hbase多表输出

﹏ヽ暗。殇╰゛Y 2022-08-13 08:29 137阅读 0赞

1.设置输出格式 job.setOutputFormatClass(MultiTableOutputFormat.class);

2.reduce时声明表名 ImmutableBytesWritable putTable1 = new ImmutableBytesWritable(Bytes.toBytes("analyzer\_w1"));

3.reduce写数据 context.write(putTable1, put);

例子：

package example;  
  
  
import java.io.ByteArrayOutputStream;  
import java.io.DataOutputStream;  
import java.io.IOException;  
  
  
import org.apache.hadoop.conf.Configuration;  
import org.apache.hadoop.hbase.HBaseConfiguration;  
import org.apache.hadoop.hbase.HConstants;  
import org.apache.hadoop.hbase.client.Put;  
import org.apache.hadoop.hbase.client.Result;  
import org.apache.hadoop.hbase.client.Scan;  
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;  
import org.apache.hadoop.hbase.mapreduce.MultiTableOutputFormat;  
import org.apache.hadoop.hbase.mapreduce.TableInputFormat;  
import org.apache.hadoop.hbase.mapreduce.TableOutputFormat;  
import org.apache.hadoop.hbase.util.Base64;  
import org.apache.hadoop.hbase.util.Bytes;  
import org.apache.hadoop.io.Text;  
import org.apache.hadoop.io.Writable;  
import org.apache.hadoop.io.compress.CompressionCodec;  
import org.apache.hadoop.io.compress.GzipCodec;  
import org.apache.hadoop.mapreduce.Job;  
import org.apache.hadoop.mapreduce.Mapper;  
import org.apache.hadoop.mapreduce.Reducer;  
  
  
import util.HbaseServiceUtil;  
/\*\*  
\* 多表输出  
\* @author lijl  
\*  
\*/  
public class MultiTableOutputMR \{  
static class MultiTableOutputMapper extends Mapper<ImmutableBytesWritable,Result,ImmutableBytesWritable,Text>\{  
  
  
@Override  
protected void map(ImmutableBytesWritable key, Result value,  
Context context) throws IOException, InterruptedException \{  
context.write(key, new Text(value.getValue("baseInfo".getBytes(), "aa".getBytes())));  
\}  
  
\}  
static class MultiTableOutputReducer extends Reducer<ImmutableBytesWritable,Text,Writable,Put>\{  
  
  
@Override  
protected void reduce(ImmutableBytesWritable key, Iterable<Text> values,  
Context context)  
throws IOException, InterruptedException \{  
ImmutableBytesWritable putTable1 = new ImmutableBytesWritable(Bytes.toBytes("analyzer\_w2"));  
ImmutableBytesWritable putTable2 = new ImmutableBytesWritable(Bytes.toBytes("analyzer\_w3"));  
for(Text value:values)\{  
Put put = new Put(key.get());  
put.add("baseInfo".getBytes(), "ab".getBytes(),value.toString().getBytes());  
context.write(putTable1, put);  
context.write(putTable2, put);  
\}  
\}  
  
\}  
static String convertScanToString(Scan scan) throws IOException \{  
 ByteArrayOutputStream out = new ByteArrayOutputStream();  
 DataOutputStream dos = new DataOutputStream(out);  
 scan.write(dos);  
 return Base64.encodeBytes(out.toByteArray());  
 \}  
public static void main(String\[\] args) throws IOException, InterruptedException, ClassNotFoundException \{  
Configuration conf = HbaseServiceUtil.getConfiguration();  
String inputTableName = "analyzer\_w1";  
//String OutputTableName = "test1";  
Scan scan = new Scan();  
scan.setCaching(100); // 1 is the default in Scan, which will be bad for  
// MapReduce jobs  
scan.setCacheBlocks(false); // don't set to true for MR jobs  
conf.set(TableInputFormat.SCAN, convertScanToString(scan));  
 conf.set(TableInputFormat.INPUT\_TABLE, inputTableName);  
Job job = new Job(conf);  
  
  
 job.setInputFormatClass(TableInputFormat.class);  
 job.setOutputFormatClass(TableOutputFormat.class);  
  
 job.setMapOutputValueClass(Text.class);  
 job.setMapOutputKeyClass(ImmutableBytesWritable.class);  
 job.setOutputKeyClass(ImmutableBytesWritable.class);  
 job.setOutputValueClass(Writable.class);  
  
 job.setOutputFormatClass(MultiTableOutputFormat.class);  
  
  
 job.setMapperClass(MultiTableOutputMapper.class);  
 job.setReducerClass(MultiTableOutputReducer.class);  
  
job.setNumReduceTasks(2);  
job.setJarByClass(MultiTableOutputMR.class);  
job.setJobName("MultiTableOutPut");  
System.exit(job.waitForCompletion(true) ? 0 : 1);  
\}  
  
  
\}