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JavaFx Project not be able to build after downgrade to jdk11 [duplicate]

When running a JUnit test, using IntelliJ IDEA, I get
How can I correct this?
Using SDK 1.7
Module language level is 1.7
Maven build works fine. (That's why I believe this in IDEA configuration issue)

Most likely you have incorrect compiler options imported from Maven here:
Also check project and module bytecode (target) version settings outlined on the screenshot.
Other places where the source language level is configured:
Project Structure | Project
Project Structure | Modules (check every module) | Sources
Maven default language level is 1.5 (5.0), you will see this version as the Module language level on the screenshot above.
This can be changed using maven-compiler-plugin configuration inside pom.xml:
<project>
[...]
<build>
[...]
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
[...]
</build>
[...]
</project>
or
<project>
[...]
<properties>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
[...]
</project>
IntelliJ IDEA will respect this setting after you Reimport the Maven project in the Maven Projects tool window:

IntelliJ 15, 2016 & 2017
Similar to that discussed below for IntelliJ 13 & 14, but with an extra level in the Settings/Preferences panel: Settings > Build, Execution, Deployment > Compiler > Java Compiler.
IntelliJ 13 & 14
In IntelliJ 13 and 14, check the Settings > Compiler > Java Compiler UI to ensure you're not targeting a different bytecode version in your module.

In IntelliJ IDEA 14.1 the "Target bytecode version" is in a different place.
The following change worked for me:
File > Settings... > Build, Execution, Deployment > Compiler > Java Compiler : change Target bytecode version from 1.5 to 1.8

Have you looked at your build configuration it should like that if you use maven 3 and JDK 7
<build>
<finalName>SpringApp</finalName>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
...
</plugins>
...
</build>

I ran into this and the fix was to go to Project Settings > Modules > click on the particular module > Dependencies tab. I noticed the Module SDK was still set on 1.6, I changed it to 1.7 and it worked.

I've found required options ('target bytecode version') in settings > compiler > java compiler in my case (intelij idea 12.1.3)

Modify the compiler setting file of the project in the following path and change the 'target' to 1.7:
/project/.idea/compiler.xml
<bytecodeTargetLevel>
<module name="project-name" target="1.7" />
</bytecodeTargetLevel>

I resolved it by setting the field blank:
Settings > Compiler > Java Compiler > Project bytecode version
Than IntelliJ uses the JDK default version.

From one moment to the other I also got this error without a clear reason. I changed all kinds of settings on the compiler/module etc. But in the end I just recreated the IntelliJ project by reimporting the Maven project and the issue was solved. I think this is a bug.
IntelliJ 12 129.961

I've hit this after just minor upgrade from IntelliJ IDEA 14 to v14.1.
For me changing an edit of top/parent pom helped and then clicked re-import Maven (if it is not automatic).
But it maybe just enough to Right Click on module(s)/aggregated/parent module and Maven -> Reimport.

I resolved bellow method
File >> Project Structure >> Project >> Project Language Level
--> do set proper version (ex: 1.5)

check
.idea/misc.xml
sometimes you need to change languageLevel="JDK_1_X" attribute manually

If it is a Gradle project, in your build.gradle file, search for following settings:
sourceCompatibility = "xx"
targetCompatibility = "xx"
For all subrpojects, in your root build.gradle file, you may put:
subprojects { project ->
sourceCompatibility = "1.7"
targetCompatibility = "1.7"
}
Although you can manually set language levels in Idea > Settings, if it is a Gradle project, Idea automatically synchronizes module .iml files from Gradle settings ( tested with Idea 15+). So all your manual changes are overriden when gradle is refreshed.
Based on Gradle documentation, if these are not set, then current JVM configuration is used.

I found another way to run into this error. You can get this if you have been re-organizing your directory structure, and one of your poms is pointing to the old parent which no-longer configures javac (because that configuration was moved to a middle level). If this happens the top level defaults to 1.5 and the misbehaving lower level pom inherits it.
So another thing to check when you see this error is that your pom structure is matching your directory structure properly.

If Maven build works fine, try to synchronizing structure of Maven and IntelliJ IDEA projects.
In the Maven tool window, click refresh button . On pressing this button, IntelliJ IDEA parses the project structure in the Maven tool window.
Note that this might not help if you're using EAP build, since Maven synchronization feature may be broken sometimes.

If all the previous solutions haven't worked for you (which was my case), you can delete intellij config files:
project_directory/.idea/compiler.xml
project_directory/.idea/encodings.xml
project_directory/.idea/misc.xml
project_directory/.idea/modules.xml
project_directory/.idea/vcs.xml
project_directory/.idea/workspace.xml
etc.
Intellij will regenerate new ones later.
However, BE CAREFUL, this will also delete all intellij configuration made on the projet (i.e: configuration of debug mode, ...)

You need to change Java compiler version in in build config.

Make sure right depency is selected.
File > Project Structure
Select your project and navigate to Dependencies tab. Select right dependancy from dropdown or create new.

Maven 2.5.1 doesn't support JDK 7 [duplicate]

In Eclipse Juno, I installed the latest m2e plugin (1.2.20120903-1050). In preferences, I have added jdk1.7.0_11 in Java -> Installed JREs -> Add, and then specified the location (C:\Program Files\Java\jdk1.7.0_11). When I create a new Maven project and run it, I get a warning:
Build path specifies execution environment J2SE-1.5. There are no JREs installed in the workspace that are strictly compatible with this environment.
I am not sure how to resolve this.
I believe it is a Maven problem because I do not have this error when I run normal Java projects. I read here that I should change the "maven-compiler-plugin.pom" and change the source and target from 1.5 to something more appropriate. In my case, 1.7. I have done this, but I still get the warning.

All of the answers above may work for the time being but whenever you run maven on the command line or Maven → Update project… the JDK will be reset, this was also the question as I understand it.
To fix this for good add the following code to your pom file. Remember to do a Maven → Update project… afterwards or mvn clean compile at the command line.
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
</plugins>
</pluginManagement>
</build>

Right-click on your project
Click Properties
Click the "Java Compiler" option on the left menu
Under JDK compliance section on the right, change it to "1.7"
Run a Maven clean and then Maven build.

I know this is an old topic. I had the same problem. I tested all the answers about this topic. And nothing worked here... but i found another solution.
Go to pom->overview and add these to you properties:
Name: "maven.compiler.target" Value: "1.7"
and
Name: "maven.compiler.source" Value: "1.7"
Now do a maven update.

For imported maven project and JDK 1.7 do the following:
Delete project from Eclipse (keep files)
Delete .settings directory, .project and .classpath files inside your project directory.
Modify your pom.xml file, add following properties (make sure following settings are not overridden by explicit maven-compiler-plugin definition in your POM)
<properties>
<maven.compiler.source>1.7</maven.compiler.source>
<maven.compiler.target>1.7</maven.compiler.target>
</properties>
Import updated project into Eclipse.

I'm using Juno 4.2 with latest spring, maven plugin and JDK1.6.0_25.
I faced same issue and here is my fix that make default after each Eclipse restart:
List item
Right-click on the maven project
Java Build Path
Libraries tab
Select current wrong JRE item
Click Edit
Select the last option (Workspace default JRE (jdk1.6.0_25)

If you are getting following type of error
Then do the following steps-->>
Go to Windows. Then select Preferences, in Which select java(on the left corner).
In java select Installed JREs and check your JRE(if you have correctly installed jdk and defined environment variables correct then you will see the current version of the installed java here)as shown -
(I have Java 8 installed)
Check the check box if it is not checked. Click apply and close.
Now Press Alt+Enter to go into project properties,or go via right clicking
on project and select Properties.
In Properties select Java Build Path on left corner
Select Libraries
And click edit(after selecting The JRE System Library...)
In edit Click and select Workspace default JRE. Then click Finish
In Order and Export Check the JRE System Library.
Then Finally Apply and close
Clean the project and then build it.
Problem Solved..Cheers!!

In order to update your project to the latest version of java available in your environment, follow these steps:
Open your pom.xml file
Switch your view to Effective POM tab
Open Find Dialog (ctrl + F) to search for maven-compiler-plugin
Copy the the following lines
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
Click on pom.xml tab to open your project pom configuration
Inside your <build> ... </build> configuration section, paste the configuration copied and modify it as...
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
save your configuration
Right Click in your project Click on [Maven -> Update Project] and Click on OK in the displayed update dialog box.
Done!

I was facing the same issue. In pom.xml I have specified maven compiler plugin to pick 1.7 as source and target. Even then when I would import the git project in eclipse it would pick 1.5 as compile version for the project. To be noted that the eclipse has installed runtime set to JDK 1.8
I also checked that none of the .classpath .impl or .project file is checked in git repository.
Solution that worked for me: I simply deleted .classpath files and did a 'maven-update project'. .classpath file was regenerated and it picked up 1.7 as compile version from pom file.

I got an error in Eclipse Mars version as "Build path specifies execution environment J2SE-1.5. There are no JREs installed in the workspace that are strictly compatible with this environment.
To resolve this issue, please do the following steps,
"Right click on Project
Choose Build path
Choose Configure Build path
Choose Libraries tab
Select JRE System Library and click on Edit button
Choose workspace default JRE and Finish
Problem will be resolved.

When creating a maven project in eclipse, the build path is set to JDK 1.5 regardless of settings, which is probably a bug in new project or m2e.

I tested all the answers about this topic. And nothing worked here… but I found another solution.
Go to pom -> overview and add these to your properties:
Name: “maven.compiler.target” Value: “1.8”
and
Name: “maven.compiler.source” Value: “1.8”
Now do a maven update.

Maven "build path specifies execution environment J2SE-1.5", even though I changed it to 1.7

In Eclipse Juno, I installed the latest m2e plugin (1.2.20120903-1050). In preferences, I have added jdk1.7.0_11 in Java -> Installed JREs -> Add, and then specified the location (C:\Program Files\Java\jdk1.7.0_11). When I create a new Maven project and run it, I get a warning:
Build path specifies execution environment J2SE-1.5. There are no JREs installed in the workspace that are strictly compatible with this environment.
I am not sure how to resolve this.
I believe it is a Maven problem because I do not have this error when I run normal Java projects. I read here that I should change the "maven-compiler-plugin.pom" and change the source and target from 1.5 to something more appropriate. In my case, 1.7. I have done this, but I still get the warning.

All of the answers above may work for the time being but whenever you run maven on the command line or Maven → Update project… the JDK will be reset, this was also the question as I understand it.
To fix this for good add the following code to your pom file. Remember to do a Maven → Update project… afterwards or mvn clean compile at the command line.
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
</plugins>
</pluginManagement>
</build>

Right-click on your project
Click Properties
Click the "Java Compiler" option on the left menu
Under JDK compliance section on the right, change it to "1.7"
Run a Maven clean and then Maven build.

I know this is an old topic. I had the same problem. I tested all the answers about this topic. And nothing worked here... but i found another solution.
Go to pom->overview and add these to you properties:
Name: "maven.compiler.target" Value: "1.7"
and
Name: "maven.compiler.source" Value: "1.7"
Now do a maven update.

For imported maven project and JDK 1.7 do the following:
Delete project from Eclipse (keep files)
Delete .settings directory, .project and .classpath files inside your project directory.
Modify your pom.xml file, add following properties (make sure following settings are not overridden by explicit maven-compiler-plugin definition in your POM)
<properties>
<maven.compiler.source>1.7</maven.compiler.source>
<maven.compiler.target>1.7</maven.compiler.target>
</properties>
Import updated project into Eclipse.

I'm using Juno 4.2 with latest spring, maven plugin and JDK1.6.0_25.
I faced same issue and here is my fix that make default after each Eclipse restart:
List item
Right-click on the maven project
Java Build Path
Libraries tab
Select current wrong JRE item
Click Edit
Select the last option (Workspace default JRE (jdk1.6.0_25)

If you are getting following type of error
Then do the following steps-->>
Go to Windows. Then select Preferences, in Which select java(on the left corner).
In java select Installed JREs and check your JRE(if you have correctly installed jdk and defined environment variables correct then you will see the current version of the installed java here)as shown -
(I have Java 8 installed)
Check the check box if it is not checked. Click apply and close.
Now Press Alt+Enter to go into project properties,or go via right clicking
on project and select Properties.
In Properties select Java Build Path on left corner
Select Libraries
And click edit(after selecting The JRE System Library...)
In edit Click and select Workspace default JRE. Then click Finish
In Order and Export Check the JRE System Library.
Then Finally Apply and close
Clean the project and then build it.
Problem Solved..Cheers!!

In order to update your project to the latest version of java available in your environment, follow these steps:
Open your pom.xml file
Switch your view to Effective POM tab
Open Find Dialog (ctrl + F) to search for maven-compiler-plugin
Copy the the following lines
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
Click on pom.xml tab to open your project pom configuration
Inside your <build> ... </build> configuration section, paste the configuration copied and modify it as...
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
save your configuration
Right Click in your project Click on [Maven -> Update Project] and Click on OK in the displayed update dialog box.
Done!

I was facing the same issue. In pom.xml I have specified maven compiler plugin to pick 1.7 as source and target. Even then when I would import the git project in eclipse it would pick 1.5 as compile version for the project. To be noted that the eclipse has installed runtime set to JDK 1.8
I also checked that none of the .classpath .impl or .project file is checked in git repository.
Solution that worked for me: I simply deleted .classpath files and did a 'maven-update project'. .classpath file was regenerated and it picked up 1.7 as compile version from pom file.

I got an error in Eclipse Mars version as "Build path specifies execution environment J2SE-1.5. There are no JREs installed in the workspace that are strictly compatible with this environment.
To resolve this issue, please do the following steps,
"Right click on Project
Choose Build path
Choose Configure Build path
Choose Libraries tab
Select JRE System Library and click on Edit button
Choose workspace default JRE and Finish
Problem will be resolved.

When creating a maven project in eclipse, the build path is set to JDK 1.5 regardless of settings, which is probably a bug in new project or m2e.

I tested all the answers about this topic. And nothing worked here… but I found another solution.
Go to pom -> overview and add these to your properties:
Name: “maven.compiler.target” Value: “1.8”
and
Name: “maven.compiler.source” Value: “1.8”
Now do a maven update.

IDEA: javac: source release 1.7 requires target release 1.7

When running a JUnit test, using IntelliJ IDEA, I get
How can I correct this?
Using SDK 1.7
Module language level is 1.7
Maven build works fine. (That's why I believe this in IDEA configuration issue)

Most likely you have incorrect compiler options imported from Maven here:
Also check project and module bytecode (target) version settings outlined on the screenshot.
Other places where the source language level is configured:
Project Structure | Project
Project Structure | Modules (check every module) | Sources
Maven default language level is 1.5 (5.0), you will see this version as the Module language level on the screenshot above.
This can be changed using maven-compiler-plugin configuration inside pom.xml:
<project>
[...]
<build>
[...]
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
[...]
</build>
[...]
</project>
or
<project>
[...]
<properties>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
[...]
</project>
IntelliJ IDEA will respect this setting after you Reimport the Maven project in the Maven Projects tool window:

IntelliJ 15, 2016 & 2017
Similar to that discussed below for IntelliJ 13 & 14, but with an extra level in the Settings/Preferences panel: Settings > Build, Execution, Deployment > Compiler > Java Compiler.
IntelliJ 13 & 14
In IntelliJ 13 and 14, check the Settings > Compiler > Java Compiler UI to ensure you're not targeting a different bytecode version in your module.

In IntelliJ IDEA 14.1 the "Target bytecode version" is in a different place.
The following change worked for me:
File > Settings... > Build, Execution, Deployment > Compiler > Java Compiler : change Target bytecode version from 1.5 to 1.8

Have you looked at your build configuration it should like that if you use maven 3 and JDK 7
<build>
<finalName>SpringApp</finalName>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
...
</plugins>
...
</build>

I ran into this and the fix was to go to Project Settings > Modules > click on the particular module > Dependencies tab. I noticed the Module SDK was still set on 1.6, I changed it to 1.7 and it worked.

I've found required options ('target bytecode version') in settings > compiler > java compiler in my case (intelij idea 12.1.3)

Modify the compiler setting file of the project in the following path and change the 'target' to 1.7:
/project/.idea/compiler.xml
<bytecodeTargetLevel>
<module name="project-name" target="1.7" />
</bytecodeTargetLevel>

I resolved it by setting the field blank:
Settings > Compiler > Java Compiler > Project bytecode version
Than IntelliJ uses the JDK default version.

From one moment to the other I also got this error without a clear reason. I changed all kinds of settings on the compiler/module etc. But in the end I just recreated the IntelliJ project by reimporting the Maven project and the issue was solved. I think this is a bug.
IntelliJ 12 129.961

I've hit this after just minor upgrade from IntelliJ IDEA 14 to v14.1.
For me changing an edit of top/parent pom helped and then clicked re-import Maven (if it is not automatic).
But it maybe just enough to Right Click on module(s)/aggregated/parent module and Maven -> Reimport.

I resolved bellow method
File >> Project Structure >> Project >> Project Language Level
--> do set proper version (ex: 1.5)

check
.idea/misc.xml
sometimes you need to change languageLevel="JDK_1_X" attribute manually

If it is a Gradle project, in your build.gradle file, search for following settings:
sourceCompatibility = "xx"
targetCompatibility = "xx"
For all subrpojects, in your root build.gradle file, you may put:
subprojects { project ->
sourceCompatibility = "1.7"
targetCompatibility = "1.7"
}
Although you can manually set language levels in Idea > Settings, if it is a Gradle project, Idea automatically synchronizes module .iml files from Gradle settings ( tested with Idea 15+). So all your manual changes are overriden when gradle is refreshed.
Based on Gradle documentation, if these are not set, then current JVM configuration is used.

I found another way to run into this error. You can get this if you have been re-organizing your directory structure, and one of your poms is pointing to the old parent which no-longer configures javac (because that configuration was moved to a middle level). If this happens the top level defaults to 1.5 and the misbehaving lower level pom inherits it.
So another thing to check when you see this error is that your pom structure is matching your directory structure properly.

If Maven build works fine, try to synchronizing structure of Maven and IntelliJ IDEA projects.
In the Maven tool window, click refresh button . On pressing this button, IntelliJ IDEA parses the project structure in the Maven tool window.
Note that this might not help if you're using EAP build, since Maven synchronization feature may be broken sometimes.

If all the previous solutions haven't worked for you (which was my case), you can delete intellij config files:
project_directory/.idea/compiler.xml
project_directory/.idea/encodings.xml
project_directory/.idea/misc.xml
project_directory/.idea/modules.xml
project_directory/.idea/vcs.xml
project_directory/.idea/workspace.xml
etc.
Intellij will regenerate new ones later.
However, BE CAREFUL, this will also delete all intellij configuration made on the projet (i.e: configuration of debug mode, ...)

You need to change Java compiler version in in build config.

Make sure right depency is selected.
File > Project Structure
Select your project and navigate to Dependencies tab. Select right dependancy from dropdown or create new.

Can't compile project when I'm using Lombok under IntelliJ IDEA

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.