An example for explaining how to work with HBase Java API – CRUD.
What is HBase? See: HBase – Operational Database on Hadoop – Part: Basics and Shell
How many column families? HBase currently does not do well with anything above two or three column families so keep the number of column families in your schema low. See: https://hbase.apache.org/book.html#number.of.cfs
Structure of HBase Key-Value object
Key: row_key | col_family | col_qualifier | timestamp
Value: cell_vallue
Prerequisites
- OS: Linux (RHEL 7.9)
- Hadoop: Cloudera (CDP 7.1.7 SP1)
- Authentication via Kerberos
- OpenJDK 64-Bit 1.8.0_292
HBase Java API – CRUD
HBaseClientConnect,java (path: /hbase-crud/src/main/java/eu/placko/examples/hbase/)
package eu.placko.examples.hbase;
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.MasterNotRunningException;
import org.apache.hadoop.hbase.client.*;
public class HBaseClientConnect {
public static void main(String[] args) throws IOException {
new HBaseClientConnect().connect();
}
private void connect() throws IOException {
Configuration config = HBaseConfiguration.create();
try {
HBaseAdmin.available(config);
System.out.println("\n*** HBase is running. ***");
} catch (MasterNotRunningException ex) {
System.out.println("\n*** HBase is not running. ***" + ex.getMessage());
return;
}
HBaseClientOperations HBaseClientOperations = new HBaseClientOperations();
HBaseClientOperations.run(config);
}
}
HBaseClientOperations.java (path: /hbase-crud/src/main/java/eu/placko/examples/hbase/)
package eu.placko.examples.hbase;
import java.io.IOException;
import java.util.Map;
import java.util.NavigableMap;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.util.Bytes;
public class HBaseClientOperations {
private static final TableName tb = TableName.valueOf("shop");
private static final byte[] cf = Bytes.toBytes("shop");
private static final byte[] rk1 = Bytes.toBytes("1");
private static final byte[] rk2 = Bytes.toBytes("2");
private static final byte[] cq1 = Bytes.toBytes("category");
private static final byte[] cq2 = Bytes.toBytes("product");
private static final byte[] cq3 = Bytes.toBytes("size_eu");
private static final byte[] cq4 = Bytes.toBytes("color");
private static final byte[] cq5 = Bytes.toBytes("sex");
private static final byte[] cq6 = Bytes.toBytes("price_eu");
public void run(final Configuration config) throws IOException {
try (final Connection connection = ConnectionFactory.createConnection(config)) {
final Admin admin = connection.getAdmin();
deleteTable(admin);
createTable(admin);
final Table table = connection.getTable(tb);
put(table);
get(table);
update(table);
delete(admin);
connection.close();
}
}
public static void deleteTable(final Admin admin) throws IOException {
if (admin.tableExists(tb)) {
admin.disableTable(tb);
admin.deleteTable(tb);
}
}
public static void createTable(final Admin admin) throws IOException {
if(!admin.tableExists(tb)) {
TableDescriptor desc = TableDescriptorBuilder.newBuilder(tb)
.setColumnFamily(ColumnFamilyDescriptorBuilder.of(cf))
.build();
admin.createTable(desc);
}
}
public static void put(final Table table) throws IOException {
System.out.println("\n*** Create/Insert - BEGIN ***");
table.put(new Put(rk1).addColumn(cf, cq1, Bytes.toBytes("shoes")));
table.put(new Put(rk1).addColumn(cf, cq2, Bytes.toBytes("productA")));
table.put(new Put(rk1).addColumn(cf, cq3, Bytes.toBytes("42")));
table.put(new Put(rk1).addColumn(cf, cq4, Bytes.toBytes("black")));
table.put(new Put(rk1).addColumn(cf, cq5, Bytes.toBytes("m")));
table.put(new Put(rk1).addColumn(cf, cq6, Bytes.toBytes("44.50")));
table.put(new Put(rk2).addColumn(cf, cq1, Bytes.toBytes("shoes")));
table.put(new Put(rk2).addColumn(cf, cq2, Bytes.toBytes("productA")));
table.put(new Put(rk2).addColumn(cf, cq3, Bytes.toBytes("42")));
table.put(new Put(rk2).addColumn(cf, cq4, Bytes.toBytes("white")));
table.put(new Put(rk2).addColumn(cf, cq5, Bytes.toBytes("m")));
table.put(new Put(rk2).addColumn(cf, cq6, Bytes.toBytes("40.50")));
System.out.println("OK");
System.out.println("*** Create/Insert - END ***");
}
public static void get(final Table table) throws IOException {
System.out.println("\n*** Read/Select - BEGIN ***");
//System.out.println(table.get(new Get(Bytes.toBytes("1"))));
//System.out.println(table.get(new Get(Bytes.toBytes("2"))));
for (int i = 1; i < 3; i++) {
Get get = new Get(Bytes.toBytes(Integer.toString(i)));
Result result = table.get(get);
String row = Bytes.toString(result.getRow());
//String specificValue = Bytes.toString(result.getValue(Bytes.toBytes(Bytes.toString(cf)),
Bytes.toBytes(Bytes.toString(cq1))));
//System.out.println("latest cell value in shoes:category for row 1 is: " + specificValue);
// Traverse entire returned rows: 1 and 2
System.out.println(row);
NavigableMap<byte[], NavigableMap<byte[],NavigableMap<Long,byte[]>>> map = result.getMap();
for (Map.Entry<byte[], NavigableMap<byte[], NavigableMap<Long, byte[]>>> navigableMapEntry : map.entrySet()) {
String family = Bytes.toString(navigableMapEntry.getKey());
System.out.println("\t" + family);
NavigableMap<byte[], NavigableMap<Long, byte[]>> familyContents = navigableMapEntry.getValue();
for (Map.Entry<byte[], NavigableMap<Long, byte[]>> mapEntry : familyContents.entrySet()) {
String qualifier = Bytes.toString(mapEntry.getKey());
System.out.println("\t\t" + qualifier);
NavigableMap<Long, byte[]> qualifierContents = mapEntry.getValue();
for (Map.Entry<Long, byte[]> entry : qualifierContents.entrySet()) {
Long timestamp = entry.getKey();
String value = Bytes.toString(entry.getValue());
System.out.printf("\t\t\t%s, %d\n", value, timestamp);
}
}
}
}
System.out.println("*** Read/Select - End ***");
}
public static void update(final Table table) throws IOException {
System.out.println("\n*** Update - BEGIN ***");
table.put(new Put(rk1).addColumn(cf, cq1, Bytes.toBytes("shoes")));
table.put(new Put(rk1).addColumn(cf, cq2, Bytes.toBytes("productA")));
table.put(new Put(rk1).addColumn(cf, cq3, Bytes.toBytes("42")));
table.put(new Put(rk1).addColumn(cf, cq4, Bytes.toBytes("black")));
table.put(new Put(rk1).addColumn(cf, cq5, Bytes.toBytes("m")));
table.put(new Put(rk1).addColumn(cf, cq6, Bytes.toBytes("42.50")));
System.out.println("OK");
get(table);
System.out.println("*** Update - End ***");
}
public static void delete(final Admin admin) throws IOException {
System.out.println("\n*** Delete - BEGIN ***");
deleteTable(admin);
System.out.println("OK");
System.out.println("*** Delete - End ***");
}
}
pom.xml (path: /hbase-crud/)
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>eu.placko.examples.hbase</groupId>
<artifactId>hbase-crud</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>hbase-crud</name>
<description>An example for explaining how to work with HBase Java API – CRUD</description>
<packaging>jar</packaging>
<properties>
<revision>Local-SNAPSHOT</revision>
<maven.compiler.source>1.7</maven.compiler.source>
<maven.compiler.target>1.7</maven.compiler.target>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<jar.main.class>eu.placko.examples.hbase.HBaseClientConnect</jar.main.class>
</properties>
<!-- HBase -->
<dependencies>
<dependency>
<groupId>org.apache.hbase</groupId>
<artifactId>hbase-client</artifactId>
<version>2.5.2</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<archive>
<manifest>
<mainClass>eu.placko.examples.hbase.HBaseClientConnect</mainClass>
</manifest>
</archive>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
</plugin>
</plugins>
<pluginManagement />
</build>
</project>
README.md (path: /hbase-crud/)
HOW TO CONFIGURE THE PROJECT
path: /hbase-crud/src/main/resources/
add core-site.xml from /etc/hbase/conf.cloudera.hbase/
add hbase-site.xml from /etc/hbase/conf.cloudera.hbase/
Building and Running
Build
To build the application it is required to have this installed:
Java 9
Maven 3.x
Then just run this:
mvn clean install assembly:single
Run
$ su <user>
$ cd /home/<user>
$ chmod 770 ./hbase/hbase-crud-0.0.1-SNAPSHOT-jar-with-dependencies.jar
$ chown <user>:<user> ./hbase/hbase-crud-0.0.1-SNAPSHOT-jar-with-dependencies.jar
$ kinit -kt /etc/security/keytabs/<user>.keytab <user>
$ java -jar ./hbase-crud-0.0.1-SNAPSHOT-jar-with-dependencies.jar
Result
*** HBase is running. ***
*** Create/Insert - BEGIN ***
OK
*** Create/Insert - END ***
*** Read/Select - BEGIN ***
1
shop
category
shoes, 1674459300795
color
black, 1674459300856
price_eu
44.50, 1674459300872
product
productA, 1674459300836
sex
m, 1674459300864
size_eu
42, 1674459300845
2
shop
category
shoes, 1674459300879
color
white, 1674459300916
price_eu
40.50, 1674459300931
product
productA, 1674459300892
sex
m, 1674459300924
size_eu
42, 1674459300904
*** Read/Select - End ***
*** Update - BEGIN ***
OK
*** Read/Select - BEGIN ***
1
shop
category
shoes, 1674459300968
color
black, 1674459301013
price_eu
42.50, 1674459301029
product
productA, 1674459300997
sex
m, 1674459301022
size_eu
42, 1674459301006
2
shop
category
shoes, 1674459300879
color
white, 1674459300916
price_eu
40.50, 1674459300931
product
productA, 1674459300892
sex
m, 1674459300924
size_eu
42, 1674459300904
*** Read/Select - End ***
*** Update - End ***
*** Delete - BEGIN ***
OK
*** Delete - End ***
1st step: Create/Insert
________________________________
/ /t1 (version 1) /
|_______________|_______________|
|row_key |cf:cq6 |
|_______________|_______________|
|1 |44.50 |
|_______________|_______________|
|2 |40.50 |
|_______________|_______________|
2nd step: Update
________________________________
/ /t1 (version 1) /
/_______________/_______________/
/ /t2 (version 2) /
|_______________|_______________|
|row_key |cf:cq6 |
|_______________|_______________|
|1 |42.50 |
|_______________|_______________|
|2 |40.50 |
|_______________|_______________|Source Code
https://github.com/mplacko/hbase-crud
Placko's database KB 