Hadoop2.5.2导出数据到Hbase

留作备份用，本分类下所有例子都是自己亲自测试过的。

package jyw.test;

import java.io.IOException; 
import java.util.Iterator; 
import java.util.StringTokenizer; 
 
import org.apache.hadoop.conf.Configuration; 
import org.apache.hadoop.fs.Path; 
import org.apache.hadoop.hbase.HBaseConfiguration; 
import org.apache.hadoop.hbase.HColumnDescriptor; 
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.KeyValue; 

import org.apache.hadoop.hbase.client.HBaseAdmin;

import org.apache.hadoop.hbase.client.Put;

import org.apache.hadoop.hbase.mapreduce.TableOutputFormat; 
import org.apache.hadoop.hbase.mapreduce.TableReducer; 
import org.apache.hadoop.hbase.util.Bytes; 
import org.apache.hadoop.io.IntWritable; 
import org.apache.hadoop.io.LongWritable; 
import org.apache.hadoop.io.Text; 
import org.apache.hadoop.io.NullWritable; 
import org.apache.hadoop.mapreduce.Job; 
import org.apache.hadoop.mapreduce.Mapper; 
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat; 
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat; 
 /*
  * 简单map reduce算数
  * */
public class WordCountHBase { 
 
  /* 实现 Map 类    
   *   输入类型 默认文件读取到的索引位置  long类型
   *   输入值类型   字符串
   *   输出 类型  字符串
   *   输出值类型   数字
  */
  public static class Map extends 
      Mapper<LongWritable, Text, Text, IntWritable> { 
    private final static IntWritable one = new IntWritable(1); 
    private Text word = new Text(); 
 
    public void map(LongWritable key, Text value, Context context) 
        throws IOException, InterruptedException { 
      StringTokenizer itr = new StringTokenizer(value.toString()); 
      while (itr.hasMoreTokens()) { 
        word.set(itr.nextToken()); 
        context.write(word, one); 
      } 
    } 
  } 
 
  /* 实现 Reduce 类
   * map 的输出类型
   * map 的输出值类型
   * tablereduce 输出类型是null,
   * 输出值类型 put 
  */
  public static class Reduce extends 
      TableReducer<Text, IntWritable, NullWritable> { 
	    
	  public static Configuration configuration = null;
	    static
	    {
	        configuration = HBaseConfiguration.create();
	        //configuration.set("hbase.master", "192.168.0.201:60000");
	     //   configuration.set("hbase.zookeeper.quorum", "idc01-hd-nd-03,idc01-hd-nd-04,idc01-hd-nd-05");
	        //configuration.set("hbase.zookeeper.property.clientPort", "2181");
	    }
	    public  String  selectRowKey(String tablename, String rowKey) throws IOException
	    {
	        HTable table = new HTable(configuration, tablename);
	        Get g = new Get(rowKey.getBytes());
	        Result rs = table.get(g);
            String retstr="";
	        for (KeyValue kv : rs.raw())
	        {
	         
	          retstr= new String(kv.getValue());
	        }
	        return retstr;
	    }   
	  
    public void reduce(Text key, Iterable<IntWritable> values, 
        Context context) throws IOException, InterruptedException { 
 
      int sum = 0; 
 
      Iterator<IntWritable> iterator = values.iterator(); 
      while (iterator.hasNext()) { 
        sum += iterator.next().get(); 
      } 
    //测试查询
      String result = selectRowKey("wordcount","product");
      
      
      // Put 实例化，每个词存一行 
      Put put = new Put(Bytes.toBytes((result+"_"+key).toString())); 
      // 列族为 content，列修饰符为 count，列值为数目 
      put.add(Bytes.toBytes("content"), Bytes.toBytes("count"), 
          Bytes.toBytes(String.valueOf(sum))); 
      
      context.write(NullWritable.get(), put); 
    } 
  
     
  } 
 
  // 创建 HBase 数据表 
  public static void createHBaseTable(String tableName)  
throws IOException { 
    // 创建表描述 
    HTableDescriptor htd = new HTableDescriptor(tableName); 
    // 创建列族描述 
    HColumnDescriptor col = new HColumnDescriptor("content"); 
    htd.addFamily(col); 
 
    // 配置 HBase 
    Configuration conf = HBaseConfiguration.create(); 
 
    //conf.set("hbase.zookeeper.quorum","127.0.0.1"); 
    //conf.set("hbase.zookeeper.property.clientPort", "2181"); 
    HBaseAdmin hAdmin = new HBaseAdmin(conf); 
 
    if (hAdmin.tableExists(tableName)) { 
      System.out.println("该数据表已经存在。"); 
   //   hAdmin.disableTable(tableName); 
   //   hAdmin.deleteTable(tableName); 
    }else { 
  
    	System.out.println("创建表：" + tableName); 
    	hAdmin.createTable(htd);
    }
  } 
 
  public static void main(String[] args) throws Exception { 
    String tableName = "wordcount"; 
    // 第一步：创建数据库表 
    WordCountHBase.createHBaseTable(tableName); 
 
    // 第二步：进行 MapReduce 处理 
    // 配置 MapReduce 
    Configuration conf = new Configuration(); 
    // 这几句话很关键 
   // conf.set("mapred.job.tracker", "master:9001"); 
    //conf.set("hbase.zookeeper.quorum","master"); 
    //conf.set("hbase.zookeeper.property.clientPort", "2181"); 
    conf.set(TableOutputFormat.OUTPUT_TABLE, tableName); 
 
    Job job = new Job(conf, "New Word Count"); 
    job.setJarByClass(WordCountHBase.class); 
 
    // 设置 Map 和 Reduce 处理类 
    job.setMapperClass(Map.class); 
    job.setReducerClass(Reduce.class); 
 
    // 设置输出类型 
    job.setMapOutputKeyClass(Text.class); 
    job.setMapOutputValueClass(IntWritable.class); 
 
    // 设置输入和输出格式 
    job.setInputFormatClass(TextInputFormat.class); 
    job.setOutputFormatClass(TableOutputFormat.class); 
 
    // 设置输入目录 
    FileInputFormat.addInputPath(job, new Path("hdfs://192.168.0.42:9000/user/jiayongwei/input/")); 
    System.exit(job.waitForCompletion(true) ? 0 : 1); 
 
  } 
}