I am new to OpenJDK,
so I'd like to apologize if it's a known issue or there is already a way to get over it.
Currently, I am trying to 'static build' the OpenJDK
so that I can remove all dynamic library dependencies
when I use the tools like java, javac, etc.
For that purpose, I found an option called '--enable-static-build' fed to the configure file.
However, it seems like it's not supported (even not allowed to enable) at the current mainstream.
Would there be any workaround to enable that option for static build?
Or, does anyone know any specific branch or GitHub tag where the static build works fine by any chance?
Many thanks in advance!
I have tried to use the configure option, --enable-static-build, but didn't work.
Related
Just starting working on an existing project at work and wanted to use Visual Studio Code as my IDE (I have used it for a recent Rails project and loved it, so wanted to try with Java).
However, whenever I try to open one of the projects I receive a ton of different errors including:
When importing java.io, java.util, or anything similar, the error:
"The import of java.io (or java.util) cannot be resolved"
Existing classes have an error:
"The implicit super constructor is undefined for default constructor. Must define explicit constructor"
Other random "cannot resolve to a type" errors.
All of these seem to stem from some sort of setting error I have with VS Code but can seem to find what it is. I have already uninstalled and reinstalled the RedHat plug-in that enables the Java language for VS Code.
I have tried setting the java_home setting in the extension to the direct location of the install but that didn't work. Tried uninstalling and reinstalling java and that also didn't work.
My operating specs are as follows:
OS: macOS Sierra
VS Code version 1.15.1
JDK version 1.8.0.144
Any idea on what may be causing this? Do you think it may be an error in how I have VS Code set up or if it's an error (or rather incompatibility) with how the existing project is set up?
I ran into a similar issue. The solution was to remove everything from VS Code's workspace storage directory, which was located at $HOME/Library/Application Support/Code/User/workspaceStorage/.
I found this solution here: https://github.com/redhat-developer/vscode-java/wiki/Troubleshooting#clean-the-workspace-directory
Update: This can now be done from within VS Code as of Language Support for Java(TM) by Red Hat Version 0.33.0. Open the command palette and type "java clean" (see official description in link).
As already mentioned previously, you require to clean the project, but that is a bit difficult thing because every folder is a Guid, and you do not know which one to clear, thus requiring you to delete everything. Starting with 0.33.0 version of the plugin you can automatically do that from within the IDE as well, use CTRL + Shift + P and type, java clean, and IDE will show you the suggestion tip for, Java: Clean the Java language server workspace. Upon selection, agree and restart the IDE. It will clean the language server workspace for you.
Another approach can be, the Maven tools within the IDE. If you have this plugin installed, you can use the side bar and utilize the Maven project helper options to perform actions like, clean, install, and package etc. For example, here is the project I am having and the options this shows,
That can be used, graphically, to manage your Maven-based projects. Also, this would work with the Java Extension Pack, not sure yet as to how it would behave with other extensions.
For me: CMD + Shift + P
Then type "Java: Clean Java language Server Workspace"
Note: This will reload/restart vscode as well.
Update:
This appears to not fix it anymore for me. In my case I am using a gradle project, and needed to set the rootProject.name in the settings.gradle to be the same as the folder name that the project is in.
I faced this issue after creating a whole Java project in one computer and then trying to run it on another computer.
After doing everything said in the other answers, what really made VS Code compile was to open each single project java file in VS Code and save it (a simple Ctrl + S). Maybe there is a simpler way of doing it, but that is what worked for me and I hope this helps anyone stuck in this issue.
Press ctrl+shift+p
then search 'java clean' and click 'java: clean java language server workspace' then click restart IDE.
I found another simple trick at least to get rid of "cannot be resolved to a type" errors which were coming from older workspaces and wrong project files I guess?. I just ran an empty main(), with the body commented out, while still keeping my local package / import commands at the start - no errors. After commenting in again, the project compiled without errors. Perhaps this refreshing effect might also help in this context?
I had to clean this folder to get it working on Windows
%APPDATA%\code\Local Storage
I've come back to project after a long diversion, and upgraded tooling. This means Netbeans 12.5, Java 17, Gradle 7.3… at least allegedly. For some reason, despite setting the Gradle version to 7.3, it appears to build with 7.0.
Per the image below, setting the Gradle version to 7.3 doesn't seem to be picked up. (That is immediately after hitting Apply.) It still tries to build with 7.0. And – for some indeterminate reason – it can't.
Restarts don't help; I can't get the configuration to be picked up. (Searches for reference to similar issues provide 5-year-old answers that are no longer relevant.) I've even tried deleting the 7.0 distribution; to no avail, it comes right back.
Can anyone provide guidance on getting this to work properly?
Netbeans 12.6 fully supports Java 17 and Gradle 7.3. Gonfiguring the Gradle wrapper for 7.3 gets picked up correctly, eliminating all errors I was experiencing.
Don't bother with gradle in Netbeans. It's a horrible, buggy disaster and 12.6 just seems to want to up the ante.
Netbeans does NOT support gradle in a meaningful way for normal users.
You now get complex multi-projects whether you want them or not.
When creating a Java Application you don't get a choice at what the Main class is called. It will be App with app.java and you will like it.
If you try to rename app.java to something useful. It will not change "Class App" to "Class Useful" it will instead change it to "ClassUsefulp". It will not rename the test file and you will be left with several syntax errors that you can have fun cleaning up.
No, you cannot rename the subproject itself. That will continue to be the extremely descriptive and useful "app" subproject. The IDE will not provide you a way to rename that.
There is no meaningful, intuitive way to create/delete/modify subprojects.
If your gradle version is somehow out of sync there is still no useful way to reset/recreate the gradle wrapper other than creating a whole new project and moving your source code over to the new project.
Oh, so you gave in and accepted the multi-project structure. You noticed that if you go through the multi-project creator GUI then you can create multiple subprojects. Yeah, good luck with that. They won't have gradle build.scripts or wrappers. You won't be able to build your awesome creation.
Want to use command line arguments? Forget it. There is no "run" element in the project properties. You cannot create different run configurations.
Want dependencies? Or any other project configuration? It's all manual editing of gradle files. There's no GUI to assist non-gradle-wizards.
Yeah. you can probably work around a lot of this by dropping to a command line shell and editing the gradle scripts/files manually and running gradle commands manually. A) you're going to need to be a gradle wizard, and B) why are you using an IDE in the first place? you've got gradle, you've got vi available. Bathe in the nostalgia because you'll have to anyways.
Do you like the idea of gradle? Do you use Netbeans? Stick with Ant, or Maven if you need external dependencies; you'll thank me later.
I would like to programmatically set/create a breakpoint in another file at an arbitrary line number in Eclipse. I would love to see a generic solution, but I guess I have to rely on the Eclipse JDT plugin for it. How can I do that? I tried something like:
JDIDebugModel.createLineBreakpoint(resource, typeName, lineNumber, -1, -1, 0, false, null);
But I have two problems with it:
I have to include a whole lot of libraries to my build path to make it work, e.g. /usr/local/eclipse/plugins/org.eclipse.core.resources_3.9.0.v20140514-1307.jar. If I add them, they require other ones etc. I probably have to add all Eclipse plugins/libraries to make it work.
How do I get a proper resource in order to give it to the method above? Giving a null value will most probably not work. But all implementations of IResource are internal...
I also thought about directly communicating with the JDI, but I could not get it going in combination with the Eclipse debugger (here is a great, but german resource for it).
If it is not possible from arbitrary code, would it be possible from within an Eclipse plugin? This would also be an option, though not preferable.
I could not find any solution for it and hope to get some help here. Thanks in advance!
Most Eclipse plugins can only be run in the Eclipse environment because they rely on the Eclipse/OSGi plugin infrastructure being initialized properly.
Since JDIDebugModel.createLineBreakpoint requires an IResource object it can only be used in the Eclipse IDE (or an RCP based on the IDE) with a workspace.
So, yes, you can use this in a Eclipse plugin which would have to be installed in to Eclipse or an Eclipse RCP.
Hi i've been trying to install the library on Thinking in Java book 4th edition and i hit a very thick brick wall. I've done everything that the guide from the website told me to do and i still can't get the library to work. From what i've read it seems that the problem is from the build.xml files. having no xml knowledge I am clueless about how I have to modify it in order for it to work. In both cmd and eclipse I am getting these error
c:\TIJ4\code\build.xml
Build Failed
c:\TIJ4\code\build.xml:59:J2SE5 required
Can anyone tell me what I should do ?
I am using eclipse if there is a simpler solution by using eclipse rather than ant please help me out. It's been a week now and I still can't make it work.
The important thing to do is to realize that your ant file has a specific java requirement.
Something to try that might fix this very easily : I believe you can remove any references to a specific JDK, and if you have a reasonably up to date JDK, the build will succeed.
The definete fix : Look into the exact (line 59) of your build file, and try to satisfy the java version that line requires. Java is generally backwords compatible -- something designed to run in J2SE5 should run in the latest JDK. Its not terribly difficult to update your JDK (just google for instructions on your OS).
The most common mistake I see is that people who have the java run time installed believe they also have the Java SDK as well.
Does this "install the library" means you want to look at the code and run them in your eclipse? If so I can share my experience with you.
First run the Eclipse.py script; this will add package info to the source code
Create a new Java project in Eclipse, and then just copy all the source code folders to the src source folder in eclipse, these folders will then be recognized as Java packages.
You should be able to run the classes with a main function.
You can also configure which java version to use for this project in Eclipse build path. 1.5 or higher will work.
I am working on a soucre code which was developed using java 1.4 but now we want to migrate it to java 6. I was able to compile it but there are tons of warnings related to use of java generics wherever we have made use of collections framework. It is possible to remove them by manually make changes to them, but I wanna know if is there any tool which can run on the source code and remove all the warnings by making necessary changes ot the code. Any help will be highly appreciated.
Cheers,
Nitin Ware
Eclipse has an option to try to infer the type arguments for generic types. It's not fool-proof, but it's a start. It's available from the "Refactor" option in the context menu when you right-click inside the class's code.
Open your code with Eclipse, select your Package or Project and in the Refactor menu select "Infer Generic Type Arguments". It will infer the types and correctly change almost all the warnings. Correct the last ones by hand.
Unfortunately sometimes the plugin sometimes crash while trying to do it. I'd also try to do it with IntelliJ IDE. Edit: I've tried with InteliJ and it also failed. Nothing happened after 2 days running. The newer eclipse almost worked, just crashed in 2 files. I'm using it in a very old project with non-standard paths. Maybe you'll have better luck.
You could suppress warnings as a compiler option
-nowarn or -Xlint:none
see http://java.sun.com/javase/6/docs/technotes/tools/solaris/javac.html#options
In eclipse you can set the "Target" JVM to 1.4, that should fix your problem in the editor. I think you can also specify a target option to javac, but I'm not sure about that.