I am so frustrated right now. I was trying to follow this tutorial
https://www.callicoder.com/java-read-write-csv-file-opencsv/ to use openCSV in java to read some file. After I set up every thing. I got these error.
And, then I did some research. And I follow the answer https://stackoverflow.com/a/42929382/8371801
Now my pom look like this
Then the problem fixed. Every thing works perfect. So I just want to know what happened. What does pom file exactly do? What does Maven exactly do? I did many researches on line but I am still so confused. Why my java version is 10.1 it still work when I enter 1.8 in pom.
Maven does many things. In your case it downloads the opencsv library for you and invokes javac for you.
The properties you've set in your pom.xml (one of maven's configuration files) control whats passed in javac's -source and -target options.
Essentially thru maven you have defined what version of java to use. You can also do the same kind of thing going to the modules->dependencies in the module settings.
A useful link
Difference between intellij Project make and Maven Compile?
Related
I wonder if anyone is using codenameone with lombok in Eclipse. I've googled, but all I could find is an old question of mine.
A tiny success
I've tried it, took a demo project, modified nothing and opened it in my Eclipse configured for Lombok. When compiling, I got the same stacktrace as here. I've added
/usr/lib/jvm/java-8-oracle/lib/tools.jar
to the path under Preferences -> Installed JREs -> Edit -> JRE system libraries (which may be a pure non-sense) and it didn't help.
Then I've replaced compiler="modern" by compiler="extJavac" in build.xml and it compiles. I can even use Lombok annotations and they compile and work in the simulator.
The problem
I'm afraid, this was the simple part. I guess, for submitting, I need to replace the source code by the output of delombok. I've tried to submit it as is and nothing happened (no error, no response).
Has anyone done it already?
Any tips?
You shouldn't change the classpath but if the bytecode has access to the properties then it should "just work". If you look at the build.xml file you will notice that it has targets for every one of the supported platforms and before the target occurs you will see a compilation target that packages the JAR that's sent to the servers.
Steve wrote a post about porting other languages to Codename One. This is simple by comparison.
It actually works! All I had to do was to
add the path to lombok.jar to the Java Build Path1
in the javac call of the jar task
replace compiler="modern" by compiler="extJavac"
add the path to lombok.jar to the classpath
1 This is not recommended as the dependency is unavailable on the build server, but that's exactly right. Lombok is a compile-time only dependency and the build seems to be based on the dist.jar, where Lombok has already done its job.
One year later: There was a problem with my old setup, so I installed everything anew and it seems to work. Just note that there are three javac tasks in the build.xml.
I have found this nowhere on SO or in the documentation, but I would like to create a single jar containing both the binaries and the source code. My project is a mix of Scala and Java, if it adds anything to the question.
I've found this Github project which seems interesting and might enable me to do this, but I could not manage to set it up despite of the instructions. I think it is anyway a bit overkill for my use case. Any idea ?
I am new to enterprise application developement and trying to create a REST server with Spring REST, JPA taking to mySQL database and Javascript on the client side. As I see loads of opensource libraries doing specific task, I started off with using 'maven project' with different 'arch type' (which is nothing but predefined POM with relevent libraries as I understand) provided by Eclipse. But I often run into version mismatch issues, in many cases found specific solution to that perticular libraries in StackOverflow or other sites.
Hence I started looking for a information these version dependancies such as, this version of JPA works with that version of Hibernate library and so on. I checked maven repository of major libraries, I did not find such information so far.
My queries are:
Where can I find these information about the versions dependancies?
Are these pre defined POM in eclipse reliable? Who owns them, where can I get last modified dates on these maven 'arch types'? (I find the ones I choose having fairly old version of libraries).
If I have to start off on my own creating a Maven dependacies, where will I get information about what are the dependent libraries, for example, if I need spring MVC, for sure it needs java servlet library. I am worried becuase the maven 'spring-mvc-jap' arch type whooping 50 libaries as dependancies.(Coming from embeded domain, I find to too hard to digest :D). So not sure if it is the right way.
Please correct if I am missing anything in my understanding.
You can find this information, if you are using maven and some IDE you can go to the dependancy and make click un > and this will show the librarys used for this dependancy or if you want to use the console you have http://maven.apache.org/plugins/maven-dependency-plugin/examples/resolving-conflicts-using-the-dependency-tree.html this will show the same that the IDE.
After normally in the documentation of the library used, you can find some doc about the dependancy about this.
Other solution is get the .jar and use 7zip to see the POM and know the dependancy used.
And for finish my answer if the IDE tell you that you dont have x dependancy normally you have to add this because any of the other dependancy used have it (they used only for the compiling task), but sometime somes projet change a lots of code between the version .a to .b so you will have some problem using the version .b, at this moment i didnt find one good and easy way to fix this, only using the way that i told you (only if i found some problem in the compilation)
3> I am not sure how it works in eclipse but in IntelliJ IDEA when you start using some class without proper dependency IDEA suggest you to add proper dependency automatically. The same approach should be in eclipse.
I'd like to make Gradle use Eclipse project dependencies. Unlike this question, I don't want to do any export as I don't want to hunt down problems due to forgetting to re-export after a change. And unlike this question, I don't want to integrate Gradle into Eclipse at all, as I'm satisfied with how my Eclipse works (it's much faster than a Gradle build) and I'm also afraid that my Eclipse 3.7.2 may be too old for such games.
Ideally, I'd like something like
dependencies {
compile allFilesFromEclipse()
}
Actually, getting the JARs would suffice.
What I've tried: Just some light googling. I could imagine parsing the .classpath file myself, but it's not done in 5 minutes, so I'm asking if there's an existing solution.
I am afraid you won't find much help. It is not obvious what problem you want to solve here. Most developers prefer to base their build on a build tools rather than expect that they will replicated an IDE setup everywhere.
As for Eclipse 3.7.2: I am not sure why you want to stick with that but gradle eclipse generates files that work with this version.
I have some groovy files in Eclipse and my project has the Groovy nature. I don't use the GroovyBuilder (I don't think you need to now. there were problems in the past when java files referenced groovy and vice versa). Sometimes when I run my project I get a "Stubbed Method" error and I need to do a project clean for the groovy files to rebuild. Any ideas why I need to do this and what causes the files to need rebuilding if I'm not changing them?
thanks,
Jeff
It sounds like you are using an old version of the plugin. Please upgrade to V2 of groovy-eclipse (still in alpha, but quite stable).
The update site is available here:
http://dist.codehaus.org/groovy/distributions/greclipse/snapshot/e3.5/
Also, be sure to convert all your old groovy projects to the new format (see the groovy preferences page).