I have following tasks:
Automatically generate java source files in the current workspace.
Compile those files after generation.
Export every generated and compiled class with needed libraries to runnable JAR file.
I already installed Eclipse SDK and I suppose what I need is to make my main class inherit some class from SDK and maybe load some other classes. But i don't know what do I need exactly and where to look. I'd appreciate some clues.
I suggest you look at M2T-JET to generate not only the Java files, but the project, any necessary folders and any other resources you need. One of those resources would be a jardesc file which is used by the JDT to persist jar export options. You can play around with those options to define the jar and export, then generate the jardesc file along with the other generated resources.
M2T-JET can be invoked programmatically, so once that single invocation generates your entire project, your plugin can make the call to the JDT to export the jar using the jardesc file.
Related
(I couldn't figure out how to upload my screen capture to stackoverflow. So this is a streamable link: https://streamable.com/0im8tx)
In this video, VSCode opens QueriesController.class as opposed to QueriesController.java when I cmd click into QueriesController.
I have compiled provided the definitions of the jar file in my workspace:
"settings": {
"java.project.referencedLibraries": {
"include": [
"<path-to-jar-that-contains-QueriesController.jar>",
....
"sources": {
"<path-to-jar-that-contains-QueriesController.jar>": "/my/local/java/definition/src/folder",
Does anyone know why VSCode is choosing to open the definition as a .class file rather than a .java file?
I use commands to generate a simple jar package and use it in another project. It's true that when we click the class name, .class file is opened instead of .java file:
About how to generate a executable jar package, you can have a look at this reply:
Compile .java file and generate .class;
Generate manifest and pack them into jar
In general, a JAR (Java ARchive) is a package file format typically used to aggregate many Java class files and associated metadata and resources (text, images, etc.) into one file for distribution.
.java file isn't included in jar packages, and that's why you get .class file opened instead of .java file.
I am not familiar with VSCode but your problem is common across most IDEs.
Usually when a jar is made, it consists of compiled class files rather than original source codes. The reason for this is to run code as efficient and fast as possible and usually people don't want source code in jar because when running they also have to be recompiled again which is a waste of time.
Take a look at this picture. I have just downloaded a jar file from mavenrepository and it downloads the compiled version of jar. The extension is .class
What the IDE does is it tries to decompile the code with a decompiler (In this case as you can see FernFlower decompiler).
However it lacks formatting and in-code documentation the source code (.java) has. Which is why most IDEs offer to download sources. Intellij shows this right on top. Other IDEs may have this setting buried in deep. (You may have to check for yourself)
When you download sources, IDE try to contact the server and download original source code. Probably that would look something like this:
If you look closely you can see name has changed to .java which represents the source code.
VS Code has option under Java Settings, Java Download sources and Maven download sources.
It is not enabled by default. Upon enabling it, VS Code shows the proper source file, although the name appears to be .Class files.(Upon Ctrl + Clicking the symbol, with method implementations, comments, etc.,JavaDoc Comments)
If proper sources are not found in m2 repository, it shows the decompiled class file with stubbed methods. A comment similar to this is shown at the beginning of the file.
// Failed to get sources. Instead, stub sources have been generated by the disassembler.
// Implementation of methods is unavailable.
In Either of the cases, VS Code shows the maven library files as .Class files in read-only mode. Also, source files are not displayed on the Java Project Explorer.(Although even if it exists in the local .m2 repos).
Hope that helps! Happy Coding!
I am new to both Java and to the Eclipse IDE, and I am having trouble with adding a Referenced Library and actually using it in my code.
I am in a software testing class, and my assignment is to use the JWebUnit library to run some basic tests on a website of my choice. I have downloaded a zip of the library and added it to the build path, so that it shows up in my Referenced Libraries list.
When I try to actually use that library, though, the import statement gives an error.
I just cannot figure out what I am doing wrong that the base class cannot see this library.
The screenshot show that you have added the folder net as class folder to the Java Build Path. Maybe you have added the source code (.java files) or Javadoc (.html files) instead of the executable bytecode (.class files). Usually .jar files are provided containing .class files which can directly be added to the Java Build Path.
Probably you want to download e.g. the file jwebunit-3.3-release.zip from here and add all JARs contained in that ZIP (in the root folder and in lib) to your Java Build Path instead.
Is there any way I can create Java projects using a simple text editor? Not an IDE like eclipse?
I want to be able to create .jar files without the assistance of an IDE, I have all the JDK commands installed already on my computer (such as javac)
I'd like to know what file structure I need, how I need to arrange my class files, what compilation steps I need to go through etc. to be able to create jar files.
Yes, completely doable (just not much fun once the project gets bigger).
I suggest if it's not a throwaway project, use a build tool like Maven or Gradle to manage your build process, so that you don't need to assemble classpaths and resources yourself, but still retain full control of the build and test lifecycle, without IDEs. This comes at a complexity cost, of course, but once it's set up life becomes easier.
See also How can I create an executable JAR with dependencies using Maven? or the Gradle docs about creating JARs
I'd highly recommend the standard Maven source directory layout too (src/main, src/test etc) as it's both commonplace and makes for easy integration with the above tools.
Follow the below steps to create a jar file
Compile the java source using javac
Create a manifest file (if main exists) to identify main class
Use the below command to create a jar file
jar -cvfm *.class
Yeah. You can create your project structure without an IDE. But it's time consuming and you have to do everything.
To talk about creating JAR, you don't want any extra software. You can use jar utility, which comes with JDK.
Here are steps to create jar:
Compile classes which you want to in jar
Create manifest file (.mf). It's needed if you want to make jar as executable. If you want to bundle classes only together, then no need. (eg. Dependency jar)
Go to command prompt and execute following command "jar cvf MyJarName.jar *.class". Make sure java is set in environment path and you're inside the directory of classes.
cvf means "create a jar; show verbose output; specify the output jar file name.
That's all. If you want to include any folders inside jar then you can use folder name in above command after classes and it must be separated by space.
Example: jar cvf TicTacToe.jar TicTacToe.class audio images
I did some robot framework python examples with pybot, and referenced .py files as my library files. The folder structure I used was test/lib/myLib.py and test/test/myTest.robot, where /test was at the same level as the /src folder in my project in eclipse.
I then tried to do similar things with a java project using jython. I have /test/test/myTest.robot which imports the library ../lib/myLib.java. I even tried importing this file using RIDE, but it always shows up as red text, meaning the import failed. The specific message I get from using jybot on the command line is:
"Importing test library 'C:\Users\cody\git\myProject\test\lib\myLib.java' failed: ImportError: No module named myLib"
I read that I might need to add it to classpath, and I think in order to do so, I need to make it a .jar file. I'd rather not do all that if possible to just leave it as a .java file. I attempted to add the lib folder to the build path... By that I mean I added the /test/lib folder to the "Source folders on build path". I also exported the darn thing as a jar and added that as a library. All this was done from the project properties in Eclipse.
I'm pretty stuck... any ideas how to get this working?
Java being a compiled language, you need to compile your java Class before importing it with RobotFramework.
Normally, Eclipse would do that for you, and put the resulting .class files inside a bin repository. If not, you can issue the javac path/to/file.java command, and move the resulting .class file where you want it (somewhere referenced by the classpath.
From within the .robot file, you should have the line Library test/lib/myLib, without neither .java nor .class at the end.
When exporting a project as a Runnable JAR file using Eclipse, there are three choices:
1. Extract required libraries into generated JAR
2. Package required libraries into generated JAR
3. Copy required libraries into a sub-folder next to the generated JAR
However, it seems that only one of the three choices could be chosen from the Runnable JAR File Export window. I wonder if there are some ways that could mix up these methods, e.g., extracting some of the files while packaging the rest?
Note: I need this since one of my JAR file contains a ton of references to other files so 1 cannot be an option, and I am afraid that 2 might be causing some problems for me.
Thanks!
What you can do is choose "1. Extract required libraries into generated JAR" and save the build as an Ant script. Then after it finishes, edit the ant script and remove the libraries that you do not want to be extracted.