📅 最后修改于: 2020-12-03 01:56:23 🧑 作者: Mango
让我们看一个HBase示例，该示例在HBase表中导入文件数据。
我们必须通过Java API将文件中存在的数据导入到HBase表中。
Data_file.txt包含以下数据
1,India,Bihar,Champaran,2009,April,P1,1,5
2,India, Bihar,Patna,2009,May,P1,2,10
3,India, Bihar,Bhagalpur,2010,June,P2,3,15
4,United States,California,Fresno,2009,April,P2,2,5
5,United States,California,Long Beach,2010,July,P2,4,10
6,United States,California,San Francisco,2011,August,P1,6,20
Java代码如下所示
此数据必须输入到要通过JAVA API创建的新HBase表中。必须创建以下列族
"sample,region,time.product,sale,profit".
列族区域具有三个列限定符：国家，州，城市
列族时间有两个列限定符：年，月
在编写代码时，请确保存在以下jar，这是HBase所需的。
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.StringTokenizer;
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.Put;
import org.apache.hadoop.hbase.util.Bytes;
public class readFromFile {
public static void main(String[] args) throws IOException{
if(args.length==1)
{
Configuration conf = HBaseConfiguration.create(new Configuration());
HBaseAdmin hba = new HBaseAdmin(conf);
if(!hba.tableExists(args[0])){
HTableDescriptor ht = new HTableDescriptor(args[0]);
ht.addFamily(new HColumnDescriptor("sample"));
ht.addFamily(new HColumnDescriptor("region"));
ht.addFamily(new HColumnDescriptor("time"));
ht.addFamily(new HColumnDescriptor("product"));
ht.addFamily(new HColumnDescriptor("sale"));
ht.addFamily(new HColumnDescriptor("profit"));
hba.createTable(ht);
System.out.println("New Table Created");
HTable table = new HTable(conf,args[0]);
File f = new File("/home/training/Desktop/data");
BufferedReader br = new BufferedReader(new FileReader(f));
String line = br.readLine();
int i =1;
String rowname="row";
while(line!=null && line.length()!=0){
System.out.println("Ok till here");
StringTokenizer tokens = new StringTokenizer(line,",");
rowname = "row"+i;
Put p = new Put(Bytes.toBytes(rowname));
p.add(Bytes.toBytes("sample"),Bytes.toBytes("sampleNo."),
Bytes.toBytes(Integer.parseInt(tokens.nextToken())));
p.add(Bytes.toBytes("region"),Bytes.toBytes("country"),Bytes.toBytes(tokens.nextToken()));
p.add(Bytes.toBytes("region"),Bytes.toBytes("state"),Bytes.toBytes(tokens.nextToken()));
p.add(Bytes.toBytes("region"),Bytes.toBytes("city"),Bytes.toBytes(tokens.nextToken()));
p.add(Bytes.toBytes("time"),Bytes.toBytes("year"),Bytes.toBytes(Integer.parseInt(tokens.nextToken())));
p.add(Bytes.toBytes("time"),Bytes.toBytes("month"),Bytes.toBytes(tokens.nextToken()));
p.add(Bytes.toBytes("product"),Bytes.toBytes("productNo."),Bytes.toBytes(tokens.nextToken()));
p.add(Bytes.toBytes("sale"),Bytes.toBytes("quantity"),Bytes.toBytes(Integer.parseInt(tokens.nextToken())));
p.add(Bytes.toBytes("profit"),Bytes.toBytes("earnings"),Bytes.toBytes(tokens.nextToken()));
i++;
table.put(p);
line = br.readLine();
}
br.close();
table.close();
}
else
System.out.println("Table Already exists.Please enter another table name");
}
else
System.out.println("Please Enter the table name through command line");
}
}