Hello all :) I love stackoverflow where I always find answers but this time I could not so personally asking... Its bit lengthy please go through it.
I am creating a java application where one of my resource is an exe file which I need to call in the java code. But later I would convert the whole java code to a JAR file... and I would add the JAR file and the exe file for the Setup file for installation process. So when I extract the files I want my JAR file to call the exe file while running... I am doing this all in Eclipse :)
So my doubt comes here which path I should put up in the java code... ? So that it will always call the file the exe file from the same directory where the JAR file is also present.. :)
Any help would be great :) Thank you in advance :)
Assuming that you control the whole installation process; and that you also control the script that later starts a JRE to run your JAR within; my suggestion would be: simply use a property here.
In other words; your installer knows that it copied JAR and EXE to D:\example\ for example. Then just make sure that your JAR is started like:
java -jar D:\example\your.jar -D your_path=D:\example
(this is just meant as example, you would have to work that out, probably the \ in there need some special treatment for example)
Then your application can simply query for that system property "your_path" and take the value from there.
Alternatively, you could try this solution that works "pure java".
I've been trying to make a program that, evidently, opens a .zip file and extracts its contents into a .jar file(minecraft.jar, for modding Minecraft), but couldn't find any way to open a .jar file within Java to do so. Is opening a .jar file(not running it) and adding/deleting files within the .jar file possible?
First, #McDowell comment is the root of your solution: the java.util.jar package is where you'll find the tools you need.
Second, modifying the content of a JAR file on the fly is possible, but complicated and rather a lot of work. Would it not be sufficient for your purposes to open both files (the ZIP and JAR ones, if I understand correctly), extract them in a temporary directory, then re-compress the whole lot?
It seems to me the result would be exactly what you're looking for. It might take a bit of a while to run, but since it's a one-off, I don't feel it's a major issue.
I have one exe file, that is packed by Tool Jar2exe. Can anyone help me to Convert it to jar file or is it possible or not ? Below is the link of that file .
http://www.mediafire.com/?eh7dmuy9vxd9m3w
Have you tried using an archiving program such as 7-zip or winzip to open up the file, then extracting the .class files?
If those are truly binaries, then you are screwed and nothing else besides some serious reverse engineering is going to help you.
Chances however are that the exe file will contain the class files nicely packed together. Then just try to open it in 7-ZIP or similar and see if that works out.
if 7-zip doesnt work or just show libs but not main jar it means the option " hide /encrypt " was used. Hence you need to use winhex, ollydbg and ressource hacker and you'r good to go http://reverseengineeringtips.blogspot.fr/2014/12/unpacking-jar2exe-21-extracting-jar.html
I have created a program in Java using eclipse that contains a couple of folders with graphics and files that get read from and written to. What I need is a way to export the whole program in some executable format so that anyone can run my program.
I've had a look around online and I notice that people suggest creating an executable JAR file. However I have my reservations about this since I suspect it will choose to ignore the graphics & other files that the program uses, only focusing on the actual source code.
Please could someone suggest a solution to this issue, it is absolutely essential that the files and graphics are packaged up with the rest of the code.
On another related note; at present I'm referencing the files & graphics using files paths that are specific to my computer. If I were to use another solution such as creating an installable program how should I handle these filepaths? Apologies if this is a naive question, however I'm new to this sort of thing.
However I have my reservations about this since I suspect it will choose to ignore the graphics & other files that the program uses, only focusing on the actual source code.
When you think you may have a solution but it doesn't work, you should test that theory.
A jar file is absolutely the right solution for this. However, you need to make sure that Eclipse considers them as resources on the build path so that it will copy them into the jar file. Then you just need to refer to them from the jar file:
On another related note; at present I'm referencing the files & graphics using files paths that are specific to my computer. If I were to use another solution such as creating an installable program how should I handle these filepaths?
Use Class.getResource() or Class.getResourceAsStream() or the ClassLoader equivalents. That will let you load your resources directly from the jar file, without even having separate files on the file system.
I would like to modify a file inside my jar. Is it possible to do this without extracting and re jarring, from within my application?
File i want to modify are configuration files, mostly xml based.
The reason i am interested in not un jarring is that the application is wrapped with launch4j if i unjar it i can't create the .exe file again.
You can use the u option for jar
From the Java Tutorials:
jar uf jar-file input-file(s)
"Any files already in the archive having the same pathname as a file being added will be overwritten."
See Updating a JAR File.
Much better than making the whole jar all over again. Invoking this from within your program sounds possible too. Try Running Command Line in Java
You can use Vim:
vim my.jar
Vim is able to edit compressed text files, given you have unzip in your environment.
Java jar files are the same format as zip files - so if you have a zip file utility that would let you modify an archive, you have your foot in the door. Second problem is, if you want to recompile a class or something, you probably will just have to re-build the jar; but a text file or something (xml, for instance) should be easily enough modified.
As many have said, you can't change a file in a JAR without recanning the JAR. It's even worse with Launch4J, you have to rebuild the EXE once you change the JAR. So don't go this route.
It's generally bad idea to put configuration files in the JAR. Here is my suggestion. Search for your configuration file in some pre-determined locations (like home directory, \Program Files\ etc). If you find a configuration file, use it. Otherwise, use the one in the JAR as fallback. If you do this, you just need to write the configuration file in the pre-determined location and the program will pick it up.
Another benefit of this approach is that the modified configuration file doesn't get overwritten if you upgrade your software.
Not sure if this help, but you can edit without extracting:
Open the jar file from vi editor
Select the file you want to edit from the list
Press enter to open the file do the changers and save it
pretty simple
Check the blog post for more details
http://vinurip.blogspot.com/2015/04/how-to-edit-contents-of-jar-file-on-mac.html
I have similar issue where I need to modify/update a xml file inside a jar file.
The jar file is created by a Spring-boot application and the location of the file is BOOT-INF/classes/properties
I was referring this document and trying to replace/update the file with this command:
jar uf myapp.jar BOOT-INF/classes/properties/test.xml
But with this, it wont change the file at the given location. I tried all the options also but wont work.
Note: The command I am executing from the location where jar file is present.
The solution I found is:
From the current location of jar file, I created folders BOOT-INF/classes/properties
Copy the test.xml file into the location BOOT-INF/classes/properties.
Run the same command again. jar uf myapp.jar BOOT-INF/classes/properties/test.xml
The xml file has been changed in the jar file.
Basically you need to create a folder structure like where the file is located into the jar file. Copy the file at that location and then execute the command.
The problem with the documentation is that, it does not have enough examples as well as explanation around common scenarios.
This may be more work than you're looking to deal with in the short term, but I suspect in the long term it would be very beneficial for you to look into using Ant (or Maven, or even Bazel) instead of building jar's manually. That way you can just click on the ant file (if you use Eclipse) and rebuild the jar.
Alternatively, you may want to actually not have these config files in the jar at all - if you're expecting to need to replace these files regularly, or if it's supposed to be distributed to multiple parties, the config file should not be part of the jar at all.
To expand on what dfa said, the reason is because the jar file is set up like a zip file. If you want to modify the file, you must read out all of the entries, modify the one you want to change, and then write the entries back into the jar file. I have had to do this before, and that was the only way I could find to do it.
EDIT
Note that this is using the internal to Java jar file editors, which are file streams. I am sure there is a way to do it, you could read the entire jar into memory, modify everything, then write back out to a file stream. That is what I believe utilities like 7-Zip and others are doing, as I believe the ToC of a zip header has to be defined at write time. However, I could be wrong.
Yes you can, using SQLite you can read from or write to a database from within the jar file, so that you won't have to extract and then re jar it, follow my post http://shoaibinamdar.in/blog/?p=313
using the syntax "jdbc:sqlite::resource:" you would be able to read and write to a database from within the jar file
Check out TrueZip.
It does exactly what you want (to edit files inline inside a jar file), through a virtual file system API. It also supports nested archives (jar inside a jar) as well.
Extract jar file for ex. with winrar and use CAVAJ:
Cavaj Java Decompiler is a graphical freeware utility that reconstructs Java source code from CLASS files.
here is video tutorial if you need:
https://www.youtube.com/watch?v=ByLUeem7680
The simplest way I've found to do this in Windows is with WinRAR:
Right-click on the file and choose "Open with WinRAR" from the context menu.
Navigate to the file to be edited and double-click on it to open it in the default editor.
After making the changes, save and exit the editor.
A dialogue will then appear asking if you wish to update the file in the archive - choose "Yes" and the JAR will be updated.
most of the answers above saying you can't do it for class file.
Even if you want to update class file you can do that also.
All you need to do is that drag and drop the class file from your workspace in the jar.
In case you want to verify your changes in class file , you can do it using a decompiler like jd-gui.
As long as this file isn't .class, i.e. resource file or manifest file - you can.