahidiHttpClient;
import com.ushahidi.java.sdk.util.Validate;

/**
 * @author eyedol
 * 
 */
public abstract class BaseTask {

    private static Gson gson;

    static {
        GsonBuilder builder = new GsonBuilder();
        builder.registerTypeAdapter(Date.class, new DateDeserializer());
        gson = builder.create();
    }

    /** The Ushahidi deployment URL */
    protected String url;

    private static final String API = "/api";

    private Authentication authentication;

    protected UshahidiHttpClient client;

    /**
     * Create a the task using the default {@link UshahidiHttpClient}
     * 
     * @param url
     *            The Ushahidi deployment
     * @param task
     *            The task to be performed
     * @param client
     *            The HttpClient
     */
    public BaseTask(String url, String task, UshahidiHttpClient client) {
        if (url == null) {
            throw new IllegalArgumentException("URL cannot be null");
        }

        if (task == null) {
            throw new IllegalArgumentException("Task cannot be null");
        }

        if (client == null) {
            throw new IllegalArgumentException("Client cannot be null");
        }

        this.url = Validate.removeTrailingSlashes(url) + API;
        this.client = client;
        this.client.setRequestParameters("task", task);
        this.client.setRequestParameters("resp", "json");
    }

    /**
     * Create a task using the default {@link UshahidiHttpClient}
     * 
     * @param url
     *            The Ushahidi deployment
     * @param task
     *            The task to be performed
     */
    public BaseTask(String url, String task) {
        this(url, task, new UshahidiHttpClient());
    }

    /**
     * Get configured http client
     * 
     * @return non-null client
     */
    public UshahidiHttpClient getClient() {
        return client;
    }

    public void setAuthentication(String username, String password) {
        if (username == null || username.length() == 0) {
            throw new IllegalArgumentException("Username may not be null or empty");
        }

        if (password == null || password.length() == 0) {
            throw new IllegalArgumentException("Password may not be null or empty");
        }

        authentication = new PasswordAuthentication(username, password);
        client.setAuthentication(authentication);
    }

    /**
     * Return the configured URL
     * @return
     */
    public String getUrl() {
        return this.url;
    }

    /**
     * Deserialize the JSON string into Java objects representing the various
     * Ushahidi models.
     * 
     * @param json
     *            the json string to be converted
     * @param cls
     *            the class for the model
     * @return The Object related to the Ushahidi API model
     */
    public static <T> T fromString(String json, Class<T> cls) {
        return gson.fromJson(json, cls);
    }

    /**
     * Deserialize the JSON from a stream object 
     * 
     * @param s The stream
     * @param cls The class for the model
     * @return The related object
     */
    public static <T> T fromStream(InputStream s, Class<T> cls) {
        return cls.cast(gson.fromJson(new JsonReader(new InputStreamReader(s)), cls));

    }

    /**
     * Deserialize JSON from a URL
     * 
     * @param url The URL to the json string
     * @param cls The class for the model
     * 
     * @return The related object
     * 
     * @throws MalformedURLException
     * @throws IOException
     */
    public static <T> T fromUrl(String url, Class<T> cls) throws MalformedURLException, IOException {
        return fromStream(new URL(url).openStream(), cls);
    }

    /**
     * Get the configured Gson object.
     * @return
     */
    public Gson getGson() {
        return gson;
    }
}