一个简单的hadoop/hbase程序

 

mapper

public class OfferMapper extends TableMapper<Text, IntWritable> {

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

    /**
     * rowkey,value,context
     */
    public void map(ImmutableBytesWritable key, Result value, Context context) throws IOException,
            InterruptedException {
     
        String titleValue = Bytes.toString(value.getValue(Bytes.toBytes("title"), null));
  
              for(KeyValue kv : value.list()){
                 System.out.println(kv.getValue().toString());
                  word.set(kv.getValue());
                  context.write(word, one);
              }

    }

}

 

     reducer:

 

public class OfferReducer extends Reducer<Text,IntWritable,Text,IntWritable> {
    
    private IntWritable result = new IntWritable();

    public void reduce(Text key, Iterable<IntWritable> values, Context context) throws IOException,
            InterruptedException {
        
        int sum = 0;
        for (IntWritable val : values) {
            sum += val.get();
        }
        result.set(sum);
        context.write(key, result);
    }
 

}

 

 

 

public class OfferTask {

    final static String NAME = "OfferTask";

    /**
     * Sets up the actual job.
     * 
     * @param conf The current configuration.
     * @param args The command line parameters.
     * @return The newly created job.
     * @throws IOException When setting up the job fails.
     */
    public static Job createSubmittableJob(Configuration conf, String[] args) throws IOException {
        String tableName = args[0];
        // Path inputDir = new Path(args[1]);
        Job job = new Job(conf, NAME + "_" + tableName);
        job.setJarByClass(OfferTask.class);
       
    
        Scan myScan = new Scan();
        TableMapReduceUtil.initTableMapperJob(tableName, myScan, OfferMapper.class, Text.class,
                IntWritable.class, job);
       
        TableMapReduceUtil.initTableReducerJob(tableName, OfferReducer.class, job);

  
       job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(IntWritable.class);
       
        FileOutputFormat.setOutputPath(job, new Path(args[1]));

        return job;
    }

    /**
     * @param args
     */
    public static void main(String[] args) throws Exception {

        Configuration conf = new Configuration();
        String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();
        if (otherArgs.length != 2) {
            System.err.println("Usage: OfferTask <tableName> <out>");
            System.exit(2);
        }
    
        Job job = createSubmittableJob(conf, otherArgs);
        System.exit(job.waitForCompletion(true) ? 0 : 1);
    }