理解HBase在Hadoop体系结构中的角色;
熟练使用HBase操作常用的Shell命令;
熟悉HBase操作常用的Java API。
二、实验平台
操作系统:
Hadoop版本:3.2.2
HBase版本:2.2.2
JDK版本:1.8
Java IDE:eclipse
三、实验内容和要求
使用HBase Shell命令完成下列任务:
列出HBase所有的表的相关信息,例如表名;
list
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在终端打印出指定的表的所有记录数据;
scan 'Student'
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向已经创建好的表添加和删除指定的列族或列;
添加
put 'Student','s000','S_Name','Huangkaiyu'
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删除
delete 'Student','s000','S_Name'
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清空指定的表的所有记录数据;
truncate 'Student'
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统计表的行数。
count 'Student'
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2.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)
2015001 Zhangsan male 23
2015002 Mary female 22
2015003 Lisi male 24
create 'Student','S_No','S_Name','S_Sex','S_Age'
put 'Student','s001','S_No','2015001'
put 'Student','s001','S_Name','Zhangsan'
put 'Student','s001','S_Sex','male'
put 'Student','s001','S_Age','23'
put 'Student','s002','S_No','2015002'
put 'Student','s002','S_Name','Mary'
put 'Student','s002','S_Sex','female'
put 'Student','s002','S_Age','22'
put 'Student','s003','S_No','2015003'
put 'Student','s003','S_Name','Lisi'
put 'Student','s003','S_Sex','male'
put 'Student','s003','S_Age','24'
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课程表(Course)
课程号(C_No) 课程名(C_Name) 学分(C_Credit)
123001 Math 2.0
123002 Computer Science 5.0
123003 English 3.0
create 'Course','C_No','C_Name','C_Credit'
put 'Course','c001','C_No','123001'
put 'Course','c001','C_Name','Math'
put 'Course','c001','C_Credit','2.0'
put 'Course','c002','C_No','123002'
put 'Course','c002','C_Name','Computer'
put 'Course','c002','C_Credit','5.0'
put 'Course','c003','C_No','123003'
put 'Course','c003','C_Name','English'
put 'Course','c003','C_Credit','3.0'
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选课表(SC)
学号(SC_No) 课程号(SC_Cno) 成绩(SC_Score)
2015001 123001 86
2015001 123003 69
2015002 123002 77
2015002 123003 99
2015003 123001 98
2015003 123002 95
put 'SC','sc001','SC_Sno','2015001'
put 'SC','sc001','SC_Cno','123001'
put 'SC','sc001','SC_Score','86'
put 'SC','sc002','SC_Sno','2015001'
put 'SC','sc002','SC_Cno','123003'
put 'SC','sc002','SC_Score','69'
put 'SC','sc003','SC_Sno','2015002'
put 'SC','sc003','SC_Cno','123002'
put 'SC','sc003','SC_Score','77'
put 'SC','sc004','SC_Sno','2015002'
put 'SC','sc004','SC_Cno','123003'
put 'SC','sc004','SC_Score','99'
put 'SC','sc005','SC_Sno','2015003'
put 'SC','sc005','SC_Cno','123001'
put 'SC','sc005','SC_Score','98'
put 'SC','sc006','SC_Sno','2015003'
put 'SC','sc006','SC_Cno','123002'
put 'SC','sc006','SC_Score','95'
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同时,请编程完成以下指定功能:
createTable(String tableName, String[] fields): 创建表,参数tableName为表的名称,字符串数组fields为存储记录各个域名称的数组。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。
建立person表,代码如下:
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.Admin;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
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);
}
HTableDescriptor hTableDescriptor = new HTableDescriptor(tablename);
for (String str : fields) {
HColumnDescriptor hColumnDescriptor = new HColumnDescriptor(str);
hTableDescriptor.addFamily(hColumnDescriptor);
}
admin.createTable(hTableDescriptor);
close();
}
public static void init() {
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() {
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();
}
}
}
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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files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。
增加Score记录,代码如下:
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://localhost:9000/hbase");
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("person", "Score", fields, values);
} catch (IOException e) {
e.printStackTrace();
}
}
}
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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。
原文链接:https://blog.csdn.net/qq_50596778/article/details/120552574