使用eclipse开发hbase程序

 

一：在eclipse创建一个普通的java项目

二：新建一个文件夹，把hbase需要的jar放进去，我这里把hbase/lib/*.jar 下所有的jar都放进去了，最后发现就用到了下面三个jar包

hadoop-common-2.6.4.jar
hbase-common-1.2.4.jar
hbase-client-1.2.4.jar

三：

将你在服务器中配置的hbase-site.xml文件复制到ecplise工程里（在工程的跟目录下新建一个文件夹命名conf，右键conf文件--->build path---->use as source folder）

 

 

四：新创建一个测试类，就可以写代码了

package com.zhang.insert;

import java.io.IOException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.CellUtil;
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.Admin;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Get;
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.client.Result;
import org.apache.hadoop.hbase.util.Bytes;
import org.junit.Test;

public class HbaseInsert1 {
    public static Log log=LogFactory.getLog(HbaseInsert1.class);
    public static String tableName="employees";//表名
    public static String columnFamily="student_name";//列族
    public static String rowFamily="h2";//行键
    static Configuration conf=null;

    static{
        Configuration confi=new HBaseConfiguration().create();
        conf=confi;
         //指定zookeeper
        conf.set("hbase.zookeeper.quorum", "node4");
        System.setProperty("hadoop.home.dir", "E:\\hadoop-2.6.4");//设置hadoop的安装目录，如果在eclipse已经设置过可以不用设置

    }
    /**
     * 创建表
     * HBaseAdmin
     * HTableDescriptor
     */
    @Test
    public void testCreateTable(){

        HBaseAdmin admin=null;
        HTableDescriptor htd=null;
        try {
             admin=new HBaseAdmin(conf);
            //判断要创建的表是否已经存在
            if(admin.tableExists(al_TableName)){
                System.out.println(tableName+"表已经存在");
                return;
            }else{
                htd=new HTableDescriptor(al_TableName.getBytes());
                //设置列族
                htd.addFamily(new HColumnDescriptor(columnFamily));
                admin.createTable(htd);
                System.out.println(tableName+"表创建成功！！！");
            }
        }catch (IOException e) {
            e.printStackTrace();
        }
    }
    /**
     * 删除表
     */
    @Test
    public void testDeletTable(){
        HBaseAdmin admin=null;
        try {
            admin=new HBaseAdmin(conf);
            if(admin.tableExists(tableName)){
                System.out.println("table is exits");
                //如果表存在，则注为失效状态
                admin.disableTable(tableName);//删除表
                admin.deleteTable(tableName);
                System.out.println("删除成功");
            }
        } catch (IOException e) {
            e.printStackTrace();
        }

 

问题：

1，在创建表的时候抛出异常

java.io.IOException: Could not locate executable null\bin\winutils.exe in the Hadoop binaries.

这个异常是因为你缺少winutils.exe

需要下载这个文件，然后放到你的/hadoop/bin/  即可

2：

2017-01-04 22:20:05,567 INFO [main-SendThread(127.0.0.1:2181)] zookeeper.ClientCnxn (ClientCnxn.java:logStartConnect(975)) - Opening socket connection to server 127.0.0.1/127.0.0.1:2181. Will not attempt to authenticate using SASL (unknown error)

下面异常是因为连接的zk不对，需要指定你的zk

Configuration conf=new HBaseConfiguration().create();
conf.set("hbase.zookeeper.quorum", "node4");//node4 是你的服务器的名称

 

3：这个异常是我在创建表后，使用'scan'和'put'都会抛出下面错误

ERROR: No server address listed in hbase:meta for region employess_info,,1483706778862.6d09a04dec7bfba654d6b393ba966534. containing row

 

我使用 scan 'hbase:meta'查询hbase元数据

ROW COLUMN+CELL
hbase:namespace,,1482832588064.6899522395b4ee74 column=info:regioninfo, timestamp=1482832590934, value={ENCODED => 6899522395b4ee74d8a55be4b8f31fb9, NAME => 'hbase:namespace,,1482832588064.6
d8a55be4b8f31fb9. 899522395b4ee74d8a55be4b8f31fb9.', STARTKEY => '', ENDKEY => ''}
hbase:namespace,,1482832588064.6899522395b4ee74 column=info:seqnumDuringOpen, timestamp=1483554191715, value=\x00\x00\x00\x00\x00\x00\x00\x0D
d8a55be4b8f31fb9.
hbase:namespace,,1482832588064.6899522395b4ee74 column=info:server, timestamp=1483554191715, value=hadoop-node4.com:16201
d8a55be4b8f31fb9.
hbase:namespace,,1482832588064.6899522395b4ee74 column=info:serverstartcode, timestamp=1483554191715, value=1483554113504
d8a55be4b8f31fb9.
student,,1482855412525.d49d109d9fe387bdcda9f748 column=info:regioninfo, timestamp=1482855420324, value={ENCODED => d49d109d9fe387bdcda9f748f2d959e3, NAME => 'student,,1482855412525.d49d109d9
f2d959e3. fe387bdcda9f748f2d959e3.', STARTKEY => '', ENDKEY => ''}
student,,1482855412525.d49d109d9fe387bdcda9f748 column=info:seqnumDuringOpen, timestamp=1483554191720, value=\x00\x00\x00\x00\x00\x00\x00\x0D
f2d959e3.
student,,1482855412525.d49d109d9fe387bdcda9f748 column=info:server, timestamp=1483554191720, value=hadoop-node4.com:16201
f2d959e3.
student,,1482855412525.d49d109d9fe387bdcda9f748 column=info:serverstartcode, timestamp=1483554191720, value=1483554113504
f2d959e3.
student_1,,1483556027914.ded9aeece2edc985bf9999 column=info:regioninfo, timestamp=1483556033173, value={ENCODED => ded9aeece2edc985bf9999d0744fad1e, NAME => 'student_1,,1483556027914.ded9aee
d0744fad1e. ce2edc985bf9999d0744fad1e.', STARTKEY => '', ENDKEY => ''}
3 row(s) in 0.4820 seconds

 

（这个异常是因为我的eclipse工程里没有hbase-site.xml文件，所以操作是habse默认的。因为我在创建表后，对表进行操作虽然报错，但是我重启集群之后，再对表进行操作就没问题了，所以我觉得是ecplise的问题，不是hbase的问题，查看hbase:meta数据也是正常的）