Hey i am hoping to write a program where the program automatically just copy pastes all my dad's documents from D:\office folder. So whenever I plug-in my pen-drive , the program silently copies all documents inside my pen-drive. Also all files should be pasted to a hidden folder in the pen-drive (so it remains private) . Synchronization capability also required ...So which language should be easy and where to get started ...any idea ??.
Seems to me that some spyin' is about to be goin' on here. :P
I'd recommend C++. Not extremely easy as .Net's tillyvally but fast, framework independent, convenient to manipulate Windows API. You wanna do advanced stealth app, you can't pick the easy way.
Why use the clipboard when you could just use shell commands???
Maybe write an autostart batch file on your pen drive that copies files to/from your flash drive as needed.
I infer you are on Windows. Window has a plethora of functions to manipulate files. A few functions are below.
CopyFile Copies an existing file to a new file.
FindFirstFile Searches a directory for a file or subdirectory name that matches a specified name.
FindFirstFileEx Searches a directory for a file or subdirectory name and attributes that match those that are specified.
FindNextFile Continues a file search.
MoveFile Moves an existing file or directory and its children.
On and on. These and many more functions are documented here.
File Management Functions
Copy or move the files to the pen drive.
HTH
I hate to be the person who suggests this (I don't like .NET that much):
Make a C# (or VB if you must) Console app, or Forms app (if you want to get fancy). The .NET framework will make this kind of program VERY easy and it might be fun. Unless you want to increase your proficiency in C/C++, i would suggest NOT doing it in those languages since there is a learning curve and it is a little complex to do some simple things.
"Just paste" or "synchronize"?
For synchronization, unison is a good bet, see http://en.wikipedia.org/wiki/Unison_(file_synchronizer). For "just paste", you could code a call to a batch calling XCOPY from with the Windows Autoplay mechanism.
Sounds like a secret covert operation you're talking about, though...
I think that you will need to do a lot of work to get a less than satisfactory result.
I would suggestion you instead have a look at DropBox, which is free up to 2Gb of storage which automatically synchronizes between all registered computers, plus has a special folder which allows for web access. Very nice.
I would suggest to use Camel framework of Java, there you can easily run service which will for example automatically copy data from your flash disk after plug in, to folder which you specify etc.
Good tutorial how to start is here:
https://www.youtube.com/watch?v=dmtXkA7FlwA
Related
I am maintaining a Spring Boot project. There is this code:
BufferedReader reader = new BufferedReader(new FileReader("./setting_mail_sender.txt"));
Where should the file be located in this case?
In 'the current working directory'. And where is that? Who knows!
Whomever wrote that code messed up. It's not a good idea to use the CWD for anything in any java code unless you specifically know you want it. And generally, that's only the case when you're writing command line tools in the vein of the various tools you find in your average linux distro's /bin dir - a rare occurrence, given that the JVM isn't really designed for that kind of thing.
There are 3 different best practices for 'data files' depending on the nature of the data:
Static, unchanging data - as much part of your app as your class files are. These should be loaded with MyClass.class.getResource("name-of-resource.txt") and shipped the same way your classes are. For example, inside the jar file.
Config files. These should usually be in System.getProperty("user.home") - the user's home dir; /Users/yourusername on macs, /home/yourusername on linux, C:\Users\YourUserName on windows. Best practice is to ship a 'template' version of the settings file if relevant in the jar file, and upon detecting that there is no config file present at all, to write out the template (and you load the template in via MyClass.class.getResource). If a template is not a good idea, something in a similar vein. Bad practice is to have the installer do this, and have your app be broken or leave the user having to peruse complex documentation to (re)create the config file. A different way to do it right is to have a config page in your app (a window, menu bar setting, web app thing - something with a user interface) where you can change settings and the config file is simply the way you store that data.
Changing data files. For example, you ship H2 (an all-java database engine) with your app and it needs to write its database file somewhere. This is a bit tricky; user home is not the right place for such data files, but you can't really 'find' the dir where your app is installed either. Even if you can, on non-badly-designed OSes, apps usually cannot (and should not!) be able to write to that location anyway. The location where this data is stored should definitely be configurable, so one easy way out is to require that the user explicitly picks a place. Otherwise I'm afraid you're stuck having to write per-OS code - find /Users/myusername/Library/Application Support/yourappname on mac, which is the right place. As far as I know there is no library to do this right.
None of them involve 'require that the user start the app with the right CWD'. There are good reasons for that: It can be hard to configure, and it's not something users think of to configure. For example, when setting up a java app as a recurring task in windows, you can configure the working dir for such a process, but it's not something that's usually considered as crucial configuration. When running a java app from the command line, who knows what the working dir is. You'll end up with an app that usually works, except in some circumstances when it magically doesn't, and most of your users have no idea that the difference between the magic run that works and the one that does not, is the directory they were in when they started the java app.
If you can edit that code, do so - figure out which of the 3 different kinds of data this is about (sounds like the second bullet: Config stuff, so should be in user home, and the app's name should be part of the file name) - and fix it. for example, that should be:
try (var in = Files.newBufferedReader(Paths.get(System.getProperty("user.home"), "myapp-mail.conf")) {
}
This solves a whole bunch of problems:
Uses try-with to avoid resource leakage.
Reads from user.home, avoiding current working directory as relevant setting.
Actually uses UTF-8 encoding (whereas your code will, at least until java 17, do 'platform default'. It's somewhat unlikely you want that, as it means your config file is not portable; copying it from one computer to another may break things. You presumably don't want this.
If errors occur, the error messages are improved (one of the downsides of the 'old' file API).
If you can't change this code, figure out what the CWD is; put the files there, and ensure that, however you start this spring boot project, you always start it from that directory. If you can't change this code but you can run some code in that JVM, you can print it: System.out.println(Paths.get(".").toAbsolutePath()) will show it to you.
I've been learning Java for a month now. I've already managed to code some very simple stuff like prime number generator and a simple calculator. Now i'd love to try working on something more complex.
Here's my idea - I'd love to make a program that can copy pictures from SD card or USB with a single click (something that my parents can use very easily to copy all their photos to a folder without my help)
I was brainstorming quite a bit about it and before i start i want to ask following questions:
1. Are there any inbuilt Java methods that can help me with the following task?
2. What are the other (non-beginner) Java features that i'd need to read about?
I want to start it from the scratch, make it simple at first and progressively add more features to practice and learn some more.
Any pointers or tips much appreciated.
I'd suggest doing this as a script. The script can invoke java if you'd like to improve your java skills. However, scripting languages can also copy/move files very easily. If you choose java, read about file I/O, reading files, writing files, etc.
Here's a link for windows. Not sure what your operating system is, but you could create an executable script on mac, linux, etc.
http://www.wikihow.com/Write-a-Batch-File
I am writing/planning to write a program that takes in a java file (or multiple java files), and edits and adds functions/classes/variables and then outputs a new java file (or multiple files).
Is there a C++ or Java library that
Can recognize and output names of classes/functions within a text file
Can recognize and output the names of the input arguments for said classes/functions
Can allow me to insert code at specific lines or within specific functions
Can search for a given variable name/value
Maintains original file formatting
I would prefer not having to manually code something to do the above, so any help would be appreciated.
Thank you in advance!
EDIT: I currently use Eclipse, and am unsure of how to proceed. So to further explain my question:
In eclipse, if I write a program that opens another .java file, How would I go about 'asking' eclipse to output, say, all the class names of the .java file I just opened?
Also I will explain the 'purpose' of this project to further clarify. I want to write a program that can take in any java file, and turn it into a class that can implemented remotely via RMI. To do this I will need to add an execute() function, have the file implement Task and Serializable and add a few variables, etc... Based on my knowledge, doing this in Eclipse would require manual editing of the program, but I would like to completely automate this process.
Thank you, again.
Much of what you need can be found in a modern IDE; and some very good IDEs are open source (eclipse and Intellij IDEA Community Edition for Java). You might look there to see if there are modules that suite your needs.
Looks like you are talking of a tool like eclipse. You might not be looking for a full fledged IDE, but the requirements that you have mentioned are fulfilled by any basic IDE.
If you wish to make one of your own, you can do that using eclipse rich client platform.
All that you would need from Java is the reflection API.
I stumbled upon the need to find out (inside Java code) which files are dynamically loaded by an SWF-file. Is there any possibility to get a list of paths of every object referenced inside?
I tried out some libraries without proper documentation and gave up. Although I ran out of Google Search Phrases... ;)
Maybe there is an external tool which can be accessed by Java via command line?
Ggreat thanks in advance
Maybe you can get to the information you need using the dump tool which is part of Apparat.
I use actionscript more than Java, so I also recommend having a look at AS3SWF which is a great library you could use to load and analyze the swf you need. Think of it as decompiling at runtime.
Either way, the SWF Format Specifications will come in handy.
I'm not sure there's something that does exactly what you want, but I imagine you could collect all the strings (DefineText tags), loop through them and run an URL RegEx against them.
I think even if you could analyze a SWF file, you can't be sure to get this information. I have Flex Project (finally a swf file) which dynamically loads some modules, but the names (URLs) of the available modules are requested from the server. So there is no chance to retrieve this information from the main swf file.
I am developing a small game in Java and I am shipping it as a single Jar file. I want to store the high scores/best times for that game somewhere. Instead of storing it in a separate file, I would like to store it in the application itself (inside the Jar) so that its not lost. Is this possible at all ? If so, how to do it programatically.
Java does not give you tools to modify the JARs which are currently run. If you really want to do it, you have to guess the location of the JAR by yourself (which might reside on a read-only filesystem) and modify it the same way you would modify any archive file.
Bottom line: it's a very bad idea, don't do it! See this question for a much more reasonable solution.
Nothing is impossible, but storing it in the jar file would make it very complicated. You might also end up with unwanted side effects like "Permission Denied" errors when the jar is owned by another user. Virus scanners might get nervous when they see jar files change without reason, etc....
I would look to the Preferences API for storing this kind of info.
I think it is a bad idea to try and store anything in the jar file. Another option is to have a web based service offered to the people playing with your game. The game could connect through a web service to your hosted server and then store everything centrally there. Not sure if it is exactly what you want but it's just an idea. It would also allow people to compete with each other.
Java JAR file is a ZIP-Archive, so you could possibly access it with standard ZIP-Tools and just extract one hisghscores.txt file, modify it and then pack it back again.