{ "version": "https://jsonfeed.org/version/1", "title": "Scala", "description": "Object-Oriented Meets Functional", "home_page_url": "go/scala", "feed_url": "feed/scala.json", "icon": "https://cdn.v2ex.com/navatar/c8ff/e9a5/124_large.png?m=1488098428", "favicon": "https://cdn.v2ex.com/navatar/c8ff/e9a5/124_normal.png?m=1488098428", "items": [ { "author": { "url": "member/timzaak", "name": "timzaak", "avatar": "https://cdn.v2ex.com/gravatar/7dffd67fee36487e77dabd9f1abbd8e7?s=73&d=retro" }, "url": "t/1141501", "title": "\u8fd9\u4e2a\u5206\u7c7b\u597d\u4e45\u6ca1\u65b0\u5e16\u5b50\u4e86\uff0c\u8bb0\u5f55\u4e0b\u6700\u65b0\u7528 scala 3 \u5199\u7684\u9879\u76ee", "id": "t/1141501", "date_published": "2025-06-27T08:31:51+00:00", "content_html": "

https://github.com/timzaak/log-http-proxy\nmitm http/https \u4ee3\u7406\uff0c \u9762\u5411 Qt \u7b49\u4e0d\u65b9\u4fbf\u8c03\u8bd5 https/http \u8bf7\u6c42\u7684\uff0c\u5f00\u542f\u540e\uff0c \u684c\u9762\u5f00\u53d1\u7528 switchHosts \u4fee\u6539\u4e0b dns \u89e3\u6790\uff0c\u53ef\u5728 web \u9875\u9762\u5c31\u53ef\u770b\u5230 http \u8bf7\u6c42\u5185\u5bb9\u3002

https://github.com/timzaak/table2case\n\u5c06\u6570\u636e\u5e93 table \u8f6c\u6362\u6210 case class \uff0c\u5e76\u5199\u5165\u5230\u6587\u4ef6\u4e2d\uff0c\u989d\u5916\u652f\u6301 scalasql \uff0c\u51cf\u5c11\u91cd\u590d\u5de5\u4f5c\u3002

\u5c31\u662f\u89c9\u5f97\u6bcf\u6b21 run \u7684\u65f6\u5019\u8981 compile \u4e00\u6b21\uff0c\u7b49\u7684\u65f6\u95f4\u534a\u5206\u949f\u6709\u70b9\u957f\u3002

\u7f51\u4e0a\u4e0b\u8f7d\u7684\u4ed3\u5e93\uff0c\u6211\u7684\u6587\u4ef6\u51e0\u4e4e\u4e0d\u4f1a\u6539\u52a8\uff0c\u80fd\u4e0d\u80fd\u8df3\u8fc7 compile \uff1f

\u719f\u6089\u7684\u5927\u4f6c\u8bf7\u6307\u70b9\u4e00\u4e0b\uff0c\u65e0\u8bba\u662f\u80fd\u4e0e\u4e0d\u80fd\u3002

PS\uff1a\u6587\u4ef6\u5728\u8fd9

RT.

\u5f88\u591a\u56e2\u961f\u5185\u5199\u6570\u636e\u6d41\uff0c\u5206\u4e3a\u7528 java \u3001scala \u3001python \u4e09\u6ce2\u3002

\u9274\u4e8e\u76ee\u524d scala \u4e0d\u6e29\u4e0d\u706b\uff0c\u751a\u81f3\u70ed\u5ea6\u6709\u4e0b\u964d\u7684\u8d8b\u52bf\u3002

\u662f\u5426\u6709\u5fc5\u8981\u5728\u516c\u53f8\u5185\u90e8\u9f13\u52b1\u7528 scala \uff1f

\u662f\u5426\u6709\u5fc5\u8981\u7edf\u4e00\u4f7f\u7528 java \u5f00\u53d1\uff0c\u51cf\u5c11\u5f00\u53d1\u8bed\u8a00\u7684\u6280\u672f\u6808\u7684\u590d\u6742\u5ea6\uff08 scala \u8f83\u590d\u6742\u4e14\u5e94\u7528\u4e0d\u5e7f\u6cdb\uff09\uff1f

\u56f0\u6270\u4e86\u633a\u957f\u4e00\u6bb5\u65f6\u95f4\u7684\u95ee\u9898\uff0c\u53d1\u51fa\u6765\u4f9b\u5927\u5bb6\u8ba8\u8bba\u4e00\u4e0b\u3002

\u6700\u8fd1\u63a5\u624b\u4e00\u4e2a\u9879\u76ee\u8981\u6c42\u8865\u4e0a\u5355\u5143\u6d4b\u8bd5\uff0c\u8fd9\u4e2a\u9879\u76ee\u662f\u505a spark \u7684\uff0c\u5c31\u662f Scala \u5199\u7684 ETL \u7a0b\u5e8f\u3002\u8bf7\u95ee\u9488\u5bf9\u8fd9\u79cd\u9879\u76ee\u7528\u4ec0\u4e48\u6d4b\u8bd5\u6846\u67b6\u505a\u6bd4\u8f83\u597d\uff1f

spark ml \u5bfc\u51fa\u6a21\u578b pmml \u6587\u4ef6\u4e0d\u6210\u529f\uff0c\u4e0b\u9762\u662f scala \u4ee3\u7801

 val pmml = new PMMLBuilder(trainingData.schema, model).build()\n val targetFile = \"target/model.pmml\"\n val fis: FileOutputStream = new FileOutputStream(targetFile)\n val fout: StreamResult = new StreamResult(fis)\n JAXBUtil.marshalPMML(pmml, fout)\n

Exception in thread \"main\" java.lang.IllegalArgumentException: Expected string, integral, double or boolean data type, got vector data type\n\tat org.jpmml.sparkml.SparkMLEncoder.createDataField(SparkMLEncoder.java:169)\n\tat org.jpmml.sparkml.SparkMLEncoder.getFeatures(SparkMLEncoder.java:76)\n\tat org.jpmml.sparkml.feature.VectorIndexerModelConverter.encodeFeatures(VectorIndexerModelConverter.java:52)\n\tat org.jpmml.sparkml.FeatureConverter.registerFeatures(FeatureConverter.java:50)\n\tat org.jpmml.sparkml.PMMLBuilder.build(PMMLBuilder.java:114)\n

\u5982\u9898\uff0c\u5728\u5927\u6570\u636e\u67b6\u6784\u7ec4\u5de5\u4f5c\uff0c\u7ec4\u91cc\u7684\u8bed\u8a00\u662f scala\uff0c\u4f1a\u7528 scala \u5199\u4e00\u4e9b\u5de5\u4f5c\u548c\u6846\u67b6\uff0c\u5e76\u4e14\u5199\u4e00\u4e9b flink\uff0cspark \u7a0b\u5e8f\u3002

\u4e2a\u4eba\u7684\u786e\u5f88\u559c\u6b22 scala\uff0c\u4f46\u5b83\u7684\u590d\u6742\u4e5f\u8ba9\u4eba\u671b\u800c\u5374\u6b65\uff0c\u5e73\u65f6\u5199 flink \u548c spark \u90fd\u4f1a\u7528 scala \u5199\u3002

\u4f46\u662f\u4e2a\u4eba\u4e0d\u559c\u6b22\u592a\u591a\u7684\u8bed\u6cd5\u7cd6\u548c\u7279\u6b8a\u7b26\u53f7\uff0c\u800c\u4e14 akka \u7684\u6d88\u606f\u7f16\u7a0b\u6a21\u578b\u611f\u89c9\u4e5f\u4e0d\u5bb9\u6613\u8fdb\u884c\u62bd\u8c61\u3002

\u4ece\u4e2a\u4eba\u804c\u4e1a\u53d1\u5c55\u89d2\u5ea6\u770b\u4e5f\u60f3\u7528 springboot,\u6bd5\u7adf springboot \u8fd8\u662f\u53d7\u4f17\u6bd4\u8f83\u5e7f\u3002

\u600e\u4e48\u641e\uff1f

\u6700\u8fd1 scala \u5927\u795e\u674e\u6d69\u6bc5\u51fa\u4e86\u672c\u4e66 \u300a hands on scala \u300b. \u7c97\u7565\u770b\u4e86 free chapters , \u611f\u89c9\u5199\u7684\u8fd8\u53ef\u4ee5, \u4f46\u662f\u540e\u9762\u5f88\u591a\u5b9e\u7528\u7ae0\u8282\u662f\u6536\u8d39\u7684, \u6709\u4e70\u4e86\u8fd9\u672c\u4e66\u7684\u5417? \u5199\u7684\u548b\u6837?

\u94fe\u63a5\u5982\u4e0b\nhttps://www.handsonscala.com/

object test {\n def main(args: Array[String]): Unit = {\n def listTestD = (0 to 20000000).toList\n var l1 = System.currentTimeMillis()\n var sum = 0\n listTestD.foreach{x=> if (x%2==0) sum = x}\n println(System.currentTimeMillis()-l1)\n sum = 0\n l1 = System.currentTimeMillis()\n listTestD.filter(_%2==0).foreach(sum = _)\n println(System.currentTimeMillis()-l1)\n }\n}\n

\u6267\u884c\u7ed3\u679c\u662f\uff1a\n17585,\n21059\n\u6548\u7387\u5dee 20%\u5de6\u53f3

\u907f\u514d\u7f13\u5b58\uff0c\u5bf9\u6389\u4e24\u4e2a foreach

object test {\n def main(args: Array[String]): Unit = {\n def listTestD = (0 to 20000000).toList\n var l1 = System.currentTimeMillis()\n var sum = 0\n listTestD.filter(_%2==0).foreach(sum = _)\n println(System.currentTimeMillis()-l1)\n sum = 0\n l1 = System.currentTimeMillis()\n listTestD.foreach{x=> if (x%2==0) sum = x}\n println(System.currentTimeMillis()-l1)\n }\n}\n

\u6267\u884c\u7ed3\u679c\u662f\uff1a\n35082,\n16201\n\u6548\u7387\u5dee\u8fd1 50%\u3002

\u5982\u679c listTestD \u5b58\u50a8\u4e00\u4e2a\u5bf9\u8c61\u7684\u5185\u5bb9\uff0c\u6548\u7387\u662f\u4e0d\u662f\u4f1a\u5dee\u66f4\u5927\uff1f

\u7f51\u4e0a\u80fd\u8bd5\u7684\u89e3\u51b3\u65b9\u6848\u5168\u8bd5\u8fc7\u4e86\uff0c\u8fd8\u662f\u62c9\u4e0d\u52a8\u4f9d\u8d56

##\u4e3b\u8981\u66f4\u65b0\u4e3a:

\n
• out-of-box Coursier library management
\n
• IO improvements
\n
• super shell
\n
• experimental ClassLoader layering
\n

\n

\"Combined together we hope these features will improve the user experience of running your builds.\"

\n

\u8be6\u7ec6 release note

Scala \u4e2d\u5e38\u7528\u7684\u7b2c\u4e09\u65b9\u65e5\u5fd7\u5e93\uff0c\u6211\u8fd9\u8fb9\u4e86\u89e3\u7684\u6709 log4s^1\u548c Scala\nLogging^2\u4e24\u4e2a\u3002

\u5728 Scala Logging \u4e2d\uff1a

logger.debug(s\"Some $expensive message!\")\n

\u4f1a\u88ab Scala \u7684\u5b8f\u8f6c\u6362\u6210\uff1a

if (logger.isDebugEnabled) logger.debug(s\"Some $expensive message!\")\n

\u56e0\u4e3a\u5728\u5b9e\u9645\u4ee3\u7801\u8fd0\u884c\u65f6\uff0c\u5b9e\u9645\u4e0a\u4f1a\u5148\u505a\u5b57\u7b26\u4e32\u63d2\u503c\uff0c\u7136\u540e\u5728\u770b\u65e5\u5fd7\u7ea7\u522b\u4e3a DEBUG \u7684\u65e5\u5fd7\u662f\u5426\u9700\u8981\u8f93\u51fa\u3002\u6240\u4ee5\u6211\u4eec\u901a\u8fc7 if \u8bed\u53e5\uff0c\u9632\u6b62\u4e0d\u5fc5\u8981\u7684\u5b57\u7b26\u4e32\u64cd\u4f5c\uff0c\u8fdb\u800c\u6539\u5584\u6027\u80fd\u3002

\u90a3\u4e48 Scala Logging \u662f\u5982\u4f55\u505a\u5230\u6539\u5199\u8868\u8fbe\u5f0f\u7684\u5462\uff1f

\u5728\u4e0a\u4e00\u7bc7^3\u5b9e\u73b0 lombok.Data \u7684\u65f6\u5019\uff0c\u6211\u4eec\u5b9e\u9645\u4e0a\u662f\u901a\u8fc7\u6ce8\u89e3\u544a\u8bc9\u7f16\u8bd1\u5668\uff0c\u6211\u4eec\u9700\u8981\u5728\u8be5\u6ce8\u89e3\u6240\u4f5c\u7528\u7684\u7c7b\u4e0a\u9762\u751f\u6210 getter \u548c setter\u3002\u8bf4\u767d\u4e86\uff0c\u5c31\u662f\u6ce8\u89e3 @data \u8ba9\u6211\u4eec\u5b9a\u4f4d\u5177\u4f53\u7684\u7c7b\uff0c\u7136\u540e\u6211\u4eec\u518d\u63d2\u5165\u4ee3\u7801\u3002\u800c\u8fd9\u4e2a\u4f8b\u5b50\u5b9e\u9645\u4e0a\u662f\u76f4\u63a5\u5c06\u751f\u6210\u4ee3\u7801\u7684\u89c4\u5219\u548c\u5177\u4f53\u7684\u65b9\u6cd5\u8854\u63a5\u8d77\u6765\u3002

\u5b8c\u6574\u7684\u5b9e\u73b0\u5982\u4e0b\u6240\u793a\uff1a

final class Logger private (val underlying: org.slf4j.Logger) {\n def debug(message: String): Unit = macro LoggerMacro.debugMessage\n}\n\nprivate object LoggerMacro {\n\n type LoggerCOntext= blackbox.Context {type PrefixType = Logger}\n\n private def deconstructInterpolatedMessage(c: LoggerContext)\n (message: c.Expr[String]) = {\n import c.universe._\n message.tree match {\n case q\"scala.StringContext.apply(..$parts).s(..$args)\" =>\n val format = parts.iterator.map({ case Literal(Constant(str: String)) => str })\n // Emulate standard interpolator escaping\n .map(StringContext.treatEscapes)\n // Escape literal slf4j format anchors if the resulting call will require a format string\n .map(str => if (args.nonEmpty) str.replace(\"{}\", \"\\{}\") else str)\n .mkString(\"{}\")\n\n val formatArgs = args.map(t => c.Expr[Any](t))\n\n (c.Expr(q\"$format\"), formatArgs)\n\n case _ => (message, Seq.empty)\n }\n }\n\n private def formatArgs(c: LoggerContext)(args: c.Expr[Any]*) = {\n import c.universe._\n args.map { arg =>\n c.Expr[AnyRef](\n if (arg.tree.tpe <:< weakTypeOf[AnyRef]) arg.tree\n else q\"$arg.asInstanceOf[_root_.scala.AnyRef]\"\n )\n }\n }\n\n def debugMessageArgs(c: LoggerContext)\n (message: c.Expr[String], args: c.Expr[Any]*): c.universe.Tree = {\n import c.universe._\n val underlying = q\"${c.prefix}.underlying\"\n val anyRefArgs = formatArgs(c)(args: _*)\n if (args.length == 2)\n q\"if ($underlying.isDebugEnabled) $underlying.debug($message, _root_.scala.Array(${anyRefArgs.head}, ${anyRefArgs(1)}): _*)\"\n else\n q\"if ($underlying.isDebugEnabled) $underlying.debug($message, ..$anyRefArgs)\"\n }\n \n def debugMessage(c: LoggerContext)\n (message: c.Expr[String]): c.universe.Tree = {\n val (messageFormat, args) = deconstructInterpolatedMessage(c)(message)\n debugMessageArgs(c)(messageFormat, args: _*)\n }\n}\n

\u9996\u5148\uff0cblackbox.Context \u4e8b\u5b9e\u4e0a\u9650\u5b9a\u4e86\u8fd9\u4e2a\u5b8f\u7684\u4f5c\u7528\u57df\u2014\u5373\u5728\u7c7b Logger \u4e4b\u4e2d\u3002\u53ef\u4ee5\u89c2\u5bdf\u5230\uff0c\u5355\u4f8b LoggerMacro \u7684\u6bcf\u4e00\u4e2a\u65b9\u6cd5\u90fd\u5e26\u6709 LoggerContext \u8fd9\u4e2a\u53c2\u6570\uff0c\u6bcf\u4e00\u4e2a\u65b9\u6cd5\u7684\u5177\u4f53\u5b9e\u73b0\uff0c\u4e5f\u548c LoggerContext \u6709\u4e00\u5b9a\u7684\u5173\u7cfb\u3002

debugMessage \u51fd\u6570\u9996\u5148\u5c06\u5b57\u7b26\u4e32\u63d2\u503c\u8fd9\u4e2a\u8868\u8fbe\u5f0f\u901a\u8fc7 deconstructInterpolateMessage \u89e3\u6784\u6210 messageFormat \u548c args\u3002\u4e0b\u9762\u8fd9\u6bb5\u4ee3\u7801\u53ef\u4ee5\u975e\u5e38\u660e\u786e\u7684\u89e3\u91ca\uff0c\u4ec0\u4e48\u662f messageFormat \u4ee5\u53ca\u4ec0\u4e48\u662f args\uff1a

logger.info(\"Info :{}\" , user.getName())\n

\u5982\u679c\u662f Scala \u7684\u5b57\u7b26\u4e32\u63d2\u503c\u7684\u8bdd\uff0c\u5c31\u662f s\"Info :${user.getName}\"\u3002

\u89e3\u6784\u4e4b\u540e\uff0c\u6211\u4eec\u53ea\u9700\u8981\u901a\u8fc7 Quasiquote \u5c06\u5e26\u6709\u6761\u4ef6\u8bed\u53e5\u7684\u4ee3\u7801\u91cd\u65b0\u6784\u9020\u8d77\u6765\u5c31\u53ef\u4ee5\u4e86\u3002

\u7f16\u8bd1\u671f\u548c\u8fd0\u884c\u65f6

\u53e6\u5916\u4e00\u4e2a\u9700\u8981\u6ce8\u610f\u7684\u70b9\u662f\uff0c\u5728\u4f7f\u7528 @data \u7684\u65f6\u5019\uff0c\u6211\u4eec\u5b9e\u9645\u4e0a\u9700\u8981\u5728\u5de5\u7a0b\u4e2d\u5f00\u542f Paradise \u63d2\u4ef6\uff0c\u800c\u6211\u4eec\u5728\u4f7f\u7528 Scala\nLogging \u7684\u65f6\u5019\uff0c\u5b9e\u9645\u4e0a\u76f4\u63a5\u4f9d\u8d56 Scala\nLogging \u5c31\u53ef\u4ee5\u4e86\uff0c\u4e0d\u9700\u8981\u5f00\u542f Paradise \u63d2\u4ef6\u3002\u8fd9\u5c31\u6d89\u53ca\u5230\u4e00\u4e2a\u95ee\u9898\uff1a\u6211\u4eec\u5728\u4e0a\u4e00\u8282\u4e2d\u505a\u4e86\u8be6\u7ec6\u89e3\u91ca\u7684\u4ee3\u7801\uff0c\u5230\u5e95\u662f\u5728\u54ea\u4e2a\u73af\u8282\u6267\u884c\u7684\u3002

\u5f88\u7b80\u5355\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u5728 debugMessage \u589e\u52a0\u65e5\u5fd7\u7684\u65b9\u5f0f\uff0c\u786e\u5b9a\u8fd9\u4e2a\u7ec6\u8282\u3002

\u6700\u7ec8\u53d1\u73b0\uff0c\u5b9e\u9645\u4e0a\uff0c\u6211\u4eec\u4f9d\u8d56\u4e86 Scala\nLogging\uff0c\u4f46\u662f\u9879\u76ee\u81ea\u8eab\u6ca1\u6709\u4f7f\u7528\u7f16\u8bd1\u63d2\u4ef6\uff0c\u5728\u7f16\u8bd1\u8fc7\u7a0b\u4e2d\uff0c\u7f16\u8bd1\u5668\u9047\u5230 Scala\nLogging \u4e2d\u4f1a\u751f\u6210\u4ee3\u7801\u7684\u65b9\u6cd5\u65f6\uff0c\u5b9e\u9645\u4e0a\u8fd8\u662f\u4f1a\u53bb\u5229\u7528\u7f16\u8bd1\u63d2\u4ef6\uff0c\u751f\u6210\u4ee3\u7801\u3002

\u603b\u7ed3

\u5b9e\u9645\u4e0a\uff0c\u8fd9\u4e00\u7bc7\u7684\u5185\u5bb9\u867d\u7136\u5728\u5b8f\u7684\u5177\u4f53\u4f7f\u7528\u63a5\u53e3\u4e0a\u548c lombok.Data \u90a3\u4e00\u7bc7\u6709\u7ec6\u8282\u4e0a\u7684\u5dee\u5f02\uff0c\u4f46\u5b9e\u9645\u4e0a\u6700\u7ec8\u751f\u6210\u4ee3\u7801\u7684\u8fd8\u662f\u5728\u4f7f\u7528 Quasiquote\uff0c\u6240\u4ee5\u5982\u4f55\u9ad8\u6548\u5730\u5728 REPL \u4e2d\u5c1d\u8bd5 Quasiquote \u81f3\u5173\u91cd\u8981\u3002Quasiquote \u662f\u4f0a\u7538\u56ed\u5143\u7f16\u7a0b\u4e2d\u6700\u67af\u71e5\u6700\u8017\u65f6\u7684\u4e00\u4e2a\u73af\u8282\uff0c\u800c\u901a\u8fc7\u4f55\u79cd\u65b9\u5f0f\u53bb\u5c06\u5e38\u89c4\u7684\u4ee3\u7801\u548c\u5b8f\u751f\u6210\u7684\u4ee3\u7801\u8854\u63a5\u8d77\u6765\uff0c\u5219\u662f\u4f0a\u7538\u56ed\u4e2d\u4e00\u6247\u9690\u79d8\u7684\u5927\u95e8\u3002

\u9605\u8bfb\u539f\u6587\uff1aScala \u5143\u7f16\u7a0b\uff1a\u5728\u65e5\u5fd7\u5e93\u4e2d\u7684\u5e94\u7528

\u5728\u300a Scala \u7f16\u7a0b\uff08 3rd \uff09\u300b\u4e2d\uff0c20.6 \u62bd\u8c61\u7c7b\u578b\u8fd9\u4e00\u8282\u4e2d\uff0c\u672c\u4eba\u6709\u4e2a\u975e\u5e38\u4e0d\u89e3\u7684\u5730\u65b9\uff0c\u4e66\u4e2d\u63d0\u5230\uff1a

class Food\n\nabstract class Animal {\n def eat(food: Food)\n}\n\nclass Grass extends Food\n\nclass Cow extends Animal {\n override def eat(food: Grass) = {}\t// \u8fd9\u4e0d\u80fd\u7f16\u8bd1\n}\t\t\t\t\t// \u5982\u679c\u80fd\u7684\u8bdd...\n\nclass Fish extends Food\n\nval bessy: Animal = new Cow\n\nbessy eat (new Fish) // ...\u4f60\u5c31\u80fd\u7ed9\u725b\u5403\u8349\u4e86\n

\u672c\u4eba\u7406\u89e3 override \u8d85\u7c7b\u65b9\u6cd5\uff0c\u65b9\u6cd5\u53c2\u6570\u662f\u4e0d\u652f\u6301\u534f\u53d8\u7684\uff0c\u4f46\u662f\u4e0a\u6587\u5047\u8bbe\u901a\u8fc7\u7f16\u8bd1\uff0c\"bessy eat (new Fish)\"\u4e0d\u662f\u672c\u6765\u5c31\u4e0d\u80fd\u8fd0\u884c\u5417\uff1f Fish \u672c\u6765\u5c31\u4e0d\u80fd\u4e0a\u8f6c\u578b\u4e3a Grass \u5440\u3002\u4f55\u51b5\u5982\u4e0b\u91cd\u5199 eat \u65b9\u6cd5\u5c82\u4e0d\u662f\u540c\u6837\u6709\u8fd9\u4e2a\u95ee\u9898\uff1f

class Cow extends Animal {\n override def eat(food: Food): Unit = {}\n}\n\nval cow = new Cow\n\ncow eat new Fish\n// \u80fd\u901a\u8fc7\u7f16\u8bd1\u4e14\u8fd0\u884c\n

\u5c0f\u5f1f\u4e0d\u624d\uff0c\u4e00\u76f4\u6ca1\u7406\u89e3\uff0c\u5e0c\u671b\u5404\u4f4d\u5927\u4f6c\u8f7b\u55b7

\u5927\u5bb6\u597d\uff0c\u8bf7\u6559\u4e0b\u5173\u4e8e\u7528 Flume+kafka+Spark \u5b9e\u73b0\u5b9e\u65f6\u76d1\u63a7\u9519\u8bef\u65e5\u5fd7\u62a5\u8b66\u7684\u529f\u80fd\u3002\n\u76ee\u524d Flume \u548c Kafka \u7684\u76f8\u5173\u529f\u80fd\u5df2\u7ecf\u901a\u4e86\u3002\u4f46\u662f spark \u6ca1\u4ec0\u4e48\u4f7f\u7528\u7ecf\u9a8c\u3002\n\u770b\u7f51\u4e0a\u6559\u7a0b\u662f\u8981\u81ea\u5df1\u5199 Scala \u811a\u672c\u7136\u540e\u6253\u6210 jar \u5305\u7ed9 Spark \u6267\u884c\u3002

\u6211\u60f3\u7528 spark \u5b9e\u73b0\u68c0\u6d4b kafka \u7684\u6570\u636e\u6d41\uff0c\u5982\u679c\u53d1\u73b0 error \u5b57\u6837\uff0c\u5c31\u53d1\u9001\u90ae\u4ef6\u3002\n\u8bf7\u95ee\u5404\u4f4d\u5927\u4f6c\u6709\u6ca1\u6709\u76f8\u5173\u811a\u672c\u6216\u8005\u6559\u7a0b\u7684\u5730\u5740\u53ef\u4ee5\u53c2\u8003\u7684\uff1f

\u8c22\u8c22\u5927\u5bb6\u3002

\u9996\u5148\u7528 scala-native \u7684 g8 \u6a21\u677f\u521b\u5efa\u4e00\u4e2a\u811a\u624b\u67b6\uff1a

$ sbt new scala-native/scala-native.g8\n...\nA minimal project that uses Scala Native. \n\nname [Scala Native Seed Project]: scala-native-playground\n\nTemplate applied in /path/to/scala-native-playground\n

\u53ea\u8981\u8f93\u5165\u4f60\u60f3\u521b\u5efa\u7684\u5de5\u7a0b\u7684\u540d\u5b57\uff0c\u6574\u4e2a\u811a\u624b\u67b6\u5c31\u642d\u5efa\u8d77\u6765\u4e86\u3002

\u6211\u4eec\u8bd5\u7740\u7f16\u8bd1\u8fd0\u884c\u4e00\u4e0b\u8fd9\u4e2a\u811a\u624b\u67b6\uff1a

$ cd scala-native-playground\n$ sbt\nsbt:scala-native-playground> compile\n[info] Non-compiled module 'compiler-bridge_2.11' for Scala 2.11.12. Compiling...\n[info] Compilation completed in 6.179s.\n[info] Done compiling.\n[success] Total time: 177 s, completed 2019-2-24 10:24:54\nsbt:scala-native-playground> run\n[error] no clang60, clang-6.0, clang50, clang-5.0, clang40, clang-4.0, clang39, clang-3.9, clang38, clang-3.8, clang37, clang-3.7, clang found in $PATH. Install clang ( http://www.scala-native.org/en/latest/user/setup.html)\n[error] no clang++60, clang++-6.0, clang++50, clang++-5.0, clang++40, clang++-4.0, clang++39, clang++-3.9, clang++38, clang++-3.8, clang++37, clang++-3.7, clang++ found in $PATH. Install clang ( http://www.scala-native.org/en/latest/user/setup.html)\n[error] (nativeClang) no clang60, clang-6.0, clang50, clang-5.0, clang40, clang-4.0, clang39, clang-3.9, clang38, clang-3.8, clang37, clang-3.7, clang found in $PATH. Install clang ( http://www.scala-native.org/en/latest/user/setup.html)\n[error] (nativeClangPP) no clang++60, clang++-6.0, clang++50, clang++-5.0, clang++40, clang++-4.0, clang++39, clang++-3.9, clang++38, clang++-3.8, clang++37, clang++-3.7, clang++ found in $PATH. Install clang ( http://www.scala-native.org/en/latest/user/setup.html)\n[error] Total time: 0 s, completed 2019-2-24 10:26:01\n

\u80fd\u6b63\u5e38\u7f16\u8bd1\uff0c\u4f46\u662f\u8fd0\u884c\u7684\u65f6\u5019\u4f1a\u62a5\u9519\u3002\u6309\u7167\u63d0\u793a\uff0c\u6211\u4eec\u9700\u8981\u5b89\u88c5\u4e00\u4e9b\u4f9d\u8d56\uff1a

$ sudo apt install clang libunwind-dev\n

\u7136\u540e\uff0c\u5728\u91cd\u65b0\u5728 sbt \u7684 REPL \u91cc\u9762\u6572 Run \u5c31\u53ef\u4ee5\u4e86\u3002\u5927\u6982\u662f\u8fd9\u6837\uff1a

sbt:scala-native-playground> run\n[info] Linking (534 ms)\n[info] Discovered 800 classes and 4709 methods\n[info] Optimizing (debug mode) (742 ms)\n[info] Generating intermediate code (242 ms)\n[info] Produced 39 files\n[info] Compiling to native code (332 ms)\n[info] Linking native code (immix gc) (60 ms)\nHello, world!\n[success] Total time: 3 s, completed 2019-2-24 10:27:45\n

\u6574\u4e2a\u8fc7\u7a0b\u8fd8\u662f\u6bd4\u8f83\u6d41\u7545\u7684\uff0c\u6ca1\u6709\u9047\u5230\u7279\u522b\u6d6a\u8d39\u65f6\u95f4\u7684\u4e8b\u60c5\uff0cby the way\uff0c\u6211\u6240\u7528\u7684 Scala Native \u7248\u672c\u662f 0.3.8\uff0c\u8fd9\u4e00\u70b9\u4eceproject/plugins.sbt\u53ef\u4ee5\u77e5\u9053\u3002

$ cat project/plugins.sbt \naddSbtPlugin(\"org.scala-native\" % \"sbt-scala-native\" % \"0.3.8\")\n

====> \u70b9\u6211\u8fd4\u56de\u6587\u7ae0\u76ee\u5f55 <====

\u6211\u5728\u4ee3\u7801Link\u91cc\u770b\u5230

import ...\n\nobject DataAssign\nobject InitAssign\n\ntrait DataPrimitives[T <: Data] {\n// ... Other codes\n

\u5176\u4e2d\u4e0a\u9762\u8fd9\u4e24\u4e2a object \u8fd9\u91cc\u90fd\u6ca1\u6709\u5177\u4f53\u5b9e\u73b0\u3002\u8bf7\u95ee\u8fd9\u662f\u4ec0\u4e48\u7528\u6cd5\uff0c\u6709\u4ec0\u4e48\u53c2\u8003\u6750\u6599\u4e48\uff1f\n\u8c22\u8c22

\u95ee\u9898\uff1a\u4ec0\u4e48\u5e94\u7528\u573a\u666f\u4e0b group by \u6bd4 reduce by \u66f4\u597d\uff1f

\u5f53\u65f6\u61f5\u903c\u4e86\uff0c\u611f\u89c9\u4e0d\u662f\u9ed8\u8ba4\u90fd\u5c3d\u91cf\u4f7f\u7528 reduce by \u5417\uff0c\u73b0\u5728\u6211\u80fd\u60f3\u5230\u7684\u60c5\u51b5\u4e5f\u53ea\u6709\u5728 key \u503c\u975e\u5e38\u5c11\u7684\u60c5\u51b5\u4e0b\u7528 group by \u6bd4\u8f83\u597d\uff0c\u4e0d\u77e5\u9053\u5bf9\u4e0d\u5bf9\u3002

\u518d\u770b twitter \u7684 Scala School\uff0c\u6709\u4e00\u6bb5\u4ee3\u7801\u770b\u4e0d\u61c2\uff0c\u7279\u6765\u6c42\u6559

def f(s: String) = \"f(\" + s + \")\" \ndef g(s: String) = \"g(\" + s + \")\"\n\n// \u5c31\u662f\u8fd9\u91cc\u770b\u4e0d\u61c2\n\nval fComposeG = f _ compose g _\n

\u60f3\u95ee\u4e00\u4e0b \u8fd9\u4e2a _ \u5728\u8fd9\u91cc\u662f\u4ec0\u4e48\u4f5c\u7528\uff1f \u8fd9\u662f\u4e00\u79cd\u4ec0\u4e48\u7528\u6cd5\u5440?

\u65e0\u610f\u95f4\u53d1\u73b0\u4e86 v2 \u8fd8\u6709 scala \u7684\u6807\u7b7e\uff0c\u53c8\u770b\u5230\u4e86t/431491\u3002
\n\u6240\u4ee5\u5c31\u5ba3\u4f20\u4e00\u4e0b telegram \u7684\u7fa4\u7ec4\u3002

\u4e4b\u524d\u7ecf\u9a8c\u4e3b\u8981\u662f Haskell \uff08\u5927\u5b66\u4ece\u5927\u4e00\u5199\u5230\u6bd5\u4e1a\uff09\uff0c\u73b0\u5728\u5de5\u4f5c\u4e86\u7ecf\u5e38\u5199 Scala\uff0c\u5ea7\u6807\u6df1\u5733\uff0c\u5e0c\u671b\u627e\u5230\u5927\u672c\u8425\u4e00\u8d77\u4ea4\u6d41 /\u4ecb\u7ecd\u5de5\u4f5c

zhihu: https://www.zhihu.com/people/Martinawd

\u770b\u5230\u4e00\u7bc7\u4e0d\u9519\u7684\u535a\u6587\uff0c\u4ecb\u7ecd Scala \u7c7b\u578b\u7cfb\u7edf\uff1aScala's types of types\u3002

\u4e8e\u662f\u628a\u5b83\u7ffb\u8bd1\u6210\u4e2d\u6587\u4e86\uff0c\u8be6\u89c1 Scala \u4e2d\u4e0d\u540c\u7c7b\u578b\u7684\u7c7b\u578b\u3002\n\u4e0d\u8fc7\u6709\u51e0\u4e2a\u7ae0\u8282\u539f\u4f5c\u8005\u8fd8\u672a\u5b8c\u6210\u3002

\u6b22\u8fce\u6307\u70b9\u548c\u5efa\u8bae\u3002

\u6700\u8fd1\u5f00\u59cb\u5b66\u4e60 Scala\uff0c\u60f3\u501f\u6b64\u673a\u4f1a\u5f00\u59cb\u953b\u70bc\u81ea\u5df1\u5199\u65e5\u5fd7\u548c\u603b\u7ed3\u3002\n\u521a\u603b\u7ed3\u4e86\u4e09\u7ae0\uff0c\u5e0c\u671b\u80fd\u4fdd\u6301\u66f4\u65b0\u3002:)

Scala \u81ea\u5b66

Scala \u6982\u89c8(\u7b2c\u4e00\u7bc7)

Scala \u7684\u7c7b\u4e0e\u5bf9\u8c61(\u7b2c\u4e8c\u7bc7)

\u53c2\u8003\u4e66\u7c4d

Programming in Scala \u7b2c\u4e09\u7248

\u6700\u8fd1\u5b66\u4e60 Scala\uff0c\u5728\u770b\u300a Scala \u7f16\u7a0b\u300b(programming in scala)\uff0c\u770b\u5230\u4e86 20 \u7ae0\uff0c\u73b0\u5728\u77e5\u8bc6\u7279\u522b\u96f6\u6563\uff0c\u5b66\u5f97\u5f88\u4e0d\u8e0f\u5b9e\u3002\u4e5f\u5c1d\u8bd5\u8fc7\u5b66\u4e60 play \u6846\u67b6\uff0c\u7f51\u4e0a\u67e5\u5230\u7684\u8d44\u6599\u4e0d\u591a\uff08\u4e2d\u6587\u82f1\u6587\u611f\u89c9\u90fd\u633a\u5c11\uff09\uff0c\u53ef\u4ee5\u501f\u9274\u7684\u4f8b\u5b50\u4e5f\u5f88\u5c11\uff08\u4e3b\u8981\u662f\u5176\u4e2d\u7528\u4e86\u5f88\u591a\u5176\u5b83\u7684\u5e93\uff0c\u5bfc\u81f4\u6211\u73b0\u5728\u53bb\u5199\u7684\u8bdd\u53ea\u80fd \u201c\u590d\u5236\u7c98\u8d34\u201d \u5176\u4e2d\u7684\u4ee3\u7801\uff0c\u5f88\u591a\u539f\u7406\u4e0d\u7406\u89e3\uff09\u3002

\u8bf7\u95ee\u600e\u6837\u7ed3\u5408\u9879\u76ee\u53bb\u5b9e\u8df5\u5462\uff1f\u6216\u8005\u8bf4\u54ea\u4e9b\u6846\u67b6\uff08\u6a21\u5757\uff09\u9002\u5408\u521d\u5b66\u8005\u5b66\u4e60\uff08\u9605\u8bfb\uff09\u5462\uff1f\u5e0c\u671b\u5927\u5bb6\u80fd\u8c08\u8c08\u81ea\u5df1\u7684\u60f3\u6cd5\uff0c\u8c22\u8c22\uff01

Play Framework \u4ece\u95ee\u4e16\u81f3\u4eca\u5df2\u7ecf\u5341\u4e2a\u5e74\u5934\u4e86\uff0c\u4f46\u662f\u53ef\u60dc\u7684\u662f\u8fd9\u4e48\u4f18\u79c0\u7684\u6846\u67b6\u5728\u56fd\u5185\u5374\u9c9c\u4e3a\u4eba\u77e5\u3002\u5c24\u5176\u662f\u5f53 Play Framework 2.x \u53d1\u5e03\u4ee5\u540e\uff0c\u57fa\u4e8e Scala \u8bed\u8a00\u91cd\u5199\u4e86\u6574\u4e2a\u6846\u67b6\u3002\u5f53 Scala \u548c Play Framework \u76f8\u9047\uff0c\u8fd9\u672c\u8be5\u662f\u4e00\u6bb5\u7f8e\u597d\u7684\u4f73\u8bdd\uff0c\u53ef\u7ed3\u5c40\u5374\u662f\uff0c\u9762\u5bf9 Scala \u8bed\u8a00\u66f4\u591a\u7684\u4eba\u671b\u800c\u5374\u6b65\u3002 \u8fd9\u5176\u5b9e\u90fd\u662f\u56e0\u4e3a\u4eba\u4eec\u6f5c\u610f\u8bc6\u91cc\u5bf9\u672a\u77e5\u4e8b\u7269\u5145\u6ee1\u6050\u60e7\u3002\u4f46\u5176\u5b9e Scala \u6ca1\u90a3\u4e48\u53ef\u6015\uff0c\u76f8\u53cd\u4e86\u89e3\u5b83\u4e00\u70b9\u4f60\u4f1a\u89c9\u5f97\u5b83\u5f88\u53ef\u7231\u3002\u4f8b\u5982\u5f88\u591a\u4eba\u770b\u5230 Scala \u4f7f\u7528::\u62fc\u63a5\u5143\u7d20\uff0c\u4f7f\u7528:::\u62fc\u63a5\u5217\u8868\uff0c\u4f8b\u5982\uff1a

val list1 = List(\"c\", \"a\", \"l\", \"a\")\nval list2 = s :: list1 // list2: (s, c, a, l, a)\nval list3 = List(\"p\", \"l\", \"a\", \"y\")\nval list4 = list3 ::: list2 // list4: (p, l, a, y, s, c, a, l, a)\n

\u7136\u540e\u5c31\u5f00\u59cb\u5410\u69fd\uff1aWTF\uff0c\u8fd9\u662f\u4ec0\u4e48\u9b3c\uff1f \u522b\u6025\uff0c\u7ed9\u6211\u4e00\u5206\u949f\u65f6\u95f4\uff0c\u770b\u770b\u80fd\u5426\u8bf4\u670d\u4f60!\n\u9996\u5148\u4f60\u9700\u8981\u4e86\u89e3\u4e00\u4e2a\u57fa\u672c\u6982\u5ff5\uff0c\u5728 Scala \u4e2d\u4e00\u5207\u90fd\u662f\u65b9\u6cd5\uff1a

\"a\" * 3 //\u7b49\u4ef7\u4e8e: \"a\".*(3)\n2 - 1 //\u7b49\u4ef7\u4e8e: 2.-(1)\n

\u6240\u4ee5\u6ca1\u9519\uff0c\u4f60\u4e4b\u524d\u770b\u5230\u7684::\u548c:::\u81ea\u7136\u4e5f\u662f\u65b9\u6cd5\uff0c\u53ea\u4e0d\u8fc7\u662f\u4e3a\u4e86\u7b80\u6d01\uff0c\u7701\u7565\u4e86.\u548c()\u3002List \u662f\u7531 head \u548c tail \u62fc\u63a5\u5728\u4e00\u8d77\u7684\u9012\u5f52\u7ed3\u6784(\u8fd9\u79cd\u8bbe\u8ba1\u5728\u6a21\u5f0f\u5339\u914d\u65f6\u975e\u5e38\u65b9\u4fbf)\u3002List \u7684\u5b9a\u4e49\u53ef\u4ee5\u5199\u6210\u5982\u4e0b\u5f62\u5f0f:

head :: tail\n

head \u662f\u9996\u5143\u7d20\uff0ctail \u662f\u5269\u4f59\u7684 List\u3002\u4ed4\u7ec6\u77a7\u77a7\uff0c::\u770b\u8d77\u6765\u662f\u4e0d\u662f\u5f88\u50cf\u80f6\u6c34\uff0c\u5c06\u5217\u8868\u7684\u5934\u548c\u5c3e\u7d27\u7d27\u5730\u7c98\u5728\u4e00\u8d77\uff0c\u66f4\u8fdb\u4e00\u6b65\uff0c:::\u53ef\u4ee5\u628a\u4e24\u4e2a\u5217\u8868\u7c98\u5728\u4e00\u8d77\u3002\u8fd9\u6837\u7684\u4ee3\u7801\u662f\u4e0d\u662f\u5f88\u7b80\u6d01\uff0c\u5e76\u4e14\u5bcc\u6709\u8868\u8fbe\u529b\uff01 \u5728 Scala \u4e2d\uff0c\u8fd9\u79cd\u7b80\u6d01\u7684\u8bbe\u8ba1\u6bd4\u6bd4\u7686\u662f\uff0c\u4f8b\u5982\u6211\u4eec\u518d\u6765\u770b\u770b\u5982\u4f55\u6784\u5efa\u4e00\u4e2a Map \u5b9e\u4f8b\uff1a

val map = Map(\"name\" -> \"PlayScala \u793e\u533a\", \"url\" -> \"http://www.playscala.cn\")\n

\u611f\u53d7\u4e00\u4e0b\uff0c\u662f\u4e0d\u662f\u975e\u5e38\u6e05\u6670\u660e\u4e86\u3002 \u5f53\u7136 Scala \u7684\u9b45\u529b\u8fdc\u4e0d\u6b62\u5982\u6b64\uff0c\u5f53\u4f60\u6162\u6162\u4e86\u89e3\u5b83\u65f6\uff0c\u4f60\u4f1a\u6162\u6162\u6df1\u9677\u800c\u65e0\u6cd5\u81ea\u62d4\u3002\n\u8bb2\u4e86\u90a3\u4e48\u591a\uff0c\u6211\u53ea\u60f3\u544a\u8bc9\u4f60 Scala \u5e76\u4e0d\u53ef\u6015\uff0c\u5176\u5b9e\u5728 Play Framework \u4e2d\uff0c\u4f60\u6839\u672c\u5c31\u4e0d\u9700\u8981\u62b1\u7740 Scala \u4e66\u7c4d\u5543\u5b8c\u518d\u5199\u4ee3\u7801\uff0cPlayScala \u793e\u533a\u4f1a\u4e3a\u4f60\u51c6\u5907\u4e00\u7bc7 30 \u5206\u949f\u7684\u4e3a Play \u521d\u5b66\u8005\u51c6\u5907\u7684 Scala \u57fa\u7840\u77e5\u8bc6\uff0c\u8bfb\u5b8c\u4f60\u5c31\u53ef\u4ee5\u6295\u5165 Play Framework \u7684\u6000\u62b1\u4e86\u3002

\u597d\u4e86\uff0c\u56de\u5f52\u6b63\u9898\uff0c\u90a3\u4e3a\u4ec0\u4e48\u8981\u521b\u5efa PlayScala \u793e\u533a\u5462\uff1f \u4e3b\u8981\u539f\u56e0\u662f\u56fd\u5185 Play Framework \u7684\u7b2c\u4e00\u624b\u4e2d\u6587\u5b66\u4e60\u8d44\u6599\u975e\u5e38\u7a00\u7f3a\uff0c\u867d\u7136\u5728\u7f51\u4e0a\u53ef\u4ee5\u627e\u5230\u4e00\u4e9b\u6559\u7a0b\uff0c\u4f46\u662f\u77e5\u8bc6\u7684\u788e\u7247\u5316\u5f88\u4e25\u91cd\uff0c\u5e76\u4e14\u5f88\u591a\u8d28\u91cf\u8f83\u5dee\u7684\u6587\u7ae0\u4f1a\u5f71\u54cd\u521d\u5b66\u8005\u7684\u8ba4\u77e5\u3002PlayScala \u793e\u533a\u6b63\u662f\u57fa\u4e8e\u8fd9\u6837\u7684\u539f\u56e0\u800c\u8bde\u751f\u7684\uff0c\u5e76\u4e14\u5e0c\u671b\u80fd\u591f\u5b9e\u73b0\u4ee5\u4e0b\u51e0\u4e2a\u613f\u666f\uff1a

\n
• PlayScala \u793e\u533a\u5f00\u653e\u6e90\u7801\uff0c\u5e0c\u671b\u901a\u8fc7\u5927\u5bb6\u7684\u52aa\u529b\uff0c\u5c06 Play Framework \u5f00\u53d1\u7684\u6700\u4f73\u5b9e\u8df5\u5168\u90fd\u56ca\u62ec\u8fdb\u6765\uff0c\u4f9b\u5927\u5bb6\u65e5\u5e38\u5f00\u53d1\u53c2\u8003\u3002
\n
• \u7ef4\u62a4\u4e00\u4e2a\u9ad8\u8d28\u91cf\u7684\u300e\u5b66\u4e60\u300f\u677f\u5757\uff0c\u7cfb\u7edf\u800c\u5168\u9762\u5730\u4ecb\u7ecd Play Framework \u5f00\u53d1\u7684\u76f8\u5173\u77e5\u8bc6\uff0c\u5e76\u5c06 PlayScala \u793e\u533a\u6e90\u7801\u4e2d\u7684\u6700\u4f73\u5b9e\u8df5\u5728\u8fd9\u91cc\u4ee5\u6587\u6863\u7684\u5f62\u5f0f\u9610\u8ff0\uff0c\u4f60\u53ef\u4ee5\u8ba4\u4e3a\u5b83\u662f Play Framework \u5b98\u65b9\u6587\u6863\u7684\u4e00\u4e2a\u6709\u529b\u8865\u5145\u3002
\n
• \u63d0\u4f9b\u4e00\u4e2a\u4ea4\u6d41\u4e92\u52a8\u5e73\u53f0\u3002PlayScala \u793e\u533a\u7684\u300e\u5206\u4eab\u300f\u548c\u300e\u95ee\u7b54\u300f\u677f\u5757\u662f\u4e3a\u300e\u5b66\u4e60\u300f\u677f\u5757\u670d\u52a1\uff0c\u8fd9\u4e24\u4e2a\u677f\u5757\u6c89\u6dc0\u4e0b\u6765\u7684\u77e5\u8bc6\u6700\u7ec8\u4f1a\u88ab\u6536\u5f55\u5230\u300e\u5b66\u4e60\u300f\u677f\u5757\u3002
\n

\u5e0c\u671b\u5728\u5927\u5bb6\u7684\u4e00\u8d77\u52aa\u529b\u4e0b\uff0c\u53ef\u4ee5\u8ba9\u66f4\u591a\u7684\u4eba\u4e86\u89e3\u5e76\u52a0\u5165 Play Framework \u7684\u5f00\u53d1\u884c\u5217\uff0c\u4e0d\u65ad\u589e\u5f3a Play Framework \u5728\u56fd\u5185\u7684\u5f71\u54cd\u529b\u3002

\n

\u6b22\u8fce\u6765\u8bbf\uff1a PlayScala \u793e\u533a

\n

\u5982\u9898\uff0c\u4e0b\u8f7d\u4e86 2.9g \u7684\u6570\u636e\u4e0d\u719f\u6089 scala \u4e0d\u77e5\u9053\u600e\u4e48\u8bfb\u53d6\u51fa\u6765\nreadme \u5982\u4e0b

\u201c\u5982\u679c\u4f7f\u7528 scala,\u53ef\u4ee5\u4f7f\u7528\u5982\u4e0b case class \u89e3\u6790\u51fa\u6570\u636e

\ncase class Answer(answer_id: Long,\n\t\t\t\t question_id: Long,\n\t\t\t\t question_title: String, \n\t\t\t\t question_topics: Array[Long], \n\t\t\t\t votup_count: Long)\n\ncase class Article(id: Long, title: String, votup_count: Long)\ncase class Question(question_followers: Long, \n\t\t\t\t\tquestion_id: Long, \n\t\t\t\t\tquestion_title: String, \n\t\t\t\t\tquestion_topics: Array[Long])\n\ncase class userStringId(CREATED_ANSWERS: Array[Answer],\n CREATED_ARTICLES: Array[Article],\n CREATED_QUESTIONS: Array[Question],\n FOLLOWED_QUESTIONS: Array[Question],\n VOTEUPED_ANSWERS: Array[Answer],\n VOTEUPED_ARTICLES: Array[Article],\n followers_count: Long,\n id: String)\n\ncase class userDigitalId(CREATED_ANSWERS: Array[Answer],\n CREATED_ARTICLES: Array[Article],\n CREATED_QUESTIONS: Array[Question],\n FOLLOWED_QUESTIONS: Array[Question],\n VOTEUPED_ANSWERS: Array[Answer],\n VOTEUPED_ARTICLES: Array[Article],\n followers_count: Long,\n id: Long)\n

\u5982\u9898.\u5df2\u53d1\u73b0\u7684\u597d\u50cf\u6709 spark.

\u5982\u9898\uff0c\u600e\u4e48\u5c06\u6e90\u7801\u8fde\u540c\u5b57\u8282\u7801\u4e00\u5e76\u6253\u5305\u5728\u4e00\u8d77\uff0c\u8fd9\u6837\u53ef\u4ee5\u76f4\u63a5\u67e5\u770b jar \u91cc\u6bcf\u4e2a class \u7684\u6e90\u7801\uff1f

\u7531\u4e8e\u9879\u76ee\u7528\u5230\u4e86 HDP \u7684\u4e1c\u897f\uff0c\u6240\u4ee5\u6211\u5728 build.sbt \u91cc\u9762\u6dfb\u52a0\u4e86 resovlers \uff0c

resolvers += \"Hortonworks Repository\" at \"http://repo.hortonworks.com/content/repositories/releases/\"\n\nresolvers += \"Hortonworks Jetty Maven Repository\" at \"http://repo.hortonworks.com/content/repositories/jetty-hadoop/\"\n

\u4f46\u662f\uff0c\u5982\u679c\u6211\u4f7f\u7528-Dsbt.override.build.repos=true \u7684\u8bdd\uff0c\u8fd9\u4e2a resolvers \u5c31\u4f1a\u88ab\u8986\u76d6\u6389\uff0c\u6ca1\u6cd5\u4f7f\u7528\u4e86\uff0c\u6709\u4eba\u80fd\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\u5417\uff1f\u611f\u8c22

\u5728 IDEA \u4e2d\uff0c build.sbt \u4e2d\uff0c\u6709\u7684\u4f9d\u8d56\u4e0b\u9762\u6709\u7ea2\u8272\u6ce2\u6d6a\u7ebf\uff0c\u663e\u793a\u6709\u4f9d\u8d56\u6ca1\u6709\u89e3\u51b3\uff0c\u4f46\u662f\u4e8b\u5b9e\u662f\u8fd9\u4e9b\u4f9d\u8d56\u5305\u5df2\u7ecf\u4e0b\u8f7d\u4e0b\u6765\u4e86\uff0c\u4e5f\u6ca1\u6709\u4f9d\u8d56\u6ca1\u89e3\u51b3\u7684\u62a5\u9519\uff0c\u5728\u7a0b\u5e8f\u4e2d\u53ef\u4ee5\u4f7f\u7528\u3002

\u6709\u670b\u53cb\u9047\u5230\u8fc7\u8fd9\u4e2a\u95ee\u9898\u5417\uff1f

http://scala-lang.org/news/2.12-roadmap/

\u56fd\u5e86\u628a scala \u7f16\u7a0b\u770b\u4e86\u5927\u534a\uff0c\u6709\u4ec0\u4e48\u7ec3\u624b\u7684\u5c0f\u9879\u76ee\u4e48\uff1f\u6709\u6ca1\u6709\u7ec4\u7ec7\u5440\uff1f

Java \u867d\u7136\u662f\u4f7f\u7528\u4eba\u6570\u6700\u591a\u7684\u8bed\u8a00, \u4f46\u662f\u5176\u5197\u4f59\u7684\u4e66\u5199\u65b9\u5f0f\u4e3a\u4eba\u6240\u8bdf\u75c5. Scala \u4e0d\u4ec5\u5b8c\u5168\u517c\u5bb9 Java \u800c\u4e14\u8fd8\u5e26\u6765\u4e86\u51fd\u6570\u5f0f\u7f16\u7a0b\u4ee5\u53ca Actor \u6a21\u578b\u5e76\u53d1\u673a\u5236. \u6211\u73b0\u5728\u5df2\u7ecf\u5bf9 Scala \u8bed\u8a00\u8822\u8822\u6b32\u52a8\u4e86, \u6562\u95ee V2EX \u6709 Scala \u7231\u597d\u8005\u5417? \u4f60\u4eec\u64b8 Scala \u611f\u89c9\u5982\u4f55? \u6709\u4ec0\u4e48\u5207\u8eab\u611f\u53d7\u7684\u597d\u5904\u6216\u574f\u5904\u5417?

https://mkaz.com/2011/05/31/10-scala-one-liners-to-impress-your-friends/

\u6709\u65f6\u5019\u4e0d\u662f\u60f3\u5b66,\u800c\u662f\u67d0\u9879\u76ee\u662f\u7528\u67d0\u8bed\u8a00\u5199\u7684,
\n\u8981\u57fa\u4e8e\u8fd9\u4e2a\u9879\u76ee\u505a\u4e2a\u4e1c\u897f,\u4e8e\u662f\u88ab\u903c\u7740\u5b66\u4e00\u95e8\u65b0\u7684\u8bed\u8a00,\u8fd9\u8be5\u662f\u6709\u591a\u60b2\u50ac\u554a:(

\u8fd9\u91cc\u6709\u4eba\u641e\u8fc7scala\u4e48?
\n\u8fd9\u8d27\u4e0a\u624b\u662f\u5426\u8981\u5f88\u591a?\u91cc\u9762\u662f\u4e0d\u662f\u4e5f\u6709\u5f88\u591a\u7684lib\u8981\u5b66?
\n\u989d\u7684\u795e\u554a,\u6551\u6551\u6211\u5427:(

(A,B,C) => (A,(B,C)) \u8fd9\u4e00\u6b65\u597d\u8bf4\uff0c\u76f4\u63a5\u53d6 head tail \u5c31\u53ef\u4ee5\u4e86\u3002\u4f46\u662f\u53d6\u6bcf\u4e00\u4e2a\u5143\u7d20\u90fd\u505a\u8fd9\u4e2a\u64cd\u4f5c\u600e\u4e48\u641e\uff1f