I am looking to right an application that limits the number of times a user can print something, its there anything in Java that will allow me to control the printing dialogue to this aim?
Im going to look into these:
http://www.wildcrest.com/Software/J2PrinterWorks/documentation/J2Printer14.html
http://www.softframeworks.com/products/products.php
This is probably something you'll need to implement yourself as it is too-specific a requirement to have been included in the JDK's API.
Assuming you've developed a standalone Swing application you could consider using the Preferences class to store the number of times a user has printed a document for a given date. On Windows this translates to storing information in the registry and is therefore "hidden" from the user to a certain extent, but would allow you to reset the value in an emergency using regedit.
The advantage of this approach is that the user cannot circumvent the print-threshold by simply restarting the application.
I decided to go with J2Printer. I allows the suppression of the print dialogue.
Related
I'm writing a terminal version of my Java application, and this is the first time I do this. I tried Scanner and Console, but as far as I investigated, these classes only allow me to receive user input after he/she finish inputting (no manipulating/filtering).
For example, I want the user inputs his age, but if he inputs a meaningless string, all I can do is validating the string and requesting him to input again. What I really want is only allow him to input integer, i.e when he press any key which is not a number, the character will not be displayed on console. Using Swing and JTextField I can do this easily with DocumentFilter, but with console only, I still haven't found a way.
Any help is appreciated. Thanks all.
Java has something called robot API which u can use to control keyboard mouse etc...
Not the recommended way :)
Since the console is not Java program (its a c program) you have limited way to interface with it, perhaps you can write native API to get more control over it. I have not tried it but if needed use this option.
I have created a an application for a project - it's very basic... what I would like to do next is see how users are using my application e.g. buttons pressed, which page is viewed the most, for how long etc.
I am new to java and I do not understand how I can implement such thing; I have an idea but do not know whether it is efficient;
I would add a counter for each of the buttons in my app, whenever a button is pressed the counter increases by 1 and so on and so forth;
To see how long a user stays on a page, I could add a timer when the user enters the page, timer starts and stops when user exits.
...
Would something like this is viable and efficient? are there better ways of implementing such algorithm.
Not sure if there are, I searched but couldn't find any, does google offer such service like they do for websites with google analytic.
I am sorry, I've no to show this, as I haven't actually starting doing it. Wanted to get a grasp of it before I do and find out whether it is the correct strategy.
I would really appreciate your help.
https://developers.google.com/analytics/devguides/collection/android/v4/
Analytics for android apps maybe its what u are looking for
Start here: http://www.google.com/analytics/mobile/
https://developers.google.com/analytics/devguides/collection/android/v4/
You could also go with that you stated already, and add those values to an array. Just note that this will require you to turn on some permissions which might make your app unpalatable for some individuals.
I have a Java Desktop App, the users of the application have the availability to set the aplications language.
By now i manage it in the database, i call the value of a field called - userLanguage - which is an Integer, and when the user has logged in depending on this value i set the corresponding text to each element on the app by using a switch ( case 1: set labels text ENGLISH, case 2: set labels text SPANISH ... etc)
But i've heard that control the language from the database is an insult, and i would like to know which's a nice way to do it, or what's the best way to do so, it doesn't matter how difficult it would be but the efficence of the method to internationallize an app is what metters for me.
I would actually handle this problem using the Java Preferences. It keeps the preferences for each user separately in a system independent way (for you at least). If you use XML you need to create a SAX/DOM parser or if you use a DB you need to use jdbc. Neither XML or the DB is a bad or a tough solution, I just think the preferences are the easiest.
For internationalization, I would use a ResourceBundle that localized for different Locales. It is a pretty big topic see The Java internationalization (I18n) tutorial
Java Preferences is what you are looking for then.
Or, instead of using XML file you can use Properties.
...i've heard that control the language from the database is an insult...
I do not agree with that. I think it is scenario dependent, and in your case I think you should keep it the way it is to avoid unnecessary work, unless there is an absolute need for keeping the preferred idiom outside your DB.
You've received two answers, both of which are plainly wrong. If you have Java Desktop Application, you should this code:
Locale locale = Locale.getDefault(Locale.Category.DISPLAY);
This will give you valid User Interface language for your application - the one user set in his OS preferences. If you want to keep the language in a database or in some kind of preferences, you'll be forcing users to chose language. What for? I've already set what language I want. If you don't have it, let Java fall back to your application's default.
In case you wonder, if you use ResourceBundle, the default would be the one without a Locale in its name. That is unless you override this process by using custom ResourceBundle.Control.
I am using Java to write a console program that retrieving stock ticks from a data source and printing to the console in table format.
However I don't know how to update the value in the table. Once I got a new price for the stock, I want to refresh the value in the console. I don't want to clear my console and print the entire table with a single value update everytime, it looks pretty stupid. Any suggestions are welcome.
The console is OS specific, while native programs can perform coordinate based updates within a console Window, this isn't something inherently supported by Java which treats the console as input and output streams.
Theoretically you could write a program to perform such updates and have Java talk to it via JNI, though this would, in my opinion, be overkill. You'd be far better spending your time writing a Swing or Web based application in which this type of behaviour is far more easily achieved.
I was working on creating a weather application in Java using Weather Underground and I found that it does have data for some cities.
Initially, I was planning on using GeopIP to get the user's location automatically but since the support for cities is limited I decided to let the user choose the city every time the program starts.
I want the user to be able to choose a city from one that is supported by Weather Underground. The user will enter the name and as he/she enters the name, the possible locations will be displayed in a way similar to the one shown in the picture.
My question is:
How do I implement this search feature ?
My initial guess was to create a Vector containing all the names of the cities and then use brute force to find the match and display in a JPopup or a JWindow containing a JList but I guess there has to be a better method
Rephrase:
What I do not understand is WHAT INFO do I keep in the data structure I must use ? Should I manually create a list of cities that Weather Underground supports or is there another way to do it ?
Take a look at the Trie data structure (also known as digital tree or prefix tree). Autocompletion is one of the most common examples of it's usefulness.
The following article has a nice an very approachable explanation:
Roll your own autocomplete solution using Tries.
if you google autosuggestcombobox you will get some interesting results:
This one is written in JavaFX - I have used and extended it myself already. It is quite useful. What you get "for free" with JavaFX: a context menu with right-mouse click which is auto-generated containing some of the usual "stuff", like cut, copy & paste and even undo! So, I can recommend that solution. To get into JavaFX isn't so hard - and I think it is much easier to learn than Swing - and looks so much cooler! However this implementation has some drawbacks - especially when the layout is not left-aligned, because it is simply a text field on top of a combobox.
OK - but if you want to stick to Swing - you could probably use this one. I haven't used that myself, but the code looks quite straightforward and pretty clean - cleaner than the implementation for JavaFX I must admit (but that had some nice features). So - maybe you try - and extend it? It is built simply on JComboBox.