这里写目录标题
一、实验目的
(1)理解HBase在Hadoop体系结构中的角色;
(2)熟练使用HBase操作常用的Shell命令;
(3)熟悉HBase操作常用的Java API。
二、实验环境
(1)Linux操作系统(CentOS7.5)
(2)VMware Workstation Pro 15.5
(3)远程终端工具Xshell7
(4)Xftp7传输工具
(5)Hadoop版本:3.1.3;
(6)HBase版本:2.2.2;
(7)JDK版本:1.8;
(8)Java IDE:Idea。
三、实验内容
(一)编程实现以下指定功能,并用Hadoop提供的HBase Shell命令完成相同任务:
(1) 列出HBase所有的表的相关信息,例如表名;
(2) 在终端打印出指定的表的所有记录数据;
(3) 向已经创建好的表添加和删除指定的列族或列;
(4) 清空指定的表的所有记录数据;
(5) 统计表的行数。
1. 列出HBase所有的表的相关信息,例如表名;
Shell命令
hbase> list
代码
package com.xusheng.HBase.shiyan1;import org.apache.hadoop.conf.Configuration;import org.apache.hadoop.hbase.*;import org.apache.hadoop.hbase.client.*;import org.apache.hadoop.hbase.util.Bytes;import java.io.IOException;import java.util.List;
/**
* 1. 编程实现以下指定功能,并用Hadoop提供的HBase Shell命令完成相同任务:
*(1) 列出HBase所有的表的相关信息,例如表名、创建时间等;
*(2) 在终端打印出指定的表的所有记录数据;
*(3) 向已经创建好的表添加和删除指定的列族或列;
*(4) 清空指定的表的所有记录数据;
*(5) 统计表的行数。
*/
public class shiyan11 {
public static Configuration configuration;
public static Connection connection;
public static Admin admin;
//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();}}
//(1)列出HBase所有的表的相关信息,例如表名、创建时间等
public static void listTables(String stu) throws IOException {
init();//建立连接
List<TableDescriptor> tableDescriptors = admin.listTableDescriptors();
for(TableDescriptor tableDescriptor : tableDescriptors){
TableName tableName = tableDescriptor.getTableName();
System.out.println("Table:" + tableName);}
close();//关闭连接
}
public static void main(String[] args) throws IOException {
listTables("s1");}}
结果
2. 在终端打印出指定的表的所有记录数据;
Shell命令
hbase> scan 's1'
代码
package com.xusheng.HBase.shiyan1;import org.apache.hadoop.conf.Configuration;import org.apache.hadoop.hbase.*;import org.apache.hadoop.hbase.client.*;import org.apache.hadoop.hbase.util.Bytes;import java.io.IOException;
/**
* 1. 编程实现以下指定功能,并用Hadoop提供的HBase Shell命令完成相同任务:
*(1) 列出HBase所有的表的相关信息,例如表名、创建时间等;
*(2) 在终端打印出指定的表的所有记录数据;
*(3) 向已经创建好的表添加和删除指定的列族或列;
*(4) 清空指定的表的所有记录数据;
*(5) 统计表的行数。
*/
public class shiyan12 {
public static Configuration configuration;
public static Connection connection;
public static Admin admin;
//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();}}
//(2)在终端打印出指定的表的所有记录数据
public static void getData(String tableName)throws IOException{
init();
Table table = connection.getTable(TableName.valueOf(tableName));
Scan scan = new Scan();
ResultScanner scanner = table.getScanner(scan);//获取行的遍历器
for(Result result:scanner){
printRecoder(result);}
close();}
//打印一条记录的详情
public static void printRecoder(Result result)throws IOException{
for(Cell cell:result.rawCells()){
System.out.print("行健: "+new String(Bytes.toString(cell.getRowArray(),cell.getRowOffset(), cell.getRowLength())));
System.out.print("列簇: "+new String( Bytes.toString(cell.getFamilyArray(),cell.getFamilyOffset(), cell.getFamilyLength())));
System.out.print(" 列: "+new String(Bytes.toString(cell.getQualifierArray(),cell.getQualifierOffset(), cell.getQualifierLength())));
System.out.print(" 值: "+new String(Bytes.toString(cell.getValueArray(),cell.getValueOffset(), cell.getValueLength())));
System.out.println("时间戳: "+cell.getTimestamp());}}
public static void main(String[] args) throws IOException {
getData("s1");}}
结果
3. 向已经创建好的表添加和删除指定的列族或列;
Shell命令
先在Shell中创建表s1,作为示例表,命令如下:
hbase> create 's1','score'
然后,可以在s1中添加数据,命令如下:
hbase> put 's1','zhangsan','score:Math','69'
之后,可以执行如下命令删除指定的列:
hbase> delete 's1','zhangsan','score:Math'
代码
package com.xusheng.HBase.shiyan1;import org.apache.hadoop.conf.Configuration;import org.apache.hadoop.hbase.*;import org.apache.hadoop.hbase.client.*;import org.apache.hadoop.hbase.util.Bytes;import java.io.IOException;
/**
* 1. 编程实现以下指定功能,并用Hadoop提供的HBase Shell命令完成相同任务:
*(1) 列出HBase所有的表的相关信息,例如表名、创建时间等;
*(2) 在终端打印出指定的表的所有记录数据;
*(3) 向已经创建好的表添加和删除指定的列族或列;
*(4) 清空指定的表的所有记录数据;
*(5) 统计表的行数。
*/
public class shiyan13 {
public static Configuration configuration;
public static Connection connection;
public static Admin admin;
//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();}}
//(3)想已经创建好的表添加和删除指定的列族或列
//向表添加数据
public static void insterRow(String tableName,String rowKey,String colFamily,String col,String val) throws IOException {
init();
Table table = connection.getTable(TableName.valueOf(tableName));
Put put = new Put(rowKey.getBytes());
put.addColumn(colFamily.getBytes(), col.getBytes(), val.getBytes());
table.put(put);
table.close();
close();}
//删除数据
public static void deleRow(String tableName,String rowKey,String colFamily,String col) throws IOException {
init();
Table table = connection.getTable(TableName.valueOf(tableName));
Delete delete = new Delete(rowKey.getBytes());
//删除指定列族
delete.addFamily(Bytes.toBytes(colFamily));
//删除指定列
delete.addColumn(Bytes.toBytes(colFamily),Bytes.toBytes(col));
table.delete(delete);
table.close();
close();}
public static void main(String[] args) throws IOException {
insterRow("s1","1001","score1","english","33");
deleRow("s1","zhangsan","score","Math");}}
结果
4. 清空指定的表的所有记录数据;
Shell命令
hbase> truncate 's1'
代码
package com.xusheng.HBase.shiyan1;import org.apache.hadoop.conf.Configuration;import org.apache.hadoop.hbase.*;import org.apache.hadoop.hbase.client.*;import org.apache.hadoop.hbase.util.Bytes;import java.io.IOException;
/**
* 1. 编程实现以下指定功能,并用Hadoop提供的HBase Shell命令完成相同任务:
*(1) 列出HBase所有的表的相关信息,例如表名、创建时间等;
*(2) 在终端打印出指定的表的所有记录数据;
*(3) 向已经创建好的表添加和删除指定的列族或列;
*(4) 清空指定的表的所有记录数据;
*(5) 统计表的行数。
*/
public class shiyan14 {
public static Configuration configuration;
public static Connection connection;
public static Admin admin;
//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();}}
//(4)清空指定的表的所有记录数据
public static void clearRows(String tableName)throws IOException{
init();
TableName tablename = TableName.valueOf(tableName);
admin.disableTable(tablename);
admin.deleteTable(tablename);
TableDescriptorBuilder tableDescriptor = TableDescriptorBuilder.newBuilder(tablename);
admin.createTable(tableDescriptor.build());
close();}
public static void main(String[] args) throws IOException {
clearRows("tableName");}}
5. 统计表的行数
Shell命令
hbase> count 'Student'
代码
package com.xusheng.HBase.shiyan1;import org.apache.hadoop.conf.Configuration;import org.apache.hadoop.hbase.*;import org.apache.hadoop.hbase.client.*;import org.apache.hadoop.hbase.util.Bytes;import java.io.IOException;
/**
* 1. 编程实现以下指定功能,并用Hadoop提供的HBase Shell命令完成相同任务:
*(1) 列出HBase所有的表的相关信息,例如表名、创建时间等;
*(2) 在终端打印出指定的表的所有记录数据;
*(3) 向已经创建好的表添加和删除指定的列族或列;
*(4) 清空指定的表的所有记录数据;
*(5) 统计表的行数。
*/
public class shiyan15 {
public static Configuration configuration;
public static Connection connection;
public static Admin admin;
//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();}}
//(5)统计表的行数
public static void countRows(String tableName)throws IOException{
init();
Table table = connection.getTable(TableName.valueOf(tableName));
Scan scan = new Scan();
ResultScanner scanner = table.getScanner(scan);
int num =0;for(Result result = scanner.next();result!=null;result=scanner.next()){
num++;}
System.out.println("行数:"+ num);
scanner.close();
close();}
public static void main(String[] args) throws IOException {
countRows("Student");}}
结果
6. 整合代码
代码
package com.xusheng.HBase.shiyan;import org.apache.hadoop.conf.Configuration;import org.apache.hadoop.hbase.client.ClusterConnection;import org.apache.hadoop.hbase.*;import org.apache.hadoop.hbase.client.*;import org.apache.hadoop.hbase.util.Bytes;import java.io.IOException;import java.util.Scanner;
public class xu {
public static Configuration configuration;
public static Connection connection;
public static Admin admin;
public static long ts;
static Scanner sc=new Scanner(System.in);
public static void main(String[] args) throws IOException{while(true){
System.out.println("\n1、列出所有表的信息;");
System.out.println("2、打印指定表的所有记录数据;");
System.out.println("3、向创建好的表添加或删除指定的列族或列;");
System.out.println("4、清空指定表的所有记录数据;");
System.out.println("5、通过表的行数;");
System.out.println("请输入你的选择:");
int no=sc.nextInt();if(no==1){
First();}else if(no==2){
System.out.println("输入你要查询的表:");
String tablename=sc.next();
Second(tablename);}else if(no==3){
System.out.println("输入你要操作的表:");
String tablename=sc.next();
System.out.println("输入你要操作的行建名:");
String rowKey=sc.next();
System.out.println("输入你要操作的列组名:");
String colFamily=sc.next();
System.out.println("输入你要操作的列限定符名:");
String col=sc.next();
System.out.println("输入你要操作的参数值:");
String val=sc.next();
Third(tablename,rowKey,colFamily,col,val);}else if(no==4){
System.out.println("输入你要操作的表:");
String tablename=sc.next();
Fourth(tablename);
System.out.println("成功清空!");}elseif(no==5){
System.out.println("输入你要操作的表:");
String tablename=sc.next();
fift(tablename);}}}
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 First() throws IOException{
init();
HTableDescriptor hTableDescriptor[]=admin.listTables();for(HTableDescriptor s:hTableDescriptor ){
System.out.println(s.getNameAsString());}
close();}
public static void Second(String tablename) throws IOException{
init();
Table table=connection.getTable(TableName.valueOf(tablename));
Scan scan=new Scan();
ResultScanner res=table.getScanner(scan);for(Result result:res){
showCell(result);}}
public static void Third(String tableName, String row, String column,String c ,String val) throws IOException{
System.out.println("1、添加列;2、删除列");
int no=sc.nextInt();if(no==1){
insertRow(tableName,row,column,c,val);}else if(no==2){
deleteRow(tableName,row,column,c);}}
public static void Fourth(String tablename) throws IOException{
init();
//HBaseAdmin admin1=new HBaseAdmin(configuration);
//HTableDescriptor ht=admin1.getTableDescriptor(TableName.valueOf(Bytes.toBytes(tablename)));
TableName tableName=TableName.valueOf(tablename);
admin.disableTable(tableName);
admin.deleteTable(tableName);
//admin.createTable(ht);
close();}
public static void fift(String tablename) throws IOException{
init();
Table table=connection.getTable(TableName.valueOf(tablename));
Scan scan=new Scan();
ResultScanner scanner=table.getScanner(scan);
int n=0;for(Result result=scanner.next();result!=null;result=scanner.next()){
n++;}
System.out.println("行数有"+n);
scanner.close();
close();}
public static void insertRow(String tableName, String row, String column,String c ,String val) throws IOException {
init();
Table table=connection.getTable(TableName.valueOf(tableName));
Put put=new Put(row.getBytes());
put.addColumn(column.getBytes(), c.getBytes(), val.getBytes());
table.put(put);
System.out.println("成功添加!");
table.close();
close();}
public static void deleteRow(String tableName, String row, String column,String c) throws IOException{
init();
Table table=connection.getTable(TableName.valueOf(tableName));
System.out.println("1、删除列族;2、删除列限定符");
Scanner sc=new Scanner(System.in);
int no=sc.nextInt();
Delete delete=new Delete(row.getBytes());if(no==1){
delete.addFamily(Bytes.toBytes(column));
System.out.println("成功删除"+column+"这个列族");}else if(no==2){
delete.addColumn(Bytes.toBytes(column), Bytes.toBytes(c));
System.out.println("成功删除"+c+"这个列限定符");}
table.delete(delete);
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))+" ");}}}
结果
(1) 列出HBase所有的表的相关信息,例如表名;
(2) 在终端打印出指定的表的所有记录数据;
(3) 向已经创建好的表添加和删除指定的列族或列;
前后对比:
(4) 清空指定的表的所有记录数据;
(5) 统计表的行数。
(二)HBase数据库操作
1. 现有以下关系型数据库中的表和数据(见表14-3到表14-5),要求将其转换为适合于HBase存储的表并插入数据:
表14-3 学生表(Student)
(1)学生Student表
创建表的HBase Shell命令语句如下:
create 'Student','S_No','S_Name','S_Sex','S_Age'
插入数据的HBase Shell命令如下:
第一行数据
put 'Student','s001','S_No','2015001'
put 'Student','s001','S_Name','Zhangsan'
put 'Student','s001','S_Sex','male'
put 'Student','s001','S_Age','23'
第二行数据
put 'Student','s002','S_No','2015002'
put 'Student','s002','S_Name','Mary'
put 'Student','s002','S_Sex','female'
put 'Student','s002','S_Age','22'
第三行数据
put 'Student','s003','S_No','2015003'
put 'Student','s003','S_Name','Lisi'
put 'Student','s003','S_Sex','male'
put 'Student','s003','S_Age','24'
表14-4 课程表(Course)
(2)课程Course表
创建表的HBase Shell命令语句如下:
create 'Course','C_No','C_Name','C_Credit'
插入数据的HBase Shell命令如下:
第一行数据
put 'Course','c001','C_No','123001'
put 'Course','c001','C_Name','Math'
put 'Course','c001','C_Credit','2.0'
第二行数据
put 'Course','c002','C_No','123002'
put 'Course','c002','C_Name','Computer'
put 'Course','c002','C_Credit','5.0'
第三行数据
put 'Course','c003','C_No','123003'
put 'Course','c003','C_Name','English'
put 'Course','c003','C_Credit','3.0'
表14-5 选课表(SC)
(3)选课表
创建表的HBase Shell命令语句如下:
create 'SC','SC_Sno','SC_Cno','SC_Score'
插入数据的HBase Shell命令如下:
第一行数据
put 'SC','sc001','SC_Sno','2015001'
put 'SC','sc001','SC_Cno','123001'
put 'SC','sc001','SC_Score','86'
第二行数据
put 'SC','sc002','SC_Sno','2015001'
put 'SC','sc002','SC_Cno','123003'
put 'SC','sc002','SC_Score','69'
第三行数据
put 'SC','sc003','SC_Sno','2015002'
put 'SC','sc003','SC_Cno','123002'
put 'SC','sc003','SC_Score','77'
第四行数据
put 'SC','sc004','SC_Sno','2015002'
put 'SC','sc004','SC_Cno','123003'
put 'SC','sc004','SC_Score','99'
第五行数据
put 'SC','sc005','SC_Sno','2015003'
put 'SC','sc005','SC_Cno','123001'
put 'SC','sc005','SC_Score','98'
第六行数据
put 'SC','sc006','SC_Sno','2015003'
put 'SC','sc006','SC_Cno','123002'
put 'SC','sc006','SC_Score','95'
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。
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:
(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还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。
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:
(3)scanColumn(String tableName, String column)
浏览表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,只需要列出该列的数据。
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:
(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。
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:
(5)deleteRow(String tableName, String row)
删除表tableName中row指定的行的记录。
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:
对比运行前和运行后的结果,可以看出删除一行数据成功!
四、心得体会
(1)HB ase 定义
HBase 是一种分布式、可扩展、支持海量数据存储的 NoSQL 数据库。
(2)HBase 数据模型
逻辑上,HBase 的数据模型同关系型数据库很类似,数据存储在一张表中,有行有列。
但从 HBase 的底层物理存储结构(K-V)来看,HBase 更像是一个 multi-dimensional map。
(3)HBase 逻辑结构
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