【Hbase】Java调用Hbase接口实现数据库操作

继上一篇文章

我们首先来替换下hbase的lib目录下hadoop相关的jar包，换成2.6的

在eclipse的java project中，直接引入hbase的lib下的所有jar

省的到时候这个类找不到，那个类找不到的，不然你就一个一个的jar去添加，尝试，找个最小集

下面看下java代码的实现吧

HBaseUtil

package hbase;

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

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.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;

public class HBaseUtil {

private Configuration conf;

private HBaseAdmin admin;

public HBaseUtil() throws IOException {
Configuration cnf = new Configuration();
this.conf = HBaseConfiguration.create(cnf);
this.admin = new HBaseAdmin(this.conf);
}

public HBaseUtil(Configuration conf) throws IOException {
this.conf = HBaseConfiguration.create(conf);
this.admin = new HBaseAdmin(this.conf);
}

public void createTable(String tableName, String columnFamily[]) {
try {
if (this.admin.tableExists(tableName)) {
System.out
.println("Table : " + tableName + " already exists !");
} else {
HTableDescriptor td = new HTableDescriptor(tableName);
int len = columnFamily.length;
for (int i = 0; i < len; i++) {
HColumnDescriptor family = new HColumnDescriptor(
columnFamily[i]);
td.addFamily(family);
}
admin.createTable(td);
System.out.println(tableName + " 表创建成功！");
}
} catch (Exception e) {
e.printStackTrace();
System.out.println(tableName + " 表创建失败！");
}
}

public void deleteTable(String tableName) {
try {
if (this.admin.tableExists(tableName)) {

admin.disableTable(tableName);
admin.deleteTable(tableName);
System.out.println(tableName + " 表删除成功！");
} else {
System.out.println(tableName + " 表不存在！");
}
} catch (Exception e) {
e.printStackTrace();
System.out.println(tableName + " 表删除失败！");
}
}

public void insertRecord(String tableName, String rowKey,
String columnFamily, String qualifier, String value) {
try {
HTable table = new HTable(this.conf, tableName);
Put put = new Put(rowKey.getBytes());
put.add(columnFamily.getBytes(), qualifier.getBytes(),
value.getBytes());
table.put(put);
System.out.println(tableName + " 表插入数据成功！");
} catch (Exception e) {
e.printStackTrace();
System.out.println(tableName + " 表插入数据失败！");
}
}

public void deleteRecord(String tableName, String rowKey) {
try {
HTable table = new HTable(this.conf, tableName);
Delete del = new Delete(rowKey.getBytes());
table.delete(del);
System.out.println(tableName + " 表删除数据成功！");
} catch (Exception e) {
e.printStackTrace();
System.out.println(tableName + " 表删除数据失败！");
}
}

public Result getOneRecord(String tableName, String rowKey) {
try {
HTable table = new HTable(this.conf, tableName);
Get get = new Get(rowKey.getBytes());
Result rs = table.get(get);
System.out.println(tableName + " 表获取数据成功！");
return rs;
} catch (IOException e) {
e.printStackTrace();
return null;
}

}

public List<Result> getAllRecords(String tableName) {
try {
HTable table = new HTable(this.conf, tableName);
Scan scan = new Scan();
ResultScanner scanner = table.getScanner(scan);
List<Result> list = new ArrayList<Result>();
for (Result r : scanner) {
list.add(r);
}
scanner.close();
System.out.println(tableName + " 表获取所有记录成功！");
return list;
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return null;
}
}

}

以上工具类是包含了所有的表的操作，下面再来看一个测试类

HBaseDemo

package hbase;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;

public class HbaseDemo {

public static void main(String[] args) {
Configuration config = new Configuration();
config.set("hbase.zookeeper.quorum", "com23.authentication,com22.authentication,com21.authentication");
config.set("hbase.zookeeper.property.clientPort", "2181");
//config.set("hbase.master", "192.168.11.179:6000");

try {
HBaseUtil  hbase = new HBaseUtil(config);
String tableName = "flume";
String[] columnFamily = {"chiwei","lining","taotao"};
hbase.createTable(tableName, columnFamily);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}

}

大家自行去测试吧，下面说下代码原理

HBaseConfiguration

对hbase进行配置

Configuration cnf = new Configuration(); this.conf = HBaseConfiguration.create(cnf); this.admin = new HBaseAdmin(this.conf); Configuration config = new Configuration(); config.set("hbase.zookeeper.quorum", "com23.authentication,com22.authentication,com21.authentication"); config.set("hbase.zookeeper.property.clientPort", "2181");

HBaseAdmin

管理Hbase数据库表信息的接口

返回值	函数	描述
void	addColumn(String tableName, HColumnDescriptor column)	向一个已经存在的表添加咧
checkHBaseAvailable(HBaseConfiguration conf)	静态函数，查看HBase是否处于运行状态
createTable(HTableDescriptor desc)	创建一个表，同步操作
deleteTable(byte[] tableName)	删除一个已经存在的表
enableTable(byte[] tableName)	使表处于有效状态
disableTable(byte[] tableName)	使表处于无效状态
HTableDescriptor[]	listTables()	列出所有用户控件表项
void	modifyTable(byte[] tableName, HTableDescriptor htd)	修改表的模式，是异步的操作，可能需要花费一定的时间
boolean	tableExists(String tableName)	检查表是否存在

1、创建表

public void createTable(String tableName, String columnFamily[]) {
try {
if (this.admin.tableExists(tableName)) {
System.out
.println("Table : " + tableName + " already exists !");
} else {
HTableDescriptor td = new HTableDescriptor(tableName);
int len = columnFamily.length;
for (int i = 0; i < len; i++) {
HColumnDescriptor family = new HColumnDescriptor(
columnFamily[i]);
td.addFamily(family);
}
admin.createTable(td);
System.out.println(tableName + " 表创建成功！");
}
} catch (Exception e) {
e.printStackTrace();
System.out.println(tableName + " 表创建失败！");
}
}

HTableDescriptor表的名字及其表的列族

返回值	函数	描述
void	addFamily(HColumnDescriptor)	添加一个列族
HColumnDescriptor	removeFamily(byte[] column)	移除一个列族
byte[]	getName()	获取表的名字
byte[]	getValue(byte[] key)	获取属性的值
void	setValue(String key, String value)	设置属性的值

1、判断表是否存在
2、实例化表的描述符

3、依次添加列族

4、创建表

2、删除表

public void deleteTable(String tableName) {
try {
if (this.admin.tableExists(tableName)) {
admin.deleteTable(tableName);
System.out.println(tableName + " 表删除成功！");
} else {
System.out.println(tableName + " 表不存在！");
}
} catch (Exception e) {
e.printStackTrace();
System.out.println(tableName + " 表删除失败！");
}
}

通过HBaseAdmin接口来删除表

3、插入一行记录

public void insertRecord(String tableName, String rowKey,
String columnFamily, String qualifier, String value) {
try {
HTable table = new HTable(this.conf, tableName);
Put put = new Put(rowKey.getBytes());
put.add(columnFamily.getBytes(), qualifier.getBytes(),
value.getBytes());
table.put(put);
System.out.println(tableName + " 表插入数据成功！");
} catch (Exception e) {
e.printStackTrace();
System.out.println(tableName + " 表插入数据失败！");
}
}

实例化一个put对象，rowkey按照是每行的一个关键字，相当于主键，然后put添加列族和列修饰符以及列内容，最后调用table的put方法

4、查询一条记录

public Result getOneRecord(String tableName, String rowKey) {
try {
HTable table = new HTable(this.conf, tableName);
Get get = new Get(rowKey.getBytes());
Result rs = table.get(get);
System.out.println(tableName + " 表获取数据成功！");
return rs;
} catch (IOException e) {
e.printStackTrace();
return null;
}
}

查询需要实例化Get对象，通过rowkey主键来查询

Result rs = hbase.getOneRecord("flume", "love");
for (Cell cell : rs.rawCells()) {
System.out.println(new String(cell.getRow()) + " "
+ new String(cell.getFamily()) + " "
+ new String(cell.getQualifier()) + " "
+ new String(cell.getValue()));
}

5、删除一条记录

public void deleteRecord(String tableName, String rowKey) {
try {
HTable table = new HTable(this.conf, tableName);
Delete del = new Delete(rowKey.getBytes());
table.delete(del);
System.out.println(tableName + " 表删除数据成功！");
} catch (Exception e) {
e.printStackTrace();
System.out.println(tableName + " 表删除数据失败！");
}
}

实例化Delete对象，通过rowkey删除

6、查询所有记录

public List<Result> getAllRecords(String tableName) {
try {
HTable table = new HTable(this.conf, tableName);
Scan scan = new Scan();
ResultScanner scanner = table.getScanner(scan);
List<Result> list = new ArrayList<Result>();
for (Result r : scanner) {
list.add(r);
}
scanner.close();
System.out.println(tableName + " 表获取所有记录成功！");
return list;
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return null;
}
}

通过实例化Scanner对象，逐条添加到list集合中

List<Result> list = hbase.getAllRecords("flume");
Iterator<Result> it = list.iterator();
while(it.hasNext()) {
Result rs = it.next();
for (Cell cell : rs.rawCells()) {
System.out.println(new String(cell.getRow()) + " "
+ new String(cell.getFamily()) + " "
+ new String(cell.getQualifier()) + " "
+ new String(cell.getValue()));
}
}