As far as I understand, Lombok uses Java's Annotation Processors to generate additional methods.
With Maven 3.5 it works perfectly without adding any additional configuration, just add dependecy to Lombok and put some annotations like #Getter, #Setter.
However, if I open this project in IntelliJ IDEA 2018.2, all usages of generated getters/setters are highlighted as errors. I have Annotation Processing turned on, I tried to built project in IntelliJ or build in Maven and then use in IntelliJ, but it still requires Lombok Plugin to avoid false errors.
Is it some kind of bug? Error in workflow? Or maybe Lombok is using not only Annotation Processors, but some other stuff I didn't know and that's why IntelliJ + javac cannot figure out how to deal with it? It would be strange as javac itself compiles those files without errors
I know there are many questions "I have errors while using Lombok" and answers like "use the plugin". I'm not asking if I should use plugin, but why I should use it, why IntelliJ cannot handle it without plugin while javac does
IntelliJ's code analysis engine does not use javac or run annotation processors. Instead, IntelliJ uses its own Java parser and reference resolution logic, and builds its own code model. The Lombok plugin extends the code model to provide information about declarations generated by the Lombok annotation processor.
It's because IDEA syntax highlighter uses internal Java parser. If IDEA used just javac, then it wouldn't be able to highlight syntax errors as you type. It also gives much better hints about wrong code, so each Java construct, feature or annotation must be implemented by JetBrains team or there's plugin for it like in this case.
Annotation processing option is just for building project which is done via javac, but it's not for syntax highlighting.
Ale IDEs use lombok plugin be it intelij-idea or eclipse.
javac works fine with it - but remember that it works when for example you build you project with mvn clean package.
Then when you have your IDE - it works differntly - the code is not processed like in build task.
The plugin make it know to IDE what is this annotation and what code it generates underhood without need of javac.
Related
I have proper dependencies
And lombok plugin was installed, so Android Studio know where generation was applied but i still got an error
Please can anyone give me idea what is happening?
EDIT:
from kotlin 1.7.20 with K2 compiler it is possible.
https://kotlinlang.org/docs/whatsnew1720.html#support-for-kotlin-k2-compiler-plugins
OLD:
Ok, I guess my problem somewhat solved. My project have mixed Kotlin\Java code, I found this closed issue in project lombok: https://github.com/projectlombok/lombok/issues/1169
Corresponding to this lombok cant work in Kotlin\Java code normal way cause reasons... and there is two solutions:
Multi module project where all Java code with lobmok separated from Kotlin code and java module should using only java compiler.
Use special plugin from Kotlin which in part solving issue https://kotlinlang.org/docs/lombok.html
Another dum-dum solution: drop lombok annotation on java class and then using some instruments delombok it.This way no javac will be required.
I´m implementing a library in Kotlin that it will be used from Java.
It would be possible to create an annotation and AOP code in Kotlin, and then being used from Java.+
If that possible a documentation or example it would be awesome. I cannot find anything with that interoperability.
Regards.
As for the annotation, there should not be any problem implementing it in Kotlin.
As for the aspect, when compiled with the Kotlin compiler it shall end up being a regular JVM class with all the necessary #AspectJ annotations, but it will not be an aspect because it was not compiled by the AspectJ compiler which as of today only understands Java source code.
If you use such an "unfinished" aspect via LTW (load-time weaving), the AspectJ weaver can finish it into an aspect while it is being loaded, so that scenario should work.
In the case of trying to use the unfinished aspect for compile-time or binary weaving against Java (or Kotlin) target classes, an intermediate step to finish the unfinished aspect using the AspectJ compiler would be necessary, but I never tried that and do not know if it is even possible. It would be interesting to try. I do not speak Kotlin, but maybe it would be fun to try if you have something for me to start with like a sample project, ideally built with Maven. If there is any way to pull this off, we would end up using the AspectJ Maven plugin for just like #dreamcrash suggested, just in a different way.
BTW, I need more information from you about what you mean by "use from Java". Please elaborate.
Update: I just gave it a quick try:
Annotation + aspect both in Kotlin
Compile with Kotlin compiler into my-aspect.jar, aspectjrt.jar on the class path
Package Kotlin classes into a JAR
Java class using annotation from Kotlin aspect JAR
Compile with ajc, my-aspect.jar on the inpath and aspectjrt.jar and kotlin-stdlib.jar on the class path.
Result is e.g. in bin directory, both the Java class and the two Kotlin classes from the JAR, but the aspect this time finished by ajc (bigger class file than original).
Run Java program with bin folder, aspectjrt.jar and kotlin-stdlib.jar on the class path.
Works nicely, aspect kicks in.
The only step remaining is to "mavenise" this in connection with AspectJ Maven plugin, which should be fairly easy. But the answer to your question is: Yes, you can implement an aspect in Kotlin and use it combined with Java target classes. The downside of course is that you need the Kotlin standard library on the class path, not just the AspectJ runtime as usual.
Update 2: I created a Maven multi-module playground project for myself and for your convenience. Just clone my GitHub repository, then build and run according to the read-me file.
I am attempting to use lombok (https://projectlombok.org/) to help with "boilerplate" code generation. I have added the maven dependency and have also added the lombok maven plugin to the <build> element in the POM.
One of the things I was also told to do was to place the lombok-annotated code in src/main/lombok instead of src/main/java. I assume that I keep the package directory structure the same as in src/main/java.
This seems a little odd, but I did this and lombok did generate source files with all the getter/setter/equals/hashCode etc methods. They are placed in e.g. target/generated-sources/lombok/x/y/z/MyClass.java. This is kind of what I would expect having used other code generation tools like XJC.
My question is: how do I get this generated source to be "visible" to eclipse and the compile environment? I'm getting compile errors all over the place because it can't "see" the generated code. This occurs in eclipse as well as when I attempt to do a mvn clean install.
UPDATE:
I have already tried installing lombok into eclipse. It generates the getters/setters/etc, but there is a bug introduced somewhere that breaks the auto-complete feature of eclipse. I removed it from eclipse and am just trying to get maven to do the generation (or delombok-ing).
I've just installed Lombok (after a while) in my new Eclipse (STS) installation, and i was a bit "annoyed" by the lack of generated sources.
I found a hint however on this page that the generated structure is visible in the "Outline" view. (Look for the screenshots)
If you don't have Outline view open yet, enable it in the menu: Window / Show view / Outline.
Download Lombok jar (https://projectlombok.org/download) and execute it java -jar lombok.jar and select your eclipse installed folder.Restart eclipse and rebuild project.
To verify Lombok installation, please check Help -> About eclipse. Lombok entry show show at bottom.
You have to enable annotation processing for Eclipse to be able to pick up generated code.
Right-click on the project and select Properties.
Open Java Compiler and then Annotation Processing. Check Enable
annotation processing.
Open Java Compiler -> Annotation Processing -> Factory Path. Check
Enable project specific settings. Add your Lombok JAR file to the list.
Clean and build the project.
My problem was using full namespace annotation: #lombok.Getter, and I resolved it by doing import lombok.Getter and do #Getter
I just discovered google's AutoValue library, which seems great.
I'm trying to compile the example project which I downloaded from here
But the project doesn't compile.
The compiler complains about the AutoValue_ constructor symbol not being recognized.
Can someone explain what I am doing wrong?
I am using auto-value-1.3.jar
Thanks
IntelliJ does not enable annotation processors by default.
You can follow the official guide. You need to go to the Annotation Processors page and click + to create a new profile. Then you have to associate your module with this profile. In the end you only need to enable annotation processing for this profile and everything should work.
The IntelliJ editor might not find the generated class files though and still display the name red. But it should not affect the build.
In my Java project, i use Lombok tool to generate getter and setter.
It works perfectly with Maven, without any configuration.
For what reason i need to configure Eclipse for Lombok ?
I already know how to configure Eclipse : https://projectlombok.org/download.html
Why i have to add the following line in my eclipse.ini ?
-javaagent:lombok.jar
The Lombok site states:
Lombok copies your source files to another directory,
replacing all lombok annotations with their desugared form.
So configuring is done just because of source code modification. Without "javaagent" would be difficult.
Lombok uses Java annotation processor. So, irrespective of which IDE you use, if Lombok's jar is available for javac, your getters and setters get generated and all other functionality of Lombok works as expected.
Maven adds dependent jars (including Lombok's) to -classpath parameter of javac, so you wouldn't need a Java agent to instrument the code for you.