Cant find Packages in Eclipse - java

Recently I have been working on coding Minecraft mods. Yesterday i updated to a 64 bit version of Java, and I began to receive an error that said something of this nature: "Java returned error = 13". I looked around, and discovered that my Eclipse was not 64 bit, so I went to Eclipse, and downloaded the latest 64 bit version. I then replaced my normal eclipse folder with the new one, and it launched fine. However, when I open Eclipse, (I open the exact same workspace as I did before all of this happened), I don't see anything in the Package Explorer view. Nothing at all. Typically it says MDK Example or something like that, and within that are all of my packages, etc.
Here is my question: How can I make it to where I see all of my files in the package explorer like they used to? I am using the same Workspace...
Just a warning: I code a lot, and I believe that now I'm quite skilled at it, however I am not good with computers themselves (hence why I find myself in this predicament). If I need to completely start over, I can, and I can copy over my code. It would be a nuisance but if that is all that is left to do I will do so.
Thank you for reading! Please help if you can :)

I remember encountering a similar problem after having switched the location of my workspace.
Try the following: Choose a different location for your workspace and then choose File>Import>General>"Existing Projects into Workspace".

Related

Why does any collection object not recognized? (VSCode) [duplicate]

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

Visual Studio Code - Java - Import Errors and More

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

Eclipse Mars: code is gone

Please, help! I opened Eclipse Mars to continue coding and my code is gone! I don't know what could have caused this but it's all gone. Does anyone have any idea what can I do?
Note: I tried to right-click the java file->Replace With->Previous from local history. But a message says "No local history available for selected resource". Is there any other way?
Thank you in advance!
The first step in debugging this problem is to find out if the code is still exists without using Eclipse. Several possibilities come to mind:
The code is still where you expect, the files exist and the content is OK.
The code is still where you expect, the files exist, but the files are empty.
The workspace directory does not exist any more.
You need to use a file explorer program to find the files and check they are not empty. Try opening them with Notepad++ or similar. If you are lucky, option 1 will be the answer, and Eclipse has got confused. Just use File/Switch Workspace to set the workspace to the directory and all should come right.
Options 2 & 3 indicate you have lost data. There is probably little chance of recovery. Revert to your backups (you do have them?). Otherwise learn a lesson and set up a GIT or SVN server (or subscribe to a cloud service). I just use a very old laptop running Ubuntu with SVN server installed.
As a side issue, Eclipse does not randomly delete or empty files. There are millions of developers world-wide using Eclipse, and if it existed, such behavior would be all over the internet.
I had the same problem and found my file with a strange name in local history with this path:
".metadata/.plugins/org.eclipse.core.resources/.history/"
It was not the last version but better than nothing :)

MCP must specify URI Scheme in Eclipse

I recently became interested in Minecraft modding, so I downloaded MCP (Minecraft Coder Pack) and Eclipse. After running decompile.bat, I opened Eclipse using the workspace provided by MCP. At first I was given a list of errors related to missing libraries, but I easily fixed that by fixing their paths. Then I continued following the video tutorial I was using and pressed "Run" and selected "Client" as the project to run. Eclipse gave me the following error:
Must specify a URI scheme:MCP_LOC/jars
I have been Googling this for the past 20 minutes with no success. What is wrong, and how do I fix it?
I can probably still program mods for Minecraft and even recompile them with MCP, but it will be difficult to test them. Does anyone know what's wrong?
NEVER START IN ECLIPSE
Try This vid for 1.7.3
Its a nice little series about minecraft modding.

Eclipse behaves inconsistently after system crash

I have an urgent and puzzling problem with Eclipse. My system crashed on itself this morning, and after I rebooted, I can run a program perfectly within Eclipse, by right-click on the Java file and choose 'Run as Java Application'. However, after I make the project into a .jar file, and execute that, the behavior of the program simply does not reflect what the code does.
I have checked that I am compiling the right project, and running the same code from the same project within Eclipse does not cause any problem. And btw, I am using a plug-in called fat jar to compile the .jar file, if that makes any difference. I have used the same plug-in numerous times before to compile the very same project, and never had any problem.
Does anyone know what might be causing this weird/inconsistent behavior of Eclipse? Do I need to re-install Eclipse and fat jar to fix this? Thanks.
My usual procedure for strange things like this is,
A) Clean and build again i.e. Project -> Clean
B) (not so eclipse related) Since I am usually using a build tool, do the same thing from the tool to ensure its eclipse.
C) If it gets really bad, I'll start a new eclipse workspace and try from there.
D) Iff I had just installed a new plugin before things went strange I'd think about reinstalling
It sounds extremely strange :)
But Eclipse can, and has, acted strange before. I have had problems in both Java, C++ and PHP development during the years that could only be fixed with a resinstall of Eclipse. You could probably fix it by digging around, but the time it takes to find and fix these types of strange problems in Eclipse is simply not worth it.
Good luck!
Please try to Reset Perspective first (Before reinstall eclipse)
Window->Reset Perspective.

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