Scala 宏找不到 java.util.List、java.lang.Object
Scala macro can't find java.util.List, java.lang.Object
更新：请参阅下面的答案以了解 此 问题的解决方案。还有第二个问题（宏现在找不到Pojo），关于第二个问题的问题在这里：Scala macro can't find my java class
我正在创建一个 scala 宏来从 POJO 自动生成大小写 类（以便更好地使用 avro）。
除了编译器在 java 类 和 java.lang.Object.
等内置 java 类 上阻塞外，一切都“有效”
我的问题是：如何在宏中生成代码，以便编译器解析 java 类?
示例错误消息：
（Pojo.java 中没有 // 注释）
[info] Compiling 1 Scala source to /Users/marcin/development/repo/problemdemo/target/scala-2.11/classes...
fieldType:java.util.List
fieldType:Int
fieldType:java.util.List
Expr[Any](case class Demo extends scala.Product with scala.Serializable {
<caseaccessor> <paramaccessor> val baz: java.util.List[com.squarefoot.Pojo] = _;
<caseaccessor> <paramaccessor> val bar: Int = _;
<caseaccessor> <paramaccessor> val foo: java.util.List[java.lang.Integer] = _;
def <init>(baz: java.util.List[com.squarefoot.Pojo], bar: Int, foo: java.util.List[java.lang.Integer]) = {
super.<init>();
()
}
})
[error] /Users/marcin/development/repos/problemdemo/src/main/scala/com/squarefoot/converters/problemdemo.scala:5: not found: type java.util.List
[error] @Caseify(classOf[com.squarefoot.Pojo])
[error] ^
[error] one error found
[error] (root/compile:compileIncremental) Compilation failed
[error] Total time: 17 s, completed Dec 11, 2016 12:00:57 PM
(Pojo.java如图)
[info] Compiling 1 Scala source to /Users/marcin/development/repos/problemdemo/target/scala-2.11/classes...
fieldType:java.lang.Object
fieldType:Int
Expr[Any](case class Demo extends scala.Product with scala.Serializable {
<caseaccessor> <paramaccessor> val qux: java.lang.Object = _;
<caseaccessor> <paramaccessor> val bar: Int = _;
def <init>(qux: java.lang.Object, bar: Int) = {
super.<init>();
()
}
})
[error] /Users/marcin/development/repos/problemdemo/src/main/scala/com/squarefoot/converters/problemdemo.scala:5: not found: type java.lang.Object
[error] @Caseify(classOf[com.squarefoot.Pojo])
[error] ^
[error] one error found
[error] (root/compile:compileIncremental) Compilation failed
[error] Total time: 6 s, completed Dec 11, 2016 12:04:29 PM
编辑：showRaw 的结果
showRaw 给出这样的输出，这对我来说很好：
ValDef(Modifiers(DEFERRED), TermName("availablebuildouts"), AppliedTypeTree(Ident(TypeName("java.util.List")), List(Ident(TypeName("com.squarefoot.buildouttype")))), EmptyTree)
problemdemo/avroschemas/src/main/java/com/squarefoot/Pojo.java:
package com.squarefoot;
public class Pojo {
//public java.util.List<Integer> foo;
public int bar;
//public java.util.List<Pojo> baz;
public java.lang.Object qux;
}
problemdemo/src/main/scala/com/squarefoot/converters/problemdemo.scala:
package com.squarefoot.converters
import com.squarefoot.Pojo
class Foomin {
val foobar: java.util.List[Int]
}
@Caseify(classOf[com.squarefoot.Pojo])
case class Demo()
problemdemo/macros/src/main/scala/com/squarefoot/converters/Caseify.scala:
package com.squarefoot.converters
import scala.language.experimental.macros
import scala.annotation.StaticAnnotation
import scala.reflect.macros.Context
/**
* Generate case class from POJO
* ex:
* @Caseify(classOf[com.squarefoot.incominglisting])
* case class Incominglisting()
* NOTE that the type parameter to classOf must be provided as a fully
* qualified name, otherwise the macro code here won't be able to find it.
*
* Generates a case class with the same members as the public, non-static
* members of the pojo
*
* Note that you must have all types used in the POJO in scope where the macro
* is invoked
*/
class Caseify[T](source: Class[T]) extends StaticAnnotation {
def macroTransform(annottees: Any*) = macro CaseifyMacro.expand_impl[T]
}
object CaseifyMacro {
/** generate case class from POJO */
def expand_impl[T](c: Context)(annottees: c.Expr[Any]*) = {
import c.universe._
// macro expand the macro expression itself to extract param
val source: Class[T] = c.prefix.tree match {
case q"new Caseify($param)" => c.eval[Class[T]](c.Expr(param))
}
val rm = scala.reflect.runtime.currentMirror
val vars =
rm.classSymbol(source).toType.members.map(_.asTerm).
filter(_.isVar).filter(_.isPublic)
lazy val fields = vars.map({f=>
val fieldName = TermName(f.name.toString)
val fieldType = TypeName(f.typeSignature.typeConstructor.toString)
val typeArgs = f.typeSignature.typeArgs.map(a=>TypeName(a.toString))
println("fieldType:"+fieldType.toString)
q"val $fieldName: $fieldType"
if(typeArgs.size > 0)
q"val $fieldName: $fieldType[..$typeArgs]"
else
q"val $fieldName: $fieldType"
})
annottees.map(_.tree) match {
case List(q"case class $newname()") => {
val q = c.Expr[Any](
// Add your own logic here, possibly using arguments on the annotation.
q"""
case class $newname(..$fields)
""")
println(q.toString)
q
}
// Add validation and error handling here.
}
}
}
SBT 文件：
problemdemo/build.sbt
name := "data-importer"
addCompilerPlugin("org.scalamacros" % "paradise" % "2.1.0" cross CrossVersion.full)
scalaVersion := "2.11.8"
val avroVersion = "1.8.1"
lazy val root =
project.in( file(".") )
.aggregate(avroschemas, macros).dependsOn(macros, avroschemas)
lazy val macros = project.dependsOn(avroschemas)
lazy val avroschemas = project
libraryDependencies ++= Seq(
"org.scala-lang" % "scala-reflect" % scalaVersion.value
)
// better error reporting
scalacOptions in Test ++= Seq("-Yrangepos")
run in Compile := Defaults.runTask(fullClasspath in Compile, mainClass in (Compile, run), runner in (Compile, run))
problemdemo/macros/build.sbt
name := "data-importer-macros"
addCompilerPlugin("org.scalamacros" % "paradise" % "2.1.0" cross CrossVersion.full)
organization := "com.squarefoot"
scalaVersion := "2.11.3"
libraryDependencies ++= Seq(
"org.scala-lang" % "scala-reflect" % scalaVersion.value
)
scalacOptions in Test ++= Seq("-Yrangepos")
problemdemo/avroschemas/build.sbt
name := "data-importer-avroschemas"
addCompilerPlugin("org.scalamacros" % "paradise" % "2.1.0" cross CrossVersion.full)
organization := "com.squarefoot"
scalaVersion := "2.11.8"
// better error reporting
scalacOptions in Test ++= Seq("-Yrangepos")
run in Compile := Defaults.runTask(fullClasspath in Compile, mainClass in (Compile, run), runner in (Compile, run))
基本上，您想要的不是 TypeName("java.util.List")（基于 http://docs.scala-lang.org/overviews/reflection/symbols-trees-types.html#tree-creation-via-reify 中的示例，目前无法测试）Select(Select(This(TypeName("java")), TypeName("util")), TypeName("List"))。如果您在 input 树上执行 showRaw，您应该会看得更准确。因此，不是 TypeName(...toString)，而是 .。也许只是删除 TypeName:
val fieldType = f.typeSignature.typeConstructor
val typeArgs = f.typeSignature.typeArgs
够不够？
所以，我还没有可用的宏，但我已经在 Alexey Romanov 的回答的帮助下解决了 这个 问题。此代码导致错误：
[error] /Users/marcin/development/repos/problemdemo/src/main/scala/com/squarefoot/converters/problemdemo.scala:10: not found: type com.squarefoot.Pojo
[error] @Caseify(classOf[com.squarefoot.Pojo])
我即将就该问题提出一个单独的问题。
package com.squarefoot.converters
import scala.language.experimental.macros
import scala.annotation.StaticAnnotation
import scala.reflect.macros.Context
/**
* Generate case class from POJO
* ex:
* @Caseify(classOf[com.squarefoot.incominglisting])
* case class Incominglisting()
* NOTE that the type parameter to classOf must be provided as a fully
* qualified name, otherwise the macro code here won't be able to find it.
*
* Generates a case class with the same members as the public, non-static
* members of the pojo
*
* Note that you must have all types used in the POJO in scope where the macro
* is invoked
*/
class Caseify[T](source: Class[T]) extends StaticAnnotation {
def macroTransform(annottees: Any*) = macro CaseifyMacro.expand_impl[T]
}
object CaseifyMacro {
/** generate case class from POJO */
def expand_impl[T](c: Context)(annottees: c.Expr[Any]*) = {
import c.universe._
// macro expand the macro expression itself to extract param
val source: Class[T] = c.prefix.tree match {
case q"new Caseify($param)" => c.eval[Class[T]](c.Expr(param))
}
val rm = scala.reflect.runtime.currentMirror
val vars =
rm.classSymbol(source).toType.members.map(_.asTerm).
filter(_.isVar).filter(_.isPublic)
val fields = vars.map({f=>
val fieldName = TermName(f.name.toString)
val fieldType = tq"${f.typeSignature.typeConstructor.typeSymbol.fullName}"
val rawTypeArgs = f.typeSignature.typeArgs.map(a=>TypeName(a.toString))
val typeArgs = tq"${rawTypeArgs}"
println("typeArgs: "+typeArgs.toString)
println("fieldType:"+fieldType.getClass.toString+"|"+fieldType.toString)
println(f.typeSignature.typeSymbol.asType.name.getClass.toString)
val arraylistname = tq"java.util.ArrayList"
println("DEBUG:"+tq"${arraylistname}".toString+"|"+f.typeSignature.typeConstructor.typeSymbol.fullName)
q"val $fieldName: $fieldType"
if(rawTypeArgs.nonEmpty) {
val appliedFieldType = tq"${arraylistname}[..$rawTypeArgs]"
q"val $fieldName: $appliedFieldType"
}
else
q"val $fieldName: $fieldType"
})
annottees.map(_.tree) match {
case List(q"case class $newname()") => {
val q = c.Expr[Any](
// Add your own logic here, possibly using arguments on the annotation.
q"""
case class $newname(..$fields)
""")
println(q.toString)
q
}
// Add validation and error handling here.
}
}
}
更新：请参阅下面的答案以了解 此 问题的解决方案。还有第二个问题（宏现在找不到Pojo），关于第二个问题的问题在这里：Scala macro can't find my java class
我正在创建一个 scala 宏来从 POJO 自动生成大小写 类（以便更好地使用 avro）。
除了编译器在 java 类 和 java.lang.Object.
等内置 java 类 上阻塞外，一切都“有效”我的问题是：如何在宏中生成代码，以便编译器解析 java 类?
示例错误消息：
（Pojo.java 中没有 // 注释）
[info] Compiling 1 Scala source to /Users/marcin/development/repo/problemdemo/target/scala-2.11/classes...
fieldType:java.util.List
fieldType:Int
fieldType:java.util.List
Expr[Any](case class Demo extends scala.Product with scala.Serializable {
<caseaccessor> <paramaccessor> val baz: java.util.List[com.squarefoot.Pojo] = _;
<caseaccessor> <paramaccessor> val bar: Int = _;
<caseaccessor> <paramaccessor> val foo: java.util.List[java.lang.Integer] = _;
def <init>(baz: java.util.List[com.squarefoot.Pojo], bar: Int, foo: java.util.List[java.lang.Integer]) = {
super.<init>();
()
}
})
[error] /Users/marcin/development/repos/problemdemo/src/main/scala/com/squarefoot/converters/problemdemo.scala:5: not found: type java.util.List
[error] @Caseify(classOf[com.squarefoot.Pojo])
[error] ^
[error] one error found
[error] (root/compile:compileIncremental) Compilation failed
[error] Total time: 17 s, completed Dec 11, 2016 12:00:57 PM
(Pojo.java如图)
[info] Compiling 1 Scala source to /Users/marcin/development/repos/problemdemo/target/scala-2.11/classes...
fieldType:java.lang.Object
fieldType:Int
Expr[Any](case class Demo extends scala.Product with scala.Serializable {
<caseaccessor> <paramaccessor> val qux: java.lang.Object = _;
<caseaccessor> <paramaccessor> val bar: Int = _;
def <init>(qux: java.lang.Object, bar: Int) = {
super.<init>();
()
}
})
[error] /Users/marcin/development/repos/problemdemo/src/main/scala/com/squarefoot/converters/problemdemo.scala:5: not found: type java.lang.Object
[error] @Caseify(classOf[com.squarefoot.Pojo])
[error] ^
[error] one error found
[error] (root/compile:compileIncremental) Compilation failed
[error] Total time: 6 s, completed Dec 11, 2016 12:04:29 PM
编辑：showRaw 的结果
showRaw 给出这样的输出，这对我来说很好：
ValDef(Modifiers(DEFERRED), TermName("availablebuildouts"), AppliedTypeTree(Ident(TypeName("java.util.List")), List(Ident(TypeName("com.squarefoot.buildouttype")))), EmptyTree)
problemdemo/avroschemas/src/main/java/com/squarefoot/Pojo.java:
package com.squarefoot;
public class Pojo {
//public java.util.List<Integer> foo;
public int bar;
//public java.util.List<Pojo> baz;
public java.lang.Object qux;
}
problemdemo/src/main/scala/com/squarefoot/converters/problemdemo.scala:
package com.squarefoot.converters
import com.squarefoot.Pojo
class Foomin {
val foobar: java.util.List[Int]
}
@Caseify(classOf[com.squarefoot.Pojo])
case class Demo()
problemdemo/macros/src/main/scala/com/squarefoot/converters/Caseify.scala:
package com.squarefoot.converters
import scala.language.experimental.macros
import scala.annotation.StaticAnnotation
import scala.reflect.macros.Context
/**
* Generate case class from POJO
* ex:
* @Caseify(classOf[com.squarefoot.incominglisting])
* case class Incominglisting()
* NOTE that the type parameter to classOf must be provided as a fully
* qualified name, otherwise the macro code here won't be able to find it.
*
* Generates a case class with the same members as the public, non-static
* members of the pojo
*
* Note that you must have all types used in the POJO in scope where the macro
* is invoked
*/
class Caseify[T](source: Class[T]) extends StaticAnnotation {
def macroTransform(annottees: Any*) = macro CaseifyMacro.expand_impl[T]
}
object CaseifyMacro {
/** generate case class from POJO */
def expand_impl[T](c: Context)(annottees: c.Expr[Any]*) = {
import c.universe._
// macro expand the macro expression itself to extract param
val source: Class[T] = c.prefix.tree match {
case q"new Caseify($param)" => c.eval[Class[T]](c.Expr(param))
}
val rm = scala.reflect.runtime.currentMirror
val vars =
rm.classSymbol(source).toType.members.map(_.asTerm).
filter(_.isVar).filter(_.isPublic)
lazy val fields = vars.map({f=>
val fieldName = TermName(f.name.toString)
val fieldType = TypeName(f.typeSignature.typeConstructor.toString)
val typeArgs = f.typeSignature.typeArgs.map(a=>TypeName(a.toString))
println("fieldType:"+fieldType.toString)
q"val $fieldName: $fieldType"
if(typeArgs.size > 0)
q"val $fieldName: $fieldType[..$typeArgs]"
else
q"val $fieldName: $fieldType"
})
annottees.map(_.tree) match {
case List(q"case class $newname()") => {
val q = c.Expr[Any](
// Add your own logic here, possibly using arguments on the annotation.
q"""
case class $newname(..$fields)
""")
println(q.toString)
q
}
// Add validation and error handling here.
}
}
}
SBT 文件：
problemdemo/build.sbt
name := "data-importer"
addCompilerPlugin("org.scalamacros" % "paradise" % "2.1.0" cross CrossVersion.full)
scalaVersion := "2.11.8"
val avroVersion = "1.8.1"
lazy val root =
project.in( file(".") )
.aggregate(avroschemas, macros).dependsOn(macros, avroschemas)
lazy val macros = project.dependsOn(avroschemas)
lazy val avroschemas = project
libraryDependencies ++= Seq(
"org.scala-lang" % "scala-reflect" % scalaVersion.value
)
// better error reporting
scalacOptions in Test ++= Seq("-Yrangepos")
run in Compile := Defaults.runTask(fullClasspath in Compile, mainClass in (Compile, run), runner in (Compile, run))
problemdemo/macros/build.sbt
name := "data-importer-macros"
addCompilerPlugin("org.scalamacros" % "paradise" % "2.1.0" cross CrossVersion.full)
organization := "com.squarefoot"
scalaVersion := "2.11.3"
libraryDependencies ++= Seq(
"org.scala-lang" % "scala-reflect" % scalaVersion.value
)
scalacOptions in Test ++= Seq("-Yrangepos")
problemdemo/avroschemas/build.sbt
name := "data-importer-avroschemas"
addCompilerPlugin("org.scalamacros" % "paradise" % "2.1.0" cross CrossVersion.full)
organization := "com.squarefoot"
scalaVersion := "2.11.8"
// better error reporting
scalacOptions in Test ++= Seq("-Yrangepos")
run in Compile := Defaults.runTask(fullClasspath in Compile, mainClass in (Compile, run), runner in (Compile, run))
基本上，您想要的不是 TypeName("java.util.List")（基于 http://docs.scala-lang.org/overviews/reflection/symbols-trees-types.html#tree-creation-via-reify 中的示例，目前无法测试）Select(Select(This(TypeName("java")), TypeName("util")), TypeName("List"))。如果您在 input 树上执行 showRaw，您应该会看得更准确。因此，不是 TypeName(...toString)，而是 .。也许只是删除 TypeName:
val fieldType = f.typeSignature.typeConstructor
val typeArgs = f.typeSignature.typeArgs
够不够？
所以，我还没有可用的宏，但我已经在 Alexey Romanov 的回答的帮助下解决了 这个 问题。此代码导致错误：
[error] /Users/marcin/development/repos/problemdemo/src/main/scala/com/squarefoot/converters/problemdemo.scala:10: not found: type com.squarefoot.Pojo
[error] @Caseify(classOf[com.squarefoot.Pojo])
我即将就该问题提出一个单独的问题。
package com.squarefoot.converters
import scala.language.experimental.macros
import scala.annotation.StaticAnnotation
import scala.reflect.macros.Context
/**
* Generate case class from POJO
* ex:
* @Caseify(classOf[com.squarefoot.incominglisting])
* case class Incominglisting()
* NOTE that the type parameter to classOf must be provided as a fully
* qualified name, otherwise the macro code here won't be able to find it.
*
* Generates a case class with the same members as the public, non-static
* members of the pojo
*
* Note that you must have all types used in the POJO in scope where the macro
* is invoked
*/
class Caseify[T](source: Class[T]) extends StaticAnnotation {
def macroTransform(annottees: Any*) = macro CaseifyMacro.expand_impl[T]
}
object CaseifyMacro {
/** generate case class from POJO */
def expand_impl[T](c: Context)(annottees: c.Expr[Any]*) = {
import c.universe._
// macro expand the macro expression itself to extract param
val source: Class[T] = c.prefix.tree match {
case q"new Caseify($param)" => c.eval[Class[T]](c.Expr(param))
}
val rm = scala.reflect.runtime.currentMirror
val vars =
rm.classSymbol(source).toType.members.map(_.asTerm).
filter(_.isVar).filter(_.isPublic)
val fields = vars.map({f=>
val fieldName = TermName(f.name.toString)
val fieldType = tq"${f.typeSignature.typeConstructor.typeSymbol.fullName}"
val rawTypeArgs = f.typeSignature.typeArgs.map(a=>TypeName(a.toString))
val typeArgs = tq"${rawTypeArgs}"
println("typeArgs: "+typeArgs.toString)
println("fieldType:"+fieldType.getClass.toString+"|"+fieldType.toString)
println(f.typeSignature.typeSymbol.asType.name.getClass.toString)
val arraylistname = tq"java.util.ArrayList"
println("DEBUG:"+tq"${arraylistname}".toString+"|"+f.typeSignature.typeConstructor.typeSymbol.fullName)
q"val $fieldName: $fieldType"
if(rawTypeArgs.nonEmpty) {
val appliedFieldType = tq"${arraylistname}[..$rawTypeArgs]"
q"val $fieldName: $appliedFieldType"
}
else
q"val $fieldName: $fieldType"
})
annottees.map(_.tree) match {
case List(q"case class $newname()") => {
val q = c.Expr[Any](
// Add your own logic here, possibly using arguments on the annotation.
q"""
case class $newname(..$fields)
""")
println(q.toString)
q
}
// Add validation and error handling here.
}
}
}