直接开门见山,代码如下:
这里是要引入的pom包
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
</dependency>
<dependency>
<groupId>org.apache.hbase</groupId>
<artifactId>hbase-client</artifactId>
<version>1.2.1</version>
</dependency>
<dependency>
<groupId>org.apache.hbase</groupId>
<artifactId>hbase-common</artifactId>
<version>1.2.1</version>
</dependency>
</dependencies>
接下来我们编写java代码对Hbase进行操作
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.*;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.filter.*;
import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;
import org.apache.hadoop.hbase.filter.FilterList.Operator;
import org.apache.hadoop.hbase.util.Bytes;
import org.junit.Before;
import org.junit.Test;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
//todo:Hbase Api操作
public class HbaseDemo {
//初始化Configuration对象
private Configuration conf=null;
//初始化链接
private Connection conn = null;
@Before
public void init() throws Exception{
conf= HBaseConfiguration.create();
// 对于hbase的客户端来说,只需要知道hbase所使用的zookeeper集群地址就可以了
// 因为hbase的客户端找hbase读写数据完全不用经过hmaster
conf.set("hbase.zookeeper.quorum","vm0:2181,vm1:2181,vm2:2181");
//获取链接
conn=ConnectionFactory.createConnection(conf);
}
/**
* 建表
* @throws Exception
*/
@Test
public void createTable() throws Exception{
//获取一个表的管理器
Admin admin = conn.getAdmin();
//构造一个表描述器,并指定表名
HTableDescriptor tableDescriptor = new HTableDescriptor(TableName.valueOf("t_user_info".getBytes()));
//构造一个列族描述器,并指定列族名
HColumnDescriptor hcd1 = new HColumnDescriptor("base_info");
// 构造第二个列族描述器,并指定列族名
HColumnDescriptor hcd2 = new HColumnDescriptor("extra_info");
// 为该列族设定一个版本数量
hcd2.setVersions(1, 3);
// 将列族描述器添加到表描述器中
tableDescriptor.addFamily(hcd1).addFamily(hcd2);
//利用表的管理器创建表
admin.createTable(tableDescriptor);
//关闭
admin.close();
conn.close();
}
/**
* 修改表
* @throws Exception
*/
@Test
public void modifyTable() throws Exception{
//获取一个表的管理器
Admin admin = conn.getAdmin();
//获取表的描述器
HTableDescriptor tableDescriptor = admin.getTableDescriptor(TableName.valueOf("t_user_info"));
//修改已有的ColumnFamily---extra_info最小版本数和最大版本数
HColumnDescriptor hcd1 = tableDescriptor.getFamily("extra_info".getBytes());
hcd1.setVersions(2,5);
// 添加新的ColumnFamily
tableDescriptor.addFamily(new HColumnDescriptor("other_info"));
//表的管理器admin 修改表
admin.modifyTable(TableName.valueOf("t_user_info"),tableDescriptor);
//关闭
admin.close();
conn.close();
}
/**
* put添加数据
* @throws Exception
*/
@Test
public void testPut() throws Exception {
//构建一个 table对象,通过table对象来添加数据
Table table = conn.getTable(TableName.valueOf("t_user_info"));
//创建一个集合,用于存放Put对象
ArrayList<Put> puts = new ArrayList<Put>();
// 构建一个put对象(kv),指定其行键 例如hbase shell: put '表名','rowkey','列族:列名称','值'
Put put01 = new Put(Bytes.toBytes("user001"));
put01.addColumn(Bytes.toBytes("base_info"), Bytes.toBytes("username"), Bytes.toBytes("zhangsan"));
Put put02 = new Put("user001".getBytes());
put02.addColumn(Bytes.toBytes("base_info"), Bytes.toBytes("password"), Bytes.toBytes("123456"));
Put put03 = new Put("user002".getBytes());
put03.addColumn(Bytes.toBytes("base_info"), Bytes.toBytes("username"), Bytes.toBytes("lisi"));
put03.addColumn(Bytes.toBytes("extra_info"), Bytes.toBytes("married"), Bytes.toBytes("false"));
Put put04 = new Put("zhang_sh_01".getBytes());
put04.addColumn(Bytes.toBytes("base_info"), Bytes.toBytes("username"), Bytes.toBytes("zhang01"));
put04.addColumn(Bytes.toBytes("extra_info"), Bytes.toBytes("married"), Bytes.toBytes("false"));
Put put05 = new Put("zhang_sh_02".getBytes());
put05.addColumn(Bytes.toBytes("base_info"), Bytes.toBytes("username"), Bytes.toBytes("zhang02"));
put05.addColumn(Bytes.toBytes("extra_info"), Bytes.toBytes("married"), Bytes.toBytes("false"));
Put put06 = new Put("liu_sh_01".getBytes());
put06.addColumn(Bytes.toBytes("base_info"), Bytes.toBytes("username"), Bytes.toBytes("liu01"));
put06.addColumn(Bytes.toBytes("extra_info"), Bytes.toBytes("married"), Bytes.toBytes("false"));
Put put07 = new Put("zhang_bj_01".getBytes());
put07.addColumn(Bytes.toBytes("base_info"), Bytes.toBytes("username"), Bytes.toBytes("zhang03"));
put07.addColumn(Bytes.toBytes("extra_info"), Bytes.toBytes("married"), Bytes.toBytes("false"));
Put put08 = new Put("zhang_bj_01".getBytes());
put08.addColumn(Bytes.toBytes("base_info"), Bytes.toBytes("username"), Bytes.toBytes("zhang04"));
put08.addColumn(Bytes.toBytes("extra_info"), Bytes.toBytes("married"), Bytes.toBytes("false"));
//把所有的put对象添加到一个集合中
puts.add(put01);
puts.add(put02);
puts.add(put03);
puts.add(put04);
puts.add(put05);
puts.add(put06);
puts.add(put07);
puts.add(put08);
//一起提交所有的记录
table.put(puts);
table.close();
conn.close();
}
/**
* 读取数据 get:一次读一行
* @throws Exception
*/
@Test
public void testGet() throws Exception {
//获取一个table对象
Table table = conn.getTable(TableName.valueOf("t_user_info"));
// 构造一个get查询参数对象,指定要get的是哪一行
Get get = new Get("user001".getBytes());
//返回查询结果数据
Result result = table.get(get);
//获取结果中的所有cell
List<Cell> cells = result.listCells();
//遍历所有的cell
for(Cell c:cells){
//获取行键
byte[] rowArray = c.getRowArray();
//获取列族
byte[] familyArray = c.getFamilyArray();
//获取列族下的列名称
byte[] qualifierArray = c.getQualifierArray();
//列字段的值
byte[] valueArray = c.getValueArray();
//打印rowArray、familyArray、qualifierArray、valueArray
// System.out.println(new String(rowArray));
// System.out.println(new String(familyArray));
// System.out.println(new String(qualifierArray));
// System.out.println(new String(valueArray));
//按指定位置截取,获取rowArray、familyArray、qualifierArray、valueArray
System.out.print(new String(rowArray, c.getRowOffset(), c.getRowLength()));
System.out.print(" "+new String(familyArray, c.getFamilyOffset(), c.getFamilyLength()));
System.out.print(":" + new String(qualifierArray, c.getQualifierOffset(), c.getQualifierLength()));
System.out.println(" " + new String(valueArray, c.getValueOffset(), c.getValueLength()));
}
//关闭
table.close();
conn.close();
}
/**
* scan 批量查询数据
* @throws Exception
*/
@Test
public void testScan() throws Exception {
//获取table对象
Table table = conn.getTable(TableName.valueOf("t_user_info"));
//获取scan对象
Scan scan = new Scan();
//获取查询的数据
ResultScanner scanner = table.getScanner(scan);
//获取ResultScanner所有数据,返回迭代器
Iterator<Result> iter = scanner.iterator();
//遍历迭代器
while (iter.hasNext()) {
//获取当前每一行结果数据
Result result = iter.next();
//获取当前每一行中所有的cell对象
CellScanner cellScanner = result.cellScanner();
//迭代所有的cell
while (cellScanner.advance()) {
//获取第一个cell对象
Cell current = cellScanner.current();
byte[] rowArray = current.getRowArray();
byte[] familyArray = current.getFamilyArray();
byte[] qualifierArray = current.getQualifierArray();
byte[] valueArray = current.getValueArray();
System.out.println(new String(rowArray, current.getRowOffset(), current.getRowLength()));
System.out.print(new String(familyArray, current.getFamilyOffset(), current.getFamilyLength()));
System.out.print(":" + new String(qualifierArray, current.getQualifierOffset(), current.getQualifierLength()));
System.out.println(" " + new String(valueArray, current.getValueOffset(), current.getValueLength()));
}
System.out.println("-----------------------");
}
//关闭
table.close();
conn.close();
}
/**
* 删除表中的列数据
* @throws Exception
*/
@Test
public void testDel() throws Exception {
//获取table对象
Table table = conn.getTable(TableName.valueOf("t_user_info"));
//获取delete对象,需要一个rowkey
Delete delete = new Delete("user001".getBytes());
//在delete对象中指定要删除的列族-列名称
delete.addColumn("base_info".getBytes(), "password".getBytes());
//执行删除操作
table.delete(delete);
//关闭
table.close();
conn.close();
}
/**
* 删除表
* @throws Exception
*/
@Test
public void testDrop() throws Exception {
//获取一个表的管理器
Admin admin = conn.getAdmin();
//删除表时先需要disable,将表置为不可用,然后在delete
admin.disableTable(TableName.valueOf("t_user_info"));
admin.deleteTable(TableName.valueOf("t_user_info"));
admin.close();
conn.close();
}
}