CODEWITHSUNDEEP
javascala
Polymerase
Polymerase

Reputation: 6791

How do Scala acquire its JVM environment?

Dev env: Scala 2.11.8, JDK 1.8.112 x64, Windows 7 x64.

Problem: Scala still sees the previous JDK 1.8.101 instead of the new one 1.8.112.

C:\Users\myUserName>java -version
java version "1.8.0_112"
Java(TM) SE Runtime Environment (build 1.8.0_112-b15)
Java HotSpot(TM) 64-Bit Server VM (build 25.112-b15, mixed mode)

C:\Users\myUserName>scala
Welcome to Scala 2.11.8 (Java HotSpot(TM) 64-Bit Server VM, Java 1.8.0_101).
Type in expressions for evaluation. Or try :help.

scala> System.getProperty("java.version")
res3: String = 1.8.0_101

The reason is the new JDK is installed in C:\Program Files\Java\jdk1.8.0_112 while the previous JDK is in C:\Program Files\Java\jdk8. JAVA_HOME = C:\Program Files\Java\jdk8. So I suppose this is why Scala sees the previous version. However, PATH 

C:\Users\myUserName>PATH
PATH=C:\ProgramData\Oracle\Java\javapath; 
... etc...
C:\Program Files (x86)\scala\bin;C:\Program Files\Java\jdk8\bin;

C:\ProgramData\Oracle\Java\javapath contains java.exe which comes from the newest JDK. This is why java -version at the command line show the latest JDK.

Question: On Windows, how to make the latest JDK the official JDK? And generally, what is the recommended practice to update JDK on Windows?

Upvotes: 0

Views: 314

Answers (1)

MarianD
MarianD

Reputation: 14141

The java command executes java.exe file from the first folder of the PATH environment variable where this file is found.

On the other hand scala command executes scala.bat batch file and this file set the java environment for scala by JAVA_HOME environment variable if it exists.

The problem is that in almost every system is the file java.exe in many different folders - some of them may be subfolders of other program folders (i. e. from Adobe or JetBrains products) which you had installed previously.

The file name is the same but versions may be (and in most cases are) different.

And the recommended practice for upgrading? Install and pray (Oracle itself has problems with it) or install and then manually adjust every application which depends from Java.

Upvotes: 1

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