I need a captcha solution for GAE in Java. My clients only have access to the IP in where my application is hosted so they can't rely on re-captcha or solutions of this kinds.
Since awt image classes are blocked. Do you know any easy solution for image generation ?
I 've found a text-to-image library which works on GAE:
Litetext
But it's not secure enough for a captcha.
You could build your own CAPTCHA images using the Images API. Preload one or more image per alphabet character into the Blobstore, then use a combination of the available transformations. These include resize, rotate, flip, crop, and composite, which will get you pretty far. The result probably won't be very resistant to concerted automated attack, but is better than nothing.
Related
I have few questions regarding development of desktop application and I can only access internet for first login where user will authenticate himself. I have an idea that I'll bring in the key used to encrypt videos from online server and save it to local db so key isn't in the code for anyone to inspect.
Is it a good method? As app will be running offline and I don't want anyone to access my videos.
I will have to decrypt one video and play it unless there is some method that decrypt and play on the fly like libmedia does it in android. I have no preference whether I have to develop it in Java or C#. Which language provides better obfuscation keeping in mind that I only need it for windows OS.
Thank you
It sounds like your are trying to develop a sort of light weight DRM solution - unfortunately, this is going to probably be lightweight in the protection it offers also.
For example, if you store the key in the DB it will still be relatively easy for someone to get to it using a regular DB viewing tool.
DRM is not really about making it impossible to copy content - more about making it hard enough to do that it is 'not worth it'.
Depending on how 'secret' or valuable your videos are your approach may be fine - i.e. you may make it enough work to find the key etc that uses won't bother. If your videos were regular studio produced content then they would probably not be happy with this level of protection.
If you do need stronger protection then regular DRM from MS, Adobe and Google etc is available through many of the standard video hosting providers (Brightcove, Ooyla, Kaltura etc) and the DRM they use will support offline playback, which I think is the requirement you have.
They will also all allow decryption and playback 'on the fly' - i.e. you don't have to decrypt the whole video before you play it back (in fact they would typically not do the whole video decryption first anyway as you would then have the whole content in clear stream making it easier to copy).
I'm working on a social website that uses upload of Images for Display Picture and Banner ( as FB Cover)
I am using AngularJs on frontend and Play Framework (JAVA) on backend.
However, I am not able to find best way to process uploaded image (cropping, resizing, etc).
Should I do it on client side in Javascript or Upload to server and do it in Java ? and which libs, i should use.
Veeery wide question, so we can just give you tips, not an answer...
Anyway last time we completed similar task with GraphicsMagick + gm4java + Jcrop quite nice, of course there is still some coding for you, but IMHO it's good start.
I'd need to do an app that runs on google app engine that would be able to automatically create some image files from GWT graphics on server that would be later automatically attached in an email that would be automatically sent once a week.
But as far as I've investigated I see no possible way to do it on server, first off, I haven't been able to use ImageCharts on google appengine I had to use ColumnCharts and LineCharts, so that would complicate the process to turn then into images, althoug I think it could be done although it could take a while, although maybe it would be impossible to do it.
Biggest problem I see is that Google App Engine has File I/O absolutely banned, so although there might be a workaround, I guess it's a difficult one, I know about blobstore, but from what I've seen it just allows you to upload already existing files from you own PC, not to create new ones.
Is there something that could be done?
I'm working on a large website project that makes heavy use of in-page graphing of data. To make the graphs interactive (the old paradigm was to post data to the server, have the server render the graph as a jpg, then send it back to the browser) we've started building the graphs in Java. It's a smooth system, but the website is still very much computer-dependent.
I'd like the site itself to work as a device-aware web application - switching layouts based on user agent strings to render a mobile-optimized version for cell phones and PDAs. But I'm concerned about the nebulous support for 3rd-party applets (Java, Flash, etc) when it comes to platforms like the iPhone.
So if you were building a web application that could be accessed either through a standard web browser or an iPhone/Blackberry/Palm device, what would you do to still display interactive graphs? Is there a workaround for using Java on the iPhone? Is there another platform we should pursue all together?
If you want to support more browsers, you may want to look at using Javascript to help decide what to do.
You could generate the graphs using the canvas element, and if the browsers doesn't support that element then you could use a Flash app, and if that doesn't work, have the graphs developed on the server and use the <img> tag and just refresh.
This third approach could also work if the browser doesn't have javascript enabled.
This way you can handle the various situations and get away from having to run Java in the browser.
The iPhone and Android browsers support HTML5 features such as "canvas", which you may want to look into. The browsers on BlackBerry phones are somewhat behind the times - they are finally releasing a WebKit-based browser for their upcoming 6.0 OS but all of the current in-market devices are quite limited in terms of browser capabilities. For those devices you're probably best off just using a static server-generated image.
I would use a JS charts library and gracefully downgrade to images when you detect an older browser.
I have this new requirement to develop a software which is a large scale image up loader in a web application. I was able to do the same using swing contains several feature like drag and drop, progress bar, remove file / files , modify, limit file size, verify file information, timer, verify at run time ..and its a very powerful tool which uploads images.
I would like to do the same in web based app, like user selects 200 images process it and click upload and it should start uploading, like to know any feasible frameworks or any API's which help me do this faster and achieve the same kind of functionality. Please point me in correct direction.
-PD
You can do upload apps, but not fancy stuff like drag and drop with run of the mill HTML. HTML5 on google chrome maybe, but I doubt you want code that only works on chrome.
Have you looked into turning your image uploader app into a java applet? Applets generally have a bad rep, but this is one of the very (in my opinion) valid uses of one...
Either turn your uploader into an applet or use a 3rd party image upload applet, such as JumpLoader. You then just embed this applet in your webpage. Turning your uploader into an applet should actually be a piece of cake since you've the UI apparently already ready. You can make use of deployJava.js script to reliably deploy an applet.