Validate IP address using Java regex

Step 1. Write a java class with name ValidateIPAddress
Step 2. Write a regex pattern. Learn more about reg expression https://docs.oracle.com/javase/tutorial/essential/regex/

public class ValidateIPAddress {
 
 private static final String PATTERN =
   "^([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\." +
   "([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\." +
   "([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\." +
   "([01]?\\d\\d?|2[0-4]\\d|25[0-5])$";
 public static void main(String []args)
    {
     //Pass input value has hard coded value or as a input parameter
            String IP = "000.12.12.034";
            System.out.println(IP.matches(PATTERN));
        

    }
}

Step 3. Description about regex

1. ^                   #line start
2. (                #  start of group 
3. [01]?\\d\\d?        # It can be one or two digits. If three digits appear, it must start either 0 or 1
4. |             # or
5. 2[0-4]\\d        # start with 2, follow by 0-4 and end with any digit (2[0-4][0-9])
6. |                   # or
7. 25[0-5]             # start with 2, follow by 5 and ends with 0-5 (25[0-5])
8. )             #  end of group #2
9. \.                  #  follow by a dot "."
10. ....               # repeat with 3 times (3x)
11. $             #end of the line
 

Step 4. Input 1. Hello.IP 2. 000.12.12.034
Step 5. Output 1. false 2.true

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Getting started with Apache Kafka on windows environment. Run kafka, zoookeeper on windows environment

This post will explain you about how to work with apache kafka on windows environment along with zookeeper and java.

Pre requesties
1. Download Java latest version and install the same.
Setup the path variables where our java is installed.
2.Download zookeeper latest version and install the same.
Setup the path variables where our zookeeper is installed.
3.Download apache kafka latest version( kafka_2.10-0.10.0.0.tgz) and install the same.

Zookeeper setup

1. Go to confdir, where we have installed our zookeeper.
2. Rename zoo_sample.cfg to zoo.cfg
3. Open zoo.cfg file
4. find dataDir=/tmp/zookeeper to C:\zookeeper-3.3.6\data

5. Setup path for zookeeper in Environment variables


6. Open the Environment variables- click the system variables C:\spark\zookeeper-3.3.6\bin
7. If we want we can change the default port no 2181 in zoo.cfg file
8. Run the Zookeeper from cmd prompt. execute zkserver command
9. We can see the below image after successful zookeeper started


Kafka setup and run kafka

1. Untar the same and go to kafka config directory
2. Look for server.properties and edit the same
3. Find the log.dirs=/tmp/kafka-logs to log.dirs= “C:\spark\kafka_2.10-0.10.0.0\kafka-logs”
4. Now go to kafka installation directory – copy the installation path
5. Open the command prompt and go to kafka installation directory-
C:\spark\kafka_2.10-0.10.0.0
6. Execute the below command from the command prompt
.\bin\windows\kafka-server-start.bat .\config\server.properties


7. Once everything fine then kafka server will start and display image as mentioned below




How to Create topics

1. Open command prompt and go to C:\spark\kafka_2.10-0.10.0.0\bin\windows
2. Copy the below command and hit enter

kafka-topics.bat --create --zookeeper localhost:2181 --replication-factor 1 --partitions 1 --topic kafkatest
         

How to create producer
1. Open command prompt and go to C:\spark\kafka_2.10-0.10.0.0\bin\windows
2. Copy the below command and hit enter

kafka-console-producer.bat –broker-list localhost:9092 --topic kafkatest 

How to create consumer
1. Open command prompt and go to C:\spark\kafka_2.10-0.10.0.0\bin\windows
2. Copy the below command and hit enter

kafka-console-consumer.bat --zookeeper localhost:2181 --topic kafkatest
        

Once Producer and consumer started then, we can start to post messages from producer and reflect in consumer.
How to replicate data from producer to consumer
1. Try to enter some data in producer window, the same data will be replicates in consumer window.


More useful commands


1. Listing all topics which we have created
-

kafka-topics.bat --list --zookeeper localhost:2181

2. describe about particular topic
-

kafka-topics.bat --list --zookeeper localhost:2181 

3. Read all messages from particular topic
-

kafka-console-consumer.bat --zookeeper localhost:2181 --topic kafkatest --from-beginning 

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