HBase的javaApi一个应用（创建删除表等）

本文为传智播客hadoop八天——第六天学习笔记

在启动HBase之前一定要启动Hadoop和Zookeeper！！今天调了一上午的错，竟然是因为没启动Zookeeper。o（╥﹏╥）o

package cn.bigdata;

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.HBaseConfiguration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.TableName;
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.BinaryComparator;
import org.apache.hadoop.hbase.filter.BinaryPrefixComparator;
import org.apache.hadoop.hbase.filter.ByteArrayComparable;
import org.apache.hadoop.hbase.filter.ColumnPrefixFilter;
import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;
import org.apache.hadoop.hbase.filter.FamilyFilter;
import org.apache.hadoop.hbase.filter.Filter;
import org.apache.hadoop.hbase.filter.MultipleColumnPrefixFilter;
import org.apache.hadoop.hbase.filter.PrefixFilter;
import org.apache.hadoop.hbase.filter.QualifierFilter;
import org.apache.hadoop.hbase.filter.RegexStringComparator;
import org.apache.hadoop.hbase.filter.RowFilter;
import org.apache.hadoop.hbase.filter.SingleColumnValueFilter;
import org.apache.hadoop.hbase.filter.SubstringComparator;
import org.apache.hadoop.hbase.util.Bytes;
import org.junit.Before;
import org.junit.Test;

public class HbaseDao {

private Configuration conf;
private HTable testDemo;

@Before
public void init() throws Exception {
conf = HBaseConfiguration.create();
//设置Hbase所依赖的Zookeeper集群，我使用的是伪分布模式，所以只有一个节点
conf.set("hbase.zookeeper.quorum", "localhost:2181");
//表名
testDemo = new HTable(conf, "testDemo01");
}

/**
* 根据键名插入数据
*
* @throws Exception
*/
@Test
public void testInsert() throws Exception {
//键名
Put name = new Put(Bytes.toBytes("rk0002"));
name.add(Bytes.toBytes("base_info"), Bytes.toBytes("name"),
Bytes.toBytes("天使"));

Put age = new Put(Bytes.toBytes("rk0002"));
age.add(Bytes.toBytes("base_info"), Bytes.toBytes("age"),
Bytes.toBytes("28"));

ArrayList<Put> puts = new ArrayList<Put>();
puts.add(name);
puts.add(age);

testDemo.put(puts);

}

/**
* 删除表
*
* @throws Exception
*/
@Test
public void testDrop() throws Exception {
//创建表和删除表都需要HBaseAdmin
HBaseAdmin admin = new HBaseAdmin(conf);
admin.disableTable("testDemo01");
admin.deleteTable("testDemo01");
admin.close();

}

/**
* 根据键名取出数据
*
* @throws Exception
*/
@Test
public void testGet() throws Exception {
Get get = new Get(Bytes.toBytes("rk0002"));
get.setMaxVersions(5);
Result result = testDemo.get(get);
List<Cell> cell = result.listCells();

for (KeyValue kv : result.list()) {
String family = new String(kv.getFamily());
System.out.println(family);
String qualifier = new String(kv.getQualifier());
System.out.println(qualifier);
System.out.println(new String(kv.getValue()));

}

}

public static void main(String[] args) throws Exception {

Configuration conf = HBaseConfiguration.create();
conf.set("hbase.zookeeper.quorum", "localhost:2181");

HBaseAdmin admin = new HBaseAdmin(conf);
//表名
TableName name = TableName.valueOf("testDemo01");

HTableDescriptor desc = new HTableDescriptor(name);
//列族
HColumnDescriptor base_info = new HColumnDescriptor("base_info");
HColumnDescriptor extra_info = new HColumnDescriptor("base_info");
//版本数
base_info.setMaxVersions(5);

desc.addFamily(base_info);
desc.addFamily(extra_info);

admin.createTable(desc);

}

}

/**
* 多种过滤条件的使用方法
* @throws Exception
*/
@Test
public void testScan() throws Exception{
HTable table = new HTable(conf, "person_info".getBytes());
Scan scan = new Scan(Bytes.toBytes("person_rk_bj_zhang_000001"), Bytes.toBytes("person_rk_bj_zhang_000002"));
// 前缀过滤器----针对行键
Filter filter = new PrefixFilter(Bytes.toBytes("rk"));

// 行过滤器
ByteArrayComparable rowComparator = new BinaryComparator(
Bytes.toBytes("person_rk_bj_zhang_000001"));
RowFilter rf = new RowFilter(CompareOp.LESS_OR_EQUAL, rowComparator);

/**
* 假设rowkey格式为：创建日期_发布日期_ID_TITLE 目标：查找 发布日期 为 2014-12-21 的数据
*/
rf = new RowFilter(CompareOp.EQUAL, new SubstringComparator(
"_2014-12-21_"));

// 单值过滤器 1 完整匹配字节数组
new SingleColumnValueFilter("base_info".getBytes(), "name".getBytes(),
CompareOp.EQUAL, "zhangsan".getBytes());
// 单值过滤器2 匹配正则表达式
ByteArrayComparable comparator = new RegexStringComparator("zhang.");
new SingleColumnValueFilter("info".getBytes(), "NAME".getBytes(),
CompareOp.EQUAL, comparator);

// 单值过滤器2 匹配是否包含子串,大小写不敏感
comparator = new SubstringComparator("wu");
new SingleColumnValueFilter("info".getBytes(), "NAME".getBytes(),
CompareOp.EQUAL, comparator);

// 键值对元数据过滤-----family过滤----字节数组完整匹配
FamilyFilter ff = new FamilyFilter(CompareOp.EQUAL,
new BinaryComparator(Bytes.toBytes("base_info")) // 表中不存在inf列族，过滤结果为空
);
// 键值对元数据过滤-----family过滤----字节数组前缀匹配
ff = new FamilyFilter(CompareOp.EQUAL, new BinaryPrefixComparator(
Bytes.toBytes("inf")) // 表中存在以inf打头的列族info，过滤结果为该列族所有行
);

// 键值对元数据过滤-----qualifier过滤----字节数组完整匹配

filter = new QualifierFilter(CompareOp.EQUAL, new BinaryComparator(
Bytes.toBytes("na")) // 表中不存在na列，过滤结果为空
);
filter = new QualifierFilter(CompareOp.EQUAL,
new BinaryPrefixComparator(Bytes.toBytes("na")) // 表中存在以na打头的列name，过滤结果为所有行的该列数据
);

// 基于列名(即Qualifier)前缀过滤数据的ColumnPrefixFilter
filter = new ColumnPrefixFilter("na".getBytes());

// 基于列名(即Qualifier)多个前缀过滤数据的MultipleColumnPrefixFilter
byte[][] prefixes = new byte[][] { Bytes.toBytes("na"),
Bytes.toBytes("me") };
filter = new MultipleColumnPrefixFilter(prefixes);

// 为查询设置过滤条件
scan.setFilter(filter);

scan.addFamily(Bytes.toBytes("base_info"));
ResultScanner scanner = testDemo.getScanner(scan);
for (Result r : scanner) {

// 直接从result中取到某个特定的value
byte[] value = r.getValue(Bytes.toBytes("base_info"),
Bytes.toBytes("name"));
System.out.println(new String(value));
}
testDemo.close();
}