Hbase实例，
hbase
版本 hadoop-2.7.3
版本 hbase-1.2.7
Hadoop启动
start-hbase.sh
进入HBASE
hbase shell
以下为HBASE安装过程
#解压文件到指定目录
tar -zxvf /hbase-1.2.7-bin.tar.gz -C /usr/lib/
#配置 hbase-site.xml 文件
/root/opt/module/hbase-1.2.7/conf
##增加
hbase.rootdir
hdfs://itcast01:9000/hbase
- 进入hbase的shell命令行，创建表member并进行查看
hbase shell
hbase>create ‘member’, ‘m_id’, ‘address’, ‘info’
遇到的主要问题：
hbase主节点HMaster启动失败
ERROR: Can’t get master address from ZooKeeper; znode data == null
注意：看错误提示运行hbase(zookeeper)的用户无法写入zookeeper文件，导致znode data为空。
解决：在hbase-site.xml指定一个运行hbase的用户有写入文件权限的目录作为zookeeper数据目录，如
（2）hbase-site.xml文件中的
hbase.rootdir hdfs://itcast01:9000/hbase rootdir中的IP设定很重要，需要设定对应的IP与core-site.xml中fs.defaultFS中的路径不相同 fs.defaultFS hdfs://itcast01:9000 不能写IP，必须在host文件里配置 域名 与hadoop配置一样 关闭hbase服务的时候，HRegionserver服务一直关不掉,修改配置文件无法重启生效， hbase-daemon.sh stop regionserver RegionServer就报错提示如下 no zookeeper to stop because no pid file /tmp/hbase-hadoop-zookeeper.pid 原因是，默认情况下pid文件保存在/tmp目录下，/tmp目录下的文件很容易丢失， 解决办法：在hbase-env.sh中修改pid文件的存放路径； 在hbase-env.sh中下面的文字默认是注释掉的，放开即可，也可以自己指定存放位置： # The directory where pid files are stored. /tmp by default. export HBASE_PID_DIR=/opt/hbase/pidsHBase 开发环境搭建（Eclipse+Maven）
第一步：Eclipse中新建Maven项目，编辑pom.xml并更新下载jar包
<projectxmlns=“http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0http://maven.apache.org/xsd/maven-4.0.0.xsd”>
4.0.0
fulong.bigdata
myHbase
0.0.1-SNAPSHOT
org.apache.hbase
hbase-client
0.96.2-hadoop2
org.apache.hadoop
hadoop-hdfs
2.2.0
jdk.tools
jdk.tools
1.7
system
${JAVA_HOME}/lib/tools.jar
第二步：将目标集群的Hadoop和HBase配置文件拷贝到工程中
目的是为了让工程能找到Zookeeper及Hbase Master。
配置文件在工程中的路径为：
/src/main/resources/hadoop
/src/main/resources/hbase
然后将这两个目录添加进工程的classpath中：
最终目录结构如下：
第三步：hbase-site.xml中添加
fs.hdfs.impl
org.apache.hadoop.hdfs.DistributedFileSystem
第四步：编写Java程序调用Hbase接口
该代码包含了部分常用HBase接口。
package myHbase;
import java.io.IOException;
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.Delete;
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.client.ResultScanner;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.filter.Filter;
import org.apache.hadoop.hbase.util.Bytes;
public class HBaseDAO {
static Configuration conf = HBaseConfiguration.create();
/**
- create a table :table_name(columnFamily)
- @param tablename
- @param columnFamily
- @throws Exception
*/
public static void createTable(String tablename, String columnFamily) throws Exception {
HBaseAdmin admin = new HBaseAdmin(conf);
if(admin.tableExists(tablename)) {
System.out.println(“Table exists!”);
System.exit(0);
}
else {
HTableDescriptor tableDesc = new HTableDescriptor(TableName.valueOf(tablename));
tableDesc.addFamily(new HColumnDescriptor(columnFamily));
admin.createTable(tableDesc);
System.out.println(“create table success!”);
}
admin.close();
}
/**
- delete table ,caution!!! ,dangerous!!!
- @param tablename
- @return
- @throws IOException
/
public static boolean deleteTable(String tablename) throws IOException {
HBaseAdmin admin = new HBaseAdmin(conf);
if(admin.tableExists(tablename)) {
try {
admin.disableTable(tablename);
admin.deleteTable(tablename);
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
admin.close();
return false;
}
}
admin.close();
return true;
}
/* - put a cell data into a row identified by rowKey,columnFamily,identifier
- @param HTable, create by : HTable table = new HTable(conf, “tablename”)
- @param rowKey
- @param columnFamily
- @param identifier
- @param data
- @throws Exception
*/
public static void putCell(HTable table, String rowKey, String columnFamily, String identifier, String data) throws Exception{
Put p1 = new Put(Bytes.toBytes(rowKey));
p1.add(Bytes.toBytes(columnFamily), Bytes.toBytes(identifier), Bytes.toBytes(data));
table.put(p1);
System.out.println(“put '”+rowKey+"’, ‘"+columnFamily+":"+identifier+"’, ‘"+data+"’");
}
/**
- get a row identified by rowkey
- @param HTable, create by : HTable table = new HTable(conf, “tablename”)
- @param rowKey
- @throws Exception
*/
public static Result getRow(HTable table, String rowKey) throws Exception {
Get get = new Get(Bytes.toBytes(rowKey));
Result result = table.get(get);
System.out.println("Get: "+result);
return result;
}
/**
- delete a row identified by rowkey
- @param HTable, create by : HTable table = new HTable(conf, “tablename”)
- @param rowKey
- @throws Exception
*/
public static void deleteRow(HTable table, String rowKey) throws Exception {
Delete delete = new Delete(Bytes.toBytes(rowKey));
table.delete(delete);
System.out.println("Delete row: "+rowKey);
}
/**
- return all row from a table
- @param HTable, create by : HTable table = new HTable(conf, “tablename”)
- @throws Exception
*/
public static ResultScanner scanAll(HTable table) throws Exception {
Scan s =new Scan();
ResultScanner rs = table.getScanner(s);
return rs;
}
/**
- return a range of rows specified by startrow and endrow
- @param HTable, create by : HTable table = new HTable(conf, “tablename”)
- @param startrow
- @param endrow
- @throws Exception
/
public static ResultScanner scanRange(HTable table,String startrow,String endrow) throws Exception {
Scan s =new Scan(Bytes.toBytes(startrow),Bytes.toBytes(endrow));
ResultScanner rs = table.getScanner(s);
return rs;
}
/* - return a range of rows filtered by specified condition
- @param HTable, create by : HTable table = new HTable(conf, “tablename”)
- @param startrow
- @param filter
- @throws Exception
*/
public static ResultScanner scanFilter(HTable table,String startrow, Filter filter) throws Exception {
Scan s =new Scan(Bytes.toBytes(startrow),filter);
ResultScanner rs = table.getScanner(s);
return rs;
}
public static void main(String[] args) throws Exception {
// TODO Auto-generated method stub
HTable table = new HTable(conf, “apitable”);
// ResultScanner rs = HBaseDAO.scanRange(table, “2013-07-10*”, “2013-07-11*”);
// ResultScanner rs = HBaseDAO.scanRange(table, “100001”, “100003”);
ResultScanner rs = HBaseDAO.scanAll(table);
for(Result r:rs) {
System.out.println("Scan: "+r);
}
table.close();
// HBaseDAO.createTable(“apitable”, “testcf”);
// HBaseDAO.putRow(“apitable”, “100001”, “testcf”, “name”, “liyang”);
// HBaseDAO.putRow(“apitable”, “100003”, “testcf”, “name”, “leon”);
// HBaseDAO.deleteRow(“apitable”, “100002”);
// HBaseDAO.getRow(“apitable”, “100003”);
// HBaseDAO.deleteTable(“apitable”);
}
}
运行结果图：