IntelliJ inspection gives "Cannot resolve symbol" but still compiles code

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.

1. Go to File -> Project Strucutre -> Modules
2. In Click on modules which have red underline
3. Got to "Dependencies" tab
4. 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.

My Project Structure:

src -> main -> scala -> mypackages

What worked:

Right click on the scala folder, and click "Mark Directory as Sources Root".

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.

If your maven project is a multi-module project, check if some of the modules are ignored by intellij.

1. 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).

2. Right click on the ignored module and choose Unignore Projects.

Then wait for intellij to finish indexing, after which it will work.

I had problem with Maven Importer JDK - somehow it switched itself to JDK 11, but Maven Project reload worked only with JDK 8.

For Gradle projects:

1. Exit IntelliJ IDEA
2. Delete the <problematic-project-root>/.idea directory
3. Delete the <problematic-project-root>/.gradle directory
4. Delete all .iml files in <problematic-project-root>
   • windows command prompt: DEL /S /Q *.iml
   • linux: find . | grep -e .iml$ | xargs rm
5. Re-import the project into IntelliJ IDEA with Gradle

Yes, sounds like you have to create libraries containing the JARs you need and add them as a dependency in your module.

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.

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.

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.

1. Open "Settings"
2. Search for "Maven"
3. Click on "Ignored Files" under "Maven"
4. Uncheck the pom.xml files contains the missing dependencies
5. Click "OK"
6. Click File -> Invalidate Caches/Restart...
7. Click "Invalidate and Restart"

In my case, my project was using Lombok and I was missing the Lombok Plugin in IntelliJ. After installing it everything worked fine.

In IntelliJ IDEA 2020.3, select:

1. File > Invalidate Caches / Restart... > Invalidate and Restart

2. 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

In my case, only buildDir is removed. In this case, File | Invalidate Caches does not work.

When I do Build | Make Project before File | Invalidate Caches, everything works fine.

None of the above solutions solved it for me. I had the same issue where the code compiled fine but IntelliJ showed that it could not find the import. Even though IntelliJ suggested the import in the first place from code completion.

My solution was to move everything to the default package, delete the com.foo.bar package, then create it again and move everything back.

mvn idea:idea worked for me. Found it here. Spent more than an hour, hope it helps someone

Remove the :iml file found in java and test folders inside the project and invalidate and restart .

It will ask can I remove the projects . Put Yes. The error will goes off.

"File -> Invalidate Cache and Restart" will resolve all dependencies.

What worked for me was to "Mark as directory source root" the directory in which the red marked class was, after it the red mark disappeared. Seems that for some reason it was unmarked.

I tried invalidating cache, it didnt work for me.

However, I tried removing the jdk from Platform Settings and added it back and it worked.

Here's how to do it.

Project Settings -> SDKs -> Select the SDK -> Remove (-) -> Add it back again (+)

In my case, a colleague added Lombok to the project, and I had to install the Idea Lombok plug-in. In your case, it may be something else that requires a plug-in.

For Intellij Idea users this commands before even importing project might help :

./gradlew build
./gradlew idea

if maven project then just go to settings ->build tools - >maven ->importing. check the checkbox "import maven project automatically". will solve the problem.

Invalidate Caches worked for me but after running the application had the same error.

So I tried (Intellij):

1 - Menu bar - Refactor | Build | Run | Tools

• click Build then Rebuild Project

2 - MVN clean

3 - Right click on project > Maven > Generate Sources and Update Folder

Hope this works for you.

Thanks

Or maybe the file you import is too large.this is my case,when I change the Intellij property: iead.max.intellisen.filesize (path is ${idea dir}/bin/idea.properties) to a larger value,like 25000, and restart the IDE,the problem disappeared. Hope this helps.

I had a similar issue when I switched to a new computer.

I copied all the IDEA files (even the related %APPDATA%-folders), but then the Maven build was successfully, but IDEA did not find any classes from the dependencies, when building it.

The solution: I started with a new and clean IDEA profile by removing the folders from the %APPDATA%-folders

For Idea 2017.1 + Gradle, the plugin is somehow buggy. Tried all synchronize, invalidate + restart, nothing worked. According to https://github.com/gradle/gradle/issues/2315, this worked for me:

1. Close Idea
2. Type gradle idea in command line (should generate 3 files: .iml, .ipr, .iws)
3. Run idea and open the created file .ipr, this should import your project from scratch, with hard-wired dependencies in those 3 files

If nothing works out, right click on your source directory , mark directory as "Source Directory" and then right click on project directory and maven -> re-import.

this resolved my issue.

What helped me to resolve this issue:

I have had another branch, have switched to that branch and built the project with mvn clean install. Everything was ok, then switched back to the master and build the project again and the errors disappeared. Invalidate caches and restart didn't help me.

sometimes, when you create package like com.mydomain.something the directory structure does not get created and you are left with a single folder named "com.mydomain.something" in this case you should create directory structure, like

com
|_mydomain
  |_something 

Go to File->Project Structure -> SDKs and check if your SDK file path is correct.

Had trouble importing standard java libraries such as java.beans.*

Fixed it on my Redhat 7 system by pointing it to the correct JRE path.

File->ProjectStructure->SDKs->1.8 Changed 'JDK home path:' to /usr/lib/jvm/java-1.8.0-openjdk-1.8.0161-2.b14.el7.x86_64 instead of /usr/lib/jvm/java-1.8.0-openjdk-1.8.0161-2.b14.el7_4.x86_64

The former path to jdk(with the _4 difference in path) hardly had anything in it. It was missing many java libraries.

If all my pom.xml files are configured correctly and I still have issues with Maven in IntelliJ I do the following steps

1. Read how to use maven in IntelliJ lately
2. Make sure IntelliJ is configured to use Bundled Maven 3
3. Find and TERMINATE actual java process that is executing Maven 3 repos indexing for IntelliJ(Termination can be done while IntelliJ is running). In case any problems with indices or dependencies not available(thought repositories were configured in pom.xml).
4. Forced Update for all repositories in "IntelliJ / Settings / Build Tools / Maven / Repositories / ". Takes most of the time, disk space and bandwidth! Took me 20+ minutes to update index for Maven central repo.
5. Hit Re-import all Maven project once again from IntelliJ
6. It is a good practice to do steps 1-4 to leave IntelliJ and its demon java processes running over night, if you have multiple repositories and a complex project, so you have everything in sync for the next day. You can in theory use all popular indexed repos out there and launch index update for all repos at the same time(I suppose IntelliJ creates a queue and runs updates one after another) then it can take hours to complete(you will need to increase heap space for that too).

P.S. I've spent hours to understand(step 3) that IntelliJ's java demon process that handles maven index update was doing something wrong and I simply need to make IntelliJ to start it from scratch. Problem was solved without even restarting IntelliJ itself.

For MAVEN,

I tried all of the above methods, but couldn't find the solution,

So below are the steps I tried(A mix of some solutions),

1. mvn clean

2. mvn idea:clean

3. Invalidate cache and restart

4. Remove all the extra .iml files you see in the project structure.

5. At the root directory of your project, run mvn idea:idea and mvn clean install, to reimport all the dependencies of your maven project.

(Make sure you don't have extra .iml files other than the project/subprojects .iml files)

check import Maven projects automatically, fixed my issue. I spent two hours figuring out where I am doing wrong. Finally was able to fix it.

The number one suggestion of Invalidate Caches/Restart... did not work for me nor did any of the other solutions. It ended up being that my maven repos were incorrectly set up, I fixed this by manually overriding the settings.xml and repository directory:

File -> Settings... -> Build, Execution, Deployment -> Build Tools -> Maven

Then for User settings file and Local repository, check the Override and point it to the correct settings.xml and repository directory.

This seems to happen to me mostly when the dependency jar is also a Fat Jar. Fortunately I had control over the building of the Fat Jar, after making it a non Fat Jar then things just worked. None of the other fixes on any of the answers or comments here worked for me. Also probably noteworthy is that my code was in Kotlin and the Fat Jar was bundling some Kotlin dependencies as well.

verify successfully. my idea version is 2019.2

Quick fix: 1.use maven install you dependent module,then reimport all module 2.compile current module,if still not found,close your all idea window,restart idea.

1. Find out the package in your pom file which can not find.
2. Then delete them from your local repository.

My project faced the same problem because one of the jars in the pom couldn't load properly.

I tested all the solutions above and finally decided to empty my Maven repository manually (I actually deleted the .m2 folder on linux). It did the trick.

Previous answers didn't work for me. Switched from version 2020.1 to 2018.2 and things seem fine.

For Ivy users and and IntelliJIdea2020.xx

If nothing helps for the already answered,
Close IntelliJ and delete completely the folder:
C:\Users\{username}\AppData\Local\JetBrains\IntelliJIdea2020.xx
Restart IntelliJ project and it should resolve the previous not correctly loaded dependencies.

I faced a similar kind of problem while using lib build with Kotlin. I included the library through gradle. Intellij was able to run my application but not to resolve some classes and its method. Then I realized that the Kotlin plugin version in my Intellij is outdated and is lower than the Kotlin version that build the library. So I updated the Kotlin plugin from File--> Settings-->Languages & Frameworks-->Kotlin and it resolved the problem.

I tried File | Invalidate Caches, deleting the .idea folder, cache folder, reimporting the project. But nothing worked.

So updating the corresponding plugin can be helpful.

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:

1. Refresh Project Indexes
2. Rescan Project Indexes
3. Reopen Project
4. Drop Shared Indexes
5. Reindex Project
6. Invalidate Caches and Restart

Steps 1- 3 fixed it for my project.

I had a problem where IntelliJ coudn't resolve classes like String or List and even java. The issue was no SDK was used for the project and going into File> Project Structure > Project > SDK and setting the appropriate SDK and clicking on apply fixed it for me

I used to have 2020.1 community. And I fixed the issue installing 2020.3 ultimate.

This seems to happen to me with a Kotlin library.

None of the other fixes on any of the answers or comments here worked for me.

Invalidate caches & Restart in Intellij worked for me but after restart I need to wait for reindexing everything. For my project it takes for more that 10 minutes.

I've discovered that it wasn't rare to have the problem gone after a simple restart without cache invalidation. Not always but it helps quite often.

For a simple solution, I simply just deleted my version of IntelliJ (and all related files) and reinstalled it. After reimporting the project these errors were gone.