运行Scala脚本时Classpath失效问题求助

我已在目录/Users/satchwinston/Development/test/lib下成功编译了一个名为bnc.Encryption的Java类，使用Java 21和Scala 3.3.1，未启用Metals扩展。通过执行./encryptor运行Scala脚本，该脚本的shebang为#!/usr/bin/env scala -explain -classpath "/Users/satchwinston/Development/test/lib"。

执行后出现以下错误：

-- [E006] Not Found Error: /Users/satchwinston/Development/test/scala-cli/src/main/scala/./encryptor:7:7 
7 |import bnc.Encryption
  |       ^^^
  |       Not found: bnc
  |-----------------------------------------------------------------------------
  | Explanation (enabled by `-explain`)
  |- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  | The identifier for `bnc` is not bound, that is,
  | no declaration for this identifier can be found.
  | That can happen, for example, if `bnc` or its declaration has either been
  | misspelt or if an import is missing.
   -----------------------------------------------------------------------------
1 error found
Errors encountered during compilation

我的encryptor Scala脚本内容如下：

#!/usr/bin/env scala -explain -classpath "/Users/satchwinston/Development/test/lib"
/* $Id$ */

import java.nio.file.Files
import java.nio.file.Path

import bnc.Encryption

val usage = """
  Usage: encryptor ([-e] | [-d]) ([-in filename] | <arg>) > <filename>
"""

def encrypt(string: String): String =
  Encryption.encrypt(string)

def decrypt(string: String): String =
  Encryption.decrypt(string)

@main def encryptor(args: String*): Unit =
  if (args.isEmpty || args.length != 2 || args.length != 3) {
    println(usage)
    sys.exit(1)
  }

  val e: Boolean = args(0) == "-e"
  val d: Boolean = args(0) == "-d"
  val in: String = if (args(1) == "-in") args(2) else ""
  val str: String = if (args(1) != "-in") args(1) else ""

  if (e && str.length() > 0)
    println(encrypt(str))
  else if (e)
    println(encrypt(Files.readString(Path.of(in))))
  else if (d && str.length > 0)
    println(decrypt(str))
  else if (d)
    println(decrypt(Files.readString(Path.of(in))))
  else {
    println(usage)
    sys.exit(1)
  }

  sys.exit(0)

1. 检查Java类的目录结构 #

Java类的包名bnc对应实际目录结构，编译后的Encryption.class必须放在/Users/satchwinston/Development/test/lib/bnc/目录下，而非直接放在lib根目录。如果当前lib下只有Encryption.class，需要创建bnc子目录并将class文件移入。

2. 修复shebang参数传递问题 #

#!/usr/bin/env仅支持单个参数，当前shebang中的scala -explain -classpath "..."会被当作一个整体参数，导致env无法识别。可通过两种方式解决：

方式一：拆分shebang与运行参数 #

将脚本开头的shebang改为：

#!/usr/bin/env scala

然后通过命令行直接传递参数运行：

scala -explain -classpath "/Users/satchwinston/Development/test/lib" ./encryptor

方式二：用bash脚本包装 #

创建bash脚本encryptor：

#!/bin/bash
scala -explain -classpath "/Users/satchwinston/Development/test/lib" "$0".scala "$@"

将原Scala代码保存为encryptor.scala，给bash脚本添加执行权限：chmod +x encryptor，之后直接运行./encryptor即可。

3. 验证classpath有效性 #

先通过Scala REPL测试classpath是否正确：

scala -classpath "/Users/satchwinston/Development/test/lib"

进入REPL后尝试执行import bnc.Encryption，若能成功导入，说明classpath和目录结构无问题。

内容的提问来源于stack exchange，提问作者user4202824