第七次作业

1.任务：

• 列出HBase所有的表的相关信息，例如表名
• 
• 在终端打印出指定的表的所有记录数据；
• 
• 向已经创建好的表添加和删除指定的列族或列；
• 
• 清空指定的表的所有记录数据
• 
• 统计表的行数
• 

• 2.关系型数据库中的表和数据（教材P92上)，要求将其转换为适合于HBase存储的表并插入数据。

  创建表

• 

   

   ‘Student’表中添加数据插入数据

•  

   

   

    ‘Course’表中添加数据

• 

   

    ‘SC’表中添加数据

• 

   

   3. 编程完成以下指定功能（教材P92下)：

  （1）createTable(String tableName, String[] fields)创建表。

• import org.apache.hadoop.conf.Configuration;

  import org.apache.hadoop.hbase.HBaseConfiguration;

  import org.apache.hadoop.hbase.TableName;

  import org.apache.hadoop.hbase.client.ColumnFamilyDescriptor;

  import org.apache.hadoop.hbase.client.ColumnFamilyDescriptorBuilder;

  import org.apache.hadoop.hbase.client.Connection;

  import org.apache.hadoop.hbase.client.Admin;

  import org.apache.hadoop.hbase.client.ConnectionFactory;

  import org.apache.hadoop.hbase.client.TableDescriptorBuilder;

  import org.apache.hadoop.hbase.util.Bytes;

  import java.io.IOException;

   

  public class CreateTable {

      public static Configuration configuration;

      public static Connection connection;

      public static Admin admin;

       

      public static void init(){//建立连接

          configuration = HBaseConfiguration.create();

          configuration.set("hbase.rootdir","hdfs://localhost:9000/hbase");

          try{

              connection = ConnectionFactory.createConnection(configuration);

              admin = connection.getAdmin();

          }catch(IOException e){

              e.printStackTrace();

          }

      }

      public static void close(){//关闭连接

          try{

              if(admin != null){

                  admin.close();

              }

              if(connection != null){

                  connection.close();

              }

          }catch(IOException e){

              e.printStackTrace();

          }

      }

      public static void createTable(String tableName,String[] fields) throws IOException{

          init();

          TableName tablename = TableName.valueOf(tableName);//定义表名

          if(admin.tableExists(tablename)){

              System.out.println("table is exists!");

              admin.disableTable(tablename);

              admin.deleteTable(tablename);

          }

          TableDescriptorBuilder tableDescriptor = TableDescriptorBuilder.newBuilder(tablename);

          for(int i=0;i<fields.length;i++){

              ColumnFamilyDescriptor family = ColumnFamilyDescriptorBuilder.newBuilder(Bytes.toBytes(fields[i])).build();

              tableDescriptor.setColumnFamily(family);

          }

          admin.createTable(tableDescriptor.build());

          close();

      }

      public static void main(String[] args){

          String[] fields = {"id","score"};

          try{

              createTable("test",fields);

          }catch(IOException e){

              e.printStackTrace();

          }

      }

  }

 （2）addRecord(String tableName, String row, String[] fields, String[] values)

 

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import java.io.IOException;

import org.apache.hadoop.conf.Configuration;

import org.apache.hadoop.hbase.HBaseConfiguration;

import org.apache.hadoop.hbase.TableName;

import org.apache.hadoop.hbase.client.Admin;

import org.apache.hadoop.hbase.client.Connection;

import org.apache.hadoop.hbase.client.ConnectionFactory;

import org.apache.hadoop.hbase.client.Put;

import org.apache.hadoop.hbase.client.Table;

 

 

public class addRecord {

    public static Configuration configuration;

    public static Connection connection;

    public static Admin admin;

     

    public static void init(){//建立连接

        configuration = HBaseConfiguration.create();

        configuration.set("hbase.rootdir","hdfs://localhost:9000/hbase");

        try{

            connection = ConnectionFactory.createConnection(configuration);

            admin = connection.getAdmin();

        }catch(IOException e){

            e.printStackTrace();

        }

    }

    public static void close(){//关闭连接

        try{

            if(admin != null){

                admin.close();

            }

            if(connection != null){

                connection.close();

            }

        }catch(IOException e){

            e.printStackTrace();

        }

    }

    public static void addRecord(String tableName,String row,String[] fields,String[] values) throws IOException{

        init();//连接Hbase

        Table table = connection.getTable(TableName.valueOf(tableName));//表连接

        Put put = new Put(row.getBytes());//创建put对象

        for(int i=0;i<fields.length;i++){

            String[] cols = fields[i].split(":");

            if(cols.length == 1){

                put.addColumn(fields[i].getBytes(),"".getBytes(),values[i].getBytes());

            }

            else{

                put.addColumn(cols[0].getBytes(),cols[1].getBytes(),values[i].getBytes());

            }

            table.put(put);//向表中添加数据

        }

        close();//关闭连接

    }

    public static void main(String[] args){

        String[] fields = {"Score:Math","Score:Computer Science","Score:English"};

        String[] values = {"90","90","90"};

        try{

            addRecord("grade","S_Name",fields,values);

        }catch(IOException e){

            e.printStackTrace();

        }

    }

}

　（3）scanColumn(String tableName, String column)

 

import java.io.IOException;

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.Admin;

import org.apache.hadoop.hbase.client.Connection;

import org.apache.hadoop.hbase.client.ConnectionFactory;

import org.apache.hadoop.hbase.client.Get;

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.client.Table;

import org.apache.hadoop.hbase.util.Bytes;

 

 

public class scanColumn {

    public static Configuration configuration;

    public static Connection connection;

    public static Admin admin;

     

    public static void init(){//建立连接

        configuration = HBaseConfiguration.create();

        configuration.set("hbase.rootdir","hdfs://localhost:9000/hbase");

        try{

            connection = ConnectionFactory.createConnection(configuration);

            admin = connection.getAdmin();

        }catch(IOException e){

            e.printStackTrace();

        }

    }

    public static void close(){//关闭连接

        try{

            if(admin != null){

                admin.close();

            }

            if(connection != null){

                connection.close();

            }

        }catch(IOException e){

            e.printStackTrace();

        }

    }

    public static void showResult(Result result){

        Cell[] cells = result.rawCells();

        for(int i=0;i<cells.length;i++){

            System.out.println("RowName:"+new String(CellUtil.cloneRow(cells[i])));//打印行键

            System.out.println("ColumnName:"+new String(CellUtil.cloneQualifier(cells[i])));//打印列名

            System.out.println("Value:"+new String(CellUtil.cloneValue(cells[i])));//打印值

            System.out.println("Column Family:"+new String(CellUtil.cloneFamily(cells[i])));//打印列簇

            System.out.println();

        }

    }

    public static void scanColumn(String tableName,String column){

        init();

        try {

            Table table = connection.getTable(TableName.valueOf(tableName));

            Scan scan  = new Scan();

            scan.addFamily(Bytes.toBytes(column));

            ResultScanner scanner = table.getScanner(scan);

            for(Result result = scanner.next();result != null;result = scanner.next()){

                showResult(result);

            }

        } catch (IOException e) {

            e.printStackTrace();

        }

        finally{

            close();

        }

    }

    public static void main(String[] args){

        scanColumn("Student","S_Age");

    }

}

　　（4）modifyData(String tableName, String row, String column)

 

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;

import org.apache.hadoop.hbase.HBaseConfiguration;

import org.apache.hadoop.hbase.TableName;

import org.apache.hadoop.hbase.client.Admin;

import org.apache.hadoop.hbase.client.Connection;

import org.apache.hadoop.hbase.client.ConnectionFactory;

import org.apache.hadoop.hbase.client.Put;

import org.apache.hadoop.hbase.client.Table;

 

 

public class modifyData {

    public static Configuration configuration;

    public static Connection connection;

    public static Admin admin;

    public static void init(){//建立连接

        configuration = HBaseConfiguration.create();

        configuration.set("hbase.rootdir","hdfs://localhost:9000/hbase");

        try{

            connection = ConnectionFactory.createConnection(configuration);

            admin = connection.getAdmin();

        }catch(IOException e){

            e.printStackTrace();

        }

    }

    public static void close(){//关闭连接

        try{

            if(admin != null){

                admin.close();

            }

            if(connection != null){

                connection.close();

            }

        }catch(IOException e){

            e.printStackTrace();

        }

    }

    public static void modifyData(String tableName,String row,String column,String value) throws IOException{

        init();

        Table table = connection.getTable(TableName.valueOf(tableName));

        Put put = new Put(row.getBytes());

        String[] cols = column.split(":");

        if(cols.length == 1){

            put.addColumn(column.getBytes(),"".getBytes(), value.getBytes());

        }

        else{

            put.addColumn(cols[0].getBytes(), cols[1].getBytes(), value.getBytes());

        }

        table.put(put);

        close();

    }

    public static void main(String[] args){

        try{

            modifyData("Student","1","S_Name","Tom");

        }

        catch(Exception e){

            e.printStackTrace();

        }

    }

}

　　（5）deleteRow(String tableName, String row)

 

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;

import org.apache.hadoop.hbase.HBaseConfiguration;

import org.apache.hadoop.hbase.TableName;

import org.apache.hadoop.hbase.client.Admin;

import org.apache.hadoop.hbase.client.Connection;

import org.apache.hadoop.hbase.client.ConnectionFactory;

import org.apache.hadoop.hbase.client.Delete;

import org.apache.hadoop.hbase.client.Table;

 

 

public class deleteRow {

    public static Configuration configuration;

    public static Connection connection;

    public static Admin admin;

    public static void init(){//建立连接

        configuration = HBaseConfiguration.create();

        configuration.set("hbase.rootdir","hdfs://localhost:9000/hbase");

        try{

            connection = ConnectionFactory.createConnection(configuration);

            admin = connection.getAdmin();

        }catch(IOException e){

            e.printStackTrace();

        }

    }

    public static void close(){//关闭连接

        try{

            if(admin != null){

                admin.close();

            }

            if(connection != null){

                connection.close();

            }

        }catch(IOException e){

            e.printStackTrace();

        }

    }

    public static void deleteRow(String tableName,String row) throws IOException{

        init();

        Table table = connection.getTable(TableName.valueOf(tableName));

        Delete delete = new Delete(row.getBytes());

        table.delete(delete);

        close();

    }

    public static void main(String[] args){

        try{

            deleteRow("Student","3");

        }catch(Exception e){

            e.printStackTrace();

        }

    }

}