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();
}
}
}
