在sbt項目的classpath中添加tools.jar

Question

scala 2.9.1 控制台中的':javap' 命令需要'classpath' 中的tools.jar（來自JDK6）。 從 cmd-line 可以使用“-cp”參數或 CLASSPATH 環境變量來完成。

如何對使用“控制台”和“控制台快速”命令從 SBT 調用的 Scala 控制台執行相同操作？

Answer 1

長答案，這可能會在其他地方幫助你。

如果我想了解 SBT 中的某些內容，我會inspect它：

> inspect console
[info] Task: Unit
[info] Description:
[info]  Starts the Scala interpreter with the project classes on the classpath.
[info] Provided by:
[info]  {file:/home/dcs/github/anti-xml/}default-39679a/compile:console
[info] Dependencies:
[info]  compile:compilers(for console)
[info]  compile:full-classpath
[info]  compile:scalac-options(for console)
[info]  compile:initial-commands(for console)
[info]  compile:streams(for console)
[info] Delegates:
[info]  compile:console
[info]  *:console
[info]  {.}/compile:console
[info]  {.}/*:console
[info]  */compile:console
[info]  */*:console
[info] Related:
[info]  test:console

好的， compile:full-classpath有一個有趣的依賴compile:full-classpath 。 我希望它是compile:full-classpath(for console) ，但它不是。 不過，在這種情況下，它不應該給我帶來麻煩。 讓我們inspect一下。

> inspect compile:full-classpath
[info] Task: scala.collection.Seq[sbt.Attributed[java.io.File]]
[info] Description:
[info]  The exported classpath, consisting of build products and unmanaged and managed, internal and external dependencies.
[info] Provided by:
[info]  {file:/home/dcs/github/anti-xml/}default-39679a/compile:full-classpath
[info] Dependencies:
[info]  compile:exported-products
[info]  compile:dependency-classpath
[info] Reverse dependencies:
[info]  compile:console
[info] Delegates:
[info]  compile:full-classpath
[info]  *:full-classpath
[info]  {.}/compile:full-classpath
[info]  {.}/*:full-classpath
[info]  */compile:full-classpath
[info]  */*:full-classpath
[info] Related:
[info]  compile:full-classpath(for doc)
[info]  test:full-classpath
[info]  test:full-classpath(for doc)
[info]  *:full-classpath(for console)
[info]  runtime:full-classpath
[info]  compile:full-classpath(for console)

好的，我可以進一步研究依賴關系，但我認為沒有必要。 讓我們看看里面有什么：

> show compile:full-classpath
[warn] Credentials file /home/dcs/.ivy2/.credentials does not exist
[info] List(Attributed(/home/dcs/github/anti-xml/target/scala-2.9.1/classes), Attributed(/home/dcs/.sbt/boot/scala-2.9.1/lib/scala-library.jar))
[success] Total time: 0 s, completed Dec 7, 2011 3:49:30 PM

好的，沒有什么出乎意料的。 讓我們添加tools.jar 。

要更改某些內容，我必須使用set ，並且我必須遵守一堆駝峰式案例和其他規則才能使其正常工作。 如果我有compile:full-classpath(for console) ，那將成為fullClasspath in Compile in console 。 請注意Compile的大寫，並且full-classpath變為fullClasspath ，以及元素名稱的一般重新排序。 詳情請看這里。

我認為人們應該能夠獲取show （或者至少是inspect ）的輸出並將其反饋給set ，但情況並非如此（無論如何），所以只需學習這些轉換規則即可。

我不想重新輸入所有內容，只需添加一個 JAR 文件。 我需要為此使用+= 。 可以在此處找到用於更改事物的運算符。

類路徑似乎需要一些Attributed東西。 在 SBT wiki 中查看有關Classpath的詳細文檔，並找出如何提出一個。 幸運的是，我可能想要更改的大多數值並不像這個值那樣難以創建。

> set fullClasspath in Compile += Attributed.blank(file("/usr/lib/jvm/java-6-sun-1.6.0.26/lib/tools.jar"))
[info] Reapplying settings...
[info] Set current project to anti-xml (in build file:/home/dcs/github/anti-xml/)

似乎奏效了。 讓我們show它的內容來確認一下，因為即使編寫compile而不是Compile也可能讓它改變錯誤的東西。

> show compile:full-classpath                                                                             
[warn] Credentials file /home/dcs/.ivy2/.credentials does not exist
[info] List(Attributed(/home/dcs/github/anti-xml/target/scala-2.9.1/classes), Attributed(/home/dcs/.sbt/boot/scala-2.9.1/lib/scala-library.jar), Attributed(/usr/lib/jvm/java-6-sun-1.6.0.26/lib/tools.jar))
[success] Total time: 0 s, completed Dec 7, 2011 3:50:07 PM

是的，它在那里。 讓我們測試一下：

> console
[warn] Credentials file /home/dcs/.ivy2/.credentials does not exist
[info] Starting scala interpreter...
[info] 
import com.codecommit.antixml._
bookstore: com.codecommit.antixml.Elem = <bookstore><book><title>For Whom the Bell Tolls</title><author>Hemmingway</author></book><book><title>I, Robot</title><author>Isaac Asimov</author></book><book><title>Programming Scala</title><author>Dean Wampler</author><author>Alex Payne</author></book></bookstore>
books: com.codecommit.antixml.Zipper[com.codecommit.antixml.Elem] = <book><title>For Whom the Bell Tolls</title><author>Hemmingway</author></book><book><title>I, Robot</title><author>Isaac Asimov</author></book><book><title>Programming Scala</title><author>Dean Wampler</author><author>Alex Payne</author></book>
Welcome to Scala version 2.9.1.final (Java HotSpot(TM) 64-Bit Server VM, Java 1.6.0_26).
Type in expressions to have them evaluated.
Type :help for more information.

scala> :javap com.codecommit.antixml.Elem
Compiled from "node.scala"
public class com.codecommit.antixml.Elem extends java.lang.Object implements com.codecommit.antixml.Node,com.codecommit.antixml.Selectable,scala.ScalaObject,scala.Product,scala.Serializable{
    public static final scala.Function1 tupled();
    public static final scala.Function1 curry();
    public static final scala.Function1 curried();
    public static final boolean isValidName(java.lang.String);
    public scala.collection.Iterator productIterator();
    public scala.collection.Iterator productElements();
    public java.lang.Object $bslash(com.codecommit.antixml.Selector, com.codecommit.antixml.CanBuildFromWithZipper);
    public java.lang.Object $bslash$bslash(com.codecommit.antixml.Selector, com.codecommit.antixml.CanBuildFromWithZipper);
    public java.lang.Object $bslash$bslash$bang(com.codecommit.antixml.Selector, com.codecommit.antixml.CanBuildFromWithZipper);
    public java.lang.Object select(com.codecommit.antixml.Selector, com.codecommit.antixml.CanBuildFromWithZipper);
    public com.codecommit.antixml.Zipper toZipper();
    public scala.Option prefix();
    public java.lang.String name();
    public com.codecommit.antixml.Attributes attrs();
    public scala.collection.immutable.Map scope();
    public com.codecommit.antixml.Group children();
    public com.codecommit.antixml.Elem canonicalize();
    public java.lang.String toString();
    public com.codecommit.antixml.Group toGroup();
    public com.codecommit.antixml.Group copy$default$5();
    public scala.collection.immutable.Map copy$default$4();
    public com.codecommit.antixml.Attributes copy$default$3();
    public java.lang.String copy$default$2();
    public scala.Option copy$default$1();
    public com.codecommit.antixml.Elem copy(scala.Option, java.lang.String, com.codecommit.antixml.Attributes, scala.collection.immutable.Map, com.codecommit.antixml.Group);
    public int hashCode();
    public boolean equals(java.lang.Object);
    public java.lang.String productPrefix();
    public int productArity();
    public java.lang.Object productElement(int);
    public boolean canEqual(java.lang.Object);
    public com.codecommit.antixml.Elem(scala.Option, java.lang.String, com.codecommit.antixml.Attributes, scala.collection.immutable.Map, com.codecommit.antixml.Group);
}

成功！！！

當然，這次會議是謊言。 我到達那里花了更長的時間，但這主要是練習。

Answer 2

https://github.com/ensime/ensime-server/blob/master/build.sbt#L35

// epic hack to get the tools.jar JDK dependency
val JavaTools = List[Option[String]] (
  // manual
  sys.env.get("JDK_HOME"),
  sys.env.get("JAVA_HOME"),
  // osx
  try Some("/usr/libexec/java_home".!!.trim)
  catch {
    case _: Throwable => None
  },
  // fallback
  sys.props.get("java.home").map(new File(_).getParent),
  sys.props.get("java.home")
).flatten.map { n =>
  new File(n + "/lib/tools.jar")
}.find(_.exists).getOrElse (
  throw new FileNotFoundException (
    """Could not automatically find the JDK/lib/tools.jar.
      |You must explicitly set JDK_HOME or JAVA_HOME.""".stripMargin
  )
)