Use hbase HTable - Java Big Data

Description

Use hbase HTable
Demo Code

import java.io.IOException;
import java.util.*;

import org.apache.hadoop.fs.Path;
import org.apache.hadoop.conf.*;
import org.apache.hadoop.io.*;
import org.apache.hadoop.mapred.*;
import org.apache.hadoop.util.*;
import org.apache.hadoop.conf.Configuration;

import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.client.HBaseAdmin;
import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hbase.client.HTablePool;
import org.apache.hadoop.hbase.client.Put;

public class textPredict {

    public static class HMap extends MapReduceBase implements
            Mapper<LongWritable, Text, Text, Text> {

        //private final static IntWritable one = new IntWritable(1);
        private Text word = new Text();

        public void map(LongWritable key, Text value,
                OutputCollector<Text, Text> output, Reporter reporter)
                throws IOException {
            String oneline = value.toString();

            String[] values = oneline.split("\t");
            int count = Integer.parseInt(values[1]);
            String[] words = values[0].split(" ");
            int length = words.length;
            //filter the count smaller than 2
            if (count > 1 && length > 1) {
                String rowKey = "";
                for (int i = 0; i < length - 1; i++) {
                    rowKey = rowKey + " " + words[i];
                }//from w w w .  j a  v  a  2s .c  o  m
                String nextWord = words[length - 1];
                String nextWordCount = nextWord + " "
                        + String.valueOf(count);
                word.set(rowKey);
                output.collect(word, new Text(nextWordCount));
            }

        }
    }

    public static class combine extends MapReduceBase implements
            Reducer<Text, Text, Text, Text> {
        public void reduce(Text key, Iterator<Text> values,
                OutputCollector<Text, Text> output, Reporter reporter)
                throws IOException {
            Map<String, Integer> hm = new HashMap<String, Integer>();
            //int sum = 0;
            while (values.hasNext()) {
                String[] wordCount = values.next().toString().split(" ");
                hm.put(wordCount[0], Integer.parseInt(wordCount[1]));
                //sum += Integer.parseInt(wordCount[1]);

            }
            List<Map.Entry<String, Integer>> hmList = new ArrayList<Map.Entry<String, Integer>>(
                    hm.entrySet());
            Collections.sort(hmList,
                    new Comparator<Map.Entry<String, Integer>>() {
                        public int compare(Map.Entry<String, Integer> o1,
                                Map.Entry<String, Integer> o2) {
                            return (o2.getValue() - o1.getValue());
                            //return (o1.getKey()).toString().compareTo(o2.getKey());
                        }
                    });

            int i = 0;
            for (Map.Entry<String, Integer> s : hmList) {
                if (i == 5)
                    break;
                String wordCount = s.getKey() + " "
                        + String.valueOf(s.getValue());
                output.collect(key, new Text(wordCount));
                i++;
            }
        }
    }

    public static class Reduce extends MapReduceBase implements
            Reducer<Text, Text, Text, Text> {

        //Configuration conf = HBaseConfiguration.create();
        //HBaseAdmin admin = new HBaseAdmin(conf);

        private Configuration hconf = null;

        public void configure(JobConf conf) {
            hconf = HBaseConfiguration.create();
        }

        public void insertData(String tableName, String key, String data,
                String probability) {
            HTablePool pool = new HTablePool(hconf, 1000);
            HTable table = (HTable) pool.getTable(tableName);
            Put put = new Put(key.getBytes());
            put.add("predictFamily".getBytes(), data.getBytes(),
                    probability.getBytes());
            try {
                table.put(put);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        public void reduce(Text key, Iterator<Text> values,
                OutputCollector<Text, Text> output, Reporter reporter)
                throws IOException {
            Map<String, Integer> hm = new HashMap<String, Integer>();
            //int sum = 0;
            while (values.hasNext()) {
                String[] wordCount = values.next().toString().split(" ");
                hm.put(wordCount[0], Integer.parseInt(wordCount[1]));
                //sum += Integer.parseInt(wordCount[1]);
                //output.collect(key, new Text(wordCount));
            }
            List<Map.Entry<String, Integer>> hmList = new ArrayList<Map.Entry<String, Integer>>(
                    hm.entrySet());
            Collections.sort(hmList,
                    new Comparator<Map.Entry<String, Integer>>() {
                        public int compare(Map.Entry<String, Integer> o1,
                                Map.Entry<String, Integer> o2) {
                            return (o2.getValue() - o1.getValue());
                            //return (o1.getKey()).toString().compareTo(o2.getKey());
                        }
                    });

            int i = 0;
            for (Map.Entry<String, Integer> s : hmList) {
                if (i == 5)
                    break;
                insertData("predict", key.toString(), s.getKey(),
                        String.valueOf(s.getValue()));
                i++;
            }
        }

    }

    public static void main(String[] args) throws Exception {
        JobConf conf = new JobConf(textPredict.class);
        conf.setJobName("textPredict");

        conf.setOutputKeyClass(Text.class);
        conf.setOutputValueClass(Text.class);

        conf.setMapperClass(HMap.class);
        conf.setCombinerClass(Reduce.class);
        conf.setReducerClass(Reduce.class);

        conf.setInputFormat(TextInputFormat.class);
        conf.setOutputFormat(TextOutputFormat.class);

        FileInputFormat.setInputPaths(conf, new Path(args[0]));
        FileOutputFormat.setOutputPath(conf, new Path(args[1]));

        JobClient.runJob(conf);
    }
}
Use hbase HTable - Java Big Data

Description

Demo Code

Related Tutorials
