Related
Related Questions:
Intellij IDEA doesn't detect changes
How to clean project cache in Intellij idea like Eclipse's clean?
The answers does not seem to work.
File -> Synchronize, VCS -> Refresh File Status, File -> Invalidate Cache seem to be good solutions, but they do not work at all.
Also one of the file is greyed out just yesterday. But I am seeing this problem for two weeks now.
I have rebuild the project. Still it does not work.
Please help. I am using intelliJ version.
Should I delete .IntelliJIdea13>system>log?
Please look at this link too:
https://github.com/pantsbuild/pants/issues/564
I did change the folder in which my project file exists, and created a new folder with the same name and update from the SVN
"What seems to be happening is that when you don't use the --idea-project-dir override, a new directory with the name of the project is created.
./pants goal idea ... --idea-project-name=zun123463
Generated IntelliJ project in /Users/zundel/Development/java/.pants.d/idea/idea/IdeaGen/zun123463
When you use the --idea-project-dir flag, you don't get a separate directory to hold the .iml files:
./pants goal idea ... --idea-project-name=zun123463 --idea-project-dir=squarepants/idea
Generated IntelliJ project in /Users/zundel/squarepants/idea/
I'm not sure what is the best course of action. On the one hand, the current behavior gives the user exactly what they ask for so maybe we should leave --idea-project-dir alone. On the other hand, it doesn't act the same as if you don't specify the flag and sets you up for failure. I'm going to propose a patch that tacks on --idea-project-name onto the end of --idea-project-dir.
"
is this the problem?
How do I fix it?
Please help
I had this problem last night and it was a pain. My solution was to delete the .idea folder, invalidate caches, and reimport the project. I thought the problem was related to the scala plugin, but I guess its not.
This problem can be solved by deleting logs, caches, indexes and temp files at the IntelliJIdea13/system folder
So I'm making a java application in Neatbeans 7.4, been working at it for a while, everything was fine, running the project worked fine, but now when I hit run project, I get the error
Error: Could not find or load main class phleveledit.MainWindow
Java Result: 1
BUILD SUCCESSFUL (total time: 0 seconds)
I can't think of what I did right before this started happening, so I don't know what I should change.. The code doesn't appear to have any errors. Here's a screenshot of the IDE+project folder
Image (http://puu.sh/5ldYB) :
Any ideas?
Edit: Unfortunately I happened to fix this problem by removing some code, which probably had some errors Netbeans couldn't detect, but I don't know what was exactly wrong so can't vote on a correct answer.
Right click on your Project in the project explorer
Click on properties
Click on Run
Make sure your Main Class is the one you want to be the entry point. (Make sure to use the fully qualified name i.e. mypackage.MyClass)
Click OK.
Clean an build your project
Run Project :)
If you just want to run the file, right click on the class from the package explorer, and click Run File, or (Alt + R, F), or (Shift + F6)
Just close the Netbeans. Go to C:\Users\YOUR_PC_NAME\AppData\Local\Netbeans and delete the Cache folder. The open the Netbeans again and run the project.
It works like magic for me.
(AppData folder might be hidden probably, if so, you need to make it appear in Folder Options).
You can :
RightClick on project node and go to Set configuration
Select the main class for your application.
Then clean and build.
Even if the above steps don't work for you then then delete the Netbeans cache by deleting the (index) folder
User\.netbeans\SOME_NUMBER_reflecting_your_version\var\cache\index\
Sometimes due to out of memory space error, NetBeans does not load or find main class.
If you have tried setting the properties and still it is not working then try
Select the project from the project explorer
Click on Run in the Menu Bar
Click on Compile
It worked for me.
This condition happens to me every 6-months or so. I think it happens when closing NetBeans under very low memory conditions. I discovered that it could be easily corrected by (1) Rename your project, including its folder name using right-click on project explorer's project name---I put a simple suffix on the original name ("_damaged"). (2) Try BUILD. If that is successful, which it is for me, give three cheers. (3) Repeat step (1) to restore the original project name. BUILD and RUN should start without trouble.
I guess that the 'rename the project and folder' process causes a special rediscovery of the applications main location.
Try to rename the package name and the class/jframe names... The clean and build the application.
Right Click on the package name
Go to Refactor
Select Rename
Give it a meaningful name, preferably all in small letters
Click on Refactor
Do the same for the class/jframe names.
Last Select Run from Menu
7.Select Clean and build main project
That should do it!!! All best
I had the same issue once. The problem was not in the code. The cause was... renaming the project folder to some other non supporting name. My project name was "MobStick" and I renamed it to "MobStick - May 26, 2014 04:00PM". Renaming it back to normal solved my problem.
I have run into this error a couple of times as well and for me the above solutions did not work. What does seem to work is going to the Project Properties, and under Compiling toggling Compile on Save.
Using NetBeans 8.1, I got the dread
Error: Could not find or load main class
from carelessly leaving an empty line in the Project Properties > Run > VM Options field. Until you click in the field, you may not see the caret flashing out of place. Remove the empty line to restore equanimity.
I just ran into this problem. I was running my source from the command line and kept getting the same error. It turns out that I needed to remove the package name from my source code and then the command line compiler was happy.
The solutions above didn't work for me so maybe this will work for someone else with a similar problem.
I had the same problem, I had the package and class named the same. I renamed the class, then clean and build. Then I set the main class in the "run" under the properties of the project. I works now.
I found the following steps useful:
Right-click on the project in the left toolbar.
Hover over the 'Set Configuration' item.
Click on 'Customize...'
Click on 'Browse...' by the 'Main Class:' item.
Select the correct class.
Click 'Select Main Class'.
Click 'OK'.
My problem was that, apparently, my package name was being listed twice. Selecting the class using the dialog changed 'aclass.MainClass' to just 'MainClass'.
Hope this helps,
-HewwoCraziness
Edit: This is expanding on Mary Martinez's answer.
You can solve it in these steps
Right-click on the project in the left toolbar.
Click on properties.
Click on Run
Click the browse button on the right side.(select your main class)
Click ok
Possible Fixes:
Fix 1
Go to project properties (right click on the folder of your project in netbeans)
On left tab where it shows the categories, click on the "Run" selection
Then click on Browse to find the Main class you use on your project
Fix 2
Go to C:\Users\name\AppData\Local\Netbeans
delete the Cache folder.
Rebuild and Run
Fix 3
Download most recent version of Netbeans
Fix 4
Download most recent version of JDK and configure Netbeans to use that
I had the same problem for 3,4 days. On my PC my Jar file snapshot would give me this error while on my laptop it would work fine, I tried all the tricks shown above and on other forums like deleting cache, selecting main project file, etc, but somehow I was sure the reason it cannot find the main class when I would execute the JAR file was may be due to classpath issue in maven configuration, and I was right and I fixed it using following steps:
Right-click on the project, and go to the properties
Inside the properties go to Actions
On the right side in Actions select "Run Project" and you will see properties below
Inside "Set Properties" make sure exec.args=classpath %classpath "package_name"
In my case, the package name was accompanied by the main class. So my main class was Login while the package name was com.mycompany.islamic_center_app1, When I checked the entry was
com.mycompany.islamic_center_app1.Login
All I did was remove ".Login" from com.mycompany.islamic_center_app1 and it was fixed, no more errors.
close netbeans.
open netbeans again.
choose new project>>java application.
click next.
deselect create main class.
now make the application
clean build run
For more reference watch this video
try this it work out for me perfectly
go to project and right click on your java file at the right corner,
go to properties,
go to run,
go to browse, and then
select Main class.
now you can run your program again.
I had the same problem and I moved the project to a location where the path had no none-english letter and that fixed the problem
if you are on window os, then try to start NetBeans via administrative mode. right click on NetBeans icon and "Run as Administrative".
If none of the above works (Setting Main class, Clean and Build, deleting the cache) and you have a Maven project, try:
mvn clean install
on the command line.
Had the same problem here. Usually Clean and Build solves much of the problem. It happened to be caused by a wrongly installed plugin.
I faced the similar issue with Netbeans 10 and JDK 1.8.
I was not able to choose the right class to launch the project
When I compile or run the project, it shows me the Class name as "initializing view, please wait ...", I could not select the class name.
The issue was resolved with the NetBeans11.3, I am able to choose the correct Class file without any other changes, and the project is launched without any issues.
I had the same issue but none of this thread's solutions worked for me. Finally, it was OneDrive that caused the issue (for once more). So, I simply moved the NetBeansProjects folder from Documents which is synced with OneDrive, to C:\Users\yourName\AppData\Local\NetBeans (selected this path as there is already a NetBeans folder) and that was it, case closed.
If you also have NetBeansProjects to a OneDrive syncing folder it is worth trying this solution, just be sure that the path you will select is not synced with OneDrive. Also, remember to close Netbeans before making the folder change and after you move the folder to the new path you need just to open Netbeans again, go to file menu/open project and select your project from the new path.
My Eclipse (Indigo) was running just fine. I created a simple class Hello. It is placed in package cont in the folder ch13. However, when I try to run it from Eclipse I get info from Java Virtual Machine Launcher:
Could not find the main class: cont.Hello.
I tried to run other classes from this package and they run just fine (that is the classes that existed there before). However any new class I create in this package has these problems. Actually any new class I create in Eclipse runs into this problems. I decided to check how it works from the command line. It seems that the problem still exist - I get same error. I checked the path and it is C:\Program Files\Java\jdk1.7.0_02\bin, which is correct (note the other classes are running from Eclipse just fine). I tried to run with java -cp . Hello and there are some Errors produced starting with java.lang.NoClassDefFoundError: Hello (wrong name: cont/Hello). Code itself is simple:
package cont;
public class Hello {
public static void main(String[] args){
System.out.println("Hello");
}
}
How can I fix it so that my classes still run under Eclipse?
.metadata is corrupted.
Steps:
Warning: Deleting .metadata will delete all your Eclipse configurations, plugins, project setups. Make a backup before you attempt this!
Stop eclipse, delete .metadata in workspace and restart eclipse
Import Project
Run again
Removing the Run Configuration
Sometimes I have a similar problems in some pre-release versions of eclipse. For fix the error, I delete the Run Configuration. You can find that in menu Run, Run Configurations...
Then I launch the app with Alt+Shift+X, then J. If this don't work, Ctrl+F11.
Deleting the .metadata directory
In another way, the configuration settings for your current workspace may are corrupted. Those settings are in the .metadata directory in your current workspace 1. In that case, there is no other choice than delete the directory:
Close eclipse.
Delete the .metadata directory.
Start eclipse.
Import the projects.
Run the project again.
Notes
You will see that directory with File > Switch Workspace > Other...
I have solved the issue following way:
Go to Run Configuration (Right Click on Java File->Run->Run Configuration).
Go to ClassPath Tab:
Click on Advanced -> Add Folders -> Add bin directory (which has class file in it for Java source code)
Re run the code, now it will solve the issue. It worked for me
Note: This worked in the past and I received many up votes. Perhaps this is not a solution anymore - but it once was - as the eclipse version was indicated.
Problem
This can also be caused by a Java Build Path Problem.
In my case, I had a an error:
A cycle was detected in the build path of project {project}. The cycle consists of projects {x, y, z}.
This can occur when you include other projects in the build path of the project you wish to run. In fact, all the projects will fail to run with the error
Could not find the main class: Example.class
Solution
Open
Windows -> Preferences -> Java-> Compiler -> Building -> Build Path Problems
Uncheck the Abort build when build path errors occur toggle
This seems like a can of worms if you end up with other build path errors I image. So use with caution.
Note: This only works if you have a "cycle error". This error message can be found in the "Markers" tab
I found the solution to this here
Info
Java 1.8.0_152
Eclipse Photon (June 2018)
Renaming the main class should be enough (and easiest):
- Go to your class and set cursor to your class name;
- ALT + Shift + R and rename the class (build if not done automatically);
- You should be able to run it now;
- Rename the class to the old name if you want;
You must have main function in your class. Like
public class MyDataBase {
public static void main(String args[]) {
}
}
I had this same problem in a Maven project. After creating the src/test/java folder within the project the error went away.
Another tip: I initialized static fields in a wrong order - surprisingly it didn't bring up a Problem (NullPointerException?), instead Eclipse complained with exactly the message OP posted. Correcting the static initialization order made the class run-able. Example:
private static ScriptEngineManager factory = null;
private static ScriptEngine engine = null;
static {
engine = factory.getEngineByName("JavaScript");
// factory is supposed to initialize FIRST
factory = new ScriptEngineManager();
}
I found the way to fix this problem was to rename the project. If you give it a name with strange characters (in my case, :), it will have trouble locating your class. I don't know if this rule applies to numbers, but try renaming the project or making a new one and copying the files. Name it without any numbers or special characters.
I solved this error by closing the project, removing it from eclipse and then importing it again.
Might be a little simpler than to redo the whole workspace setup.
I had this issue after upgrading to the Eclipse 2019-12 release. Somehow the command line to launch the JVM got too long and I had to enable the jar-classpath option in the run configuration (right click on file -> run as -> run configs).
I read so many blogs and tried so many tricks but my problem not resolved. I was able to run the code but not able to generate the jar file. :( Sad..
But I tried something which might be very silly but worked for me and bought eclipse on trace. What I did was..
Just deleted the main method from the class. Saved it. Did undo to bring the main class back. Tada... Issue resolved...
Just one think would like to say, keep your eclipse in "Build Autometically" mode.
Move your file into a subdirectory called cont
Standard troubleshooting steps for Eclipse should include deleting and re-importing the project at some point, which when I have dealt with this error has worked.
I solved my issue by doing this:
cut the entire main (CTRL X) out of the class (just for a few seconds),
save the class file (CTRL S)
paste the main back exactly at the same place (CTRL V)
Strangely it started working again after that.
It is possible to have 2 groovy-xxx-all.jar files by excample in lib directory. which makes that an app is not running
I had the same problem, this is my solution:
I manually deleted the bin folder of the project
Then I refreshed the project which recompiled the whole project and created a new bin with all .class files
I did it because when I performed Clean(project->clean) my .class files were not getting deleted. the above solution works for me hope its useful to others.
I had the same problem.I solved with following command maven:
mvn eclipse:eclipse -Dwtpversion=2.0
PS: My project is WTP plugin
If you are using a pre-defined run configuration, go to classpath and try "Restore Default Entries". This will reconfigure the classpath for that configuration.
This worked for me finally :
RUN -> RUN CONFIGURATIONS -> DELETE THE RUN CONFIGURATION
CLOSE ECLIPSE
REOPEN ECLIPSE
CREATE RUN CONFIGURATION AGAIN.
Tadaaaa !! It works
I keep getting this when trying to start a new project
ERROR: Unable to open class file C:\Users\Levi\Desktop\Android\workspace\Droid1\gen\com\androidbook\droid1\R.java: No such file or directory
I tried changing preferences to alter build path to project, but it still wouldnt work,,,
Is subfolder on desktop a bad place to install Eclipse?
Clean works sometimes and should be tried. I also find that blowing away the gen directory and refreshing will cause it be to rebuilt. Try that as well.
However, sometimes even that doesn't work and I've been forced to remove the project from Eclipse and then re-import it. This, unfortunately, works for me every time if the above has not.
Good luck.
Im also getting that error, running a Project->Clean in Eclipse helps for me.
Project->Clean should certainly fix this (unless your resources won't compile for some seperate reason).
I remember that the first time I ran Eclipse (in mid 2009, can't remember if it was Galileo or Ganymede or whatever) on Windows Vista, it presented several problems that were eventually traced to Eclipse itself being in a directory whose path contained a space...
Usually, the above tips (refresh, clean) work for me. But lately I had a very persistant instance of this error, which was caused by something else:
One of the layout .xml files in res/layout contained a reference to a custom view (org.company.project1.MyView). However, I had changed the package path (org.company.project2.MyView), so the reference had become invalid.
Thus, if everything fails try browsing your layout .xml files for invalid custom element definitions.
Cheers
after spending hours trying to ultimatly discover the issue behind the Class Issue not being found, resolved,or directory not there issue....
sometimes yes the issue is due to a bad binary or xml... as sometime a clean will do the trick or a xml edit will solve the day.. when all else fails.... this may do it..
"create a new workspace"
go into the workspace.... and then
Switch to your old workspace... in the newly formed workspace...
this was my silver bullet. so frustrating to not have a solid answer.
using Version: Helios Service Release 2
Build id: 20110218-0911
I've downloaded, unzipped and setup Eclipse 3.4.2 with some plugins (noteable, EPIC, Clearcase, QuantumDB, MisterQ).
Now I find when I'm editing Java projects the code completion is not working. If I type String. and press ctrl+space a popup shows "No Default Proposals" and the status bar at the bottom shows "No completions available".
Any ideas?
Try restoring the default options in 'Windows > Preferences > Java > Editor > Content Assist > Advanced'
An example of the kind of data you see in this preference screen, however not necessarily what you currently have.
(From Vadim in this blog post " Content Assist Duplicates in Eclipse (Mylyn)":
if have duplicate Mylyn entries, uncheck the duplicate entries that do not contain "(Mylyn)" in their name)
The Eclipse help page defines the default list to restore:
Select the proposal kinds contained in the 'default' content assist list:
Other Java Proposals,
SWT Template Proposals,
Template Proposals,
Type Proposals
I'm adding an answer here in case someone else finds this on Google. Same symptoms; different problem. For me, the type caches had become corrupt.
From http://mschrag.blogspot.co.nz/2009/01/open-type-cant-find-your-class.html
Quit Eclipse
Go to workspace/.metadata/.plugins/org.eclipse.jdt.core
Remove *.index and savedIndexNames.txt
Restart Eclipse and search Ctrl+T for the offending type. The indexes will be rebuilt.
In case someone comes here and want to activate the autocomplete function, go to
Preferences -> Java -> Editor -> Content Assist.
Then in the Auto Activation section fill in Auto activation triggers for Java:
abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ._
For those running Xfce + having IBus plugin activated, there might be keyboard shortcut conflict.
See more info on my blog: http://peter-butkovic.blogspot.de/2013/05/keyboard-shortcut-ctrlspace-caught-in.html
UPDATE:
as suggested by #nhahtdh's comment, adding the some more info to answer directly: IBus plugin in Xfce uses by default Ctrl+Space shortcut for keyboard layout switching. To change it, go to: Options and change it to whatever else you prefer.
Check the lib of your project. It may be that you have include two such jar files in which same class is available or say one class in code can be refrenced in two jar files. In such case also eclipse stops assisting code as it is totally confused.
Better way to check this is go to the file where assist is not working and comment all imports there, than add imports one by one and check at each import if code-assist is working or not.You can easily find the class with duplicate refrences.
Another solution which worked for me is to go to Java--> Appearence --> Type Filters and do disable all
None of these worked for me.
I was experiencing this issue in only once particular class. What finally worked for me was to delete the offending class and recreate it. Problem solved... mystery not so much!
If you have installed Google Toolbar for IE, may be you can face the same problem. Because, the toolbar capture the shortcut ctrl+Space.
I had this problem and like #Marc, only on a particular class. I discovered that I needed to designate Open With = Java Editor. As a Eclipse newbie I hadn't even realized that I was just using a plain text editor.
In the package explorer, right-click the file and chose "Open With".
I faced this problem, and spent hours trying to figure out the issue. tried to follow the steps mentioned in the different answers above, the solution I found is on the same lines as Mona suggested, but slightly different. Tried to add as a comment to Mona's answer but no option was available.
Issue with my eclipse was, classpath somehow got corrupted and all the jars and dependent projects were missing. after taking the latest .classpath from repository it worked fine.
Check that you did not filter out many options inside the Window > Preferences > Java > Appearance > Type Filters
Items in this list will not be appear in quick fix, be autocompleted, or appear in other various places like the Open Type dialog.
I also face this issue but it is resolved in different way.
Steps that I follow may be helpful for others.
Right click on project (the one you are working on)
Go to Properties > Java Build Path > JRE System Library
Click Edit... on the right
Choose the JRE 7
Once you have you configuration checked and completion is still not working:
make sure you have the right directory structure.
Do you see the right icon beside the file?:
It will tell you how the file will be treated by Eclipse:
I am posting this answer as I had that story with with Maven webapp artifact. By default Maven-WebApp does not create folder for sources and I put my Java into resources, wondering for 5 minutes what was going on... :)
Running STS on Java Spring Boot projects, here's what works for me :
Maybe this helps other people who come across the same issue.
My setup: old Gradle project (version Gradle 2.12) made by someone else, imported using the Gradle Import Wizard into STS (Eclipse Oxygen.2 (4.7.2)).
Code completion did not work either (and I still have hollow Js at the Java files), but at least I got the code completion to work by doing:
right click on the project folder > Properties > Gradle > Configure Workspace Settings > Java > Editor > Content Assist > Advanced
check "Java Proposals in upper window.
2x Apply & Close
I have run into this problem since upgrading to Eclipse 2019-09. Based on some of the suggestions above, this is what worked for me.
I had to go to Eclipse -> Preferences -> Java -> Editor -> Content Assist -> Advanced.
I found out that if I turn on any of the key binding proposals, Java Non-Type, Java, Java (Task-Focused) or Java Type proposal, then I was able to use auto complete. If I turned them all on, then not only did auto complete work, but I got duplicate methods listed. I am guessing, but I will probably used Java Type Proposals. Any clarification of what differs for these four types would be appreciated.
In my case, Intellisense had only disappeared in a few classes in one project. It turned out this was because of a missing library on the build path (although it worked previously).
So definitely check all the errors or problems in Eclipse and try to find if a library may be missing
For those who use the latest 3-19 eclipse build:
It just happened to me when upgrading from Oxygen to 3-19 eclipse version, so I assume the auto-complete feature does not migrated correctly during the upgrade process.
The only solution that worked for me was to create a new eclipse workspace, and import the project/s to it. It might take a few minutes, but it worth it - comparing to the time spent on other solutions...
I ran into this and it ended up being I was opening the file with the text editor and not the java editor.
For me the issue was a conflict between several versions of the same library. The Eclipse assist was using an older version than maven.
I had to go to the .m2 directory and delete the unwanted lib version + restart eclipse.
I experience problems on Eclipse Neon when editing a file which does not belong to the project directory. When I copy the same file to the project root directory, not even to the src directory, the completion starts working.
When the file is opened from a different directory, only completion for JRE works. That is for example: java. completes, but junit. does not.
Just in case anyone got to a desperate point where nothing works... It happened to us that the content assist somehow shrunk so no suggestion was shown, just the "Press Ctrl+Space for non-Java..." could be seen.
So, it was just a matter of dragging the corner of the content assist to enlarge the pop-up.
I know, embarrassing. Hope it helps.
Note: this was an Ubuntu server with Xfce4 using Eclipse Oxygen.
If you're experiencing this in an enum, or when initializing an array with anonymous classes, it's a known bug in Eclipse. See Eclipse content assist not working in enum constant parameter list.
We can change the settings as per our requirement.
Suppose we want to make java proposal as highest priority we need to do changes as shown below.
Windows > Preferences > Java > Editor > Content Assist > Advanced
Choose Java proposal and click on up button
For me in Sep 2021 it was an odd Eclipse bug. I had a multi-line string inside an annotation in my Class. This caused just that particular class to fail when trying to code complete (even though the class compiled just fine).