CODEWITHSUNDEEP
javapackageprivatejava-9jshell
Isaac Saffold
Isaac Saffold

Reputation: 1185

Importing Package-Private Classes to JShell

I was playing around with JShell after the Java 9 release, and I tried importing a package I made. As the entire application I'm coding it for will be contained in that package, every class but one (which I haven't coded yet) is package-private. My classpath is correct, but I still can't use any of the types declared in the package in JShell (it throws a "cannot find symbol" error). Do I need to make them public for them to be accessible, or is there some way I can test package-private classes? Here's the exact code I tried.

My current directory is 

C:\Users\Sylvaenn\OneDrive\Documents\Programs\Java\src

My class path is 

C:\Users\Sylvaenn\OneDrive\Documents\Programs\Java\cls

and the package directory (for the bytecode) is 

C:\Users\Sylvaenn\OneDrive\Documents\Programs\Java\cls\collatz

CollatzSequence is a package-private class contained in collatz.

PS C:\Users\Sylvaenn> cd OneDrive\Documents\Programs\Java\src
PS C:\Users\Sylvaenn\OneDrive\Documents\Programs\Java\src> jshell
|  Welcome to JShell -- Version 9
|  For an introduction type: /help intro

jshell> import collatz.*;

jshell> CollatzSequence seq = new CollatzSequence(BigInteger.ONE);
|  Error:
|  cannot find symbol
|    symbol:   class CollatzSequence
|  CollatzSequence seq = new CollatzSequence(BigInteger.ONE);
|  ^-------------^
|  Error:
|  cannot find symbol
|    symbol:   class CollatzSequence
|  CollatzSequence seq = new CollatzSequence(BigInteger.ONE);
|                            ^-------------^

jshell> /imports
|    import java.io.*
|    import java.math.*
|    import java.net.*
|    import java.nio.file.*
|    import java.util.*
|    import java.util.concurrent.*
|    import java.util.function.*
|    import java.util.prefs.*
|    import java.util.regex.*
|    import java.util.stream.*
|    import collatz.*

jshell>

Upvotes: 7

Views: 2128

Answers (2)

Naman
Naman

Reputation: 31888

From the JEP#220 - The Java Shell (Read-Eval-Print Loop)

A snippet may not declare a package or a module. All JShell code is placed in a single package in an unnamed module. The name of the package is controlled by JShell.

That is the reason probably why you are not able to declare a package within JShell.

As the tool documentation suggests though you can give this a try:-

The default startup script consists of several common imports. You can personalize your startup entries with the /set start command.

where you can set the classpath or the modulepath of the class you would make use of :

jshell --class-path C:\Users\Sylvaenn\OneDrive\Documents\Programs\Java\cls

Upvotes: 4

rmuller
rmuller

Reputation: 12859

As far as i know (correct me if i am wrong), you cannot create a Class in a specific package using JShell (classes created within JShell are always in the default package).

That being said, you cannot access your package-private classes from within JShell. This is "normal" Java behaviour.

Upvotes: 4

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