Conexion de una base de datos de PostgreSql 8.2 a Java

Search file directory (recursive method) with java language

Convert InputStream to byte[]

Convert java.awt.Canvas to java.awt.image.BufferedImage

Snippet for display one frame in full screen mode.

Convert
java.awt.Canvas to java.awt.image.BufferedImage or java.awt.image.Image

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.

A GroovyClassLoader demonstration. The given domain is a german water flow meter system; I think, you shouldn't be able to understand the domain, but you should be able to understand, how to load a Groovy class in Java via a GroovyClassLoader.

This gets the information off youtube when you add a youtube link.

please change the dev_id to your own my is:BnvzCjJ_Bzw

http://www.youtube.com/my_profile_dev

put a link in eg. http://www.youtube.com/watch?v=xOJnKgsWPGw

This is a very convenient way to remove all doubles from a List in Java. The only prerequisite is that the elements in the list have proper equals and hashCode methods.

It work by using the constructor of a Set that takes a Collection as an argument.

I poured the snippet in a little program so can run it straight away.

I use something similar to this in an application named Shock 3. It provides you with your own Custom settings that can handle your own Custom types as well.

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)

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.

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.

This snippet illustrates following:

1. Using http request to get the data
2. Parsing RSS feeds
3. Sending email

This code illustrates using ruby REXML package. It converts J2EE web application deployment descriptor web.xml into Freemind mindmap document.

This class intended to collect TODO comments from java/c++/etc source files.

Example:

protected readFileData (String path) throws IOException {
// TODO: add try...catch block for IOException
InputStream is = new FileInputStream(path);
...
}


See also DirectoryScanner class.

Configurable number formatter.

Implementation-independent XML builder.

This class uses reflection to locate option setters. Client class must contains methods setFile (to receive file names from the command line) and setOption### (to receive option ###).

(See also adapter-based implementation)

Based on "Random Password Generation"

What is Dijkstra Algorithm? click on the link above and first understand what the algorithm is all about. in short it calculates the shortest path from A to F or vise versa. This code i can guarantee is the simplest and easiest code to understand. just search on google and try to compare this code and other dijkstra code and you will see what i am talking about. i spent alot of time myself and my instructor to guide me on the rite path.
http://en.wikipedia.org/wiki/Dijkstra%27s_algorithm(Description)
to see how the algorithm really works go on this website it tells you step by step how to update the cost and which path to choose.
http://renaud.waldura.com/doc/java/dijkstra/
Please give some time to understand the algorithm first and then you can see my code. if you done understand the algorithm it is very useless. i know alot of people need Dijkstra algorithm in java for their HW assignment or Test. i am giving you the solution step by step. anyone who wants to understand please go to the url i have posted above and once you have understand then run the code and for those people who just want to copy so that they can get 90% in their test No Problem Here it is .
First open a notepad and name that file anything like data.txt or datas.txt and make sure the file looks something like this and in this format.
0 3 100 5 100 100 (100 represents infinity)
3 0 6 7 7 100
100 6 0 5 5 3
5 7 5 0 1 100
100 7 5 1 0 2
100 100 3 100 2 0
i name this file as a data.txt file. i have 6 nodes. and A is always the starting node which has the cost of 0 so by looking at the first line i
know that A to A have distance 0, A to B is 3, A to c is Infinity, A to D is 5, A to E is Infinity(means no edge connected with A), A to F is Infinity.
for second line(B to A is 3, and then vise versa) and for the 3rd line it starts for C and etc..
save the txt file by any name and then copy the code which i have posted and then to run type this:
javac routing.java
java routing data.txt
you will get the output. i will say this one more time understand how the algorithm works or ......................

I was looking for an easy way to populate a combo box with strings taken from an enumeration, and also to be able to pull out Enum objects from the combo box. After some searching, I found EnumComboBoxModel on the JDesktop website, but was not able to find any code.

Instead I came up with an easier solution that did not require me to define a new Model class, but instead uses javax.swing.DefaultComboBoxModel.

Sorry for the disorganization of the code, but hopefully you get the idea.

This function returns a Date object being set at 12 A.M. It is useful for comparing dates where you don't know if they'll come set at the beginning of the day or not.

Classe que pren una frase i una clau i obté com a sortida el missatge encriptat usant l'algorisme de Vigenère.

Classe que donada una frase té com a sortida la mateixa frase però havent-li aplicat la xifra del cèsar (per defecte amb valor 3).

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

I've seen XML 2 Array functions done in other ways but this is the shortest implementation I've seen yet. I didnt write it myself though, but I thought I'd submit it for common good of this site. It uses regex and works prefectly.

A simple tool used for fast Exponentiation. Very useful if you are creating your own cryptograpgic methods.

A simple tool used for fast Exponentiation. Very useful if you are creating your own cryptograpgic methods.

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");

If you only want to compare yyyy-mm-dd you can use the java.sql.Date class, the valueOf method does the trick. It's perfectly safe as the sql Date class is a subclass of the Date class.

Check out the docs here for more detail.

enjoy

This class allows you to retrieve a companies current stock quote from Yahoo Finance, as well as current news feed entries for that company.

Method for get n random number's

Servlet returning an image.

Fixed the regular expression to check for more strict requirements.

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...)

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

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/.

Another solution recommends using a text match pattern.
This works, but as long as you've got mail.jar in your classpath anyway, you might as well use this technique instead. (Plus, I think it works with older JDK 1.2+, whereas pattern.compile is 1.4+)

Note that it also accepts a comma-separated list of emails, just like a To: or CC: address line would.

Another way to generate a unique ID.

Reading and writing to a URL connection, thanks to Java.

Here's a nifty trick I often use for testing.

Lets say you have a c:\foo\lib directory full of jarfiles for log4j, javamail...whatever.

Modern J2EE containers do a nice job of letting you deploy a jarfile with your code and have a lib directory full of jarfiles like this, but what if you just want to run a quick client from the command line?

Here's what you do:

Do you find yourself implementing toString on your objects all the time, and wondering why (the debugger seems to do a pretty good job of it all by itself)...well, here's a bit of introspection applied to the problem. This is for all those quick debug sessions where you just want to do System.out.println(myComplexObject).

Instead, just do System.out.println(DebugPrint.toString(myComplexObject));

A handy class I use all the time to encapsulate the idea of whether two events coincide. For example, given a time period representing a shift, and a list of time periods representing transactions or sessions or whatever, find which ones are either totally or partially within the time period. This class make it a bit easier.

Recursively delete a directory, emptying all contents.

Deletes all files of a certain extention from a folder.

Move a file quickly in java.

in the normal GZIPOutputStream you can not et the compression level. I came across this little script tonight that allows you to set the compression level for GZIPOutputStream.

Format Bytes

Log4J is a really nice Library that aims to facilitate outputting debugging information, but also relevant data, in Java applications. It is highly configurable, using both Categories and Class-Based rules, so that developers can narrow down the problems very well when debugging applications.

Simple class to allow cut and paste to clipboard.

Remove newslines from a string.

Copy a file to a new location, optionally marking the file as a temporary file (to be deleted on application exit).

Note there are issues for temporary files - not all the parent directories that might be created are guaranteed to be deleted - only the immediate parent directory will be deleted on exit if created. Other higher-level directories will not be deleted, even if the file is marked as temporary.

If you have ever written a website or java application where people paste stuff in from Word, you are likely to have hit the problem of Word using high ascii chars for "open quotes", "close quotes", reg symbol, etc...

This java class (with a single static method) can replace the most prevalent of these with normal ascii values

Hope it helps someone...

I came across this in the Java Docs, in my ever growing attempt to learn Java. I needed to implement custom listener events.

Read a eight bytes in little endian order from the given InputStream and create a long out of them.

A utility class that gets the MD5 hash of an input stream. Also includes a method for converting byte array to hex-formatted string.

Convert a password returned by JPasswordField::getPassword() into a String.

I needed these for a recent project, bits and bytes constants.

I actually like SQL. So, things like Hibernate with it's own query language don't quite fit my style. But, I don't want to code the same catch SQLException conn.close over and over either. So, I came up with this.

The idea is you extend SQLCommand (usually anonymously) override getSql(), and call execute() to get a list of whatever objects you are selecting - all the cleanup stuff is taken care of. It also handles nullable attributes more intuitively using ResultSetWrapper and PreparedStatementWrapper so that in your overridden getRow(ResultSetWrapper rs) method, you can call getInt on a nullable column and have it return null - what a concept! Also I like java.util.Date for my dates, so the wrappers convert to/from java.sql.Timestamp.

Right now I've only bothered with some basic types - it should be pretty clear how to add more if you need em.

See what ya'll think.

Oh, it uses JDK 1.5 Generics, but stripping that away would be pretty easy if you wanted 1.2 compliance.

Compare two dates in Java.

A simple implementation of a Java timer. Executes timer task every second.

More often than not, if your trying to work out what's going wrong with your subclass of InputStream, why the character encoding is getting lost in your database, or your file format reader is failing, you'll need to dump a byte buffer out in a useable form.

Here's two methods, one which appends to a StringBuffer, one which simply prints out to System.out

Tim.

(NB: The line: sb.append( "n" ) ; SHOULD have a leading slash ie: sb.append( "\n" ) ; but the formatter seems to remove it...

Change logs

-> length calculated from the array
-> charachters will not be repeated in the password