scala maven 版本冲突问题解决
scalatest_2.10-1.9.1.jar of core build path is cross-compiled with an incompatible version of Scala (2.10.0)
Eclipse - Preferences - Scala - Compiler - Build manager
uncheck withVersionClasspathVariable
More than one scala library found in the build path (/home/hadoop/eclipse/plugins/org.scala-lang.scala-library_2.11.7.v20150622-112736-1fbce4612c.jar, /usr/local/spark/spark-1.5.1-bin-hadoop2.6/lib/spark-assembly-1.5.1-hadoop2.6.0.jar).At least one has an incompatible version. Please update the project build path so it contains only one compatible scala library. hello-test Unknown Scala Classpath Problem
修改工程中的scala编译版本
右击 –> Scala –> set the Scala Installation
也可以
右击工程–> Properties –> Scala Compiler –> Use project Setting 中选择spark对应的scala版本，此处选择Lastest2.10 bundle
上述方法仍然没有解决
原因maven pom.xml 中的版本与eclipse里面设置的版本冲出
解决办法修改pom.xml
问题解决
Unsupported major.minor version 52.0
You get this error because a Java 7 VM tries to load a class compiled for Java 8
Java 8 has the class file version 52.0 but a Java 7 VM can only load class files up to version 51.0
In your case the Java 7 VM is your gradle build and the class is com.android.build.gradle.AppPlugin
简单来说，就是java的编译环境版本太低，java 8 class file的版本是52，Java 7虚拟机只能支持到51。所以需要升级到java 8 vm才行
mvn -V
Apache Maven 3.5.2 (138edd61fd100ec658bfa2d307c43b76940a5d7d; 2017-10-18T15:58:13+08:00)
Maven home: /Users/didi/maven
Java version: 1.8.0_144, vendor: Oracle Corporation
Missing artifact org.scalatest:scalatest_2.12:jar: 2.2.4
http://mvnrepository.com/artifact/org.scalatest/scalatest_2.12/3.0.3
vi /Users/didi/maven/conf/settings.xml
在maven的默认配置中，对于jdk的配置是1.4版本，那么创建/导入maven工程过程中，工程中未指定jdk版本。
对工程进行maven的update，就会出现工程依赖的JRE System Library会自动变成JavaSE-1.4。
解决方案1：修改maven的默认jdk配置
maven的conf\setting.xml文件中找到jdk配置的地方，修改如下：
[html] view plaincopy在CODE上查看代码片派生到我的代码片
解决方案2：修改项目中pom.xml文件，这样避免在导入项目时的jdk版本指定
打开项目中pom.xml文件，修改如下：
右键－》propertity
remove jre1.6
add jre1.8
运行成功
Could not resolve dependencies for project maven.scala:mavenScala:jar:0.0.1-SNAPSHOT: Failure to find org.specs2:specs2-core_2.12:jar:2.12 in https://repo.maven.apache.org/maven2 was cached in the local repository, resolution will not be reattempted until the update interval of central has elapsed or updates are forced
http://maven.outofmemory.cn/org.specs2/specs2-core_2.12.0-M4/3.8.4/
删除
scalac error: bad option: '-make:transitive'
解决方法：
（1）打开pom.xml，删除
（2）添加dependance
测试报错 删除
mvn package
[INFO] Building jar: /Users/didi/PhpstormProjects/ProjGit/Spark/ScalaMaven/MavenScala/target/MavenScala-0.0.1-SNAPSHOT.jar
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ----------------
Description Resource Path Location Type
Project configuration is not up-to-date with pom.xml. Select: Maven->Update Project... from the project context menu or use Quick Fix. MavenScala line 1 Maven Configuration Problem
右键 Maven->Update Project
至此没有错误了
