Java Web-Development Clarification

Question

I am new to java web development.

Currently I'm learning technologies such as Servlets, Jsp, and Java Frameworks like Spring etc.

I was wondering that as an end user say for a java web-site without applets, would the user of the website be required to install java in his/her machine?

Because it seems that in the case of Servlet and Jsp all execution is done at the servers end and only the result is sent back to the user in html format.

Please correct me if I'm wrong.

Answer 1

Http is a stateless and text based protocol. That means Http protocol is not able to remember its previous state and this can not hold any state of execution.Its a text based protocol so medium of exchange of information or data over this protocol is text. Main issue with this protocol is that it can handle only one request at a time and send response to user in same manner. But in current time user requirements have changed dramatically. So Http can not handle so much requests at a time as well as cant managed to send multiple response. So Here Java EE and web servers comes into effects

Web-servers provide an environments where a web-applications(servlet,jsp,Java EE) can run,executes and send responses to the client. Web- servers perform task such as:

1: Handle a Http-requests and in the same way send the responses to that requests.

2: Since, Http protocol only understand text so , Web-server parse the request as a text,then process it and then transform that response again into a text and send it to the client server.

3: Provide an environment where web-applications ,request-response and other services can run flawlessly,dynamically and with strong security undergo.

4: And last but not the least, these web-servers are designed and developed in pure java and run it thread-model so you trust your application is in safe hand.

And applets runs in different way, client side at least need JRE to provide an environment to executes an applets. Applets are differs from web-technology.

Answer 2

As you suspect, Java is only run on the servers. It is the language that accepts an HTTP Request and processes it, issuing out an HTTP Response. As with most good coding practices, this means that the server program is returning a response that is, essentially, text. The implication here is that you can write the server in any sort of programming language, or set of languages, without the browser needing to know what or why.

Thus, the browser is agnostic to the languages you use on the server.

Java Applets are different; they are compiled Java code that is downloaded by the client and run inside a local JVM. For this to work, the client requires Java to be installed. Applets can be quite small - invisible even - and thus malicious sites can use them on unsuspecting browsers to do wonky things. For this reason people are concerned about Java security holes that would allow applets to do more than they should.

Answer 3

You do not need your client systems to have Java installed.

The news about disabling java in web browser was due to some security vulerabilities in the current release (which Oracle said they will fix in October release). But you do not have to worry about it since you do not have applets in your web site. The clients would need java jre installation if you have such plugins as applets

Answer 4

hi you need to install jdk if you want to develope any java project,the jdk itself contains jre( java runtime environment),,

you can prefer below link

http://www.journaldev.com/546/difference-between-jdk-jre-and-jvm-in-java

Answer 5

No need to install java at end user(client). Because HTML renderkit return html format.

But if his or her need to developed , java is need.

Answer 6

You are correct. The java is executing on the server. The user would only have to install java if the application served applets, which as you say, is not the case here.