Java,Java,Java

SSL in Spring Boot using GoDaddy certificate on EC2

2019-12-03T13:14:00.001+05:30

In this article, we will be going to see how we can achieve the HTTPS in the spring boot application. You will get lots of items on how to use the self-generated certificate with Spring Boot. But today we are going to use the CA generated certificates with the Spring Boot so that our application will work on HTTPS.

We need the following things to work:

CA certificates including, private key and certificate. In this article, we are using the GoDaddy wild card certificate.
Spring Boot application
OpenSSL library

Convert the certificate and private key to PKCS 12

First of all, we need to convert the CA certificate to .p12 format. We need to have OpenSSL on the system to work with command. Also, we need to have all files in the same directory where we are running this command. The command required to covert the same:

openssl pkcs12 -export -in [ceritificate-name] -inkey [private-key] -name [host] -out [new-file.p12]

Here replace the values:

[ceritificate-name] with the name of the certificate
[private-key] with the private key file
[host] with the name of the host
[new-file.p12] with any name of your choice with extension .p12

Import the certificate to the key store

Now, we have generated our .p12 file next step is to convert this file to jks format. We need to do this in 2 steps. For this command to work, we need to have a Java home set environment.

1. First, import the PKCS 12 certificate by executing the following command:

keytool -importkeystore -deststorepass [password] -destkeystore [new-keystore.jks] -srckeystore [new-file.p12] -srcstoretype PKCS12

where:

[password] is the password you create while creating the private key
[new-keystore.jks] the name you have defined earlier
[new-file.p12] is the name of the .p12 file you defined earlier

2. Secondly, import the CA bundle file by executing the following command:

keytool -import -alias tomcat -trustcacerts -file [ca-bundle-file] -keystore [new-keystore.jks]

where:

[ca-bundle-file] is the name of the ca certificate
[new-keystore.jks] the name you have defined earlier

That's it. We have converted the CA certificate, (GoDaddy in our case) to jks format which will be used by the Spring Boot application.

Let's now do some configurations in Spring Boot application to run in HTTPS.
Paste the below lines in your application.yml:

server:
    ssl:
        key-password: your-password
        key-store-password: your-password
        key-store: classpath:name-of-file.jks
        key-store-type: JKS

or in the application.properties file:

server.ssl.key-password=your-password
server.ssl.key-store-password=your-password
server.ssl.key-store: classpath=name-of-file.jks
server.ssl.key-store-type=JKS

That's all we need to do. Now we are ready to run our application in HTTPS mode on EC2 instance with GoDaddy certificates.

First Time Deployment of war file to IBM Cloud

2018-01-01T17:48:00.000+05:30

In this post, I will put a very basic deployment of Java war file on the IBM Cloud. Previously, IBM Cloud was known as IBM Bluemix. But in this post, I will prefer using the IBM Cloud and not the bluemix. I was facing problem while deploying the war file on the IBM Cloud for the first time. I am not a DevOps person who knows about the servers as well. But my job was to deploy the application on the IBM Cloud I need to do it. So, I tried googling around but have no idea about how to do it. There are some examples are given but they are not so basic to be understood by a developer who wants to deploy the application in Cloud.

But I manage to do it. And I will explain all the steps that are needed to deploy the application to the Cloud. The application I am going to deploy is the Spring Boot application.

Requirements

1. IBM Cloud account.
2. IBM Bluemix CLI
3. war file (spring-boot application)

IBM Cloud Setup

After signing for IBM Cloud, go to the IBM Cloud Dashboard. IBM Cloud provides you with some free applications to test your application. From there select the filter:lite. You will see some of the free applications provided by the IBM.

Since we are using the Java we will select the liberty-for-java from there.

Now, it will ask for the name and other information. Enter the required one and it will create a Java profile in the cloud for you. Your Java environment is ready to be used by your application. You will see your dashboard as shown below after you have created a liberty-for-java app.

Yes, that's it. No other requirement is there. Now download the IBM Bluemix CLI client and setup it. It is a simple command line tool for interacting with the cloud.

War file Deployment on IBM Cloud

Go to the directory where your war file is kept and follow the below steps to deploy your application on cloud.

Enter bluemix api https://api.xx-xx.bluemix.net on command. Here xx-xx is specific to the user. You have to see what your server is providing you.
Then login to bluemix using the below command.

bluemix login -u <username> -o <organization> -s <space> Here:

username is mostly email id.
the organization is also your email id until and unless you have paid account and created other.
space is mostly dev unless otherwise created a new one

Then enter the final command that will upload the war file to the cloud.

bluemix app push <appname> -b <buildpack> -p <war file> Here:

appname is the name of the application you have created when you create a liberty for Java profile.
for buildpack, we will be using liberty-for-java, as our application is Java based.
In the end, the name of the war file.

After deployment, you will see that your instance is up and running. Your application is deployed successfully in the cloud.

You can visit your application by clicking the Visit Your URL link. Hope it helps some of my fellow friends struggling with deployment on IBM Cloud

My JUnit Write Ups

2017-06-20T19:59:00.001+05:30

I haven't written to my blog for a long time. There are times when you are busy and didn't get the time to work on the blogs.

I am writing for Java Code Geeks for some time and busy with one of the projects that I was building for a client.

Most of the blogs that I am writing was on JUnit. If you like this blogs do follow me on the Java Code Geeks at my author page.

Also, if possible do upvote my links on DZone.

I will be regularly writing on JUnit there. Hope you like those.

Hibernate Tips - a must have book

2017-03-09T20:20:00.000+05:30

Recently one of my friend Thorben Janssen started working on Hibernate Tips book. He is awesome and write wonderful blogs about Hibernate.

He is well known for his blogs about Hibernate. You can read him on thoughts-on-java.org.
He had completed the book and soon it will be available on Amazon for buying.

Hibernate Tips: More than 70 solutions to common Hibernate problems

Share maximum. Enjoy reading the Hibernate Tips.
Congratulates to Thorben.
You can reach him @thjanssen123 on twitter.

Error while configuring Spring with FreeMarker

2017-02-02T19:12:00.001+05:30

Today I got a strange problem while configuring FreeMarker with Spring. The project compiles well without any error. All seems to be fine. When I tried to run the application strangely I got following error:

Spring in Action, 4ed (Manning)

java.lang.NoSuchMethodError: freemarker.template.Configuration. Lfreemarker/template/Version;)V

Now for struggling and googling for around one hour I got the answer :)

Instant FreeMarker Starter

I am using Spring 4.3.5.RELEASE and FreeMarker 2.3.20 before I found the answer. This isstrange but the actual problem lies with the version compatibility of FreeMarker with Spring. It seems that Spring had some issues with FreeMarker.

After changing the FreeMarker version from 2.3.20 to 2.3.23 all works fine.
Hope this solution help the developers out there configuring FreeMarker with Spring.

Enjoy coding!

AWS S3 processing with JetS3t library

2016-10-03T13:27:00.000+05:30

In this post we will see how we can use the Amazon AWS S3 to store objects. We will be using the JetS3t library to process our objects. JetS3t library also known as Jet Set, is widely used for processing the AWS S3 i.e. Amazon Web Services, Simple Storage Service.

Before working on AWS S3, you need to have a valid account on AWS with S3 key and S3 password. You can register here free of cost.

Amazon Web Services in Action (MANNING)

Here we will using 4 API of jets3t i.e.

Upload a document
Download a document
Listing of documents
Delete a document

We will upload images of user on S3 and then process them as specified above.

Upload: to upload image to the S3 we will be using putObject() method of the S3Service class.
Download: To download image we will be using getObject() method of S3Service class.
List: To list images we will be using listObjects() method of S3Service class.
Delete: To delete image we will be using deleteObjects() method of S3Service class. We can also delete multiple images using deleteMultipleObjects() method.

Full example is available on the GitHub. Simply download and explore it.

IndicThreads '16 - Day 2

2016-06-04T21:17:00.000+05:30

In my previous post I had given details about the first day of the IndicThreads conference. Today I will try to cover sessions for 2nd day.

The day was full of excitement as I have learned many new things. Sessions for today includes Go Language, HTTP/2, MicroServices, RxJava(Reactive Programming), Bitcoin and Blockchain.

Go Language with Angular
In this session Navneet Karnani, from Mandrake Technologies defines the scope of the Go language. He started with why we need a new language and how it can be used. He said that Go is a compiled language and it is also Open Sourced, so anybody can see code and change it to make it more better.
Session is full of code and I swear it takes a lot of effort for him to make a such a great session on Go. This session is break in 2 parts where in first part he explains about the nuisances of language and in second part he shows the integration with AngularJS

RxJava, Reactive Programming
Praveer Gupta, from ThoughWorks who had given session on Java 8 streams on first day, again done a great job by explaining how RxJava can help in building the application more powerful. RxJava is the jvm implementation of ReactiveX. Behind the scenes it uses Observer & Iterator pattern to work. He gradually takes us through the code and explains each and every bit of code.
Twitter: @praveergupta

HTTP/2
This is a real eye opener for me. Presented by Nilesh Naik(Technical Architect, Tata Consulting Services), includes a brief history of the HTTP from beginning of internet and covers through the HTTP/2. He explains why there is a need of HTTP/2. Today when we are using HTTP1.1, we have many limitations while using internet. HTTP was originated to display simple pages and not the ads, images, css, javascripts as we are using today. Clients can make limited connections with Server and it also serves the requests in that order. until previous requests were not done no new request is sent to server. But when we use HTTP/2 then we can send multiple requests at a time. Debugging can be a issue with HTTP/2 requests as data will travel in Binary.
Twitter: @NileshRaviNaik

Bitcoin (Blochchain)
Session is presented by Navin Kabra(Founder and CTO Reliscore.com). He started by explaining a simple problem of authentication in real life and how this can be achieve by using the Blockchain technology. PKI, how it works and is playing a major role in today's world. Bockchain is the main technology behind the Bitcoin, the digital currency of today's era. But, it a small part of this as we can achieve much more things from this technology. He very much clarify that technology is itself great, but there is no such control of government and it may not be in its favor.
Twitter: @ngkabra

Resilient Microservices
In this session. Gurpreet(Director Technology - Aricent) exlpains the need of the time to convert all our monolith applications to micro services. He explains how we can achieve this. What things are required, how we can achieve them, what are the blockers and what all considerations to be followed while converting the monolith applications to micro services. Simple formula that he gave is start with monolith and with time we should convert application to micro services.

Sessions were full of knowledge and I urge who so ever wants to gain knowledge should attend this conference.

I hope you have a brief introductions of what was there in this conference. Here are the details of the conference.
Twitter: @indicthreads
Slides: http://pune16.indicthreads.com/slides

You can also follow me on @vinodkashyap and @ChdJUG for more information related to Java and its realated technologies. Thanks for taking time to read.

IndicThreads '16 - Day 1

2016-06-03T22:08:00.001+05:30

Today was the first day of IndicThreads conference held at Pune.

The day was full of excitement and learning. Topics that were covered today at conference are Augmented Reality, IoT, Functional Programming, Java 8 Streams. Also included a session of Fame, a video streaming product of India.

Augmented Reality
In this session Kishor Himani (Director, PTC Global Services) explained how AR is a happening field and how we will reach and meet demands of the future. He explained about the areas where AR is creating benchmarks. Healthcare, Services, Utilities are some of the areas where AR is changing the world. AR in collaboration IoT will make a significant change in future. We can superimpose the AR with the live video. He gives an example where doctor first takes x-ray of patient and then superimpose on his body so that he knows where actually to operate.

Building Secure Connected Devices
This was the eye opener for the people who are building or try to build the IoT devices. Kedar Sovani, who works in IoT at Marvell for last 7 years explained very beautifully about the security threats and how we can make our devices secure. He told that their company is first to work on:

Apple HomeKit SDK and
Google Weave

He explained how hackers connect to your devices and how you can secure your device. TLS is the main for connected device to communicate. How devices connected with WiFi, WiFi connected with Cloud, Cloud connected with cell phones and how all these connections are used. How this can be done more securily.
Twitter: @kedarsovani

Real World IoT for Enterprises
This session is presented by Abhimanyu Prabhavalkar (VP, PAAS Develeopment, Oracle). He explained why we need to see the basic need of the customer, before start developing the IoT product. Making a product without actually doing a homework will make your product fail. He gives many examples where customers are not ready to accept changes and how he had convened many of them to work on next generation solutions.

IoT Testing and Quality Assurance
This session by Girish (SAS Research and Development India), explains about how the role of the tester is changing with the IoT applications. We need to have require many new skills in a next generation QA, so that he can work on testing of IoT products. He demonstrates how he had manage to test the IoT devices and what precautions and procedure to be followed while testing.

Functional Programming
This is very interesting and full of knowledge session by Pushkar Kulkarni( IBM Runtimes, IBM India Software Labs). The session is about history of Functional Programming. He started with Lisp and ended with idris. The idea behind this session is to make familiar with the Functional Programming and how it evolved with the times. He had covered 8 languages: Lisp, Erlang, Haskell, oCaml, Scala, Clojure, Java 8 and idris.
Twitter: @pushkar_nk

Harnessing the Power of Java 8 Streams
Now this is the session which I was waiting. Praveer Gupta, who works for ThoughtWorks explains the power of streams in Java 8. Very clearly and with explanatory examples he explains each and every details of streams. But, he also warns about the pitfalls of using streams. If not used properly, they may decrease the performance of the application. Examples used in this sessions are very good and easily understandable by audience. I have many doubts related to streams and now most of them are cleared. He has been working on a project which uses Java 8 streams in production.
Twitter: @praveergupta

Fame
This session by Rishabh Jain of fame.live explains the product they had build which is India's first online video streaming platform. He first explains how they started working on a product and what actually they are trying to make. Then he explains step by step architecture changes that they did while application use increases. How they scae their application to fulfill the demand of the customers. They also hosted the pre IIFA awards live streaming. You can try using it at here

First day at the conference was great and looking forward to the second day.

JUnit issue with Eclipse and Maven

2015-06-16T18:35:00.001+05:30

In this post I am trying to resolve one issue of JUnit with Eclipse and Maven. Sometimes while using JUnit with Eclipse and Maven we have to face certain issues. And one of them is whenever we try to run the independent test case it will run fine and will not give any type of error. But when we run to try to compile the whole project, the same test will not compile at all. This is an annoying issue if someone does not know about the functionality of how Eclipse works with JUnit and Maven.

JUnit in Action

Since there is such no exception seen in file, but project compilation fails due to same file it is very frustrated for developer to figure out the issue. I am facing this issue and found a solution by googling around many forums.
Problem: You have created a JUnit test case in the project and it is running fine, but fails to compile the whole project when try to build using Maven.
Solution: Check that the test case you have created exist in the src/test/java folder and not in src/main/java. Very funny isn't it. Actually Maven compiles the files under src/main/java to target/classes and src/test/java to target/test-classes.
So whenever you try to build the project it encounters the JUnit test class but it will not able to compile. So, put file in src/test/java folder and the project will run smoothly :)
Thanks for reading blog.

Java Bloggers Meet Oracle IDC Hyderabad

2015-06-14T20:45:00.002+05:30

Oracle India had organized a Java Bloggers meet on 13th Jun 2015, at their office at Hyderabad on the occasion of Java completing 20 years. I was also invited to the event which is very exciting for me. I am on cloud nine when I got invited for the event.

Oracle India had celebrated the event by organizing speeches by Sanket Atal - Group Vice President, R&D, Harshad Oak - Java Champion and Oracle ACE Director, and a live demonstration by Debraj Dutta, of a Bot-So a robot designed by Edifixio India and is based on IoT and fully developed using Java 8 features like streams for concurrency.

Event started by Vandana Shenoy - Director Corporate Communications , by giving a small introduction about the event and a formal introduction of the speakers.

Sanket Atal
The presentation by him is more like a discussion. We have discussed and have fun question answers, quiz in between it. Below are the points he discussed:

Java was started in 1991 under the name Project Stealth
First official release was in 1995
Duke - Java Mascot was released in 2007
Duke is based in Linux Penguin
After J2SE version 1.5, Java is known as Java SE 6
Every 2 years there will be release of Java new version
Oracle will not carry on the name of the Java as it is more with version numbers.
Java Champions is the program launched in JavaOne for recognizing leaders in Developer Community
Cloud is the growing rapidly
Oracle will start PaaS in IoT
Java is the center of computing universe
Oracle + You = Java
Java and IoT are 2 buzzwords in todays world.

Harshak Oak
He had started his presentation or more a talk with the introduction of Java birth and then he turns to his career that how he had chosen Java as his career. He had compared Java with Bollywood actor - Shahrukh Khan, as welcoming the guys with open hands. Some of the points he covered:

Java is Shahrukh Khan of programming world
DDLJ is released in same year as Java :)
Most languages are born near to same year.
Java has a very warm and welcoming culture.
Java has had the opensource spirit from Day 1
Java presenting the IoT platform for development will be a game changer
Java bloggers have a great responsibility for carrying a warm culture to the future developers
Java bloggers are the face of the Java

Debraj Dutta - Edifixio India
Edifixio India represents the robot they have developed based on Java and IoT. They have won the open challenge on IoT in 2014 organized by Oracle. Below are the commands/things that Bot-So, the name given to their robot follows:

It is based on Raspberry Pie board, Twitter4J, Google Drive and Java 8.
It connects to the internet using Wi-Fi and twitter commands.
Sends welcome message when it is started
Sense the room temperature
Take pictures and videos by a simple command and then uploads the to Google Drive and shared the URL privately with the authorized user.
Secure itself and motion sensor detects the motion and send the picture to authorized user.
GitHub URL for code

At the end of the event Java Cake was cut by Sanket Atal.

We have also have some video bytes where all bloggers have their thoughts on Java and its future.
Below is the group photograph at end of the event

In all, it is great event to attend and love to attend the same in future. I had learned a lot from it and a lot of inspiration thoughts from great leader Harshad Oak.

Here are the twitter handles of all the above mentioned people if anyone wants to follow.
@SanketAtal
@vandanashenoy
@HarshadOak
@zambiguity
@Oracle_India
@vinodkashyap

Thanks for reading this blog. Comments are welcome :)

20 year celebration of Java

2015-06-01T20:40:00.001+05:30

We at Chandigarh celebrated Java's 20th birthday on 23rd May. This was the first time that @ChdJUG had celebrated this event. It is very enjoyable and memorable event.

We had enjoyed a lot and cut a special cake on this occasion.

We hope to increase our community at Chandigarh and next year I am sure it will be bigger one :)

You can follow me on Twitter @vinodkashyap and Chandigarh JUG @ChdJUG for more updates.

RESTful Web Services - POST, PUT, GET, DELETE

2015-05-27T18:32:00.002+05:30

Web services are very common these days as everything or most of the implementation is now API based. Every social network is providing API for fetching their data. Like if you take a case of TWITTER, it provides it's API to fetch different data related to user or for analytic. There are 2 types of web services namely:

SOAP
REST

SOAP is based on WSDL and return data in XML format. But I will not talk about it here. I will be discussing about REST, an acronym for REpresentational State Transfer methods. RESTful web services are very simple to learn and implement. They are basically stateless. It is based on HTTP URI and everything is implemented using URL. In this post I will explain about the four methods that are used with REST.

POST
PUT
GET
DELETE

Let's dive deep into each of these methods of the REST.

RESTful Java Web Services: Master Core REST Concepts and Create RESTful Web Services in Java

POST
It is used for creating a new entity. It is basically used with form i.e. whenever we want to submit data.
Ex: POST /items

PUT
It is doing same thing as POST but it usually used for updating entity.
Ex: PUT /items/itemid

GET
This is the method that is used mostly in REST. It will fetch data from back end. The data can be returned in any of the forms like XML, JSON, PDF etc.
Ex: GET /items (fetching multiple items)
GET /items/itemid (fetching a single item)

DELETE
Yes, as already guessed from the name it is used to delete the record.
Ex: DELETE /items/itemid

Helpful Resources:
Jersey is the reference implementation of the JAX RS 2.0 (JSR 339).

Developing Restful Web Services with Jersey 2.0

POSTMAN It is very good light weight client for testing RESTful web services for Google Chrome and can be downloaded from here

Hope you enjoyed it.

Reset username for SVN in eclipse

2015-04-13T20:12:00.001+05:30

Sometimes we want to change the username and password for the SVN access in Eclipse or Spring Tools Suite. But it does not asks for it.
There is a very easy way of doing this. You can easily find out the solution on google :). I am writing here again to save to my memory.
The solution is for Windows platform and tried and tested on Windows 7.

Here is the path where you need to delete one folder to do the same.

1. First close Eclipse/STS if your had open it. Some times without closing first it will not work.

2. Go to C:\Users\<username>\AppData\Roaming\Subversion\auth

3. Delete svn.simple folder

4. That's it.

Now when you restart your IDE and go to SVN it will again ask you for credentials.

Note: AppData folder is hidden and not viewed by default. To make it visible follow below steps:

1. C:\Users\<username>

2. Go to menu Tools --> Folder Options --> View Tab --> Click Show hidden files, folders and drives under Hidden Files and Folders.

Happy Coding :)

IndicThreads Conference Pune '15

2015-02-09T11:43:00.001+05:30

This is one of my favorite Java conferences in India that everyone wants attend for sure. Most of the time it is based on the Java, but this time it is going far behind with IoT, Big Data, Cloud and many more interseting sessions as well. Sessions are great and speakers too.

Conference is great and people loved to join it. You will learn a lot of new things and get to know about the industry. It enhances your vision to view the future. You will get a chance to meet the great brains behind the great innovations in the industry.

This conference is organized by India's first "Java Champion Harshak Oak". He is very nice and humble guy. I had meet him before and he always answer your queries without any hesitation and a smile on his face :)

Visit the conference website: http://pune15.indicthreads.com/
See the sessions here: http://pune15.indicthreads.com/category/sessions/
See the speakers here: http://pune15.indicthreads.com/category/speakers/

I am going with 2 of my friends. I had attend it before 2 times and this is my third.
Come and enjoy the conference. Lets meet and make our career future proof

Singleton Pattern revisited

2015-01-15T21:28:00.001+05:30

As the name suggest, Singleton Pattern restricts to the creation of one and only one object of a class. This is very useful whenever we want to restrict the creation of an object to single instance. This is very small and sweet type pattern that is used in many cases.

Let's take an example and see how it is used in the code

public class SingleObject {
 private static SingleObject singleObject;

 private SingleObject() {
 }

 public static SingleObject createInstance() {
  if (singleObject == null) {
   singleObject = new SingleObject();
  }
  return singleObject;
 }
}

Line by line explanation

Line 2: creates private instance of the class

Line 4: constructor is private, so that no outer class can create object of this class

Line 7: creating a static method to get an instance of the class. We have defined method as static so that we don't need to create a object to call this method. Since it is static we can call this method by name of the class i.e. SingleObject.createInstance().

Line 8: if object is null then we will create an object of the class else we will return the previous one.

Now, this type of initialization of class is known as the classic style for Singleton.

Here, we can say that this may fail i.e. single object concept, in the multi-threaded environment. For this, we make the method synchronized. This will change something like

public static synchronize createInstance(){

Some of you think that it will be overhead as it will take more memory and so. But does it really affect it, because this will call only once at the time of creation of the object and not always.
This type of initialization of class is known as the thread-safe style for Singleton.

We can also make the object early by changing the line no 2

private static SingleObject singleObject = new SingleObject();

This is called eager initialization of the object. In this case, object is already created and whenever thread tries to call it will simply return the object. It all depends on what conditions are you building the class or calling it.

Hope everything is clear :).

Chandigarh Java User Group

2014-09-04T15:01:00.000+05:30

Its a long time I have written about any new things in Java. But few days back I had started working on starting a JUG in my local city Chandigarh. I had seen people in Chandigarh specially freshers not able to grasp a good knowledge of the Java and related technologies. They even don't know about the latest technologies and what is happening in the world of Java.

So I finally thought of starting a JUG namely Chandigarh Java User Group. I want to organize a JUG meet as soon as possible in the city. So anyone can join and start working on that side. I am very much influenced by @HarshakOak who is a Java Champion and organizes many Java events like the indicThreads. I had gone to attend those meetups some time. There you will get a lot of knowledge about what is happening around the world in the field of Java

Some of you wanted know about the procedure of joining the JUG. its pretty simple.
Join java.net and then go to Chandigarh Java User Group and join it.
There is also a official site of it. http://www.chdjug.com

You can also follow the group on twitter: @ChdJUG

Thanks

How to handle autocomplete in browsers

2012-04-25T10:28:00.000+05:30

Sometimes we face a problem while opening forms. There are some fields in the form that are always pre-filled whenever that form is opened. This is because of the auto-fill feature of the browser.

To solve that simple put the autocomplete="off" in form tag like below:

<form name="frmUser" method="post" action="test" autocomplete="off">
Name : <input type="text" name="name" />
</form>

According to the mozilla https://developer.mozilla.org/en/How_to_Turn_Off_Form_Autocompletion this happens because we are using the the two fileds in our form i.e. NAME and ADDRESS.
Like in the above form we have used the label Name. To resolve this issue we can do the following:
Simply include the name using span as below

<form name="frmUser" method="post" action="test" autocomplete="off">
<Name : <input type="text" name="abc" />
</form>

So, before making forms to production make sure to change the NAME and ADDRESS like above
Enjoy the autocomplete="off" :)

IndicThreads Java Conference 2010

2010-12-21T09:30:00.000+05:30

This is my second consecutive Java conference from IndicThreads. Here are some of the topics and the speakers who had share their valuable information. The conference is great and I recommend all to visit it once and see the difference

Harshad Oak

Harshad is the man of few words. He is the organizer and owner of the indicthreads conference. He is the Java Champion and Oracle Ace.

He started conference with the topic Java: Riding the Change where he discusses the changing the nature of the Java. What is around the corner and what Java guys need to be in mind in the coming time.

He discusses the language changes and the Oracle view on the Java.
He had given his experienced thought on the many of the scripting languages like groovy, jython etc. He clarifies that the place of Java is more superior to any of the other languages. Java superiority will be continued.

He had also told about the 5 - 95 rule which says that 5% of the people think java will be lost in the near future and rest 95% think opposite. There is a drop in the cool quotient among the new developers which led to uncertainty.

JavaFX is good upcoming scripting language and is good to try but is definitely not to rely upon.
All in all the good news that Java will rock in the future and will be a dominant language.

Saager Mhatre
Saager, the confident guy with glasses demonstrates the Domain Specific languages (DSL’s) with Groovy. DSL’s are the languages that are target to a particular type of domain. Many new languages are coming out that in the same way as Groovy.

Why do we need domain specific languages? In answer to this question Saager explains that these languages provide better domain-expert interactions and help in improved developer productivity.

After that he started a brief introduction about the Groovy. He beautifully explains how we can change the code from Java to Groovy. His main focus is on the Groovy and how it can be used as the DSL.

The use of Groovy helps to reduce the code at the minimum and with the more readability. He also demonstrates the example of Java and then step by step converting it to the Groovy.

Aniket Shaligram
Aniket is another confident and young guy who holds the session on Flex on Grails. He started explaining the use of Rich Internet Applications (RIA)

Why should we use RIA applications? Better user experience and No browser compatibility issue are two of the reasons for that. Flex is best for the RIA application for front end. After that he started with Flex details and some good example of it.

Basically the example which he explained was from the adobe site. The example demonstrates the basic CRUD functionality. This example is very good and I love it. Then he explained the why Flex is better than Silverlight and JavaFX. Maturity is one of the main reasons why Flex has taken lead.

After that he turned to the Grails and started talking about why it should be used. Some of the reasons what he had explained are: Grails is Java based, it is Groovy based and it follows the policy of DRY i.e. Don’t Repeat Yourself.

He had explained about the security plug-in and scaffolding plug-in of the Grails that help the developers with the coding part.

Jagdeesh
Jagdeesh the very talented guy from Sun Microsystems which is now Oracle presented the talk on the JavaEE 6 – Deep Dive. He had an experience of around 9 years. This can be seen from the way he is giving the session. I love the way and the knowledge he shares with the audience.

He told that JavaEE implementations are done by the two main players i.e. Glassfish and the TmaxSoft. Whenever JavaEE versioned is released there is a TCK is launched i.e. Technology Compatibility Kit that specifies that the follows all the standards.

He had described some of the best features of the JavaEE6 like Servlets 3.0 which can be used as asynchronized way. Now from JavaEE6 onwards the web.xml is optional and it is up to the developer to use it or not. We can specifies the annotations in the servlet itself that will tell them there URL pattern and name which is earlier done in web.xml .

The use of JavaEE6 in the application makes it more fast and scalable. In between the session Jagdeesh also shows the demo of the new features which were recorded by the Arun Gupta. The session continues for 2 hours but the way he delivers it does not count for it.

Many questions arised from the audience that why we should use the JavaEE6 as Spring provides most the things in better way. But Jagdeesh explains that with the new version of the Spring some of the functionalities will change and the old functionalities will stop working but in case of JavaEE6 this will not happen.
JavaEE6 is based on standards that are plus point which will help the lower versions of the software to be worked with the newer versions.

Santosh Kumar
Why OSGi matters for Enterprise Java infrastructures is the session on which Santosh talks. OSGi stands for Open Services Gateway initiative. He started by simply asking question what is OSGi?

Everyone knows (at least the people working in eclipse) that eclipse is based on the OSGi. It basically shows how we can make the application in more modular way.

Sometimes when we make some modules in the application which are good for that time but in future they might not be that good.

Is there any way that we make the application work correctly by changing the modules without disturbing the functionality of the previous running application? Now Java does not provide this type of functionality and the Java guys are working very hard to make it more modular. There is a project named Jigsaw which will be integrated into the Java 8 as per the Oracle.

This project helps the Java to be more modules driven. How OSGi handles this? In eclipse whenever we deploy a new plug-in it automatically picks it up. OSGi handles it by making the modules and there is a META-INF file each module which tells about the version number and the dependencies which it is depends upon.

Developing applications using OSGi makes faster and module driven which will help developers to develop the code. More information on OSGi can be gathered from http://www.osgi.org

Venkat L
Venkat is from IBM Bangalore and is experienced guy. He is very confident about what he is presenting. He gave the talk on the Best practices for performance evaluation and Diagnosis of Java applications.

He explains the working of the JVM. How JVM handles your code and what we should do to make our applications works smartly. We can set the garbage collection policy in the JVM according to the needs of the application. Healthcenter is a tool by IBM which can show the performance of the application but it is only for the IBM JVM.

JVM contains the JIT i.e. Just In Time complier which basically converts the byte code to the machine readable format. JVM is smart enough to see if the method is called frequently. If it does then it optimizes the method to make the code run faster. But in this case the line of code that is generated is more but this is one time activity.

JVM has been making changes from the time it is released. IBM is working on its JVM and Sun is working on its JVM. By time to time one is better than the other.

Shekhar Gulati

Shekhar is one of my favorite speakers. Spring Roo and the Cloud is the topic on which he gave the talk. He is very energetic and young and Spring loving guy.

First release of the Spring is in the October 2002. From then Spring has gone many changes. Spring Roo is one the many changes that is in existence.

Spring Roo is the development tool which generates the boiler plate code for the developer. It does not come into the picture when we talk about the runtime or compile time. It is basically a rapid development tool for the Spring projects which are based on maven.

Spring Roo is so much easy to configure and use that anybody by taking a small understanding of it can make a Spring project. It is command based and its console is written in Ruby.

His 80-90% session is demo. He drives the audience to demo and shows how within minutes any developer can make a project out of it. I love the Spring Roo functionality. Simple commands and great results.
Adding the functionality to the Spring application is child’s play. Type security setup and viola Spring security is integrated into the project. Similarly we can add logging

Why should we use Spring Roo? Because it is easy to configure and it is based on the standards. There is a specific requirement for Spring Roo that is application should be web applications and it should have database bind to it. It is very easy to learn and apply.

JMS, JSON, Spring web flow, SOLR are some of the functionalities that we can use with Sprig Roo.

Prashant

He is another guy from IBM. He gave his talk on optimizing the Java application.

His main focus is on the how to increase the performance of the application. He had given many tips how we can increase the productivity of the application.

He had also described some of the tools that can be helpful for the performance like the JLM i.e. Java Lock Monitor. It can be downloaded from http://perfinsp.sourceforge.net/jlm.net

Avoiding the synchronization in static methods and breaking the long synchronized blocks into the smaller one. He had also given introduction about some tools for memory management.

UnConference
This is something I had seen for the first time in the conference. Unconference is a talk or the discussion between the delegates on the various topics. Anybody can write the topic on the white board available so that it can be discussed.

As per Harshad this is something that is started some conferences back.
One topic is a Spring vs JavaEE6. This is very interesting and I love the way it is organized. And the role of Java in the future is also discussed.

Various tools for the increasing the performance and productivity are also discussed in this session. Some tools for the memory management are discussed. MAT (Memory Analysis Tool), yourkit, jprofile, visualVM and SpringInsight are some of the tools that will help.

Gaurav Kohli
He is the guy from the XEBIA who gives talk on the Breaking relational RDBMS and dating with HBASE. This is very interesting talk which I love because I am very new to the NoSQL. Yes, HBASE is the database which is based on the NoSQL.

He started with the discussion on the cons of the RDBMS like it cannot be scaled. Cassandra and HBASE are the two NoSQL solutions. There are also other solutions but Gaurav had main focused on the HBASE.

Cassandra is based on the performance and availability whereas HBASE is based on the availability and consistency.

Facebook has accepted Cassandra as they want performance and availability where as Yahoo is based on HBASE. HBASE is based on the key value pair. RDBMS is based on the row-column based whereas NoSQL is based on the column based only where everything is stored in columns.

In the end Gaurav told that HBASE is not a replacement of RDBMS but solves a subset of the problems that were generated by the RDBMS.

Sanjoy Singh

Sanjoy is one of my favorites and he is the last person to give the presentation. He talks about Building scalable and language independent Java services using Apache Thrift. The way he presented the session is very impressive. He started his session with line on his presentation.

COMPUTERS ARE NOT INTELLEGENT HUMANS MAKES THEM
Reading this line makes everyone go with the line but when Sanjoy added one word to the line everyone started laughing. The line becomes
COMPUTERS ARE NOT INTELLIGENT BECAUSE HUMAN MAKES THEM

Application is developed in one language by some of the developers. Problem arises when the language does not fulfill the requirement of the application. Then it is very difficult for the developers to do the task because the services are written in other language.

Then he started talking about the new framework developed at Apache known as Thrift which helps to solve the above problem. This will help to write the program written in thrift and then with some commands we can convert the code in different languages like java, php etc.

He had also given example demonstrating the same. He writes some code in a file and save the file with .thrift extension. Then he run command that generates the code for the different language depending on the command. He makes the java code as server and called that code from the php. It runs absolutely in the same way as it is written in php.

This solves the problem which is described above. Now we can write the code and then we can call in any language. That’s great!!

I am willing to see some more examples written in Apache Thrift. Since it is apache project we can download the source code and see the source of the Thrift.

I love the overall conference loves to go there again :)

Struts 2 - result type input error Resolved

2010-05-24T14:05:00.001+05:30

Some times when coding through Struts 2 we get a input error specifying that result type input missing.
But we haven't applied any validation on it. That some times creates a havoc among developers and they start complaining about the error as Struts 2 doesn't give the proper error.

Struts 2 in Action

I was also facing the same problem until I found the hole in my coding. As we all know that input type result is required when validate framework is applied. This is obvious as it will return to the input page defined in the input type result if some validation fails.
But when we haven't applied any validation and this error is displayed what can be the problem.
The problem can be:
You have created a field on the jsp let it be hidden field and you are implementing the ModelDriven interface. But you forgot to add the jsp hidden field variable in the pojo class. This will surely generate this error.

The solution to this problem is to declare a variable in the pojo with the name of the field you have declared in the jsp.
This will eliminate the error.
This solution help me to remove my error. Hope it helps you too.

Unclean shutdown of previous Apache run - Resolved

2010-05-10T14:35:00.001+05:30

Today I am having a problem with Apache restart. It is continuously giving me the Unclean shutdown of previous Apache run error.

After googling for two hours I got a answer to it. Actually I had installed a Skype on my system which uses port 80 for its some connection purpose and Apache also uses it. So simple un-check the Use port 80 option in the Advanced -- Connection tab from Skype options.

Then restart the apache it works well. Hope it works for you as well.
What a stupid mistake.

Getting height and width of image in Java

2010-04-16T15:40:00.000+05:30

Yesterday I was working on something that requires manipulation of image for getting its properties.
After searching over the internet I found a very intersting class on Java i.e ImageIO and BufferedImage class.

These classes are good enough to manipulate images. there are many other claases also. But what I need i got it from these. I found many developers searching over internet for getting properties of image and there is no good small example for that.

Thats why I thought why not creating a simple code to manipulate the image and help the developers.

Here is the small code that helps to get the height and width of the image. Enjoy it!!

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;

public class GetImage {

 public static void main(String[] args) {
  try {
   File f = new File("E:/Vinod/Docs/Pics/krishna_01.jpg");
   BufferedImage image = ImageIO.read(f);
   int height = image.getHeight();
   int width = image.getWidth();
   System.out.println("Height : " + height);
   System.out.println("Width : " + width);
  } catch (IOException ioe) {
   ioe.printStackTrace();
  }
 }
}

IndicThreads Java Conference - What a Experience

2009-12-12T19:29:00.000+05:30

Its a very good experience of attending the IndicThreads Java Conference in Pune. Its very exciting to listening to the gurus of the Java and other latest technologies.

I have learned a lot from the technology gurus specially from the Arun Gupta from the Sun Microsystems.

It is my first ever experience of attending any Java conference. IBM developerWorks is a Gold Sponsor for the event. The event is occurred in a beautiful hotel Orbett.

Harshad Oak - The very first Java Champion from India; I am very delited after meeting him. He is very nice guy and he is also the organizer of the event. I had asked him questions about how he had become the Java Champion.

I asked him the procedure for the same. He had told me in the straight forward way that it is a very simple as you have to do something very special in the field of Java.

I think he had done something good in the files of Java as he has been nominated by the community members of the Java. He might have done something very special. But I haven't asked him what he had done :)

Below I am describing about some of the speakers and there session that I have attended.

Arun Gupta

He is one my favourite speakers in the conference. He had came straight from the United States specially to attend the IndicThreads Java Conference.

He had presented two sessions and both are knowledgeable. The topics that he had presented are Java EE 6 & GlassFish v3 and Dynamic Languages & Web Frameworks in GlassFish v3.

He had also given some T-Shirts from the GlassFish Community but to those who answered his questions. I am unable to answer any questions so I haven't got any :(. But I will surely ask him to give me one :).

He had told that now Java is not a language any more; it is emerging as the platform for the different languages also. He had also thrown light on some of the scripting languages and the frameworks which are emerging as the new languages for the future and run on the JVM.

JRuby, Groovy, Jython are some the languages that are emerging. Similarly frameworks like Rails, Grails, Django are also taking up.

Some of the points from his sessions are:

Java EE 6 had been declared standard on 10th Dec '09.
Flexibility, Extensibility and easier to use are some of the features of Java EE 6.
web.xml is optional from now onwards. No I am not kidding, its real.
Some of the things that had gone extreme makeover in Java EE 6 are :

JSF 2.0
Servlet 3.0
Java Persistence 2.0
Enterprise Java Beans 3.1
Interceptors 1.1
Connector Architecture

Currently three IDE's are supporting Java EE 6.

Netbeans 6.8
Eclipse 3.4+
IntelliJ 9.0

Now session data can be same across redeployments. (that's amazing)

You can visit his blog : http://blogs.sun.com/arungupta

Twitter : @arungupta

Kamal Govindraj

He is very experienced guy. He had also given two presentations. 13 years of experience is a lot for me.

He had presented sessions on RESTful Applications using Spring MVC and Building Modular Applications. Getting knowledge on the RESTful service is a very interesting experience as I always wanted to know about it.

He had also thrown some light on the Dependency Injection

Some of the points from his sessions are:

REST stands for Representational State Transfer.
It is basically a architectural style of coding.
Its architecture is based on Http
It is scalable and loose coupled.
In REST everything is a resource and is identified by unique Id
GET, POST, PUT and DELETE are main points
Modularity helps in maintaining applications

Rajeev Palanki

Rajeev Palanki is a guy from the IBM. As I had already told that IBM DeveloperWorks is a Gold Sponsor for the Event.

His main focus is on the IBM developerWorks Community. He had thrown light on the benefits of joining the community.

He had also told about the Project Zero which is WebSphere sMash. Joining the community and meet millions of the developers and the other people of your interest will help lot of people in moving forward in future.

There are lot of people who are always available in the community who can help you to reach the level you want to reach. You can also other community members. It is something like a facebook of the tech guys.

Its very nice as I am already a member of the community for many years.
You can reach him at rpalanki@in.ibm.com

AllahBaksh Mohammeddi Asadullah

He is second favourite guy at the conference. He works for the Infosys. What a guy and what confidence. He had also presented two sessions and both were fantastic. I love the way he is describing the topics.

The topics he had presented are also very interested. GWT Internal, Tips & Tricks and Implementing search functionality using Apache Lucene & Solr are the topics that he had presented.

Listening to him is a very wonderful experience. He had explained each and every topics that he covered in a very interesting way.

Some of the points from his session are :

GWT helps in Deffered binding i.e. dynamic class loading at compile time rather than run time
Replacement Strategy and Generator Strategy are used in GWT
GWT Exporter is used to generate code
GWT Dependency Injection can be done using library GIN
Some of the GWT libraries are

GWT Mosiac
GQuery
GWT Exporter
Google GIN
GWT Incubator
GWT Drag and Drop
Spring4GWT
APO GWT

Lucene is a open source library that is used for searching
Solr is a open source Lucene based search server

Narinder Kumar

He is from the company named Xebia. He had also given the presentation on the very interesting topic. He had spoken on Java Applications on Google App Engine

He is very young, enthusiastic and confident guy. By seeing him you will not tell that he will give you the presentation is such a great way.

Some of the points from his session are:

Google App Engine is a cloud computing platform
Java on Google App Engine is Platform as a Service (PaaS)
Plugins for Eclipse and IntelliJ are in the market and can be easily found
You need to have google account to deploy your application
SSL can be configured by specifying a boolean parameter in configuration
Other google services that you get when you deploy your application on GAE are:

URL Fetch
MemCache
User Service
Mail
Image
XMPP

Additional Services that are provided are

Cron
AOP like Interface
Task Queries

For Managing and Monitoring GAE provides:

Dashboard
Reporting
Manage different versions of application
Logs

In all in all its a fantastic journey to the Java world with exciting and new technologies.
I am looking forward to the next year's Java conference from now :)

Hope I will be there also!!

IndicThreads.com Conference On Java

2009-08-31T09:38:00.003+05:30

IndicThreads.com Conference On Java is going to held on 11th and 12th Dec '09 at Pune, India.

This is very intersting event especially for java passioniors and lovers. You can join the conference by visiting the website http://j09.indicthreads.com/ or clicking on the logo on the right side of this page displaying the event like this.

I hope you will enjoy the event and the future of java and many other intersting technologies. I love to be there.

Weblogic Portal Example

2009-08-10T12:49:00.000+05:30

Here I am going to make a simple example of Weblogic Portal.

Minimum requirements:

Weblogic Portals
Weblogic Workshop
Weblogic Server

Basically when you download weblogic portals then you will have all the necessary things already installed. It can be downloaded from http://www.oracle.com/technology/software/products/ias/bea_main.html

You have to download Oracle WebLogic Portal 10.3.

Step 1: Setting up the Weblogic Workshop

Open Weblogic Workshop from Programs -> Oracle Weblogic -> Workshop for Weblogic.
Change the perspective to Portal i.e. Window -> Open Perspective -> Others -> Portal.

Step 2: Create sample application

Create new Portal EAR project from File -> New -> Portal EAR Project.
Name it sampleEAR.
Click next and proceeds with default setting.
Create new PortalWEB project from File -> New -> Portal Web Project.
Name it sampleWEB.
Associate it with sampleEAR by clicking on checkbox if it is not selected and proceeds without any change.
Now select the WebContent, right click and select New -> Portal.
Name it myportal and proceeds.
You will see default portal in the workshop.
Create a jsp e.g. myjsp and then right click on it and click on Generate Portlet.
This will create a myjsp.portlet in application.
You can drag it from the Design Panel to the Portal.
Let’s create another portal which will access the url of the other website.
Right click on WebContent select New -> Portlet.
Name it myportlet and click next.
Select Browser (URL) Portlet.
On next screen in the Content URL input box type http://www.google.com.
Check the checkboxes :

Has TitleBar
Minimizable
Maximizable
Floatable
Deletable

Click next
Drag the portlet onto the portal.

Step 3: Deploy on server

Right click on the sampleWEB and select Run As -> Run on Server.
It will open the server window.
Select the Oracle Weblogic server from the dialog box and Click next.

These are the minimum steps to build a sample portal.

You can access the application by: http://localhost:7001/sampleWEB

Enjoy the sample..

Java + You

2009-07-15T14:53:00.001+05:30