Hadoop生态圈-HBase的HFile创建方式

　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　作者：尹正杰

　　废话不多说，直接上代码，想说的话都在代码的注释里面。

一.环境准备

list
create 'yinzhengjie:WordCount3','f1','f2'
list
desc 'yinzhengjie:WordCount3'
scan 'yinzhengjie:WordCount3'

二.编写HFile创建方式的代码

1>.编写Map端代码

 1 /*
 2 @author :yinzhengjie
 3 Blog:http://www.cnblogs.com/yinzhengjie/tag/Hadoop%E7%94%9F%E6%80%81%E5%9C%88/
 4 EMAIL:y1053419035@qq.com
 5 */
 6 package cn.org.yinzhengjie.hbase.hfile;
 7 
 8 import org.apache.hadoop.io.IntWritable;
 9 import org.apache.hadoop.io.LongWritable;
10 import org.apache.hadoop.io.Text;
11 import org.apache.hadoop.mapreduce.Mapper;
12 
13 import java.io.IOException;
14 
15 public class HFileOutputMapper extends Mapper<LongWritable, Text, Text, IntWritable> {
16     @Override
17     protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
18         //得到一行数据
19         String line = value.toString();
20         String[] arr = line.split(" ");
21         //
22         for (String word : arr){
23             context.write(new Text(word),new IntWritable(1));
24         }
25     }
26 }

2>.编写Reducer端代码

 1 /*
 2 @author :yinzhengjie
 3 Blog:http://www.cnblogs.com/yinzhengjie/tag/Hadoop%E7%94%9F%E6%80%81%E5%9C%88/
 4 EMAIL:y1053419035@qq.com
 5 */
 6 package cn.org.yinzhengjie.hbase.hfile;
 7 
 8 import org.apache.hadoop.hbase.Cell;
 9 import org.apache.hadoop.hbase.CellUtil;
10 import org.apache.hadoop.hbase.KeyValue;
11 import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
12 import org.apache.hadoop.hbase.util.Bytes;
13 import org.apache.hadoop.io.IntWritable;
14 import org.apache.hadoop.io.Text;
15 import org.apache.hadoop.mapreduce.Reducer;
16 
17 import java.io.IOException;
18 
19 public class HFileOutputReducer extends Reducer<Text,IntWritable,ImmutableBytesWritable,Cell> {
20     @Override
21     protected void reduce(Text key, Iterable<IntWritable> values, Context context) throws IOException, InterruptedException {
22         int sum = 0;
23         for (IntWritable value : values) {
24             sum += value.get();
25         }
26         if(key.toString().length() > 0){
27             ImmutableBytesWritable outKey = new ImmutableBytesWritable(Bytes.toBytes(key.toString()));
28             //创建cell
29             Cell cell = CellUtil.createCell(Bytes.toBytes(key.toString()),
30                     Bytes.toBytes("f1"), Bytes.toBytes("count"),System.currentTimeMillis(),
31                     KeyValue.Type.Minimum,Bytes.toBytes(sum+""),null);
32             context.write(outKey,cell);
33         }
34     }
35 }

3>.编写主程序代码

 1 /*
 2 @author :yinzhengjie
 3 Blog:http://www.cnblogs.com/yinzhengjie/tag/Hadoop%E7%94%9F%E6%80%81%E5%9C%88/
 4 EMAIL:y1053419035@qq.com
 5 */
 6 package cn.org.yinzhengjie.hbase.hfile;
 7 
 8 import org.apache.hadoop.conf.Configuration;
 9 import org.apache.hadoop.fs.Path;
10 import org.apache.hadoop.hbase.Cell;
11 import org.apache.hadoop.hbase.HBaseConfiguration;
12 import org.apache.hadoop.hbase.HTableDescriptor;
13 import org.apache.hadoop.hbase.TableName;
14 import org.apache.hadoop.hbase.client.Connection;
15 import org.apache.hadoop.hbase.client.ConnectionFactory;
16 import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
17 import org.apache.hadoop.hbase.mapreduce.HFileOutputFormat2;
18 import org.apache.hadoop.io.IntWritable;
19 import org.apache.hadoop.io.Text;
20 import org.apache.hadoop.mapreduce.Job;
21 import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
22 import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
23 
24 public class App {
25 
26     public static void main(String[] args) throws Exception {
27 
28         System.setProperty("HADOOP_USER_NAME", "yinzhengjie");
29         Configuration conf = HBaseConfiguration.create();
30         conf.set("fs.defaultFS","file:///");
31         Connection conn = ConnectionFactory.createConnection(conf);
32         Job job = Job.getInstance(conf);
33         job.setJobName("HFile WordCount");
34         job.setJarByClass(App.class);
35         job.setMapperClass(HFileOutputMapper.class);
36         job.setReducerClass(HFileOutputReducer.class);
37         //设置输出格式
38         job.setOutputFormatClass(HFileOutputFormat2.class);
39         //设置路径
40         FileInputFormat.addInputPath(job,new Path("file:///D:\BigData\yinzhengjieData\word.txt"));
41         FileOutputFormat.setOutputPath(job,new Path("file:///D:\BigData\yinzhengjieData\hfile"));
42         //设置输出k-v
43         job.setOutputKeyClass(ImmutableBytesWritable.class);
44         job.setOutputValueClass(Cell.class);
45         //设置map端输出k-v
46         job.setMapOutputKeyClass(Text.class);
47         job.setMapOutputValueClass(IntWritable.class);
48         /**
49          *      配置和"yinzhengjie:WordCount3"进行关联，也就是说"yinzhengjie:WordCount3"这个表必须在HBase数据库中存在，
50          * 实际操作是以"yinzhengjie:WordCount3"为模板，便于生成HFile文件！
51          */
52         HFileOutputFormat2.configureIncrementalLoad(job, new HTableDescriptor(TableName.valueOf("yinzhengjie:WordCount3")),
53                 conn.getRegionLocator(TableName.valueOf("yinzhengjie:WordCount3")) );
54         job.waitForCompletion(true);
55     }
56 }

4>.查看测试结果