实验三:熟悉常用的HBase操作
实验环境:
(1)操作系统:Linux(建议 Ubuntu 16.04 或 Ubuntu 18.04)。
(2)Hadoop 版本:3.1.3。
(3)HBase 版本:2.2.2。
(4)JDK 版本:1.8。
(5)Java IDE: Eclipse。
实验内容与完成情况:
(1)现有以下关系数据库中的表和数据(见表14-3〜表14-5),要求将其转换为适合于
HBase存储的表并插入数据。
在这里插入图片描述
(1)学生Student表
创建表的HBase Shell命令语句如下:
第二行数据
第三行数据
(2)课程Course表
创建表的HBase Shell命令语句如下:
(3)选课表
创建表的HBase Shell命令语句如下:
(2)编程实现以下功能。
①createTable(String tableName, String]] fields)。
创建表,参数tableName 表的名称,字符串数组fields *存储记录各字段名的数组。 要求当HBase已经存在名为tableName的表时,先删除原有的表,再创建新的表。
Java代码:
package com.xusheng.HBase.shiyan31;import org.apache.hadoop.conf.Configuration;import org.apache.hadoop.hbase.HBaseConfiguration;import org.apache.hadoop.hbase.HColumnDescriptor;import org.apache.hadoop.hbase.HTableDescriptor;import org.apache.hadoop.hbase.TableName;import org.apache.hadoop.hbase.client.*;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 createTable(String tableName,String[] fields) throws IOException { init(); TableName tablename = TableName.valueOf(tableName); if(admin.tableExists(tablename)){ System.out.println("table is exists!"); admin.disableTable(tablename); admin.deleteTable(tablename);//删除原来的表 } TableDescriptorBuilder tableDescriptor = TableDescriptorBuilder.newBuilder(tablename); for(String str : fields){ tableDescriptor.setColumnFamily(ColumnFamilyDescriptorBuilder.newBuilder(Bytes.toBytes(str)).build()); admin.createTable(tableDescriptor.build()); } close(); } //建立连接 public static void init() { configuration = HBaseConfiguration.create(); //configuration.set("hbase.rootdir", "hdfs://hadoop102:8020/HBase"); configuration.set("hbase.zookeeper.quorum","hadoop102,hadoop103,hadoop104"); try { connection = ConnectionFactory.createConnection(configuration); admin = connection.getAdmin(); } catch (IOException e) { e.printStackTrace(); } } //关闭连接 public static void close() { try { if (admin != null) { admin.close(); } if (null != connection) { connection.close(); } } catch (IOException e) { e.printStackTrace(); } } public static void main(String[] args) { String[] fields = {"Score"}; try { createTable("person", fields); } catch (IOException e) { e.printStackTrace(); } }}
结果:
②addRecord(String tableName, String row, String]] fields, String口 values) 。
向表tableName、行row(用S_Name表示)和字符串数组fields指定的单元格中添加对 应的数据valueso其中,fields中每个元素如果对应的列族下还有相应的列限定符,用 “columnFamily: column"表示。例如,同时向MathComputerEnglish三列添加成绩时,字 符串数组 fields 为( “Score: Math” ," Score: Computer" , “Score: English” },数组 values 存储 这三门课的成绩。
Java代码:
package com.xusheng.HBase.shiyan31;import org.apache.hadoop.conf.Configuration;import org.apache.hadoop.hbase.HBaseConfiguration;import org.apache.hadoop.hbase.TableName;import org.apache.hadoop.hbase.client.*;import java.io.IOException;public class addRecord { public static Configuration configuration; public static Connection connection; public static Admin admin; public static void addRecord(String tableName, String row, String[] fields, String[] values) throws IOException { init(); Table table = connection.getTable(TableName.valueOf(tableName)); for (int i = 0; i != fields.length; i++) { Put put = new Put(row.getBytes()); String[] cols = fields[i].split(":"); put.addColumn(cols[0].getBytes(), cols[1].getBytes(), values[i].getBytes()); table.put(put); } table.close(); close(); } public static void init() { configuration = HBaseConfiguration.create(); //configuration.set("hbase.rootdir", "hdfs://hadoop102:8020/HBase"); configuration.set("hbase.zookeeper.quorum","hadoop102,hadoop103,hadoop104"); try { connection = ConnectionFactory.createConnection(configuration); admin = connection.getAdmin(); } catch (IOException e) { e.printStackTrace(); } } public static void close() { try { if (admin != null) { admin.close(); } if (null != connection) { connection.close(); } } catch (IOException e) { e.printStackTrace(); } } public static void main(String[] args) { String[] fields = {"Score:Math", "Score:Computer Science", "Score:English"}; String[] values = {"99", "80", "100"}; try { addRecord("tableName", "Score", fields, values); } catch (IOException e) { e.printStackTrace(); } }}
结果:
③scanColumn(String tableName, String column) 。
浏览表tableName某列的数据,如果某行记录中该列数据不存在,则返回null。要求 当参数column为某列族名时,如果底下有若干个列限定符,则要列出每个列限定符代表 的列的数据;当参数column为某列具体名(例如“ Score: Math")时,只需要列出该列的 数据。
Java代码:
package com.xusheng.HBase.shiyan31;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;public class scanColumn { public static Configuration configuration; public static Connection connection; public static Admin admin; public static void scanColumn(String tableName, String column) throws IOException { init(); 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()) { showCell(result); } table.close(); close(); } public static void showCell(Result result) { Cell[] cells = result.rawCells(); for (Cell cell : cells) { System.out.println("RowName:" + new String(CellUtil.cloneRow(cell)) + " "); System.out.println("Timetamp:" + cell.getTimestamp() + " "); System.out.println("column Family:" + new String(CellUtil.cloneFamily(cell)) + " "); System.out.println("row Name:" + new String(CellUtil.cloneQualifier(cell)) + " "); System.out.println("value:" + new String(CellUtil.cloneValue(cell)) + " "); } } public static void init() { configuration = HBaseConfiguration.create(); //configuration.set("hbase.rootdir", "hdfs://hadoop102:8020/HBase"); configuration.set("hbase.zookeeper.quorum","hadoop102,hadoop103,hadoop104"); try { connection = ConnectionFactory.createConnection(configuration); admin = connection.getAdmin(); } catch (IOException e) { e.printStackTrace(); } } // 关闭连接 public static void close() { try { if (admin != null) { admin.close(); } if (null != connection) { connection.close(); } } catch (IOException e) { e.printStackTrace(); } } public static void main(String[] args) { try { scanColumn("tableName", "Score"); } catch (IOException e) { e.printStackTrace(); } }}
结果:
④modifyData(String tableName, String row, String column) 。
修改表tableName,即修改行row(可以用学生姓名S_Name表示)、列column指定的 单元格的数据。
Java代码:
package com.xusheng.HBase.shiyan31;import org.apache.hadoop.conf.Configuration;import org.apache.hadoop.hbase.Cell;import org.apache.hadoop.hbase.HBaseConfiguration;import org.apache.hadoop.hbase.TableName;import org.apache.hadoop.hbase.client.*;import java.io.IOException;public class modifyData { public static long ts; public static Configuration configuration; public static Connection connection; public static Admin admin; public static void modifyData(String tableName, String row, String column, String val) throws IOException { init(); Table table = connection.getTable(TableName.valueOf(tableName)); Put put = new Put(row.getBytes()); Scan scan = new Scan(); ResultScanner resultScanner = table.getScanner(scan); for (Result r : resultScanner) { for (Cell cell : r.getColumnCells(row.getBytes(), column.getBytes())) { ts = cell.getTimestamp(); } } put.addColumn(row.getBytes(), column.getBytes(), ts, val.getBytes()); table.put(put); table.close(); close(); } public static void init() { configuration = HBaseConfiguration.create(); //configuration.set("hbase.rootdir", "hdfs://hadoop102:8020/HBase"); configuration.set("hbase.zookeeper.quorum","hadoop102,hadoop103,hadoop104"); try { connection = ConnectionFactory.createConnection(configuration); admin = connection.getAdmin(); } catch (IOException e) { e.printStackTrace(); } } public static void close() { try { if (admin != null) { admin.close(); } if (null != connection) { connection.close(); } } catch (IOException e) { e.printStackTrace(); } } public static void main(String[] args) { try { modifyData("tableName", "Score", "Math", "100"); } catch (IOException e) { e.printStackTrace(); } }}
结果:
⑤deleteRow(String tableName, String row)。
删除表tableName中row指定的行的记录。
Java代码:
package com.xusheng.HBase.shiyan31;import org.apache.hadoop.conf.Configuration;import org.apache.hadoop.hbase.Cell;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;public class deleteRow { public static long ts; public static Configuration configuration; public static Connection connection; public static Admin admin; 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); table.close(); close(); } public static void init() { configuration = HBaseConfiguration.create(); //configuration.set("hbase.rootdir", "hdfs://hadoop102:8020/HBase"); configuration.set("hbase.zookeeper.quorum","hadoop102,hadoop103,hadoop104"); try { connection = ConnectionFactory.createConnection(configuration); admin = connection.getAdmin(); } catch (IOException e) { e.printStackTrace(); } } public static void close() { try { if (admin != null) { admin.close(); } if (null != connection) { connection.close(); } } catch (IOException e) { e.printStackTrace(); } } public static void main(String[] args) { try { deleteRow("tableName", "Score"); } catch (IOException e) { e.printStackTrace(); } }}
结果:
来源地址:https://blog.csdn.net/m0_52014276/article/details/130874212
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