Hbase table之增删查

Posted 2021-04-19 Justin的后端书架

概略步骤

1. 加载Hbase 关于hadoop的配置参数

2. 利用HTable类进行表名实例化

3. 进行相应的增删改操作

代码

import org.apache.commons.io.IOExceptionWithCause;
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.TableName;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.util.Bytes;
import org.junit.Test;

import javax.ws.rs.core.Response;
import java.io.IOException;

import static org.apache.hadoop.hbase.util.Bytes.*;

public class PutExample {
    //constant definition
    public static final String colFam = "colfam1";


    public static void main(String[] args) throws IOException {
        //Configure the Hbase setting
        Configuration conf = HBaseConfiguration.create();

        //Hbase with hdfs setting
        conf.set("hbase.rootdir", "hdfs://192.168.56.160:8020/hbase");
        conf.set("hbase.zookeeper.quorum", "192.168.56.160");

        //Create Htable instance then do the insert operation
        HTable table = new HTable(conf, "test01");

        Put put = new Put(toBytes("row1"));

        put.add(Bytes.toBytes("colfam1"), toBytes("qual1"), toBytes("val1"));
        put.add(Bytes.toBytes("colfam1"), toBytes("qual2"), toBytes("val2"));

        table.put(put);
 //Scan the table
        System.out.println("Start to print out the table test01's content");
        scanTable(table);
        //Create new table for Hbase
        final HBaseAdmin hBaseAdmin = new HBaseAdmin(conf);

        createTable(hBaseAdmin);

        //Delete the table,specify the row num,column family,column name
        DeleteColumnData(table,"row1","colfam1","qual1");
    }


    public static void scanTable(final HTable hTableName) throws IOException {
        Scan scan = new Scan();
        final ResultScanner scanner = hTableName.getScanner(scan);
        for (Result result : scanner) {
            final byte[] value = result.getValue(colFam.getBytes(), "qual1".getBytes());

            try {
                System.out.println(result);
                System.out.println(new String(value));
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    public static void createTable(HBaseAdmin hBaseAdmin) throws IOException{
        if(!hBaseAdmin.tableExists("test01"));
        {
            HTableDescriptor tableDescriptor = new HTableDescriptor("Test02");
            //add col family
            HColumnDescriptor family = new HColumnDescriptor("col_f02");
            tableDescriptor.addFamily(family);
            hBaseAdmin.createTable(tableDescriptor);
        }
    }
 public static void DeleteColumnData (HTable table,String rowString,String colCFString,String colString) throws IOException{
        Delete delete = new Delete(Bytes.toBytes(rowString));
        //delete column
        delete.deleteColumn(Bytes.toBytes(colCFString), Bytes.toBytes(colString));
        delete.deleteFamily(Bytes.toBytes(colCFString));
        //delete columns
        Get get1 = new Get(Bytes.toBytes(rowString));
  get1.addColumn(Bytes.toBytes(colCFString),Bytes.toBytes(colString));

        if (get1.isCheckExistenceOnly() == true){
            delete.deleteColumns(Bytes.toBytes("colfam2"), Bytes.toBytes("qual1"));
            System.out.println("Get1: " + get1.isCheckExistenceOnly());
        }
        try {
            table.delete(delete);
        } catch (IOException e) {
            e.printStackTrace();
        }
        table.close();
    }
}

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