HBase Learning 02 (HBase API)

Language 2023-04-09 13:36:03 views: null

Article directory

Environmental preparation

After creating a new project, add it in pom.xml

<dependency>
    <groupId>org.apache.hbase</groupId>
    <artifactId>hbase-server</artifactId>
    <version>2.0.5</version>
</dependency>

<dependency>
    <groupId>org.apache.hbase</groupId>
    <artifactId>hbase-client</artifactId>
    <version>2.0.5</version>
</dependency>

DDL

Whether the judgment table exists

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.NamespaceDescriptor;
import org.apache.hadoop.hbase.NamespaceExistException;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.util.Bytes;
import java.io.IOException;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;

The following code no longer repeats the code for importing packages

public class HBase_DDL01 {
    
    
    public static void main(String[] args) throws IOException {
    
    
        Logger.getLogger("org").setLevel(Level.ERROR);//去除无用INFO信息
        System.out.println(HBase_DDL01.isTableExist("test01:student"));//true,因为这个表是存在的
    }
    //TODO 判断表是否存在
    public static boolean isTableExist(String tableName) throws IOException {
    
    
        //1.创建配置信息并配置
        Configuration configuration = HBaseConfiguration.create();
        configuration.set("hbase.zookeeper.quorum", "hadoop102,hadoop103,hadoop104");
        //2.获取与HBase的连接
        Connection connection = ConnectionFactory.createConnection(configuration);
        //3.获取DDL操作对象
        Admin admin = connection.getAdmin();
        //4.判断表是否存在操作
        boolean exists = admin.tableExists(TableName.valueOf(tableName));
        //5.关闭连接
        admin.close();
        connection.close();
        //6.返回结果
        return exists;
    }
}

create table

public class HBase_DDL {
    
    
    public static void main(String[] args) throws IOException {
    
    
        Logger.getLogger("org").setLevel(Level.ERROR);//去除无用INFO信息
        HBase_DDL.createTable("test01:student","info");//因为此表已存在
        //所以输出：“需要创建的表已存在！”
    }
    //TODO 判断表是否存在
    public static boolean isTableExist(String tableName) throws IOException {
    
    
        //1.创建配置信息并配置
        Configuration configuration = HBaseConfiguration.create();
        configuration.set("hbase.zookeeper.quorum", "hadoop102,hadoop103,hadoop104");
        //2.获取与HBase的连接
        Connection connection = ConnectionFactory.createConnection(configuration);
        //3.获取DDL操作对象
        Admin admin = connection.getAdmin();
        //4.判断表是否存在操作
        boolean exists = admin.tableExists(TableName.valueOf(tableName));
        //5.关闭连接
        admin.close();
        connection.close();
        //6.返回结果
        return exists;
    }
    //TODO 创建表
    public static void createTable(String tableName, String... cfs) throws IOException {
    
    
        //1.判断是否存在列族信息
        if (cfs.length <= 0) {
    
    
            System.out.println("请设置列族信息！");
            return;
        }
        //2.判断表是否存在
        if (isTableExist(tableName)) {
    
    
            System.out.println("需要创建的表已存在！");
            return;
        }
        //3.创建配置信息并配置
        Configuration configuration = HBaseConfiguration.create();
        configuration.set("hbase.zookeeper.quorum", "hadoop102,hadoop103,hadoop104");
        //4.获取与HBase的连接
        Connection connection = ConnectionFactory.createConnection(configuration);
        //5.获取DDL操作对象
        Admin admin = connection.getAdmin();
        //6.创建表描述器构造器
        TableDescriptorBuilder tableDescriptorBuilder = TableDescriptorBuilder.newBuilder(TableName.valueOf(tableName));
        //7.循环添加列族信息
        for (String cf : cfs) {
    
    
            ColumnFamilyDescriptorBuilder columnFamilyDescriptorBuilder = ColumnFamilyDescriptorBuilder.newBuilder(Bytes.toBytes(cf));
            tableDescriptorBuilder.setColumnFamily(columnFamilyDescriptorBuilder.build());
        }
        //8.执行创建表的操作
        admin.createTable(tableDescriptorBuilder.build());
        //9.关闭资源
        admin.close();
        connection.close();
    }
}

delete table

public class HBase_DDL {
    
    
    public static void main(String[] args) throws IOException {
    
    
        Logger.getLogger("org").setLevel(Level.ERROR);//去除无用INFO信息
        HBase_DDL.dropTable("sbtd");//随便写了一个不存在的表
        //输出“需要删除的表不存在！”
    }
    //TODO 判断表是否存在
    public static boolean isTableExist(String tableName) throws IOException {
    
    
        //1.创建配置信息并配置
        Configuration configuration = HBaseConfiguration.create();
        configuration.set("hbase.zookeeper.quorum", "hadoop102,hadoop103,hadoop104");
        //2.获取与HBase的连接
        Connection connection = ConnectionFactory.createConnection(configuration);
        //3.获取DDL操作对象
        Admin admin = connection.getAdmin();
        //4.判断表是否存在操作
        boolean exists = admin.tableExists(TableName.valueOf(tableName));
        //5.关闭连接
        admin.close();
        connection.close();
        //6.返回结果
        return exists;
    }
    //TODO 删除表
    public static void dropTable(String tableName) throws IOException {
    
    
        //1.判断表是否存在
        if (!isTableExist(tableName)) {
    
    
            System.out.println("需要删除的表不存在！");
            return;
        }
        //2.创建配置信息并配置
        Configuration configuration = HBaseConfiguration.create();
        configuration.set("hbase.zookeeper.quorum", "hadoop102,hadoop103,hadoop104");
        //3.获取与HBase的连接
        Connection connection = ConnectionFactory.createConnection(configuration);
        //4.获取DDL操作对象
        Admin admin = connection.getAdmin();
        //5.使表下线
        TableName name = TableName.valueOf(tableName);
        admin.disableTable(name);
        //6.执行删除表操作
        admin.deleteTable(name);
        //7.关闭资源
        admin.close();
        connection.close();
    }
}

create namespace

public class HBase_DDL {
    
    
    public static void main(String[] args) throws IOException {
    
    
        Logger.getLogger("org").setLevel(Level.ERROR);//去除无用INFO信息
        HBase_DDL.createNameSpace("test02");
    }
    //TODO 创建命名空间
    public static void createNameSpace(String ns) throws IOException {
    
    
        //1.创建配置信息并配置
        Configuration configuration = HBaseConfiguration.create();
        configuration.set("hbase.zookeeper.quorum", "hadoop102,hadoop103,hadoop104");
        //2.获取与HBase的连接
        Connection connection = ConnectionFactory.createConnection(configuration);
        //3.获取DDL操作对象
        Admin admin = connection.getAdmin();
        //4.创建命名空间描述器
        NamespaceDescriptor namespaceDescriptor = NamespaceDescriptor.create(ns).build();
        //5.执行创建命名空间操作
        try {
    
    
            admin.createNamespace(namespaceDescriptor);
        } catch (NamespaceExistException e) {
    
    
            System.out.println("命名空间已存在！");
        } catch (Exception e) {
    
    
            e.printStackTrace();
        }
        //6.关闭连接
        admin.close();
        connection.close();
    }
}

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DML

insert data

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.CellUtil;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.util.Bytes;
import java.io.IOException;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;

public class HBase_DML {
    
    
    public static void main(String[] args) throws IOException {
    
    
        Logger.getLogger("org").setLevel(Level.ERROR);//去除无用INFO信息
        putData("test01:student","1003","info","name","Tom");
    }

    //TODO 插入数据
    public static void putData(String tableName, String rowKey, String cf, String cn, String value) throws IOException {
    
    
        //1.获取配置信息并设置连接参数
        Configuration configuration = HBaseConfiguration.create();
        configuration.set("hbase.zookeeper.quorum", "hadoop102,hadoop103,hadoop104");
        //2.获取连接
        Connection connection = ConnectionFactory.createConnection(configuration);
        //3.获取表的连接
        Table table = connection.getTable(TableName.valueOf(tableName));
        //4.创建Put对象
        Put put = new Put(Bytes.toBytes(rowKey));
        //5.放入数据
        put.addColumn(Bytes.toBytes(cf), Bytes.toBytes(cn), Bytes.toBytes(value));
        //6.执行插入数据操作
        table.put(put);
        //7.关闭连接
        table.close();
        connection.close();
    }
}

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Single data query

public class HBase_DML {
    
    
    public static void main(String[] args) throws IOException {
    
    
        Logger.getLogger("org").setLevel(Level.ERROR);//去除无用INFO信息
        getDate("test01:student","1002","info","name");
    }

    //TODO 单条数据查询(GET)
    public static void getDate(String tableName, String rowKey, String cf, String cn) throws IOException {
    
    
        //1.获取配置信息并设置连接参数
        Configuration configuration = HBaseConfiguration.create();
        configuration.set("hbase.zookeeper.quorum", "hadoop102,hadoop103,hadoop104");
        //2.获取连接
        Connection connection = ConnectionFactory.createConnection(configuration);
        //3.获取表的连接
        Table table = connection.getTable(TableName.valueOf(tableName));
        //4.创建Get对象
        Get get = new Get(Bytes.toBytes(rowKey));
        // 指定列族查询
        // get.addFamily(Bytes.toBytes(cf));
        // 指定列族:列查询
        // get.addColumn(Bytes.toBytes(cf), Bytes.toBytes(cn));
        //5.查询数据
        Result result = table.get(get);
        //6.解析result
        for (Cell cell : result.rawCells()) {
    
    
            System.out.println("ROW:" + Bytes.toString(CellUtil.cloneRow(cell)) +
                    " CF:" + Bytes.toString(CellUtil.cloneFamily(cell))+
                    " CL:" + Bytes.toString(CellUtil.cloneQualifier(cell))+
                    " VALUE:" + Bytes.toString(CellUtil.cloneValue(cell)));
        }
        //7.关闭连接
        table.close();
        connection.close();
    }
}

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scan data

public class HBase_DML {
    
    
    public static void main(String[] args) throws IOException {
    
    
        Logger.getLogger("org").setLevel(Level.ERROR);//去除无用INFO信息
        scanTable("test01:student");
    }

    //TODO 扫描数据(Scan)
    public static void scanTable(String tableName) throws IOException {
    
    
        //1.获取配置信息并设置连接参数
        Configuration configuration = HBaseConfiguration.create();
        configuration.set("hbase.zookeeper.quorum", "hadoop102,hadoop103,hadoop104");
        //2.获取连接
        Connection connection = ConnectionFactory.createConnection(configuration);
        //3.获取表的连接
        Table table = connection.getTable(TableName.valueOf(tableName));
        //4.创建Scan对象
        Scan scan = new Scan();
        //5.扫描数据
        ResultScanner results = table.getScanner(scan);
        //6.解析results
        for (Result result : results) {
    
    
            for (Cell cell : result.rawCells()) {
    
    
                System.out.println(
                        Bytes.toString(CellUtil.cloneRow(cell))+":"+
                                Bytes.toString(CellUtil.cloneFamily(cell))+":" +
                                Bytes.toString(CellUtil.cloneQualifier(cell)) +":" +
                                Bytes.toString(CellUtil.cloneValue(cell))
                );
            }
        }
        //7.关闭资源
        table.close();
        connection.close();
    }
}

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delete data

public class HBase_DML {
    
    
    public static void main(String[] args) throws IOException {
    
    
        Logger.getLogger("org").setLevel(Level.ERROR);//去除无用INFO信息
        deletaData("test01:student","1002","info","name");
    }

    //TODO 删除数据
    public static void deletaData(String tableName, String rowKey, String cf, String cn) throws IOException {
    
    
        //1.获取配置信息并设置连接参数
        Configuration configuration = HBaseConfiguration.create();
        configuration.set("hbase.zookeeper.quorum", "hadoop102,hadoop103,hadoop104");
        //2.获取连接
        Connection connection = ConnectionFactory.createConnection(configuration);
        //3.获取表的连接
        Table table = connection.getTable(TableName.valueOf(tableName));
        //4.创建Delete对象
        Delete delete = new Delete(Bytes.toBytes(rowKey));
        // 指定列族删除数据
        // delete.addFamily(Bytes.toBytes(cf));
        // 指定列族:列删除数据(所有版本)
        // delete.addColumn(Bytes.toBytes(cf), Bytes.toBytes(cn));
        // 指定列族:列删除数据(指定版本)
        delete.addColumns(Bytes.toBytes(cf), Bytes.toBytes(cn));
        //5.执行删除数据操作
        table.delete(delete);
        //6.关闭资源
        table.close();
        connection.close();
    }

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