java api 查询hbase

朱华皓
2023-12-01

考虑到Java代码一般就是查询hbase存储的hadoop运算的结果数据,下面记录下查询的简单范例代码

package com.lvmama.crm.web.controller.csVipManager;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.util.Bytes;
import org.junit.Before;
import org.junit.Test;

import java.io.IOException;

/**
 * Created by zoubin on 2017-5-22.
 */
public class HbaseTest {
    private Configuration configuration;
    @Before
    public void setUp(){
        configuration = HBaseConfiguration.create();
        configuration.set("hbase.zookeeper.quorum", "node3,node4,node5");//通过zookeeper关联上hbase
    }

    /**
     * 根据rowkey查找数据
     * @throws IOException
     */
    @Test
    public void getResult() throws IOException {
        Get get =  new Get(Bytes.toBytes("row1"));
        HTable table = new HTable(configuration,Bytes.toBytes("test"));
        Result result = table.get(get);
        for(KeyValue keyValue: result.list()){
            System.out.println("family :" + Bytes.toString(keyValue.getFamily()));//列簇名
            System.out.println("qualifier :"+ Bytes.toString(keyValue.getQualifier()));//列名
            System.out.println("value :"+Bytes.toString(keyValue.getValue()));//列对应的值
            System.out.println("timestamp :" +keyValue.getTimestamp());//数据最后更新时间
            System.out.println("---------------------------------");
        }
    }

    /**
     * 查询指定rowkey范围的数据
     * @throws IOException
     */
    @Test
    public void getResults() throws IOException {
        Scan scan = new Scan();
        scan.setStartRow(Bytes.toBytes("row2"));
        scan.setStopRow(Bytes.toBytes("row4"));//实验发现范围取[row2,row4),左闭右开
        ResultScanner rs = null;
        HTable table = new HTable(configuration, Bytes.toBytes("test"));
        rs = table.getScanner(scan);
        for(Result r : rs){
            for (KeyValue kv : r.list()){
                System.out.println("row:" + Bytes.toString(kv.getRow()));
                System.out.println("family:"+ Bytes.toString(kv.getFamily()));
                System.out.println("qualifier:"+ Bytes.toString(kv.getQualifier()));
                System.out.println("value:" + Bytes.toString(kv.getValue()));
                System.out.println("timestamp:" + kv.getTimestamp());
                System.out.println("-------------------------------------------");
            }
        }
    }








}


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