Hbase-day02_java API连接hbase_基础版

java API连接hbase_基础版

父工程pom.xml配置

<?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>org.example</groupId>
    <artifactId>java-hadoop</artifactId>
    <packaging>pom</packaging>
    <version>1.0-SNAPSHOT</version>
    <modules>
        <module>hadoop-hdfs</module>
        <module>hadoop-mapreduce</module>
        <module>hadoop-sanguodemo</module>
        <module>anli-tuijian</module>
        <module>airPM25avg</module>
        <module>weather</module>
        <module>hadoop-hive</module>
        <module>hadoop-hbase</module>
    </modules>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <hadoop-version>2.7.6</hadoop-version>
        <junit-version>4.12</junit-version>
    </properties>
    <dependencyManagement>
        <dependencies>
            <!-- https://mvnrepository.com/artifact/org.apache.hadoop/hadoop-common -->
            <dependency>
                <groupId>org.apache.hadoop</groupId>
                <artifactId>hadoop-common</artifactId>
                <version>${hadoop-version}</version>
            </dependency>
            <!-- https://mvnrepository.com/artifact/org.apache.hadoop/hadoop-client -->
            <dependency>
                <groupId>org.apache.hadoop</groupId>
                <artifactId>hadoop-client</artifactId>
                <version>${hadoop-version}</version>
            </dependency>
            <!-- https://mvnrepository.com/artifact/org.apache.hadoop/hadoop-hdfs -->
            <dependency>
                <groupId>org.apache.hadoop</groupId>
                <artifactId>hadoop-hdfs</artifactId>
                <version>${hadoop-version}</version>
            </dependency>

            <!-- https://mvnrepository.com/artifact/com.janeluo/ikanalyzer -->
            <dependency>
                <groupId>com.janeluo</groupId>
                <artifactId>ikanalyzer</artifactId>
                <version>2012_u6</version>
            </dependency>
            <!-- https://mvnrepository.com/artifact/org.apache.hive/hive-exec -->
            <dependency>
                <groupId>org.apache.hive</groupId>
                <artifactId>hive-exec</artifactId>
                <version>1.2.1</version>
            </dependency>
            <dependency>
                <groupId>org.apache.hbase</groupId>
                <artifactId>hbase-client</artifactId>
                <version>1.7.1</version>
            </dependency>
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>${junit-version}</version>
            </dependency>
        </dependencies>

    </dependencyManagement>
</project>

子项目pom.xml配置

<?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">
    <parent>
        <artifactId>java-hadoop</artifactId>
        <groupId>org.example</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>hadoop-hbase</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.apache.hbase</groupId>
            <artifactId>hbase-client</artifactId>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-client</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-common</artifactId>
        </dependency>
    </dependencies>

</project>

java连接hbase_连接-操作-创建表-删除表-插入数据-关闭连接

package com.shujia;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.util.Bytes;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;

/**
 *     思考：
 *          1.如何将所有的学生成绩查询出来？有几种方式？
 *          2. 假如给我们一个条件查询，你会不会？比如说：查姓王，年龄在24一下，理科的，女生
 *          3. 如何用创建region呢？
 *          4，如何设置过期时间？
 *          5，hbase  的读写流程是什么样的？你可以自己画出来吗？
 *          6.hbase中涉及的数据结构有哪些？
 *          7.二级索引了解一下
 *          8.如何通过代码实现二级索引，有什么好处？
 *
 */

/**
 * @author WangTao
 * @date 2022/6/10 23:12
 */
public class ClintToHbase {
    private HConnection conn  = null;
    private HBaseAdmin hAdmin = null;
    @Before
    public void connect(){
        try {
            //1.获取Hadoop的相关配置环境
            Configuration conf = new Configuration();

            //获取zookeeper的配置
            conf.set("hbase.zookeeper.quorum", "master:2181,node1:2181,node2:2181");

            //获取与Hbase 的连接，这个连接是将来可以用户获取hbase表的
            conn = HConnectionManager.createConnection(conf);

            //将来我们要对表做DDL相关的操作，而对表的操作在hbase架构中是有HMaster的
            hAdmin = new HBaseAdmin(conf);

            System.out.println("建立连接成功："+conn+",HMaster建立连接成功："+hAdmin);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    /**
     * 在HBase中创建表
     *<p>
     *create 'students','info'
     */
    @Test
    public void createTable(){
        try {
            //使用 HTableDescriptor类创建一个表对象
            HTableDescriptor students = new HTableDescriptor("students");

            //在创建表的时候，至少指定一个列簇
            HColumnDescriptor info = new HColumnDescriptor("info");

            //将列添加到表中
            students.addFamily(info);
            //真正的执行，是由 HMAster
            //hAdmin
            hAdmin.createTable(students);
            System.out.println(Bytes.toString(students.getName())+"表创成功！！！");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    @Test
    public void deleteTable(){
        try {
            if(hAdmin.tableExists("students")){
                // 1.首先判断一下表是否存在
                //  直接删除是删除不掉的
                //  先禁用表，在删除表
                hAdmin.disableTable("students");
                hAdmin.deleteTable("students");
                System.out.println(conn.getTable("students").getName()+"表，已经被删除！！！");
            }

        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    
    /**
     * 往表中添加一条数据
     * <p>
     * put  'student','1001','info:name','WTao'
     */
    @Test
    public void putData(){
        try {
            //1.获取表的实例
            HTableInterface students = conn.getTable("students");

            //创建一个put实例，并且给一个行键（rowkey）
            Put put = new Put("1001".getBytes());

            //将这个行键对应的值，添加列簇，列，具体的值
            put.add("info".getBytes(), "name".getBytes(), "aTao".getBytes());

            //表的实例将数据添加到表中
            students.put(put);

            String s = put.toString();
            System.out.println(s);

            System.out.println(students.getName() + "表，成功插入一条数据");

        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 一次性往表中添加多条数据
     *
     * students2.txt
     */

    @Test
    public void putAll(){
        try {
            //获取表的实例
            HTableInterface students = conn.getTable("students");

            //创建一个List集合对象
            ArrayList<Put> puts = new ArrayList<>();

            //读取数据----- IO
            BufferedReader br = new BufferedReader(new FileReader("D:\\Softwore_java\\projects\\java-hadoop\\hadoop-hbase\\src\\main\\java\\com\\shujia\\students2.txt"));
            String line = null;
            while ((line = br.readLine()) != null){
                String[] split = line.split(",");
                String id = split[0];
                String name = split[1];
                String age = split[2];
                String gender = split[3];
                String clazz = split[4];

                //把每一行组成一个put对象
                Put put = new Put(id.getBytes());

                //为一行添加多列
                put.add("info".getBytes(),"name".getBytes(),name.getBytes());
                put.add("info".getBytes(),"age".getBytes(),age.getBytes());
                put.add("info".getBytes(),"gender".getBytes(),gender.getBytes());
                put.add("info".getBytes(),"clazz".getBytes(),clazz.getBytes());

                //每一行组成一个put对象后添加到集合中
                //put 'students',id,'info:name',name
                //put 'students',id,'info:age',age
                //put 'students',id,'info:gender',gender
                //put 'students',id,'info:clazz',clazz
                puts.add(put);
            }

            //调用表的put方法，将集合数据添加到表中
            students.put(puts);
            System.out.println("学生信息表添加完毕！！");

        } catch (IOException e) {
            e.printStackTrace();
        }


    }
    @After
    public void close(){
        if(conn!=null){
            try {
                conn.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
            System.out.println("conn已经关闭...");
        }
        if(hAdmin!=null){
            try {
                hAdmin.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
            System.out.println("hMaster已经关闭...");
        }

    }
}