I'm trying to use Lombok in my project that I'm developing using IntelliJ IDEA 11.
I've installed 3rd-party plugin for IDEA and it seems working fine because IDEA sees all autogenerated methods/fields.
So I have a class that uses Slf4j. I annotated it like this
import lombok.extern.slf4j.Slf4j;
#Slf4j
public class TestClass
{
public TestClass()
{
log.info("Hello!");
}
}
But when I build my project compiler spits: cannot find symbol variable log.
Could you please tell me what I'm missing here?
Update: It turned out it's RequestFactory annotation process that fails.
input files: {com.zasutki.courierApp.server.TestServlet, com.mine.courierApp.server.model.DatastoreObject}
annotations: [javax.inject.Singleton, javax.inject.Inject, lombok.Getter, lombok.Setter, com.googlecode.objectify.annotation.Id, com.googlecode.objectify.annotation.OnSave]
Processor com.google.web.bindery.requestfactory.apt.RfValidator matches [lombok.Getter, com.googlecode.objectify.annotation.Id, javax.inject.Inject, lombok.Setter, com.googlecode.objectify.annotation.OnSave, javax.inject.Singleton] and returns false.
cannot find symbol variable log
Any ideas on workarounds?
Update2: Perhaps it's not something readers want to hear but I ended up switching to Scala.
I have fixed it in IDEA 12 by setting check box Enable annotation processing in:
Settings -> Compiler -> Annotation Processors
For IDEA 2016.2:
Preferences... > Build, Execution, Deployment > Compiler > Annotation Processors
After enabling, run Build -> Rebuild Project to have annotations recognized and eliminate errors.
For IDEA 2019.2.1, depending on how the project is configured, installing the Project Lombok plugin may not be sufficient. Here is another way to use Project Lombok with IntelliJ IDEA:
Visit https://projectlombok.org/download
Download the JAR file into the project lib directory (e.g., $HOME/dev/java/project/libs).
Start the IDE.
Click File 🠖 Settings.
Expand Build, Execution, Deployment 🠖 Compiler 🠖 Annotation Processors.
Ensure Enable annotation processing is checked.
Ensure Store generates sources relative to is selected based on the project's module settings (if Module output directory doesn't work, come back and try the other setting).
Click Apply.
Click Plugins.
Click Marketplace.
Set search field to: lombok
Install Lombok.
Click OK.
Restart the IDE if prompted.
Click File 🠖 Project Structure.
Select Libraries.
Click the + symbol to add a new project library (or press Alt+Insert).
Select Java.
Set the path to: $HOME/dev/java/project/libs/lombok.jar
Click OK.
Select the modules to apply.
Click OK.
Optionally, rename lombok to Project Lombok 1.18.8.
Click OK.
The project can now import from the lombok package and use Project Lombok annotations (e.g., lombok.Setter and lombok.Getter).
Picture representation of resolving this issue.
First enable annotation processors and try. This may or may not work.
Post that, you can install the lombok plugin from intellij, (After installation Intellij will restart to enable the plugin, so make sure you save your work.(Intellij does save all the changes before restart, just to be on the safe side.)) screenshot below:
Enabling annotation processing will make it work
But if you are on a Mac, make sure you enable annotation processing(tick the checkbox) from both the places available.
1.) Intellij Idea -> Preferences -> Compiler -> Annotation Processors
2.) File -> Other Settings -> Default Settings -> Compiler -> Annotation Processors
Make sure it's added correctly to your project.
example for Gradle:
dependencies {
compileOnly 'org.projectlombok:lombok:1.18.8'
annotationProcessor 'org.projectlombok:lombok:1.18.8'
...
}
Install Lombok plugin for your IDE
Check "Enable annotation processing" checkbox in IDE (IntellijIdea), have no idea if there is anything like this for other IDEs like Eclipse.
in the latest Gradle version you should use annotationProcessor:
compileOnly 'org.projectlombok:lombok'
annotationProcessor 'org.projectlombok:lombok:1.18.8'
I'm using IntelliJ IDEA 2020.3 (Community Edition)
Here, besides install the Lombok plugin and enable annotations (explained by other answers). I also needed to set the flag -Djps.track.ap.dependencies=false to the Build Process Option¹.
I didn't need to use the -javaagent approach, neither setup the classpath.
¹. Go to: File | Settings | Build, Execution, Deployment | Compiler | "Shared build process VM options" field
References:
https://github.com/rzwitserloot/lombok/issues/2592#issuecomment-705449860
https://youtrack.jetbrains.com/issue/IDEA-250718#focus=Comments-27-4418347.0-0
Just for reference using IntelliJ 2018.3, I solved this issue (using #Data annotation to insert getter/setter) following the three steps:
File -> Settings -> Build, Execution, Deployment -> Annotation Processors -> Enable Annotation Processing;
Do remember to Apply the change.
Install plugin lombok in the same setting dialog;
It seems good enough for now, it requires to restart IntelliJ and then rebuild your project.
Best wishes :)
If you have checked both these steps as follows
Enable annotations : this is a check done in IntelliJ
preferences.
Importing lombok into IntelliJ classPath
(Preferences -> Plugins)
and still getting errors then please check the compiler - if it is JAVAC or ECLIPSE.
You can check the compiler in Preferences -> Build,Execution,Deployment -> Compiler -> Java Compiler.
Change the Use compiler to Javac (if it is Eclipse). This is what worked for me.
Including the following in the pom.xml is what worked for me:
<build>
<defaultGoal>spring-boot:run</defaultGoal>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>${java.version}</source>
<target>${java.version}</target>
<annotationProcessorPaths>
...
<path>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>${lombok.version}</version>
</path>
</annotationProcessorPaths>
</configuration>
</plugin>
</build>
As noted here, quote: "You should activate external compiler option and enable annotation processors or disable external compiler and disable all of annotation compilers to work with lombok". This fixed my problem. Note that I added the Scala plugin prior to receiving this error, so I suspect the plugin changed some of the above settings.
there is a plugin for intellij. see here: https://projectlombok.org/download.html
Do you have lombok as dependency of your project? lombok.jar must be on the classpath during compiling of the project, which is using any of lombok-annotations.
For those of you who are still having trouble:
In addition to the above steps of enabling annotation processors and installing the IntelliJ Lombok plugin, I also had to Build -> Rebuild Project.
1、install lombok plugin for IDEA
Intellij Idea -> Preferences -> Plugins -> type in lombok -> Search in Repositories -> install -> restart IDEA
2、 config lombok plugin
Enabling annotation processing will make it work
But if you are on a Mac, make sure you enable annotation processing in the following two places:
Intellij Idea -> Preferences -> Build, Execution, Deployment -> Compiler -> Annotation Processors, check the checkbox of "Enable annotation processing".
File -> Other Settings -> Default Settings -> Build, Execution, Deployment -> Compiler -> Annotation Processors, check the checkbox of "Enable annotation processing".
I was on Mac
This is my IntelliJ IDEA and Mac Version - IntelliJ IDEA 2017.1.5 Build #IU-171.4694.70 --- Mac OS X 10.12
In addition to enabling annotation processing (tick the checkbox) at these 2 places.
1.) Intellij IDEA -> Preferences -> Compiler -> Annotation Processors
.
2.) File -> Other Settings -> Default Settings -> Compiler -> Annotation Processors
I had to install Lombok plugin too to make it work.
3.) Intellij IDEA -> Preferences -> Plugins ->Browse Repositories-> Search for "Lombok"-> install plugin -> Apply and restart IDEA
It didn#t work for me with any of the above solutions. I added <scope>provided</scope> to the dependency in pom.xml and it worked.
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.16.20</version>
<scope>provided</scope>
</dependency>
If you already installed it, then for refresh just deselect and select Enable annotation in Intellij Settings.
I have faced this problem after updating the IDEA to 2018.3. I had to update all the existing plugin
After trying all the suggestions here, I have also find another kind of solution. It seems that sometimes IDEA can not obtain processors from project classpath.
So, on the Annotation Processors settings tab, you have to manually specify Processor path.
Apart from mentioned in all answers I have to add the below code in pom.xml configuration to makes mvn clean install work. Before adding this code I was getting cannot found symbol for getters and setters.
<annotationProcessorPath>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.8</version>
</annotationProcessorPath>
For me what worked:
I uninstalled the installed the Lombok plugin freshly
I ticked "Enable Annotation Plugin"
I selected "Obtain processor from the project classpath" in the same page
For IntelliJ IDEA 2020.1.1 enabling Kotlin plugin fixed this issue.
If you did everything mentioned in this question and It's still failing, don't forget to remove /target folder under your projects. And If it's still failing, restart your IDE.
And If it's still failing restart your computer.
The Jetbrains IntelliJ IDEA editor is compatible with lombok without a plugin as of version 2020.3.
I was using 2020.2 version, i updated to 2020.3 it worked just like that.
I don't think I read my final step in the answers yet. (Mac + IntelliJ Ultimate 2020.1)
Its just a silly cause in my case, but those are the ones that can take up most time because the error doesnt directly refer to it.
The same lombok error appeared to me after deleting and recloning the project.
After doing the steps mentioned earlier in this thread I still had the error, I then discovered my SKD was defaulted to version 11. I changed this back to 1.8 and everything worked again.
File --> Project Settings --> Project
I changed the Project SDK and the Project language level to 1.8
PS the location for the default settings on the mac is different in this IntelliJ version than mentioned before :
File --> New Project Settings --> Preferences for new Projects --> Build, Execution, Deployment --> Compiler --> Annotation Processors --> 'check' Enable annotation processing
Hope this helps anybody
If none of the above did'nt work , then try to change File->Project Structure->Project->Project Language Level > 8 Lambda,type annotations (Not SDK Default 8)
This worked for me .
I tried enabling lambok, restarted intellij, etc but below worked for me.
Intellij Preferences ->Compiler -> Shared Build process VM Options and set it to
-Djps.track.ap.dependencies=false
than run
mvn clean install
It may happen that even if you have it configured properly and it is visible among the libraries and in Gradle dependencies list, IntelliJ still does not have it in class path. Or it is there, but configured with different scope (ex: test instead of compile.)
First, make sure you have plugin installed and annotation processing enabled, as stated in other answers.
If you still have annotation not recognized, place cursor on it, hit ALT+ENTER (or OPTION+ENTER) and see if you have a menu option Add library: Gradle: org.projectlombok:lombok:VERSION to class path. If you can see it, choose this one and it may solve your problem.
You may check the library and it's scope in:
Project settings / Modules / Dependencies tab (search for lombok in there)
I had a similar issue when building with JDK8, set the project back to JDK7 and it worked fine. Could be an older version of Lombok that won't compile under JDK8.
If you tried all solutions presented here and still can't compile sources, also look here: Static import of builder class breaks bytecode generation in Maven - look at your sources if it has such static imports. This affects maven plugin, so compilation will fail on other build systems outside IntelliJ IDEA.
Related
I just imported a project from subversion to IntelliJ IDEA 11 - it's a maven project. But I have a problem in maven library dependencies so that I can't include all maven dependencies automatically - IDEA shows dependency errors only when I open that class/ Thats what I get here:
So I want all dependencies to be added automatically - is that possible or do I have to go through all class files to identify and add maven dependencies?!
UPDATE: After doing some modifications I found how to resolve my problem in some way. Thats what I did:
but I think logically it will not include and check new dependencies ahead?!... Is there any settings area for this in intelliJ - auto export dependencies to classpath?
IntelliJ should download and add all your dependencies to the project's classpath automatically as long as your POM is compliant and all the dependencies are available.
When importing Maven projects into IntelliJ an information box usually comes up asking you if you want to configure Auto-Import for Maven projects. That means that if you make any changes to your POM those changes will be loaded automatically.
You can enable such feature going to File > Settings > Maven > Importing, there is a checkbox that says "Import Maven projects automatically".
If that doesn't help, then I would suggest to make a full clean-up and start again:
Close your project window (and IntelliJ) and remove all *.iml files and all .idea folders (there should be one per module)
Run mvn clean install from the command line
Re-import the project into IntelliJ and pay attention when it asks you to enable auto-import
IntelliJ 2016 Update:
The Import Maven Projects automatically setting has been moved to Build, Execution, Deployment > Build Tools > Maven > Importing in your IntelliJ preferences.
Fix before IntelliJ 14
File [menu] -> Settings -> maven -> importing and uncheck "use maven3 to import project"
ref: http://youtrack.jetbrains.com/issue/IDEA-98425 (which may have a few other ideas too)
Fix IntelliJ 15+
Ran into this again, with IntelliJ 15 this time, which has no "use maven3 to import" option available anymore. The cause was that sometimes IntelliJ "doesn't parse maven dependencies right" and if it can't parse one of them right, it gives up on all of them, apparently. You can tell if this is the case by opening the maven projects tool window (View menu -> Tool Windows -> Maven Projects). Then expand one of your maven projects and its dependencies. If the dependencies are all underlined in red, "Houston, we have a problem".
You can actually see the real failure by mousing over the project name itself.
In my instance it said "Problems: No versions available for XXX" or "Failed to read descriptor for artifact org.xy.z" ref: https://youtrack.jetbrains.com/issue/IDEA-128846
and
https://youtrack.jetbrains.com/issue/IDEA-152555
It seems in this case I was dealing with a jar that didn't have an associated pom file (in our maven nexus repo, and also my local repository). If this is also your problem, "urrent work around: if you do not actually need to use classes from that jar in your own code (for instance a transitive maven dependency only), you can actually get away with commenting it out from the pom (temporarily), maven project reload, and then uncomment it. Somehow after that point IntelliJ "remembers" its old working dependencies. Adding a maven transitive exclude temporarily might also do it, if you're running into it from transitive chain of dependencies."
Another thing that might help is to use a "newer version" of maven than the bundled 3.0.5.
In order to set it up to use this as the default, close all your intellij windows, then open preferences -> build, execution and deployment -> build tools -> maven, and change the maven home directory, it should say "For default project" at the top when you adjust this, though you can adjust it for a particular project as well, as long as you "re import" after adjusting it.
Clear Caches
Deleting your intellij cache folders (windows: HOMEPATH/.{IntellijIdea,IdeaC}XXX linux ~/.IdeaIC15) and/or uninstalling and reinstalling IntelliJ itself. This can also be done by going to File [menu] -> Invalidate Caches / Restart.... Click invalidate and restart. This will reindex your whole project and solve many hard-to-trace issues with IntelliJ.
When importing the project, select pom.xml instead of the project directory. It should work.
Try to Re-Import the project from the Maven Projects panel in IntelliJ IDEA. It should download and configure all the dependencies defined in your pom.xml automatically.
If download doesn't work from IDEA for some reason, try mvn install from the command line and see if the dependencies can be fetched.
Of course all the required dependencies and any custom repositories must be defined directly in the pom.xml file.
For IntelliJ 2016-2.4 (and I believe other new-ish versions):
View > Tool Windows > Maven Projects
In the newly revealed toolbar, select Maven settings (icon of a toolset).
When this screen opens, expand the Maven menu and click 'Importing'
Here, click "Import Maven projects automatically." Also ensure that the 'JDK for Importer' option matches the JDK version you mean to use.
Click OK. Now go to the red dependency in your pom.xml, select the red lightbulb, and click 'Update Maven indices'.
What helped me:
Navigage:
Settings | Build, Execution, Deployment | Maven
Specify "Maven home directory" - the place you installed the maven
If certain maven modules are not compiling check if their pom.xml is on the "ignored files" list. In IntelliJ goto
preferences -> project settings -> maven -> ignored files
and check if the related pom.xml is ignored.
I had the same issue and tried all the answers mentioned here, none worked.
The simple solution is go to your project folder and delete all the .idea and .iml files and restart the IntelliJ ide. It works. No need to do anything with the settings.
Open IntelliJ Idea, Go to
File > Other Settings > Default Settings... > Maven (Preferences) > Importing or|
Preferences > Maven > Importing
Click on Enable Auto-import in the console.
When you create a new project you simply need to choose the option:
...
Import project from external model
Create IDEA project structure over existing external model (Eclipse, Maven...)
...
You'll find it pretty straight forward from there.
And in your case you can close your project and simply create a new one. Choose your project's directory, which will override it, making it a Maven project.
Importing Maven dependencies may not work if you import the same path several times. This may happen automatically after importing an existing maven project. I can't figure out why this happens, so I'm inclined to think it is a bug.
For example, if my project is
hibernate
src/main
src/test
the three paths may be imported as top nodes:
hibernate
src/main
src/test
If such is the case, the dependencies appear to be right, but they won't be used until you remove the superfluous paths (in this case, src/main and src/test). Once you do this, refresh and click Build > Rebuild Project. IDEA will pick up the dependencies.
A symptom of this problem is that IDEA warns you of a duplicated path when you manually check a library (second screenshot in the question).
There are several ways to re-read the dependencies in case you need it. If you go to the “Maven Projects” tab, there is a “Reimport All Maven Projects” icon at the top left of the tab. If you suspect IDEA became confused you can click on File > Invalidate Caches.
First check path Specified for User Settings file: in Settings -> Build,Execution,Development -> Build Tools -> Maven .
The field should have path of the settings.xml of your maven. Also the settings.xml should have correct path of remote repository.
Go into your project structure, under project Settings, Modules, select the dependencies table. For each dependency, change the scope from 'Test' to 'Compile'.
If in the lower right corner it says "2 processes running..." or similar, you may just need to wait for that to finish, since it may take time to download all the jars.
Reimport the project. If you install maven plugin you can use this.
Right click on the project -> Maven -> Reimport
I had a similar issue, in my case I am using a custom settings.xml which was not picked from IntelliJ.
Solution:
File > Settings > Build, Execution, Deployment > Maven: User settings file (chose here my custom settings.xml).
IntelliJ 2020.3.3
This one did it for me.
Build, Execution, Deployment > Build Tools.
Change "Reload project after changes in the build scripts":
from default "External Changes" to "Any Changes"
With this, it took a while for the project to rebuild but now I can see Maven dependencies in IntelliJ:
I ran into the problem that some subdependencies couldn't be resolved in IntelliJ 2016.3.X. This could be fixed by changing the Maven home directory in Settings > Build, Execution, Deployment > Build Tools > Maven from Bundled (Maven 3) to /usr/share/maven.
After that all subdependencies got resolved as in previous IntelliJ versions.
In my case, path for JAVA used by MAVEN was not set as JAVA_HOME as configured on the machine. Hence, it was not even trying to download the dependencies.
Steps I followed which solved this issue,
Checked for JAVA path , Settings >> Build >> Build Tools >> Importing >> JDK for importer. Pointed it to JAVA_HOME.
mvn clean install -U
Used above command to force the dependencies download.
Re imported Maven Projects
So I was also facing this problem in lots of my organisation's codebase. On addition to the answers suggested above, we can tweak around with the allocation pool memory of the jvm. This is because, the volume of the dependencies brought in large codebases may be overwhelming for the jvm for IDE to build the project completely. Hence tried increasing XMX value and it worked! Added -Xmx3072 to resolve the issue of "not building" my Java project in IntelliJ
Maven - Reimport did not work for me.
I have Spring project in STS(Eclipse) and my solution is to import project to IDEA like so:
1) File - New - Project from Existing Sources... - select directory - choose Eclipse.
2) Set Maven autoimport to true in settings.
3) Then right click in pom.xml and choose Add as Maven Project.
After this it has imported everything.
I had the similar issue with my macbook, just did a small change in pom.xml and it started downloading all dependencies:
Earlier dependencies were written as below for my windows machine:
<dependencies>
<dependency>
<groupId>javax.mail</groupId>
<artifactId>mail</artifactId>
<version>1.4</version>
</dependency>
</dependencies>
I just removed the <dependencies> and </dependencies> tags and it started downloading all the dependencies:
<dependency>
<groupId>javax.mail</groupId>
<artifactId>mail</artifactId>
<version>1.4</version>
</dependency>
I am not sure it will work for you or not.. but worked fine for me.
Thanks
Deleting the .idea folder from the project directory, and then re-importing the project as a Maven project is what worked for me.
Invalidate Caches worked for me:
File > Invalidate Caches
Checks:
Clear file system cache and Local History
Clear downloaded shared indexes
Then Invalidate and Restart
I solved this issue by updating my settings.xml file with correct mirror config, seems that intellij will try to download meta-data from repository every time the maven module imported.
Hijacking a bit to add what ended up working for me:
Go into the Maven Projects sidebar on the right edge of the IDE, and verify that your dependencies are listed correctly under your module there. Assuming they are, just ask IDEA to reimport then (the first button at the top, looks like two blue arrows forming a counter-clockwise circle).
Once I did that, and let IDEA reload the project for me, all my dependencies were magically understood.
For reference: this was with IDEA 13.1.2
I faced the same problem and tried everything suggested which did not solve the issue, I was using Intellij version 13.1.3
Finally after spending more than couple of hours trying to fix it, I decided to try an upgraded version and opened the project in version 14.1.4 which ultimately resolved the issue. I would think this as a probable bug in the previous version.
I hope this helps!
I was able to resolve it by removing unnecessary modules from Project Settings -> Modules list.
It turns out these additional modules were created automatically by IntelliJ IDEA when I created the IntelliJ project by importing from the project folder (instead of by opening pom.xml). Then, after declaring the project as Maven project, proper modules were created, and existing modules were conflicting with them. It is also possible to exclude those modules during project creation.
In my case, one of the modules was ignored for some reason.
To resolve that: Right click the problematic module and choose "Unignore Projects".
You might be working under a company's internal network.
If so, to download or add external Maven dependencies your settings.xml file under user/<username>/.m2 folder might need to be updated.
Contact your administrator to provide the right settings.xml file and then paste it into you .m2 folder.
I use IntelliJ IDEA as my development environment, and Maven for dependency management. I frequently build my project structure (directories, poms, etc) outside of IDEA and then import the project into IDEA using Import project from external model. This works great, except that in my poms I specify that the maven-compiler-plugin should use JDK 1.6, and when I import, IDEA informs me that the Language Level Changed and that Language level changes will take effect on project reload, and then prompts to reload the project. This is annoying because I always use the same JDK version.
How do I change the default JDK that IntelliJ IDEA uses, so that I don't have to reload my project every time I import a new project?
This setting is changed in the "Structure for New Projects" dialog. Navigate to "File" -> "New Projects Setup" -> "Structure..."
Next, modify the "Project SDK" and "Project Language Level" as appropriate.
Previous versions of IntelliJ IDEA had this setting in "File" -> "Other Settings" -> "Default Project Structure...".
IntelliJ IDEA 12 had this setting in "Template Project Structure..." instead of "Default Project Structure..."
Download and unpack a JDK archive file (.tar.gz) and add it as a SDK in the 'Project Structure' dialog box ( Ctrl+Alt+Shift+S )
click on the gif to enlarge
Also make sure to set an appropriate 'Project language level'. I forgot to do that when creating the GIF.
Project Structure > Project > Project language level
For Java 8 set it to 8, for Java 9 set it to 9, and so on.
I am using IntelliJ IDEA 14.0.3, and I also have same question. Choose menu File \ Other Settings \ Default Project Structure...
Choose Project tab, section Project language level, choose level from dropdown list, this setting is default for all new project.
I have found out that in recent versions of IntelliJ IDEA requires Java 1.8 but is not configured by default.
We can change the path or configure from Project Settings > Project > Project SDK
here we can edit or add the JDK´s path.
(in my case the path is located in C:\Program Files\Java\jdk1.8.0_102)
Change JDK version to 1.8
Language level File -> project Structure -> Modules -> Sources -> Language level -> 8-Lambdas, type annotations etc.
Project SDk File -> project Structure -> Project 1.8
Java compiler File -> Settings -> Build, Executions, Deployment -> Compiler -> Java compiler
One other place worth checking: Look in the pom.xml for your project, if you are using Maven compiler plugin, at the source/target config and make sure it is the desired version of Java. I found that I had 1.7 in the following; I changed it to 1.8 and then everything compiled correctly in IntelliJ.
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.3.2</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
</plugins>
</build>
The above responses were very useful, but after all settings, the project was running with the wrong version. Finally, I noticed that it can be also configured in the Dependencies window.
Idea 2018.1.3 File -> Project Structure -> Modules -> Sources and Dependencies.
To change the JDK version of the Intellij-IDE himself:
Start the IDE -> Help -> Find Action
than type:
Switch Boot JDK
or (depend on your version)
Switch IDE boot JDK
For latest version intellij, to set default jdk/sdk for new projects go to
Configure->Structure for New Projects -> Project Settings -> Project SDK
I am using IntelliJ 2020.3.1 and the File > Other Settings... menu option has disappeared. I went to Settings in the usual way and searched for "jdk". Under Build, Execution, Deployment > Build Tools > Maven > Importing I found the the setting that will solve my specific issue:
JDK for importer.
On my linux machine I use a script like this:
export IDEA_JDK=/opt/jdk14
/idea-IC/bin/idea.sh
I just imported a project from subversion to IntelliJ IDEA 11 - it's a maven project. But I have a problem in maven library dependencies so that I can't include all maven dependencies automatically - IDEA shows dependency errors only when I open that class/ Thats what I get here:
So I want all dependencies to be added automatically - is that possible or do I have to go through all class files to identify and add maven dependencies?!
UPDATE: After doing some modifications I found how to resolve my problem in some way. Thats what I did:
but I think logically it will not include and check new dependencies ahead?!... Is there any settings area for this in intelliJ - auto export dependencies to classpath?
IntelliJ should download and add all your dependencies to the project's classpath automatically as long as your POM is compliant and all the dependencies are available.
When importing Maven projects into IntelliJ an information box usually comes up asking you if you want to configure Auto-Import for Maven projects. That means that if you make any changes to your POM those changes will be loaded automatically.
You can enable such feature going to File > Settings > Maven > Importing, there is a checkbox that says "Import Maven projects automatically".
If that doesn't help, then I would suggest to make a full clean-up and start again:
Close your project window (and IntelliJ) and remove all *.iml files and all .idea folders (there should be one per module)
Run mvn clean install from the command line
Re-import the project into IntelliJ and pay attention when it asks you to enable auto-import
IntelliJ 2016 Update:
The Import Maven Projects automatically setting has been moved to Build, Execution, Deployment > Build Tools > Maven > Importing in your IntelliJ preferences.
Fix before IntelliJ 14
File [menu] -> Settings -> maven -> importing and uncheck "use maven3 to import project"
ref: http://youtrack.jetbrains.com/issue/IDEA-98425 (which may have a few other ideas too)
Fix IntelliJ 15+
Ran into this again, with IntelliJ 15 this time, which has no "use maven3 to import" option available anymore. The cause was that sometimes IntelliJ "doesn't parse maven dependencies right" and if it can't parse one of them right, it gives up on all of them, apparently. You can tell if this is the case by opening the maven projects tool window (View menu -> Tool Windows -> Maven Projects). Then expand one of your maven projects and its dependencies. If the dependencies are all underlined in red, "Houston, we have a problem".
You can actually see the real failure by mousing over the project name itself.
In my instance it said "Problems: No versions available for XXX" or "Failed to read descriptor for artifact org.xy.z" ref: https://youtrack.jetbrains.com/issue/IDEA-128846
and
https://youtrack.jetbrains.com/issue/IDEA-152555
It seems in this case I was dealing with a jar that didn't have an associated pom file (in our maven nexus repo, and also my local repository). If this is also your problem, "urrent work around: if you do not actually need to use classes from that jar in your own code (for instance a transitive maven dependency only), you can actually get away with commenting it out from the pom (temporarily), maven project reload, and then uncomment it. Somehow after that point IntelliJ "remembers" its old working dependencies. Adding a maven transitive exclude temporarily might also do it, if you're running into it from transitive chain of dependencies."
Another thing that might help is to use a "newer version" of maven than the bundled 3.0.5.
In order to set it up to use this as the default, close all your intellij windows, then open preferences -> build, execution and deployment -> build tools -> maven, and change the maven home directory, it should say "For default project" at the top when you adjust this, though you can adjust it for a particular project as well, as long as you "re import" after adjusting it.
Clear Caches
Deleting your intellij cache folders (windows: HOMEPATH/.{IntellijIdea,IdeaC}XXX linux ~/.IdeaIC15) and/or uninstalling and reinstalling IntelliJ itself. This can also be done by going to File [menu] -> Invalidate Caches / Restart.... Click invalidate and restart. This will reindex your whole project and solve many hard-to-trace issues with IntelliJ.
When importing the project, select pom.xml instead of the project directory. It should work.
Try to Re-Import the project from the Maven Projects panel in IntelliJ IDEA. It should download and configure all the dependencies defined in your pom.xml automatically.
If download doesn't work from IDEA for some reason, try mvn install from the command line and see if the dependencies can be fetched.
Of course all the required dependencies and any custom repositories must be defined directly in the pom.xml file.
For IntelliJ 2016-2.4 (and I believe other new-ish versions):
View > Tool Windows > Maven Projects
In the newly revealed toolbar, select Maven settings (icon of a toolset).
When this screen opens, expand the Maven menu and click 'Importing'
Here, click "Import Maven projects automatically." Also ensure that the 'JDK for Importer' option matches the JDK version you mean to use.
Click OK. Now go to the red dependency in your pom.xml, select the red lightbulb, and click 'Update Maven indices'.
What helped me:
Navigage:
Settings | Build, Execution, Deployment | Maven
Specify "Maven home directory" - the place you installed the maven
If certain maven modules are not compiling check if their pom.xml is on the "ignored files" list. In IntelliJ goto
preferences -> project settings -> maven -> ignored files
and check if the related pom.xml is ignored.
I had the same issue and tried all the answers mentioned here, none worked.
The simple solution is go to your project folder and delete all the .idea and .iml files and restart the IntelliJ ide. It works. No need to do anything with the settings.
Open IntelliJ Idea, Go to
File > Other Settings > Default Settings... > Maven (Preferences) > Importing or|
Preferences > Maven > Importing
Click on Enable Auto-import in the console.
When you create a new project you simply need to choose the option:
...
Import project from external model
Create IDEA project structure over existing external model (Eclipse, Maven...)
...
You'll find it pretty straight forward from there.
And in your case you can close your project and simply create a new one. Choose your project's directory, which will override it, making it a Maven project.
Importing Maven dependencies may not work if you import the same path several times. This may happen automatically after importing an existing maven project. I can't figure out why this happens, so I'm inclined to think it is a bug.
For example, if my project is
hibernate
src/main
src/test
the three paths may be imported as top nodes:
hibernate
src/main
src/test
If such is the case, the dependencies appear to be right, but they won't be used until you remove the superfluous paths (in this case, src/main and src/test). Once you do this, refresh and click Build > Rebuild Project. IDEA will pick up the dependencies.
A symptom of this problem is that IDEA warns you of a duplicated path when you manually check a library (second screenshot in the question).
There are several ways to re-read the dependencies in case you need it. If you go to the “Maven Projects” tab, there is a “Reimport All Maven Projects” icon at the top left of the tab. If you suspect IDEA became confused you can click on File > Invalidate Caches.
First check path Specified for User Settings file: in Settings -> Build,Execution,Development -> Build Tools -> Maven .
The field should have path of the settings.xml of your maven. Also the settings.xml should have correct path of remote repository.
Go into your project structure, under project Settings, Modules, select the dependencies table. For each dependency, change the scope from 'Test' to 'Compile'.
If in the lower right corner it says "2 processes running..." or similar, you may just need to wait for that to finish, since it may take time to download all the jars.
Reimport the project. If you install maven plugin you can use this.
Right click on the project -> Maven -> Reimport
I had a similar issue, in my case I am using a custom settings.xml which was not picked from IntelliJ.
Solution:
File > Settings > Build, Execution, Deployment > Maven: User settings file (chose here my custom settings.xml).
IntelliJ 2020.3.3
This one did it for me.
Build, Execution, Deployment > Build Tools.
Change "Reload project after changes in the build scripts":
from default "External Changes" to "Any Changes"
With this, it took a while for the project to rebuild but now I can see Maven dependencies in IntelliJ:
I ran into the problem that some subdependencies couldn't be resolved in IntelliJ 2016.3.X. This could be fixed by changing the Maven home directory in Settings > Build, Execution, Deployment > Build Tools > Maven from Bundled (Maven 3) to /usr/share/maven.
After that all subdependencies got resolved as in previous IntelliJ versions.
In my case, path for JAVA used by MAVEN was not set as JAVA_HOME as configured on the machine. Hence, it was not even trying to download the dependencies.
Steps I followed which solved this issue,
Checked for JAVA path , Settings >> Build >> Build Tools >> Importing >> JDK for importer. Pointed it to JAVA_HOME.
mvn clean install -U
Used above command to force the dependencies download.
Re imported Maven Projects
So I was also facing this problem in lots of my organisation's codebase. On addition to the answers suggested above, we can tweak around with the allocation pool memory of the jvm. This is because, the volume of the dependencies brought in large codebases may be overwhelming for the jvm for IDE to build the project completely. Hence tried increasing XMX value and it worked! Added -Xmx3072 to resolve the issue of "not building" my Java project in IntelliJ
Maven - Reimport did not work for me.
I have Spring project in STS(Eclipse) and my solution is to import project to IDEA like so:
1) File - New - Project from Existing Sources... - select directory - choose Eclipse.
2) Set Maven autoimport to true in settings.
3) Then right click in pom.xml and choose Add as Maven Project.
After this it has imported everything.
I had the similar issue with my macbook, just did a small change in pom.xml and it started downloading all dependencies:
Earlier dependencies were written as below for my windows machine:
<dependencies>
<dependency>
<groupId>javax.mail</groupId>
<artifactId>mail</artifactId>
<version>1.4</version>
</dependency>
</dependencies>
I just removed the <dependencies> and </dependencies> tags and it started downloading all the dependencies:
<dependency>
<groupId>javax.mail</groupId>
<artifactId>mail</artifactId>
<version>1.4</version>
</dependency>
I am not sure it will work for you or not.. but worked fine for me.
Thanks
Deleting the .idea folder from the project directory, and then re-importing the project as a Maven project is what worked for me.
Invalidate Caches worked for me:
File > Invalidate Caches
Checks:
Clear file system cache and Local History
Clear downloaded shared indexes
Then Invalidate and Restart
I solved this issue by updating my settings.xml file with correct mirror config, seems that intellij will try to download meta-data from repository every time the maven module imported.
Hijacking a bit to add what ended up working for me:
Go into the Maven Projects sidebar on the right edge of the IDE, and verify that your dependencies are listed correctly under your module there. Assuming they are, just ask IDEA to reimport then (the first button at the top, looks like two blue arrows forming a counter-clockwise circle).
Once I did that, and let IDEA reload the project for me, all my dependencies were magically understood.
For reference: this was with IDEA 13.1.2
I faced the same problem and tried everything suggested which did not solve the issue, I was using Intellij version 13.1.3
Finally after spending more than couple of hours trying to fix it, I decided to try an upgraded version and opened the project in version 14.1.4 which ultimately resolved the issue. I would think this as a probable bug in the previous version.
I hope this helps!
I was able to resolve it by removing unnecessary modules from Project Settings -> Modules list.
It turns out these additional modules were created automatically by IntelliJ IDEA when I created the IntelliJ project by importing from the project folder (instead of by opening pom.xml). Then, after declaring the project as Maven project, proper modules were created, and existing modules were conflicting with them. It is also possible to exclude those modules during project creation.
In my case, one of the modules was ignored for some reason.
To resolve that: Right click the problematic module and choose "Unignore Projects".
You might be working under a company's internal network.
If so, to download or add external Maven dependencies your settings.xml file under user/<username>/.m2 folder might need to be updated.
Contact your administrator to provide the right settings.xml file and then paste it into you .m2 folder.
I use IntelliJ IDEA as my development environment, and Maven for dependency management. I frequently build my project structure (directories, poms, etc) outside of IDEA and then import the project into IDEA using Import project from external model. This works great, except that in my poms I specify that the maven-compiler-plugin should use JDK 1.6, and when I import, IDEA informs me that the Language Level Changed and that Language level changes will take effect on project reload, and then prompts to reload the project. This is annoying because I always use the same JDK version.
How do I change the default JDK that IntelliJ IDEA uses, so that I don't have to reload my project every time I import a new project?
This setting is changed in the "Structure for New Projects" dialog. Navigate to "File" -> "New Projects Setup" -> "Structure..."
Next, modify the "Project SDK" and "Project Language Level" as appropriate.
Previous versions of IntelliJ IDEA had this setting in "File" -> "Other Settings" -> "Default Project Structure...".
IntelliJ IDEA 12 had this setting in "Template Project Structure..." instead of "Default Project Structure..."
Download and unpack a JDK archive file (.tar.gz) and add it as a SDK in the 'Project Structure' dialog box ( Ctrl+Alt+Shift+S )
click on the gif to enlarge
Also make sure to set an appropriate 'Project language level'. I forgot to do that when creating the GIF.
Project Structure > Project > Project language level
For Java 8 set it to 8, for Java 9 set it to 9, and so on.
I am using IntelliJ IDEA 14.0.3, and I also have same question. Choose menu File \ Other Settings \ Default Project Structure...
Choose Project tab, section Project language level, choose level from dropdown list, this setting is default for all new project.
I have found out that in recent versions of IntelliJ IDEA requires Java 1.8 but is not configured by default.
We can change the path or configure from Project Settings > Project > Project SDK
here we can edit or add the JDK´s path.
(in my case the path is located in C:\Program Files\Java\jdk1.8.0_102)
Change JDK version to 1.8
Language level File -> project Structure -> Modules -> Sources -> Language level -> 8-Lambdas, type annotations etc.
Project SDk File -> project Structure -> Project 1.8
Java compiler File -> Settings -> Build, Executions, Deployment -> Compiler -> Java compiler
One other place worth checking: Look in the pom.xml for your project, if you are using Maven compiler plugin, at the source/target config and make sure it is the desired version of Java. I found that I had 1.7 in the following; I changed it to 1.8 and then everything compiled correctly in IntelliJ.
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.3.2</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
</plugins>
</build>
The above responses were very useful, but after all settings, the project was running with the wrong version. Finally, I noticed that it can be also configured in the Dependencies window.
Idea 2018.1.3 File -> Project Structure -> Modules -> Sources and Dependencies.
To change the JDK version of the Intellij-IDE himself:
Start the IDE -> Help -> Find Action
than type:
Switch Boot JDK
or (depend on your version)
Switch IDE boot JDK
For latest version intellij, to set default jdk/sdk for new projects go to
Configure->Structure for New Projects -> Project Settings -> Project SDK
I am using IntelliJ 2020.3.1 and the File > Other Settings... menu option has disappeared. I went to Settings in the usual way and searched for "jdk". Under Build, Execution, Deployment > Build Tools > Maven > Importing I found the the setting that will solve my specific issue:
JDK for importer.
On my linux machine I use a script like this:
export IDEA_JDK=/opt/jdk14
/idea-IC/bin/idea.sh
Platform: IntelliJ Community Edition 10.0.3
SDK: jdk1.6.0_21
OS: Windows 7
So I have a strange situation with IntelliJ that has me completely stumped. I setup a Maven project and add log4j as a dependency in the pom.xml file. The IDEA inspections run fine and my unit tests all compile and run.
I then added hunnysoft's jmime library to my local maven repository using the mvn install:install-file as follows.
mvn install:install-file -Dfile=jmime.jar -DgroupId=jmime \
-DartifactId=jmime -Dversion=3.1.1e -Dpackaging=jar
Maven installed the jar file just fine into my local repository.
I then went into IntelliJ's Settings => Maven => Repository Services and Updated my local repository (so that IntelliJ would reindex the repository contents).
Finally, I added the following dependency to my pom.xml file (just above the log4j dependency).
<dependency>
<groupId>jmime</groupId>
<artifactId>jmime</artifactId>
<version>3.1.1e</version>
</dependency>
I now create a new class as follows:
package com.stackoverflow.question;
import org.apache.log4j.Logger;
import com.hunnysoft.jmime.ByteString;
import com.hunnysoft.jmime.Field;
import com.hunnysoft.jmime.FieldBody;
public class StackOverflowQuestion {
public Field create(String name, String text) {
Logger.getLogger(getClass()).debug("create entered");
FieldBody body = new FieldBody();
body.setText(new ByteString(text));
Field field = new Field();
field.setFieldName(name);
field.setFieldBody(body);
return field;
}
}
Now for the weirdness. IntelliJ's intention mechanism picks up and recognizes the Logger import in the maven pom file just fine. However, for all of the hunnysoft imports it reports: "Cannot resolve symbol 'ByteString/Field/FieldBody'", BUT Build => Compile 'StackOverflowQuestion.java' compiles everything correctly and the unit test I created for this class runs fine (though the intentions mark the call to create() as a problem area too).
So somewhere, somehow IntelliJ is ignoring the jmime.jar file for the intention subsystem. I'm confused because the log4j dependency works fine and everything compiles and runs fine. F12 ("Go To Declaration") works on the Logger import, but breaks on all the jmime imports.
Oh, one other thing, if I go to the 'Packages' view in the "Projects" window the "com.hunnysoft.jmime" package appears and I can see ALL of the classes I imported in the code snippet above under "Libraries". Removing the above dependency from the pom.xml file causes this package to disappear and the compilation breaks.
It appears that the inspection's classpath is broken, but there does not seem to be a setting for this anywhere in the Settings => Intentions | Compiler areas (not that I expected any such settings, I believe the IDEA should already know the correct classpath based on the pom file and JDK).
As a final experiment I created a brand new standard J2SE application project (without using maven) and added the jmime.jar file directly to the project as one of its libraries. I run into exactly the same problems as described above in this new project.
Here is the MANIFEST.MF from the jmime jar file.
Manifest-Version: 1.0
Ant-Version: Apache Ant 1.5.4
Created-By: 10.0-b23 (Sun Microsystems Inc.)
Name: com/hunnysoft/jmime/
Sealed: true
Specification-Title: Hunny JMIME
Specification-Version: 3.1.1
Specification-Vendor: Hunny Software, Inc.
Implementation-Title: com.hunnysoft.jmime
Implementation-Version: 3.1.1E
Implementation-Vendor: Hunny Software, Inc.
I don't see anything unusual in this jar file.
My best guess is that perhaps the problem might be a missing dependency issue. But AFAIK jmime is supposed to be self contained (JarAnalyzer doesn't come up with anything, but I'm not sure it would if a dependency jar is missing).
So, anyone have any IDEAs?
First of all you should try File | Invalidate Caches and if it doesn't help, delete IDEA system directory. Then re-import the Maven project and see if it helps.
In some weird cases compiled classes may report wrong info and confuse IDEA. Verify that the classes from this jar report correct names using javap.
The following trick resolved this issue for me:
Right click on the code editor
Hover on Maven and expand
Click on Reimport
My idea version is 12.0.4
None of the solutions above worked for me. What did was removing the main.iml file manually and it suddenly worked.
This was mentioned in another answer to this same question here, but this alone fixes this for me. I do all my builds in a separate terminal, outside of IntelliJ. So the cache's need to have the proper permissions set for the IntelliJ app to read them.
Run it from the project's root folder.
$ mvn -U idea:idea
For Gradle users:
You may need to synchronize your project with your build.gradle file.
You can right-click on your gradle file under the Project pane to do this, but that didn't seem to do anything for me (I suspect a bug in my version). You'll know if this happens because it wont' kick off any IntelliJ tasks that you will be waiting on. Instead, open up the Gradle Tool pane, then click the synchronize (refresh) button. This worked for me where invalidating the cache and restarting did not.
My own circumstance: I was using a Scala project with Gradle and had to do this.
One extra step, when I did File -> Invalidate Caches and restarted the IDE, open a project. It popped up a toastbox on the top-right asking me whether to enable auto-import and that solved the problem.
Inconsistent/duplicate module names in project structure was causing this issue for me.
Go to File -> Project Strucutre -> Modules
In Click on modules which have red underline
Got to "Dependencies" tab
Make sure the dependencies which are red actually exist in dependency list. If not, rename them to match existing dependency names
This can happen when IntelliJ doesn't shut down properly and thus cannot properly save renamed module names.
Another thing to check: Be sure that dependencies are not duplicated. In my case I found that a module exhibiting this behavior was misconfigured as follows: it had a dependency on another module, and it had a dependency on a jar produced by that other module. This meant for every symbol referenced in duplicate, and was ambiguous.
Has a fixed been published? Appears issue originally affected v11/12 due to a "Compiler overhaul" back in 2013. With discussion on related issues in Jira up to end of 2014.
http://youtrack.jetbrains.com/issue/IDEA-98425
Also on Jira IDEA-98425 was marked fixed but unverified (on v12.0.3). None of the following work-around helped resolve this "Unable to Resolve Symbol" issue with Version 13.1.1 on Windows
a. Delete .IdealIC13 folder (Then, File \ Invalidate Caches / Restart)
b. From Maven Projects window,
b.1 mvn -U idea:idea –〉Executing this maven goal suppose to reload the dependencies. This works prev, but since last FRI, executing this maven goal failed as it tried to recompile the project (Of course it fails as "Unable to resolve Symbols", that's what I am trying to fix by running this command in the first place) mvn -version — shows maven version referenced 3.2.5 and that it's working
b.2 Simply right click project, and Reimport
b.3 File \ Invalidate Caches / Restart
c. Tried both Enable & Disable this setting: File -> Settings -> Maven -> Importing -> "Use maven3 to import project"
d. Settings \ Maven \ Multiproject build fail policy = Fail at end (instead of Default)
Nothing works. What's happenning to IntelliJ support on Maven.
https://youtrack.jetbrains.com/issue/IDEA-99302
From JetBeans release history, https://www.jetbrains.com/company/history.jsp
IntelliJ v14 NOV 2014
IntelliJ v13 DEC 2013
I'd assume v12 fixed (although unverified) would be incorporated in subsequent releases. Any one having similar problems with which IntelliJ version? Please share your experience. IntelliJ maven support seems broken.
Press "shift" two times > "Reimport All Maven projects" always works for me.
None of the other answeres worked for me. My imports were not being resolved because IntelliJ pointed to wrong .m2 file.
IntelliJ Version: IntelliJ Idea 2018.1.5
My location for the .m2 directory was pointed to the wrong path. All I did to fix it was re-point IntelliJ to the right .m2 directory and update it.
First, go to: File->Settings->Build, Execution, Deployment->Build Tools->Maven
I had to change the User settings file: and the Local repository: to the correct location of my .m2 directory.
After this go to: File->Settings->Build, Execution, Deployment->Build Tools->Maven->Repositories
and click the Update button.
I'm jealous of all of you who resolved through File / Invalidate caches. I just spent hours trying everything on this question and a few others from around the web.
The magic menu item didn't do it for me so I invalidated the caches myself by nuking %USERPROFILE%\AppData\Local\JetBrains\IntelliJIdea2020.3\caches
Once I did this and restarted IntelliJ (2020.3), the indexes were rebuilt and my errors went away.
My Project Structure:
src -> main -> scala -> mypackages
What worked:
Right click on the scala folder, and click "Mark Directory as Sources Root".
I had problem with Maven Importer JDK - somehow it switched itself to JDK 11, but Maven Project reload worked only with JDK 8.
Update 2022
IntelliJ 2022.1 has an interactive, step-by-step process File -> Repair IDE. It leads you through 5 steps in sequence to try and resolve this problem for the current project before invalidating the caches for all projects. From the IDEA documentation:
Refresh Project Indexes
Rescan Project Indexes
Reopen Project
Drop Shared Indexes
Reindex Project
Invalidate Caches and Restart
Steps 1- 3 fixed it for my project.
In v2022.3 and the new UI, this setting is now in File -> Cache Recovery -> Repair IDE. You can also select an individual step from there.
If your maven project is a multi-module project, check if some of the modules are ignored by intellij.
Click on View -> Tool Windows -> Maven Projects, and check if some modules are ignored(Ignored modules are in grey, e.g. gs-multi-module in the following image).
Right click on the ignored module and choose Unignore Projects.
Then wait for intellij to finish indexing, after which it will work.
For Gradle projects:
Exit IntelliJ IDEA
Delete the <problematic-project-root>/.idea directory
Delete the <problematic-project-root>/.gradle directory
Delete all .iml files in <problematic-project-root>
windows command prompt: DEL /S /Q *.iml
linux: find . | grep -e .iml$ | xargs rm
Re-import the project into IntelliJ IDEA with Gradle
In IntelliJ IDEA 2020.3, select:
File > Invalidate Caches / Restart... > Invalidate and Restart
When prompted with Download pre-built shared indexes:
don't import the shared indexes: close the dialog or choose More actions > Don't show again
Yes, sounds like you have to create libraries containing the JARs you need and add them as a dependency in your module.
For another alternative.
I got this problem also when I used JDK7_07. I tried all answers here (except deleting IDEA System Directory). But, I still got the problem. So what I did it is:
Install newest JDK (it was JDK7_45), and set the Intellij's JDK to the new one, and it works.
Re-importing the project worked for me.
Right Click on Project -> Maven ->Reimport
when I did File -> Invalidate Caches and restarted the IDE,open a project. It showed a dialogue on the top-right "Maven changes detected" and gave an option to import and enable auto-import. Even after importing the project here, I had the same issue. The above step solved the problem.
Suggested solutions did not work. I had to unignore several projects, by right clicking on the pom => maven => unignore project.
Then after a
mvn clean install -T 6 -DskipTests
in the console, IntelliJ was happy again. No idea how the projects became ignored...
Sometimes, I just open project structure, and click project, then choose a SDK version.
In my case, I am trying to open a spring boot project from IntellijIdea got the same issue like unable to import all spring related files.
Then I did:
File -> Close Project -> Import Project -> Import from external model -> Choose Gradle -> Next -> Select the project from file location -> Finish
Now everything working fine as expected.
I have seen many answers here but I finally found this solution. It may use for someone like me.
I just had this issue and it would just not go away. I eventually wiped out the IntelliJ config directory in ~ and rebuilt my IntelliJ project from scratch. (This only took about 15 minutes in the end, compared to spending an hour trying to work out problems with cached files, etc.)
Note that my guess is that the initial problem was caused by something like javathings.blogspot.com/2009/11/too-many-open-files-in-intellij-idea.html (NB: as of 2018, that link is dead, but archive.org has a copy of the page from around when this answer was first written -ed.) or a disk space/memory issue causing Java to crash. IntelliJ seemed to just get corrupted.
After invalidating my cache and restarting; and confirming my maven settings were okay, I was still seeing "Cannot resolve symbol" for a module that I definitely had set as a dependency. Turns out I had it set to the wrong scope.
You can check by right clicking on your module and selecting Open Module Settings. Click the dependency tab and verify that the scope for your un-resolvable dependency is set to Compile.
Open "Settings"
Search for "Maven"
Click on "Ignored Files" under "Maven"
Uncheck the pom.xml files contains the missing dependencies
Click "OK"
Click File -> Invalidate Caches/Restart...
Click "Invalidate and Restart"
mvn idea:idea worked for me. Found it here. Spent more than an hour, hope it helps someone
In my case, my project was using Lombok and I was missing the Lombok Plugin in IntelliJ. After installing it everything worked fine.
I tried
File -> Invalidate and Restart
which did not worked for me.
Solution that really worked :
Project Structure -> Modules -> select target folder -> Right click generated-sources and select sources -> Apply -> ok