Hopefully a simple question with a simple answer! All I'm trying to do is separate a .java and .class files; I'm compiling using code-runner and have not found a way to change the default build location (same folder as .java files). I've tried searching a few keywords in the settings.json, as well as looked through the preferences/settings, but I haven't found anything useful.
Would appreciate if somebody could point me in the right direction!
maybe you can try to disable the code-runner, instead of use the "java: force java compilation" command(Ctrl+Shift+P), then the vscode will help you compile the .java file automatically, and location the .class file in the satisfied place. as the code-runner just place the .class files alongside the .java files.
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Sorry if the title doesn't say what I'm trying to do very accurately but I wasn't really sure how to describe it in one sentence. Basically I have a jar file with a java file inside it, and I want to edit the java file. I used 7zip to do so and it worked, letting me edit the code in the java file. I saved it and my new code shows up when I open the java file in netbeans. However, the new code isn't actually in effect, and my program is still using the old code. I don't know if this matters, but the java file is named Templates.java, located in a package called net.sf.dynamicreports.examples in a jar named dynamicreports-examples-5.0.0-sources.jar.
Thanks in advance for any help anyone can offer.
Edit: tried importing the jar into a new project and editing from there before putting it back into the original project, but had no luck (check comment chain for further details). Still have no idea how to fix this and would greatly appreciate any help
Your jar contains .class files and .java files.
When you create the jar, the .java files are compiled and .class files are created from them. You should have a Templates.class file that corresponds to Templates.java.
When you edited Templates.java, Templates.class was never recompiled. This class file is the one your program uses.
The appropriate way to change a jar file is unfortunately to regenerate the entire jar.
So, what you should do is open the code you used to create the jar in the first place, make your java changes there, and create a new jar.
You will need to do this even with the smallest changes.
I didn't make the jar myself unfortunately, I got it from somewhere else so I don't have the code used to make it, just the jar itself. What should I do?
Edit: I saw your comment that you did not make the jar in the first place. This isn't too big a problem since you do have the java source code. What you need to do is copy all the .java files in the jar and make a new jar with them. Or, simply use Eclipse or whatever your favorite java editor is to compile your Templates class, and copy the new Templates.class file it creates into the appropriate place in the old jar, overwriting the old one.
Where would I find the Templates.class file?
Edit 2: You find the class file in the bin folder of your project if you are using Eclipse. See this question: Find the .class file compiled by Eclipse or if you are using a different editor/compiler, search google for where it stores its .class files.
I was trying to create a .jar from a .java file for a school project but now I can't read my .java file. The code I had written was overwritten somehow and I need to know how to (if possible) revert my .jar file back to the code I had written. Thanks in advance because this is a time sensitive matter.
You could try "decompiling" your JAR file using any JAR decompiler, such as http://www.javadecompilers.com/.
You won't get exactly the source code you originally wrote, but the decompiler will do it's best to map the .class files embedded in the JAR back to Java source code.
If you are using Eclipse you can right click on your project and check in history for getting old code
So I'm not CS major or anything and I've been just poking around stuff to practice some Java skills I watched from a video. I know this isn't the major way to do it but please, let me.
So I extracted a .jar file of this: http://www.zenlunatics.com/quizcards/ (i also have its outright source version). It's open source. I used JD gui to get the source code and got everything in .java. However, once I imported it and tried to run it in Eclipse, it says there is "no main type."
I've searched around and it seems there has to be a public static ... String[] args and I don't see that in any of the generated .java files.
I tried searching about it on youtube and he's getting .class instead of .java files. So, say I renamed .jar to .zip and extracted class files, do I just edit the main .class and build? Any tips, please.
Thanks!
Looking in the source code download the main method is in the QuizCards class (QuizCards.java).
Since there is a source code download you should use that.
I deleted a Java project from my hard disk in an attempt to do some refactoring with Eclipse. Luckily I found a recent version of an Executable Jar File and decrompressed it into a bunch of .class files.
I've read some 'decompiling' threads on SO and tried showmycode.com, but I was hoping for more. Isn't it possible to convert .class files into the .java files that made them, comments included - nothing changed? Or find the in the .jar file? What are my best options if not? Other answers on the topic seem outdated. Do I need to download software?
You will not be able to get your comments back, they are lost when you go from .java to .class. As to how to do it any "Java Decompiler" can do it, your code will not be exactly what you wrote, however the code you get back will be functionally the same as what you originally wrote.
JD is a decompiler I have used before and have been happy with its output.
I have a Java JAR file that was developed to run in the browser. It works fine. There doesn't appear to be any sort of build file associated with the source code I've been given and I'm attempting to create a project and/or build script.
The source code references some third party code. What I've done is unzipped the JAR file into a folder that has this structure:
\App\src\com
\App\src\META-INF
\App\src\applet
The "com" folder contains subfolders which contain the .CLASS files for the third party libraries. "applet" contains the .JAVA source code files (one folder, maybe 15 files).
The code appears to be written in 1.4 syntax (I manually attempted to compile some of the .JAVA files and it complained that some things were deprecated and/or required the older version).
I created a Java Project in Eclipse and pointed it to the \App folder. Then I went into the Properties for the project and went to Libraries and and clicked on "Add Class Folder" and added the \App\src\com folder. Then I went to "Order and Export" and moved this to the top. I also set the Java Compiler version to 1.4.
I am getting a large number of compiler errors, all of which seem to stem from the fact that it says it can't resolve an import. This import is the set of .CLASS files contained in the "com" subfolders. The namespace matches the directory structure.
This seems like it should be really straightforward, but I've tried various things and don't seem to be making any progress. Based on what I've read I'm sure it has something to do with the pathing but I'm at a loss at this point on how to fix it.
(I'm sure it goes without saying that I'm not a Java dev.)
Any thoughts or ideas as to where I'm going wrong?
Can you please try to right click on Eclipse's Navigator. Select Import>General>archive file> (Jar file that you want to import).
You should be getting the jar file correctly imported at this point. Do tell me if you face any problems.