Getting Data from RestFB and Creating Sequence File > Hadoop

Here is a quick code to get data from Facebook using RestFB API and create Sequence file and dump you data into Hadoop Cluster.

Requirement:

• Hadoop 1.0.3 Installed as Stand Alone or Multinode. 
• Eclipse IDE for development 
• Hadoop and Apache commons jars. 
• RestFB APIs 

Steps to Create Eclipse Project.

• New Java Project. 
• Add the jar to the project. (Apache Commons and hadoop-core.1.0.3.jar) and add RestFB jar. 
• You will find all (commons and hadoop) jars under hadoop directory. 

Sequence File Content Format.

• Key – <facebook_id, facebook_name, timestamp> 
• Value – <batch_me, batch_me_friends, batch_me_likes>

Add the below code to get DATA from Facebook and generate Sequence File. Before you start you need to updated the AccessToken in the code with yours Access Token from Facebook. Take look here before you proceed.

/*
* Sequence File to HDFS Filesystem
*
* We take information from Facebook as Batch
* and then store them in Sequence file in Hadoop Distributed File System.
*
* */

import java.io.IOException;
import java.net.URI;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.LocalFileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IOUtils;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.SequenceFile;
import org.apache.hadoop.io.Text;
import static java.lang.String.format;
import static java.lang.System.currentTimeMillis;
import static java.lang.System.out;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.restfb.Connection;
import com.restfb.DefaultFacebookClient;
import com.restfb.DefaultJsonMapper;
import com.restfb.Facebook;
import com.restfb.FacebookClient;
import com.restfb.JsonMapper;
import com.restfb.Parameter;
import com.restfb.batch.BatchRequest;
import com.restfb.batch.BatchRequest.BatchRequestBuilder;
import com.restfb.batch.BatchResponse;
import com.restfb.json.JsonArray;
import com.restfb.json.JsonObject;
import com.restfb.types.Page;
import com.restfb.types.Post;
import com.restfb.types.Url;
import com.restfb.types.User;

public class SequenceFileToHDFS {
    @SuppressWarnings("deprecation")
    public static void main(String[] args) throws IOException
    {
        String accessToken = "ACCESS_TOKEN_STRING";
       
        //get current date time with Date()
        DateFormat dateFormat = new SimpleDateFormat("yyyy_MM_dd_HH_mm_ss");
        Date date = new Date(); 
        String uri = "sequence_file_"+dateFormat.format(date)+".seq";
        Configuration conf = new Configuration();
       
        /*
         * Uncomment this 2 lines below to get configuratio from the XML
         * Make sure the PATH is set right to get the configuration
         * Which will dump the Sequence file into HADOOP
        */
        //conf.addResource(new Path ("/usr/local/hadoop/conf/core-site.xml"));
        //conf.addResource(new Path ("/usr/local/hadoop/conf/hdfs-site.xml"));
       
        /*Comment these 2 lines below and uncomment above 2 lines to write the data into Hadoop*/
            FileSystem.getLocal(conf); //for local file system
            LocalFileSystem fs = FileSystem.getLocal(conf);
        /*Local Sequence End Here*/
       
        /* Uncomment line below to make it work with Configuration file above <Lines 94/95>*/
        //FileSystem fs = FileSystem.get(URI.create(uri), conf);
       
        Path path = new Path(uri);
        /*
         * Starting Facebook Retrieval
         */
       
        DefaultFacebookClient facebookClient = new DefaultFacebookClient(accessToken);
        User user = facebookClient.fetchObject("me", User.class);
        /*
         * Building Batch Request to send to Facebook
         */
               
        BatchRequest meRequest = new BatchRequestBuilder("me").build();
        BatchRequest meFriendRequest = new BatchRequestBuilder("me/friends").build();
        BatchRequest meLikeRequest = new BatchRequestBuilder("me/likes").parameters(Parameter.with("limit", 5)).build();
        /* Executing BATCH Request */
        /* This will be our Sequence Value*/
        List<BatchResponse> batchResponses =
            facebookClient.executeBatch(meRequest, meFriendRequest, meLikeRequest);
        /*
         * Based on the Response from Facebook
         * We create Sequence File.
         *
         */
       
        if(batchResponses.get(0).getCode() == 200)
        {
            /* Creating Sequence Key */
            JsonObject sequencekeyMapUser = new JsonObject();
            sequencekeyMapUser.put("facebookId", user.getId());
            sequencekeyMapUser.put("facebookName",user.getName());
            sequencekeyMapUser.put("timestamp", dateFormat.format(date));
            Text key = new Text();
            Text value = new Text();
            SequenceFile.Writer writer = null;
            try
            {
                writer = SequenceFile.createWriter(fs, conf, path, key.getClass(), value.getClass());
                key.set(sequencekeyMapUser.toString());
                value.set(batchResponses.toString());
                System.out.printf("[%s]\t%s\t%s\n", writer.getLength(), key, value);
                writer.append(key, value);
            }
            finally
            {
                IOUtils.closeStream(writer);
            }
        }
        else if(batchResponses.get(0).getCode() != 200)
        {
            System.out.printf("Access Token Expired\n");
        }
    }
}