How do I switch Eclipse from Java to C/C++? - java

I used Eclipse Java last year for a class, and this year I have another class that's requiring us to use Eclipse C. I tried installing the Eclipse C/C++ packages, but when I write in Eclipse it stays in Java. Please help!!!
Also, I don't really want to uninstall Eclipse if I don't have to, because I'm still actively working on projects.

You've basically downloaded 2 "modes" in Eclipse: Java mode, and C/C++ mode. If you type and it assumes it's Java, that's because the project you created is in "Java mode".
First, just quit out of the app and open it again. Maybe the update only enacts when the app is refreshed.
Now go File > New. If it's installed correctly, when you hover over "New", there should be the option "C/C++ Project". If there isn't, double check that you downloaded the correct extension. (Note that I'm on a Mac so the layout might be slightly different for you, but it's the same idea).

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

Other Java Proposals Missing From Eclipse

The "other java proposals" that allows you to use the Ctrl+Space shortcut is missing from my Kempler install. I have redownloaded and reinstalled fresh from Eclipse and still do not have access to the shortcut from "other java proposals".
When searching here it's been suggested it should be checked in the advanced section of the editor preferences for Java. I can't find anything about how to enable to disable it here or in the Eclipse help files so I thought I would ask.
Thanks,
Omega
Kepler doesn't have "Other java proposals" but just Java Proposals.
This option (or Java Proposals (Task-Focused)) is sometimes left unchecked when importing the project to Kepler from a workspace on an older version of eclipse. Hence, your problem might be with workspace than the eclipse dist you are using.
I just thought I would "answer" this question incase someone else had the same problem.
It turns out that Synergy+ uses the same keystroke to lock screens. Even when it's closed, and the service is still running it holds on to key binds.
So, how I fixed it was to go through task manager and kill processes one at a time until I was able to use the shortcut, then went in to Synergy and changed the keybind.

Unable to run Java program in Eclipse Juno 4.2

I reinstall my Eclipse environment every year when the new version is released. The most recent release - Juno - however, does not work as expected.
Currently, when I try running demos from Oracle, for example, it asks me to select an Ant file to run before compiling. After creating a blank Ant file to bypass the requirement (which I thought was rather dumb, since I don't think TDD is something that should be forced on people), it still refused to run, saying the "Selection could not be launched."
I understand that Juno is an update from the 3.x track to the 4.x track, but this seems a little ridiculous to me. What can or should I do so I can get Eclipse back up and running again?
Just to clarify:
All files in question are on my Eclipse workspace path
I don't do much in the way of Java development, though I know I'll need to do so soon. Hence, my unfamiliarity with the most recent version of Eclipse.
I would like to run my files & projects without Ant files. I know it has something to do with Run configs, but I don't know how to change them.
Here's what I did to run the demo from Eclipse Juno:
Downloaded the project from http://docs.oracle.com/javase/tutorial/uiswing/examples/zipfiles/components-FrameDemoProject.zip (if this is not the correct demo, then please provide the link you're using)
Unzipped it to my projects directory (not my workspace), so that you have:
PROJECTS_DIR/components-FrameDemoProject/src
PROJECTS_DIR/components-FrameDemoProject/nbproject
PROJECTS_DIR/components-FrameDemoProject/build.xml
From Eclipse, File > New > Java Project
List item Uncheck Use default location and navigate to <PROJECTS_DIR>/components-FrameDemoProject
Hit Finish
Drill down to src/components/FrameDemo.java
Right-click on FrameDemo.java and select Run As > Java Application
Let me know if any of these steps give you trouble.
Take a look at you project properties and select the Builders entry. Do you see an Ant Builder entry? Try to select or create a Java Builder entry instead.
I just created a new Java Project in Juno and added the FrameDemo.java source. In my case, the Java Builder was selected as the default for this new project.

Java perspective is not visible in eclipse

I installed eclipse on a new unubtu install, via the package manager. I have Galileo. I copied my home directory from an older machine, and tried to open that workspace. Now I dont see any java perspective.
(Possibly, all the info above is not relevant, but I just wanted to add any possible info, as this a clean install of Eclipse via package manager, so I cant think of any other non standard thing I might have done.)
What happens if you go to Window > Open Perspective > Other...? Don't you see Java listed there?
If not, I don't think the problem is related to the workspace from your previous configuration. But maybe you did copy a ~/.eclipse directory from your old machine and this one may cause problems. Try to rename it as ~/.eclipse.save for example and restart Eclipse to see if it helps.
Not sure if you mean you already checked in the usual places for perspectives, or if Java Perspective didn't show up by default...
Java perspective should be available under the "Open Perspective" icon in the top right, or by going to Window -> Open Perspective -> Java.
I don't use the Ubuntu-packaged Eclipse, though...
If you do not have a Java perspective even in "Other", you have downloaded one of the Eclipse versions intended for something else than Java. Do it again, but be certain to get the Java or the Java EE version.
Note that Eclipse IS available in the Ubuntu software repository, but it is the version which was current when that version of Ubuntu came out. For the 9.04 I use it is Eclipse 3.4 and I need 3.5, hence I downloaded it myself.
Yes, without perspective you will never be able to see an Eclipse from the viewpoint of Galileo.
The sun's radius (695,500 km) and its distance (149,000,000 km)
The moon's radius (1,737.4 km) and its distance (384,403 km)
You will need to do a "perspective divide". So the perspective radii are:
Sun: 0.00467
Moon: 0.00452
Thanks to this divide, the moon is almost big enough to block out the entire sun.
So, yes, Perspective is needed to show the Eclipse.

Categories