To create a chatprogram in java we need 2 classes one for Client and one for Server from which the client will be able to connect and exchange text messages. to compile the code simply type these commands in command prompt window:-
1)ipconfig(memorize the Ip address)
2)javac client.java
3)javac server.java
4)java server 10.69.23.203 (You need to type your own ip address)
5) After this you need to open another command prompt window(Make sure the server command prompt window is also open). now type:
java client 10.69.23.203
Thats it.
if anyone have any problems please post a comment and i will answer all of your questions or if you are having trouble in compiling.

Servlet returning an image.

This is a simple script to provide basic cross-platform XML request functionality in Javascript. It's meant to be the core component in any AJAX style framework. It is not an instantiable object, but instead is a namespaced microlibrary.

Calling is easy:
XMLRequest.GET(uri, query, callback, fallback)
uri: The location you're after
query: an associative array of form data to provide via the URL
callback: callback function of the form myCallbackFunction(objXMLHttpRequest), which is called upon successful (response = 200 OK) retrieval of the XML data
fallback: myFallbackFunction(objXMLHttpRequest), which is called upon failed (response != 200 OK) retrieval of the XML data.

XMLRequest.POST(uri, query, form, callback, fallback)
Similar, but does the query using the POST method. 'query' is the URL-appended data, still in associative array form, and 'form' is the same for the POST data.

This is a brief revision to my previous snippet. It is still what it was: a small, simple system for using XMLHttpRequest without using globals.

I'll put the API spec in the code this time, so as not to clutter the front page further.

Changes:

Changed name to HTTPRequest (far more accurate)
Added HEAD requests
Shortened code by making a GenericRequest function
Used a better method for getting an XMLHttpRequest object (checks multiple MS versions and implements the latest one)

libNog is a 9k library to provide somewhat easier browser-independence. It is not yet complete, and will be continuously revised. It grew from this snippet, and is still growing as I find things I use often.
Presently, libNog features:

A way to browser-independently get an XMLHttpRequest object.
A set of simple methods for GET, POST, HEAD, and to include other Scripts.
Simple methods for className control
A completely abstracted form of getElement*
Browser-independent methods for attaching and detaching event handlers
An event-normalization routine
A simple one-command 'Stop the Event' routine
And the big one: A simplified Class object by which classes can be built in JavaScript.

The above link will point you to the API documentation and history of libNog, as well as where to download the library.

This function converts a CSV file to a simple XML file.

This is a quick and easy class that will generate MD5 hashes from strings. I originally wrote it to insert into my Oracle database so I could generate MD5 hases for passwords from PL/SQL.

Example

String md5Hash = stringMD5("my password");

Java properties files can yield undesirable results at runtime, if there happen to be spaces at the end of some lines.

Requires a win32 port for the GNU utilities grep and sed - e.g. http://unxutils.sourceforge.net/.

if you use the same buildfiles on your local codebase and your continuous integration buildserver, the if-attribute for ant's targets comes in handy...

for this ant buildfile snippet to only create+publish javadoc when executed on the buildserver, the buildserver only has to set the referred system property, e.g. on its startup by using a Java D-option "-Dcontinuous.build=true" ...

ant buildtool website

With Java Web Start 1.5.0 all of a sudden new proxy properties were introduced (deployment.proxy.http.host, deployment.proxy.http.port and deployment.proxy.bypass.list) valid only for the webstart environment - and if that was not enough yet, it does not support the existing proxy properties, neither the standard, nor the deprecated ones from old Java releases. To topple even that, for the bypass-list the delimiters were changed to semicolon (http.nonProxyHosts has the pipe char as delimiter) ...

standard networking properties

the workaround here makes sure, that if any one of these proxy properties (deprecated, standard or webstart-5 ones) are set, that all the others get the same settings - this pays off, if you're using different third-party components relying on one specific set of these proxy properties (especially if it's beyond your power, in what kind of environment the software will be executed respectively integrated...)