本地eclipse java api连接远程虚拟机HBase

1.本地与远程连通

无论是域名或者ip都可以，另外需保证HBase在虚拟机集群上正常运行。

2.本地要有一个跟远程相同的hadoop环境

当然不相同，只要兼容也可以，现采用hadoop-2.5.0-cdh5.3.6，此版本如果在Windows系统中。在java api调用时候会报错Could not locate executable D:\Hu_software\hadoop-2.5.0-cdh5.3.6\bin\winutils.exe in the Hadoop bina

此时可以从别的拷贝一个winutils.exe到此bin来。可从winutls.exe下载,提取吗wt9x。经测试用hadoop-2.7.7也可以测试跑通，下载解压即可。

3.代码运行前准备

首先需要HADOOP_HOME的环境变量，可以配置到系统环境变量里面，也可以如下：

Eclipse->Debug/Run Configurations -> Environment (tab) -> and added

variable: HADOOP_HOME

Value: C:\hadoop-2.5.0-cdh5.3.6

最好配以log4j.properties到src目录下面,地址。

4.启动执行

（1） pom.xml

 <dependency>
	<groupId>org.apache.hbase</groupId>
	<artifactId>hbase-server</artifactId>
	<version>0.98.6-hadoop2</version>
 </dependency>

 <dependency>
	<groupId>org.apache.hbase</groupId>
	<artifactId>hbase-client</artifactId>
	<version>0.98.6-hadoop2</version>
 </dependency>

(2)java 代码 HBaseDemo.java

package com.hoult.hbase;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

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.MasterNotRunningException;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.ZooKeeperConnectionException;
import org.apache.hadoop.hbase.client.Delete;
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.util.Bytes;

public class HBaseDemo {
	//创建Hadoop以及HBased管理配置对象
	public static Configuration conf;

	static{
		//使用HBaseConfiguration的单例方法实例化
		conf = HBaseConfiguration.create();
		conf.set("hbase.rootdir","hdfs://hadoop-senior01.hoult.com:9000/hbase");//可以吧hadoop改成你的域名或Ip
		conf.set("hbase.zookeeper.quorum","hadoop-senior01.hoult.com,hadoop-senior02.hoult.com,hadoop-senior03.hoult.com");  //hbase 服务地址
		conf.set("hbase.zookeeper.property.clientPort","2181"); //端口号默认2128不用改
	}

	/**
	 * 判断表是否已存在
	 * @param args
	 * @throws IOException
	 * @throws ZooKeeperConnectionException
	 * @throws MasterNotRunningException
	 */
	public static boolean isTableExist(String tableName) throws MasterNotRunningException, ZooKeeperConnectionException, IOException{
		//在HBase中管理、访问表需要先创建HBaseAdmin对象
		HBaseAdmin admin = new HBaseAdmin(conf);
		return admin.tableExists(tableName);
	}

	/**
	 * 创建表
	 * @param args
	 * @throws IOException
	 * @throws ZooKeeperConnectionException
	 * @throws MasterNotRunningException
	 */
	public static void createTable(String tableName, String... columnFamily) throws MasterNotRunningException, ZooKeeperConnectionException, IOException{
		HBaseAdmin admin = new HBaseAdmin(conf);
		//判断表是否存在
		if(isTableExist(tableName)){
			System.out.println("表" + tableName + "已存在");
			//System.exit(0);
		}else{
			//创建表属性对象,表名需要转字节
			HTableDescriptor descriptor = new HTableDescriptor(TableName.valueOf(tableName));

			//创建多个列族
			for(String cf : columnFamily){
				descriptor.addFamily(new HColumnDescriptor(cf));
			}

			//根据对表的配置，创建表
			admin.createTable(descriptor);
			System.out.println("表" + tableName + "创建成功！");
		}
	}

	/**
	 * 删除表
	 * @param args
	 * @throws IOException
	 * @throws ZooKeeperConnectionException
	 * @throws MasterNotRunningException
	 */
	public static void dropTable(String tableName) throws MasterNotRunningException, ZooKeeperConnectionException, IOException{
		HBaseAdmin admin = new HBaseAdmin(conf);
		if(isTableExist(tableName)){
			admin.disableTable(tableName);
			admin.deleteTable(tableName);
			System.out.println("表" + tableName + "删除成功！");
		}else{
			System.out.println("表" + tableName + "不存在！");
		}

	}

	/**
	 * 向表中插入数据
	 * @param tableName
	 * @param rowKey
	 * @param columnFamily
	 * @param column
	 * @param value
	 * @throws IOException
	 */
	public static void addRowData(String tableName, String rowKey, String columnFamily, String column, String value) throws IOException{
		//创建HTable对象
		HTable hTable = new HTable(conf, tableName);
		//向表中插入数据
		Put put = new Put(Bytes.toBytes(rowKey));
		//向Put对象中组装数据
		put.add(Bytes.toBytes(columnFamily), Bytes.toBytes(column), Bytes.toBytes(value));
		hTable.put(put);
		hTable.close();
		System.out.println("插入数据成功");
	}

	/**
	 * 删除多行数据
	 * @param tableName
	 * @param rows
	 * @throws IOException
	 */
	public static void deleteMultiRow(String tableName, String... rows) throws IOException{
		HTable hTable = new HTable(conf, tableName);
		List<Delete> deleteList = new ArrayList<Delete>();
		for(String row : rows){
			Delete delete = new Delete(Bytes.toBytes(row));
			deleteList.add(delete);
		}
		hTable.delete(deleteList);
		hTable.close();
	}

	/**
	 * 得到所有的数据
	 * @param tableName
	 * @throws IOException
	 */
	public static void getAllRows(String tableName) throws IOException{
		HTable hTable = new HTable(conf, tableName);
		//得到用于扫描region的对象
		Scan scan = new Scan();
		//使用HTable得到resultcanner实现类的对象
		ResultScanner resultScanner = hTable.getScanner(scan);
		for(Result result : resultScanner){
			Cell[] cells = result.rawCells();
			for(Cell cell : cells){
				//得到rowkey
				System.out.print(Bytes.toString(CellUtil.cloneRow(cell)) + "\t");
				//得到列族
				System.out.print(Bytes.toString(CellUtil.cloneFamily(cell))+ "\t");
				System.out.print(Bytes.toString(CellUtil.cloneQualifier(cell))+ "\t");
				System.out.println(Bytes.toString(CellUtil.cloneValue(cell))+ "\t");
			}
		}

	}

	public static void main(String[] args) {
			try {
//				System.out.println(isTableExist("student"));
//				createTable("person", "basic_info", "job", "heathy");
//				dropTable("person");
				addRowData("person", "1002", "basic_info", "name", "Hoult");
				addRowData("person", "1003", "basic_info", "sex", "Male");
				addRowData("person", "1002", "basic_info", "age", "22");
				addRowData("person", "1004", "job", "dept_no", "123");
//
//				deleteMultiRow("person", "person");
//				getAllRows("person");

			} catch (Exception e) {
				e.printStackTrace();
			}
	}

}