This maybe a noob question but please help me.
I found a library called Graphview for android and I would like to customize a bit and use it in my project. I know .jar is a zip file so after I extracted it I saw 2 folders, one contains some .class files and .java files, My question is, do I just need to change the codes I want in .java files? How about those .class files? And How do I put all the changed files back to recreate a new .jar file so I can use it in my project?
Here is the library from Github :https://github.com/jjoe64/GraphView/downloads
I would
fork the original git library.
modify it.
build it.
consider providing your improvement to the original build.
I wouldn't try hacking the existing library even though you can do this if you really have to (because you have no access to the original build)
You can just clone the original project, make your changes there, and then jar the changed project.
Related
I have made a Java game using LWJGL, which requires some native files. It all works fine in Eclipse. I want to include the .dll files inside a JAR file, but everytime I try, LWJGL can't find the natives. I have already tried using jarsplice or fatjar, but to no avail. I know minecraft is also programmed using LWJGL, and it somehow manages to load the natives from another folder.
Is there a way to package native files into a JAR file and let a 3rd party library, like LWJGL access them? If not, how would I approach loading them from an external folder?
EDIT: Somehow it worked with the natives in the same directory as the JAR file. I would still like some explanation and perhaps some other methods, though.
I just ran into this a few weeks ago. Alas, I do not have links, but I found that you cannot reference native files stored inside of a jar file. You have to either programatically extract them before you reference them, or you have to install them alongside your jar file.
I went with the second option and just have Eclipse pack the whole collection into a zip file for distribution.
For the first option, one place to look would be the source code for JNA. They ship dll's/binaries inside their jar file and extract then on demand.
I am doing JAVA project based on the SSJ (Stochastic Simulation in Java) libraries. In my project I have followed the required steps to import the SSJ library files and also the source files.
When looking at the SSJ library files in the project's Libraries branch, only class files appear shown, but when I open them I can view the source code (which I couldn't before, as I hadn't imported the sources) so I assume everything was imported correctly.
When I run the examples provided with the library everything runs fine and as expected. But if I try to change the source code for the libraries for instance, changing the text on an output, the changes I make to the source files aren't reflected in the output from the java programs.
Any hint on what I might be doing wrong?
I understand this might be hard to understand or test as I can't quite create and SSCCE for this matter. The library files are hosted here (http://www.iro.umontreal.ca/~simardr/ssj/ssj-20120216.zip) and the source code here (http://www.iro.umontreal.ca/~simardr/ssj/ssj-source.html).
Thanks in advance for all your help!
Adding source to libraries it's for debugging and documentation purposes. It does not mean that Netbeans will detect changes and recompile classes automatically.
You should create a project for the library itself to recreate it from source. Changes are that if you have the source there will be a build.xmlor a pom.xml that contains the steps to compile the library and will allow to create a Java Free Form Project or a Project with existing POM.
You'd then remove the reference to library itself and add a dependency to the project.
Other option would be to add the library source to the same project you are using (and, again, removing reference to the library) but I would not recommend this unless it's a very small simple library.
EDIT. Particular ssj information.
ssj is a library where the original source code is in .tex files and it requires several programs available to generate .java files and then compile them. All this information can be found in the COMPILE.txt original file.
Since the source distribution includes .java files it is possible to generate a .jar just using Netbeans but it requires to modify the build.xml to just compile Java source files. Also when creating the Java Free Form Project is necessary to select lib as the target to Build Project.
Here it's a minimal build xml for Netbeans 7.1 to compile from Java sources.
In order to create the new *.java file from the *.tex file, you need the tcode.jar which is available in the distribution. Have you added tcode.jar as an external jar to your project?
umontreal.iro.lecuyer.tcode.Texjava is in tcode.jar
first i'd like to point out that im fairly new to netbeans and java, couldnt exactly find what i need on the web.
I downloaded a software's source files and was modifying it on netbeans. naturally when building the project, netbeans creates in (for example) documents/project_folder/dist/ a lib folder and the finished JAR file that i can use.
if i delete by mistake the source files, and would like to apply all the changes i previously made to fresh source files using the JAR and lib folder i still have, is it possible and how?
First of all it is not possible to get a source again from jar file in lib folder. Jar file is executable file which will just contain class files. You can use java decompilers to get source again.
NB do not has a version control nor auto save by default. You may have a look on git in NB7.
When you restore from Jar with decompiler there is a big chance to get the source back, even more if you know what your code is all about.
You can get the source back by using some decompiler. There are many decompilers available like DJ Decomipler. My favourite is Jd Java Decompiler. Its very small in size and does its job pretty well
I'm rather an Eclipse user but I guess both Eclipse and Netbeans are similar to a certain extent. Unless the jar has been created including the source, you won't have other choices that decompile the class files.
When needed, I usually go with JD-GUI which does a pretty good job decompiling jars.
It is not possible to retrieve exact source code from a compiled byte code. But there is a possibility to recover your code to some extent
JD is a good Java decompiler.
http://java.decompiler.free.fr/?q=jdgui
I think JD is a super hero in cases that the original source code is lost.
Keep your source code on any SCM. Use remote SCM not to loose your code. See: google code, github, launchpad etc.
I recently lost my netbeans project folder of the project that I was working on at the time. However somewhere on a server here at the company that I work at, I deployed it. So that means that I (hopefully) can still get hold of the .war file.
Is it possible to then 'unpack' this .war and get my .java source files back that I was working on at the time?
Thanks in advance!
If the .java sources aren't in the WAR (and they should not be), you'll have to take the additional step of decompiling them using a tool like JAD.
This is a good time to set up a version control system, like Subversion or Git or Mercurial, so this never happens to you again. Get into the habit of using source code management, even if you're the sole developer working on the project.
Short answer: No.
Slightly longer answer: Look for Java decompilers, but they won't give you your Netbeans project folder.
You only get *.class files from your war (rename war to zip and use a decompression tool).
Then you could decompile them.
See this related question for some suggestions.
Suppose if you had exported the source files while creating the war, you can get it. Else, JAD is your only hope that too cannot fully rely on it.
It is possible to unzip the war file where you will get only class files and other property files. Then use Java decompiler to see source code and it works really well (not recommended).
Also you can change the property files without JD and all you need to do just change the property files and zip to war file again.It will work.
But I would recommend you to maintain source code in SVN or TFS or multiple copies with version numbers in local system at any point of time.
In Eclipse, you can Import your War, it will create a new Project and set the resources in the project structure. IF your war holds the source java files, the project will cointain your sources. IF not, the packages will be empty and you will have to manually decompile your classes from bytecode to java files, using jad or another decompiler.
I have a couple files I want to include in my .jar for a game server. The files, a SQLite database and an icon, work properly when and only when I put them in the Eclipse project folder and run it straight from Eclipse. As I want this to be distributable to end-users easily, how can I include these files and use them at runtime? Thanks in advance!
Accessing files from within a jar file can be tricky depending on the code that's using them. If the code is written to open a file from the file system, you have to extract it. If your Java code opens it with Class.getResourceAsStream(), it can be read from within the jar. You mentioned an icon and SQLite. I would guess you need to extract those files. I've done this with the maven-dependency-plugin and unpack when using maven. "jar xf foo.jar icon.gif" works too.