2.HBase相关学习

1.HBase shell操作

hbase shell

查看版本

version

查看服务状态

status

查看有哪些表

list

创建表

create 'students','info'
list

查看表结构

describe 'students'

插入数据

put 'students','1001','info:name','jack'
put 'students','1001','info:sex','male'
put 'students','1001','info:age','18'
put 'students','1002','info:name','lucy'
put 'students','1002','info:age','19’

单条查询

#整行查询
get 'students','1001'
#指定列族：列
get 'students','1001','info:name'

扫描数据

scan 'students'
#左闭右开区间
scan 'students',{STARTROW => '1001', STOPROW=>'1002'}
scan 'students',{STARTROW => '1001'}

更新字段

get 'students','1001'
put 'students','1001','info:name','lilei'
put 'students','1001','info:age','20'
get 'students','1001'

count

count 'students'

变更表结构

describe 'students'
alter 'students',{NAME=>'info',VERSIONS=>3}
describe 'students'

删除数据

#展出指定列
delete 'students','1002','info:age'
#删除整行
deleteall 'students','1001'

清空表

#表下线
disable 'students'
#清空
truncate 'students'

必须先下线再清空

删除表

disable 'students'
drop 'students'

2.HBase api编程

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.gonghbase</groupId>
    <artifactId>hbase-tutorial-1103</artifactId>
    <version>1.0-SNAPSHOT</version>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>7</source>
                    <target>7</target>
                </configuration>
            </plugin>
        </plugins>
    </build>

    <properties>
        <hbase.version>2.0.2</hbase.version>
        <junit.version>4.12</junit.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.apache.hbase</groupId>
            <artifactId>hbase-client</artifactId>
            <version>${hbase.version}</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>${junit.version}</version>
        </dependency>
    </dependencies>
</project>

自动import不太好，建议import-changes

创建包和类

package com.dajiangtai.hbase.java;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.*;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.io.compress.Compression;
import org.apache.hadoop.hbase.io.encoding.DataBlockEncoding;
import org.apache.hadoop.hbase.regionserver.BloomType;
import org.apache.hadoop.hbase.util.Bytes;
import org.junit.Test;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
public class HBaseDemo {
    public static Configuration conf;

    static {
        //使用HBaseConfiguration 的单例方法实例化
        conf = HBaseConfiguration.create();
        conf.set("hbase.zookeeper.quorum", "node01");
        conf.set("hbase.zookeeper.property.clientPort", "2181");
        conf.set("zookeeper.znode.parent", "/hbase-unsecure");
    }

    //创建表
    @Test
    public void testCreateTable() throws IOException {
        // Connection实现了java中的java.lang.AutoCloseable接口。所有实现了这个接口的类都可以在try-with-resources结构中使用。

        //创建Connection是一项繁重的操作。Connection线程安全的，因此客户端可以一次创建一个连接，并与其他线程共享。
        //另一方面，HBaseAdmin和HBaseAdmin实例是轻量级的，并且不是线程安全的。
        // 通常，每个客户端应用程序实例化单个Connection，每个线程都将获得其自己的Table实例。不建议对Table and Admin进行缓存或池化。

        try (Connection connection = ConnectionFactory.createConnection(conf);
             HBaseAdmin admin = (HBaseAdmin) connection.getAdmin();) {
            TableName tableName = TableName.valueOf("students");
            if (admin.tableExists(tableName)) {
                System.out.println("table " + tableName.getNameAsString() + " exists");
            } else {
                ColumnFamilyDescriptor cfDesc = ColumnFamilyDescriptorBuilder
                        .newBuilder(Bytes.toBytes("F"))
                        .setCompressionType(Compression.Algorithm.SNAPPY)
                        .setCompactionCompressionType(Compression.Algorithm.SNAPPY)
                        .setDataBlockEncoding(DataBlockEncoding.PREFIX)
                        .setBloomFilterType(BloomType.ROW)
                        .build();

                TableDescriptor tableDesc = TableDescriptorBuilder.newBuilder(tableName)
                        .setColumnFamily(cfDesc)
                        .build();

                admin.createTable(tableDesc);
            }
        }
    }

    //向表中插入数据
    @Test
    public void testPut() throws IOException {
        TableName tableName = TableName.valueOf("students");
        try (Connection connection = ConnectionFactory.createConnection(conf);
             Table table = connection.getTable(tableName);) {

            List<Put> puts = new ArrayList<>();
            for (int i = 0; i < 10; i++) {
                Put put = new Put(Bytes.toBytes(i+""));

                put.addColumn(Bytes.toBytes("F"), Bytes.toBytes("name"), Bytes.toBytes("name" + i));
                put.addColumn(Bytes.toBytes("F"), Bytes.toBytes("age"), Bytes.toBytes(20 + i+""));
                put.addColumn(Bytes.toBytes("F"), Bytes.toBytes("address"), Bytes.toBytes("djt" + i));

                puts.add(put);
            }

            table.put(puts);
        }

    }

    //获取指定行
    @Test
    public void testGet() throws IOException {
        TableName tableName = TableName.valueOf("students");
        try (Connection connection = ConnectionFactory.createConnection(conf);
             Table table = connection.getTable(tableName);) {
            String rowkey = "2";
            Get get = new Get(Bytes.toBytes(rowkey));
            Result result = table.get(get);
            for (Cell cell : result.rawCells()) {
                System.out.println("rowkey = " + Bytes.toString(result.getRow()));
                System.out.println("列族 = " + Bytes.toString(CellUtil.cloneFamily(cell)));
                System.out.println("列限定符 = " + Bytes.toString(CellUtil.cloneQualifier(cell)));
                System.out.println("值 = " + Bytes.toString(CellUtil.cloneValue(cell)));
                System.out.println("时间戳 = " + cell.getTimestamp());
            }
        }

    }

    //获取指定行，指定列
    @Test
    public void testGet1() throws IOException {
        TableName tableName = TableName.valueOf("students");
        try (Connection connection = ConnectionFactory.createConnection(conf);
             Table table = connection.getTable(tableName);) {
            String rowkey = "2";
            Get get = new Get(Bytes.toBytes(rowkey));
            get.addColumn(Bytes.toBytes("F"), Bytes.toBytes("name"));
            get.addColumn(Bytes.toBytes("F"), Bytes.toBytes("age"));
            Result result = table.get(get);
            for (Cell cell : result.rawCells()) {
                System.out.println("rowkey = " + Bytes.toString(result.getRow()));
                System.out.println("列族 = " + Bytes.toString(CellUtil.cloneFamily(cell)));
                System.out.println("列限定符 = " + Bytes.toString(CellUtil.cloneQualifier(cell)));
                System.out.println("值 = " + Bytes.toString(CellUtil.cloneValue(cell)));
                System.out.println("时间戳 = " + cell.getTimestamp());
            }
        }
    }

    //scan全表
    @Test
    public void testScan() throws IOException {
        TableName tableName = TableName.valueOf("students");
        try (Connection connection = ConnectionFactory.createConnection(conf);
             Table table = connection.getTable(tableName);) {

            Scan scan = new Scan();

            ResultScanner resultScanner = table.getScanner(scan);

            for (Result result : resultScanner) {
                for (Cell cell : result.rawCells()) {
                    System.out.println("rowkey = " + Bytes.toString(result.getRow()));
                    System.out.println("列族 = " + Bytes.toString(CellUtil.cloneFamily(cell)));
                    System.out.println("列限定符 = " + Bytes.toString(CellUtil.cloneQualifier(cell)));
                    System.out.println("值 = " + Bytes.toString(CellUtil.cloneValue(cell)));
                    System.out.println("时间戳 = " + cell.getTimestamp());
                }
            }

        }
    }

    @Test
    public void testScan1() throws IOException {
        TableName tableName = TableName.valueOf("students");
        try (Connection connection = ConnectionFactory.createConnection(conf);
             Table table = connection.getTable(tableName);) {

            Scan scan = new Scan();

            scan.addColumn(Bytes.toBytes("F"), Bytes.toBytes("name"));
            scan.addColumn(Bytes.toBytes("F"), Bytes.toBytes("age"));

            scan.setCacheBlocks(true);
            scan.setCaching(100);
            scan.withStartRow(Bytes.toBytes(5 + ""));
            scan.withStopRow(Bytes.toBytes(8 + ""));

            ResultScanner resultScanner = table.getScanner(scan);

            for (Result result : resultScanner) {
                for (Cell cell : result.rawCells()) {
                    System.out.println("rowkey = " + Bytes.toString(result.getRow()));
                    System.out.println("列族 = " + Bytes.toString(CellUtil.cloneFamily(cell)));
                    System.out.println("列限定符 = " + Bytes.toString(CellUtil.cloneQualifier(cell)));
                    System.out.println("值 = " + Bytes.toString(CellUtil.cloneValue(cell)));
                    System.out.println("时间戳 = " + cell.getTimestamp());
                }
            }
        }
    }

    //删除数据
    @Test
    public void testDelete() throws IOException {
        TableName tableName = TableName.valueOf("students");
        try (Connection connection = ConnectionFactory.createConnection(conf);
             Table table = connection.getTable(tableName);) {

            List<Delete> deletes = new ArrayList<>();
            for (int i = 0; i < 10; i++) {
                Delete delete = new Delete(Bytes.toBytes(i + ""));
                deletes.add(delete);
            }

            table.delete(deletes);
        }
    }

    //删除表
    @Test
    public void testDeleteTable() throws IOException {
        try (Connection connection = ConnectionFactory.createConnection(conf);
             HBaseAdmin admin = (HBaseAdmin) connection.getAdmin();) {
            TableName tableName = TableName.valueOf("students");
            if (admin.tableExists(tableName)) {
                //先disable再delete
                admin.disableTable(tableName);
                admin.deleteTable(tableName);
                System.out.println("table " + tableName.getNameAsString() + " delete success");
            } else {
                System.out.println("table " + tableName.getNameAsString() + " is not exists");
            }
        }
    }

    public static void main(String[] args) {
        System.out.println("hello hbase!");

    }
}

创建表

向表中插入数据

获取指定行的数据

获取指定行，指定列数据

全表扫描

删除数据和删除表就不做演示了