I've encountered a problem where on all of my applications, there's a red cross on the top right. I can run it, but the cross doesn't seem to go away.
I've opened the run/debug configurations and it says Warning : Main method not found. I don't understand why it's not found when I already have a corresponding main class and method for each and every application.
I tried to close the project, restarting IntelliJ, restarting my laptop, refreshing my desktop, refresh Gradle by clicking Reimport All Gradle Projects, rebuild the project and clicking Invalidate Caches / Restart. I also tried other suggestions I found on StackOverflow such as deleting the .idea folder. Nothing. The red cross still shows up. I've also realized that I do not have the out folder in all of my Applications.
I just set the language level to equal my SDK version at Project Structure. Finally, it is disappeared.
In Project Settings, First make sure SDK path is correct. Preferably install and use your own SDK. Then use the same SDK in Project and Modules in Project Settings.
File->Project structure ->SDKs
Choose JDK home path, if no jdk is in the path,
you'll see an icon download jdk
download then ok
Try to copy src and gradle folders and buil.gradle and settings,gradle files in separate folder. Then open this new folder as new project in intellij. Then intellij will propose Import as gradle project... - push it.
If problem remained see you build.gradle
I have a Gradle project which opened just fine on earlier Intellij IDEA version. But with the latest IDEA build(#IU-183.4284.148) strange things happen. Before I start describing my problem I need to say than I have both JDK 8 and 11 installed.
I do the following:
I open up my existing project by clicking on build.gradle file:
Then I open as project:
I leave default settings here
I choose Delete existing project and import:
When the project deploys I see this tip, I haven't seen it before.
If i ignore this dialog and do not restore I see the following issues with my build.gradle file. I highlight the first one.
Moreover, the code in classes does not compile, it asks to setup JDK, but when I choose 1.8 nothing happens. It still asks to setup JDK
And on the other hand if i open the dialog and select the module nothing happens again, my build.gradle file still complains
Reimporting gradle does not help.
Please help
The problem was that not all Java 1.8 jars were included to classpath, that is why Setup JDK command was ignored.
Afted I added remaining jars all build.gradle issues gone away and now the code compiles.
I just installed Eclipse Oxygen and tried to open an existing project into the workbench but I get this error:
The project was not built since its build path is incomplete. Cannot
find the class file for java.lang.Object. Fix the build path then try
building this project
I tried right clicking on the project - went to Properties - Java Build Path - Libraries - Add Library - JRE System Library and selected Workbench default JRE (jre1.8.0_60).
I then cleaned and rebuilt the project but it then causes more errors to come up like:
ActionBar cannot be resolved to a type
Activity cannot be resolved to a variable
AdapterView cannot be resolved to a type
ArrayAdapter cannot be resolved to a type
Here is what made the error disappear for me:
Close eclipse, open up a terminal window and run:
$ mvn clean eclipse:clean eclipse:eclipse
Are you using Maven? If so,
Right-click on the project, Build Path and go to Configure Build Path
Click the libraries tab. If Maven dependencies are not in the list, you need to add it.
Close the dialog.
To add it:
Right-click on the project, Maven → Disable Maven Nature
Right-click on the project, Configure → Convert to Maven Project.
And then clean
Edit 1:
If that doesn't resolve the issue try right-clicking on your project and select properties. Select Java Build Path → Library tab. Look for a JVM. If it's not there, click to add Library and add the default JVM. If VM is there, click edit and select the default JVM. Hopefully, that works.
Edit 2:
You can also try going into the folder where you have all your projects and delete the .metadata for eclipse (be aware that you'll have to re-import all the projects afterwards! Also all the environment settings you've set would also have to be redone). After it was deleted just import the project again, and hopefully, it works.
In Eclipse, Right click Project -> Maven -> Update Project. It fixed errors in my project.
I'm also using Eclipse Oxygen, migrated from Mars. I faced the same error. I deleted .metadata, .recommenders folders and added projects from archive and issue is solved. I also use Android Studio but i like Eclipse much more.
At my system the Java Runtime JAR file jrt-fs.jar was not found because it was in the wrong directory. This file should be located in the "lib" subfolder. If you installed Java at "C:\Temp\java" the file should be here at C:\Temp\java\lib\jrt-fs.jar .
These are the steps to make jrt-fs.jar available to Eclipse:
Window / Preferences -> the "Preferences" Window opens
Select in the left menu: Java / Installed JREs
Press the [Add...] Button -> A window opens
Select "Standard VM" - The window "JRE Definition" opens.
Enter your path information:
JRE home = "C:\Temp\java"
JRE name = "MyJRE"
Select [Add External JARs...] to link the jrt-fs.jar
JRE system libaries: "C:\Temp\java\lib\jrt-fs.jar"
It worked for me with OpenJDK12 and Eclipse 2019-09 (4.13.0).
Eclipse reported me this error:
The project was not built since its build path is incomplete. Cannot find the class file for java.lang.Object. Fix the build path then try building this project
I had faced this problem. I added the C:\Users\Office 2\android-sdks\platforms\android-19\android.jar to the Java Build Path's Library. And the project started to run again.
The problem occurred due to my carelessness. Yesterday night I was updating the Android SDK, and at the same time I tried to run the project, while the SDK Manager was uncompressing the system image. The Project couldn't start and the error occurred.
I tried all the methods given by others. But nothing worked. It solved when I added the android.jar to the library.
I guessed it that android library is missing. not the Java, when I saw the errors only at the android methods and imports. But when I read the posts, I got confused and wasted some time trying wrong way.
I had faced the same issue and tried different solutions, I have reinstalled my JDK 11 and restarted the machine, after that the issue gets resolved.
I got this out of the blue in a workspace that was working properly before. This problem seems to indicate that the project configuration somehow got corrupted.
Restarting Eclipse didn't help, but in the same vein as the answers dealing with Maven, regenerating the Eclipse project config with:
./gradle eclipse
or
./gradlew eclipse
if you use the wrapper, solved this problem for me.
I have similar issue when importing Spring Boot, jdk 11 (using
inside docker) project to Eclipse 2019 (2021), in Ubuntu, instead when
importing to Inteelij IDEA Community or NetBeans IDEs they do
not produce the same set of after-import errors as in Eclipse.
The Spring Boot is multimodule maven projects and two child
modules give such 2 "problems" in appropriate problems tab:
The project was not built since its build path is incomplete.
Cannot find the class file for java.lang.Object. Fix the build
path then try building this project
Next 2 errors are produced in two classes of aforementioned
maven modules:
The type java.lang.Object cannot be resolved. It is
indirectly referenced from required .class files
Manipulation with adding JDK 11 to submodules buildpath
just leads to the thousands of problems. Also it is
got when I use Eclipse-File-Maven-Update.
Moreover when I try to edit most of existing classes or add new ones
I got red underline that tells
Implicit super constructor Object() is undefined for default
constructor. Must define an explicit constructor
. So almost no opportunity to use Eclipse
even at prebuild stage as docker-compose should run build and
run. Indeed I noted that such issue is produced just when project
also uses modules (module-info files introduced in java9).
When I import project on jdk 8 (even not installed on
system), or even on jdk11 without module-info files all
is fine in Eclipse after import.
Another difference is that of when I use problem old no module
project the Build Path is composed with jre environment 8 and
maven dependency items, but when using
"module-info" project the Build path contains -module path,
and -classpath. So I even do not know where to add jre 11,
indeed adding does not resolve issue, just make more errors.
So what is the resolution of the case??? What settings to do
in Eclipse?
This is my current configuration:
Eclipse IDE for Java Developers
Luna Service Release 2 (4.4.2)
Java Version 8 Update 45 Build 1.8.0_45-b15
After a time without using some Java Project folders, now Eclipse throws a lot of syntaxis errors over them:
The import javafx cannot be resolved
*** cannot be resolved to a type
The method join(String, List<String>) is undefined for the type String
The project folder never change from their location, they were error and warning free prior to left them abandoned.
I am not sure about a missing .metadata or .reccomenders or a Java version change -over no more than two months- for these projects.
What should i do to solve that?
Try cleaning your project by going to the following menu item:
Project > Clean...
If that doesn't work:
Try removing the jars from the build path and adding them again.
Double-check the jars being really on the build path (with no errors).
Make sure there is nothing in the "Problems" view.
So I have a maven module (module-A) in IntelliJ. I recently moved some classes from it into another new maven module (module-B) and added a dependency to it. Once I had done this I also modified the signature of a method of one of the moved classes (now in module-B).
I re-imported the poms so that IntelliJ would pick up the dependency changes and ensured all Java imports for the affected files were correct again. Now when I attempt to run my webapp (which depends on the two modules) I get a compile error in a class in module-A calling the modified method of the class in module-B.
The error message is basically saying that that method doesn't exist but believes the old method still exists! I click on the 'make' error and it takes me to the line in a class in module-A calling the modified method...the weird thing is, IntelliJ knows it is fine in the file. i.e. The method is not underlined in red like a compile error would normally be, but the class file name is :(
I compiled it from the command line using 'mvn install' (having also installed module-B) and it is all successful. I have deleted the classes directory in the target of both module-A and module-B and also invalidated IntelliJ's caches and restarted...still happening...any ideas?
I found out that this might help:
File -> Invalidate Caches
Maven Projects -> Reimport should help.
I spent a few hours on this same issue. All of the cleans in the world didn't help.
I deleted my out and target directory in my project and recompiled - that cleared it.
Edit: There is also a magic feature under the file menu: "Invalidate Caches / Restart" This fixes a bunch of "intellij is confused" problems.
Change "Java Compiler" setting in IDEA (User compiler javac in-process) to fix the problem.
Try to mvn clean your projects and mvn install your project B.
The maven integration with intelliJ is kind of buggy when you use the make command directly provided by Intellij. You should directly use the mvn commands, or start them from the maven panel.
I ran across a very similar problem that was driving me insane.
My code would compile fine with the ant task I normally run, but it would not build in IntelliJ, complaining about "Cannot Find Symbol blah blah"
Turns out, you can add "Excluded" files for the compiler. My file somehow got added to that list.
This list is located in File > Settings > Compiler > Excludes (IntelliJ 13)
Following steps should fix this problem :
delete .IntelliJIdea12 / .IdeaIC12 older under c:/user/.../
Invalidate Intelli's cache: File > Invalidate Caches.
This re-indexes your workspace on start-up and also clears your local history. Before you do this, commit or back up all your uncommitted changes.
Once your workspace is back after indexing, do a maven clean install.
when the build is successful, click on Maven Re-imports
This worked for me, I think it should work for others too with a similar problem.
So just stated it up this morning and it's all working!
Last night what I did do was open a new project (intelliJ project) from module-A's and module-B's parent pom and successfully got it to build, possibly doing that and then opening my original project again fixed it somehow...very annoying though
The behavior I see is similar to the one described by the original author.
Error markers show up on the right side of the editor in Intellij 14 and less so in 13.
This happens also if using Scala instead of Java and using SBT instead of Maven.
Also noticed this occurs after the second project is loaded. The first is always fine.
(After much trial and error) Figured it might be caused by Intellij's internal caches becoming somehow corrupt. "Invalidate caches" worked sometime and sometimes did not.
I work with a number of projects using Play! Framework and they use different versions of Scala and lots of dependencies.
I hypothesized the caches become corrupt because the internal key Intellij uses is not good enough to handle situations when the same class, loaded multiple times in different jars, has different signatures, and this results in the editor errors while external builds work fine.
Then the "Changing Ivy Cache Location for sbt projects in IntelliJ IDEA?" post gave the idea to segregate the ivy cache SBT and Intellij use in the hope that the ivy path is part of the internal cache key.
Paul Phillips of TypeSafe provide the "SBT extras" tooling and here I found a way to instruct SBT to use a project based ivy home, cache and SBT boot:
https: //raw.githubusercontent.com/paulp/sbt-extras/master/sbt
declare -r noshare_opts="-Dsbt.global.base=project/.sbtboot -Dsbt.boot.directory=project/.boot -Dsbt.ivy.home=project/.ivy"
How to configure Intellij
: see http://content.screencast.com/users/SemanticBeeng/folders/Snagit/media/ec8ec491-6d0c-4691-9598-916a63ba65ef/12.02.2014-08.59.png
Then did the same for the external SBT build to work in sync
: see http://content.screencast.com/users/SemanticBeeng/folders/Snagit/media/dcb287c4-200f-47f3-a937-42865675a22b/12.02.2014-09.01.png
Finally got rid of the user home based .ivy2 and all the contents.
To be sure Intellij does not use this folder I made it readonly.
This was a mistake. Intellij seems to silently fail resolve dependencies if you do this.
This solved the errors and believe they will not come back. :-)
If Intellij guys hear this: please test your releases (Scala, SBT, editor) with all the Play Framework templates from TypeSafe. The problem becomes apparent quickly this way.
I just had a similar issue that was driving me insane. I had done all the other things mentioned in the answers above because I have used Intellij forever, but none worked. In the end I found out that in the maven projects portion of Intellij, one of my modules had been marked "ignore" a simple unignore command from the context menu did the trick.
In my case, I had manually marked a directory as "Test Sources Root" but IDEA marked it on a parent Maven project. Unmarking it in File->Project structure...->Modules fixed the problem.
This could happen if you are using different version of java while building outside IntelljJ. My IntelliJ had java10 and I was using java8 while building at terminal. Changing java version to IntelliJ fixed this issue for me.
I had a very similar behavior. Running (Scala-)tests would always fail due to errors in unrelated java classes during the 'make' step.
It turned out, I had included a 'global' SDK library that collided with one of the dependencies from the project. A proper helpful error message only showed up after I deleted the 'make' step from the test.
I then deleted the duplicate library, re-added the make step to the test and everything is now working fine.
I ran into this problem today after upgrading from 12 to 13.
Later I fixed issue as I used the same name for Project and Module and looks Intellij allows this but cannot handle it correctly.
No idea why setting will impact the compilation, although there is no error in java editor. Should be a bug in version 13.
I was facing a similar issue after upgrading from IntelliJ 12 to 13. After multiple uninstalls and re-installs (of multiple intelliJ versions), numerous cleans and .m2 repository clearing, I finally figured out what my issue was.
In my intelliJ settings, the repositories mentioned in my main POM file could not be connected to. this was in turn due and alternate repository that was mentioned as a part of my pom file.
Once the POM was made to point to the correct repository, all my classes had their compilation issues resolved.
To check if your repositories are being connected to, go to File -> Settings -> Maven -> Repositories
Here, your indexed maven repositories should be connected to successfully. If they are not, then intelliJ will not be able to resolve most 3rd party and module dependencies.
I'm embarrassed to say, but we also had this problem, but it was due to a mistake in our package name.
When creating the packages for a new project I accidentally created a package called "org.package".
My project then had a directory structure like:
/src/main/java/org.package/
Which caused all sorts of havoc with IntilliJ.
Once the correct folder structure was created on the file system, IntelliJ worked great.
/src/main/java/org/package/
Note the difference in /org.package/ vs /org/package/
The fix was i made it javac instead of Ajc and i put 1.8 of course according to your jdk version.
for some reason when i invalidate and restart intellij it was set to be the default !
my version is
This happened to me...what fixed it was realising there was an extra main.iml file in the source directory. Deleting that instantly made the compile errors go away.
None of the above answers worked for me.
In my case, I had to finally create an explicit Maven Run Configuration for the module (with Command Line as "clean install") and then run it.
It is in Run > Edit Configurations
close the project
go-to the project folder and delete idea project file and .iws file
run mvn idea:idea
restart the project.
seems idea keeping the old project dependencies without cleaning even though we run file -> invalidate caches
Setting the proper Java SDK solves the issue
Right click on the project and select "Open Module Settings"
Check if you have the right Java SDK under platform settings
Check the SDK under Modules
Rebuild the project from "Build" menu
Delete the installation directory.
Remove the following directories:
~/.config/JetBrains/
~/.cache/JetBrains/
~/.local/share/JetBrains/
This will remove each and every configuration plus installation of jetbrains tools, be it IDEA, goland,etc.
Now install everything from scratch.
That's the only way it worked for me