实行三 熟悉常用的HBase操纵
一、实行目标
(1)理解HBase在Hadoop体系布局中的角色;
(2)熟练使用HBase操纵常用的Shell下令;
(3)熟悉HBase操纵常用的Java API。
二、实行平台
操纵体系:centos7;
Hadoop版本:3.3;
HBase版本:2.2.2;
JDK版本:1.8;
Java IDE:IDEA。
三、实行内容和要求
(一)编程实现以下指定功能,并用Hadoop提供的HBase Shell下令完成相同任务:
(1) 列出HBase全部的表的相干信息,例如表名、创建时间等;
(2) 在终端打印出指定的表的全部记录数据;
(3) 向已经创建好的表添加和删除指定的列族或列;
(4) 清空指定的表的全部记录数据;
(5) 统计表的行数。
(二)HBase数据库操纵
1 现有以下关系型数据库中的表和数据,要求将其转换为适合于HBase存储的表并插入数据:
学生表(Student)
学号(S_No)姓名(S_Name)性别(S_Sex)年龄(S_Age)2015001Zhangsanmale232015003Maryfemale222015003Lisimale24 课程表(Course)
课程号(C_No)课程名(C_Name)学分(C_Credit)123001Math2.0123002Computer5.0123003English3.0 选课表(SC)
学号(SC_Sno)课程号(SC_Cno)成绩(SC_Score)201500112300186201500112300369201500212300277201500212300399201500312300198201500312300295 2 请编程实现以下功能:
(1) createTable(String tableName, String[] fields)
创建表,参数tableName为表的名称,字符串数组fields为存储记录各个字段名称的数组。要求当HBase已经存在名为tableName的表的时候,先删除原有的表,然后再创建新的表。
- package Main;
- 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 main {
- 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://127.0.0.1:8020/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();
- }
- }
- }
复制代码 运行结果
(2)addRecord(String tableName, String row, String[] fields, String[] 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values。其中,fields中每个元素如果对应的列族下另有相应的列限定符的话,用“columnFamily:column”表示。例如,同时向“Math”、“Computer Science”、“English”三列添加成绩时,字符串数组fields为{“Score:Math”, ”Score:Computer Science”, ”Score:English”},数组values存储这三门课的成绩。
- package Main;
- 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 main {
- 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://127.0.0.1:8020/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 = {"85","80","90"};
- try{
- addRecord("grade","S_Name",fields,values);
- }catch(IOException e){
- e.printStackTrace();
- }
- }
- }
复制代码 3)scanColumn(String tableName, String column)
欣赏表tableName某一列的数据,如果某一行记录中该列数据不存在,则返回null。要求当参数column为某一列族名称时,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为某一列具体名称(例如“Score:Math”)时,只需要列出该列
- package Main;
- 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.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 main {
- 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:8020/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("test","id");
- }
- }
复制代码 运行结果
(4)modifyData(String tableName, String row, String column)
修改表tableName,行row(可以用学生姓名S_Name表示),列column指定的单元格的数据。
- package Main;
- 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 main{
- 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("test","1","score","100");
- }
- catch(Exception e){
- e.printStackTrace();
- }
- }
- }
复制代码 运行结果
此时row为1的score已经改为100
(5)deleteRow(String tableName, String row)
- package Main;
- 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 main {
- 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:8020/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("test","2");
- }catch(Exception e){
- e.printStackTrace();
- }
- }
- }
复制代码
此时row=2已经被删除
出现的题目
题目一
在安装hbase后master-status用欣赏器无法打开,而此时Hmaster和HregionServer,QuorumPeerMain已经启动
题目二
解决方法
题目一
在毗连Hbase后使用list下令后发现如下
发现原因是由于我启动Hbase使用的不是hbase自带的zookeeper,而是自己独立安装的,在hbase-env.sh下增加
- export HBASE_DISABLE_HADOOP_CLASSPATH_LOOKUP="true"
复制代码 重新启动后
题目解决
题目二
发现是maven导入包出现题目,再将hbase-client包换为2.5.3后题目解决
免责声明:如果侵犯了您的权益,请联系站长,我们会及时删除侵权内容,谢谢合作!更多信息从访问主页:qidao123.com:ToB企服之家,中国第一个企服评测及商务社交产业平台。 |