I use Eclipse Mars (M1) as my IDE. Today, I generated my service's Java code using Apache Thrift 0.9.2 (latest stable version) for an Android project. This version (unlke version 0.9.1) uses the "Generated" annotation from javax.annotation package, for adding some extractable documentation. It adds a line like the following line before each generated class:
#Generated(value = "Autogenerated by Thrift Compiler (0.9.2)", date = "2014-11-30")
But surprisingly, Eclipse complains about the package javax.annotation. It throws the error "the import javax.annotation cannot be resolved". My project's Java compiler compliance level is 1.6, and its minimum Android API version is API 8 (Android 2.2). How can I fix this error?
Unfortunately most of packages under javax.* are not included in Android's JDK, therefore you need to add those that you need, manually. Here the reason for not including these packages is explained.
Unluckily, there are several versions of javax.annotation package available for download, some of which don't contain the "Generated" annotation class (javax.annotation.generated). Fortunately this jar file does include that specific annotation class. So if you don't use any build system like Gradle, Ant, or Maven, all you have to do is to include the .jar file in a directory in your project (e.g. lib/) and then add this jar library to your buildpath. If you use Ant, then follow the first link.
I had the same problem and I fixed it by adding this dependency to my build.gradle file
compile group: 'javax.annotation', name: 'javax.annotation-api', version: '1.3.2'
Related
I want to understand the dependencies for a multi-module maven project and for that referred to eclipse dependency hierarchy.
I did understand fairly, however some of the things I am not able to understand at all.
Below is the screen shot.
The things which I didn't understand are:
--> managed from 1.0.2 [Compile}
--> managed from 1.0.2 (omitted for conflict with 1.0.0) [Compile]
I did search online but I got information in traces. Can anyone help me understand what they mean in easy to understand?
Thanks.
Maven builds a flat classpath from the dependency tree each for compiling ([compile]), for testing, and for running.
In a flat classpath, unlike OSGi, a dependency can only exist in one version. In your cropped screenshot, there is on the second level among other things:
kafka-streams 1.0.2 and
kafka-clients 1.0.0.
kafka-streams 1.0.2 requires kafka-clients 1.0.2 which conflicts to kafka-clients 1.0.0. Therefore kafka-streams 1.0.2 is omitted for conflicts with 1.0.0 even if the version 1.0.2 is required here ("managed from 1.0.2").
More detailed:The classpath which is used to compile or run a plain Java application is flat: all required libraries are globally specified as an ordered list. It is not possible to use a library of a specific version for one package and for another package the same library in a different version.In Maven dependencies builds a tree: each dependency might have its own dependencies. Maven maps the tree of dependencies to the classpath, an ordered list of libraries. If in the Maven dependencies tree the same library exists in different versions, it is not possible to create a flat classpath. This is a conflict.This conflict is resolved by picking one version and omitting all other versions. At the place where the picked version is used instead of the required version, (managed from <required but not picked version>) and (omitted for conflict with <picked version to use instead>) is displayed.In addition, Maven can create different classpaths to compile, to test or to run a Java application via so-called scopes. The [compile] scope is the default scope for using a library in all tasks: compiling, testing and running.
Make sure that the versions specified in the pom.xml file are compatible with each other (which is not yet the case in your screenshot): you have to upgrade kafka-clients from 1.0.0 to 1.0.2 (or downgrade the other libraries).
I have been using sbt on windows and a custom build.sbt script in conjunction with an import Chisel._ in the top-level file in order to generate Verilog from my Chisel source successfully.
I'm trying to get an IDE working on Windows to expedite Chisel development. I've gone with the Eclipse based SCALA IDE http://scala-ide.org/download/sdk.html/
I want to compile the Chisel library so that the import Chisel._ can be resolved locally, without having to go off and download the source from the repository each timeand recompile the source. When I download the Chisel-master repo from Git and include the src\main folder in my SCALA project in the SCALA IDE, I get lots of syntax errors in the Chisel SCALA files that prevent me from building the project.
Has anyone done anything like this before on Windows or have any knowledge of working with the SCALA IDE as it may just be a case of undefined symbols in the project configuration?
Not sure exactly what you did with build.sbt respect to recompile (I think it download it only the first time, then it caches it for the future). But I'm using ScalaIDE for Chisel on linux, using the default build.sbt files, maybe you can try to get it working out of the box first to help narrow down the issue.
Here are the steps I took in order to get ScalaIDE work with Chisel:
the latest Scala IDE uses 2.11.8, the current Chisel repository defaults to 2.11.7. So I had to change all the build.sbt reference to scalaVersion from 2.11.7 to 2.11.8
I used sbteclipse
https://github.com/typesafehub/sbteclipse
To create importable the workspace to setup the compilation dependencies.
Except for chiselFrontEnd. For some reason, this package is not added to the dependency. I have to Add chiselFrontEnd as a javabuildpath dependency manually (Properties/JavaBuildPath, under Projects) for my own projects.
To resolve undefined symbols, you can also add a JAR onto the project build path using Project Properties > Java Build Path > Libraries > Add External JARs...
If you are getting your JARs through Maven / SBT, they should be in:
C:\Users\<name>\.ivy2\local\edu.berkeley.cs\chisel3_2.11\jars
If you are using publish-local with chisel3, your JARs should be in
C:\Users\<name>\.ivy2\cache\edu.berkeley.cs\chisel3_2.11\jars
Note that chisel3 is compiled into one JAR, including coreMacros and chiselFrontend sub-projects
Of course, this is a more quick-and-dirty solution compared to something that can parse SBT files.
Environment: Play 2.3.0/Scala 2.11.1/IntelliJ 13.1
I used Typesafe Activator 1.2.1 to create a new project with Scala 2.11.1. After the project was created, I ran gen-idea. The generated IDEA project fails to compile with the error:
Error: scala: No 'scala-library*.jar' in Scala compiler library in test
Am I doing something wrong? Workaround?
Open File -> Project Structures -> Libraries, remove any scala sdk in it, e.g. scala-sdk-2.11.8 in the following image.
Click on +, then Scala SDK.
Select the right Scala SDK from the list, for me, it's Ivy-Scala-2.11.8 shown in the picture.
Select the current project(mine is spark-test), click OK.
Then click OK to close it.
Run again, it should work now.
Since IDEA 13 you should use SBT support which is bundled with Scala plugin.
With it there is no need to add third-party SBT plugins and run special commands; just import the project using "File -> Import project..." menu item, and it will automatically load SBT project structure and its dependencies.
I had the same issue with the .idea files generated by ./activator idea with play 2.3. A quick fix is to look in "Project Structure->modules" and note the name of the compiler library. For me it was "SBT: scala2.11.1". The look in "Project Structure->Libraries" and check the contents of this library. It should contain scala-compiler.jar, scala-library.jar, scala-reflect.jar. If this libraries are not present, add them (in my case they are located in ~/.sbt/boot/scala-2.11.1/lib).
For IDEA 15 and project exported from Activator 1.3.5 only Russell's solution helped at the moment.
I have fixed scala compiler library with adding 3 libraries located in ~/.sbt/boot/scala-2.11.1/lib to library's compiler classpath and classes. After indexing project I moved this library to global libraries of IDEA and it was saved there.
I had the same issue.
If you are building your project using external sbt i.e sbt compile then it will create or add dependencies in libraries(all external dependency also) and scala sdk will be added as SBT:scala* based on version of your scala.
So you can remove SDK with SBT as prefix and add proper SDK through Intellij.
File->Project Structure->Libraries
Remove SBT SDK and add it manually.
For me with IDEA 12, I fixed this issue when I unchecked the box for "Use external build" in Settings.Compiler.
now is 2021 year, in Mac, use IntelliJ to run scala:
core logic
Mac: brew install scala
IntelliJ: open *.scala file, then according notice to auto config java JDK and Scala SDK
detailed steps: pls refer another post's answer
I'm an absolute Scala beginner. I was wanting to get up and running. I needed to create a Scala project, not a Java project with Scala library:
I know this question was asked a couple of times on stackoverflow - but I still face some problems trying to add an additional jar file to an existing android project - using android sdk tools rev. 19.
Summary:
I use eclipse Version: 3.6.2
The project compiled and the artefacts worked with android sdk tools rev. 14/any android >2.2 (>= API 8)
The project does compile with sdk tools rev. 19/any android >2.2 BUT the artifacts do not contain the jars defined within the classpath - so I keep getting java.lang.NoClassDefFoundError exceptions
I tried to add "jar.libs.dir=lib" to my project.properties - since lib contains all the jars without any positive effect.
I also tried to create a new dummy project adding jars as I always did (all jars added to a lib folder within the project, right click on the jar > add to build path)
I tried to add the jars using import
Thank you for your help.
Rename your "lib" folder to "libs".
I created a Drools project in Eclipse (Indigo) configured to use JRE 1.7. But I get an error pointing to my .drl file:
com/sample/DroolsTest$Message : Unsupported major.minor version 51.0
The com.sample.DroolsTest.Message class is imported by the .drl file. The Drools runtime was 5.2.1 (also tried with 5.3.0.Final).
Any help would be appreciated. Thanks.
This exception doesn't seem to have to do anything with Drools in particular, but is a generic Java error. It occurs if you try to execute a Java class with a JRE that is older than the JDK that was used to compile it. For example, if you compiled the class with a JDK7 and then tried to execute it with a JDK6, you would get this error.
Just to detail above answer and comment. I had both JRE6 and JRE7 installed, with JRE7 being the default. I had to do two things to remove the error from the drools sample project.
Set the JRE for the project to 1.6
Project properties->Java Build Path->Libraries. Remove JRE System Library 1.7 and Add Library->JRE System Library->Alternate JRE->JRE6
Set the compiler compliance level for the project at 1.6.
Project properties->Java Compiler->check Enable Project specific settings and set Compiler compliance level at 1.6.