![solr-scala-client
https://github.com/takezoe/solr-scala-client
• Simple wrapper of SolrJ for Scala.
• Query converter using parser combinator.
import jp.sf.amateras.solr.scala._
val client = new SolrClient("http://localhost:8983/solr")
val result = client.query("name: ?name?")
.getResultAsMap(Map("name" -> "ThinkPad & X201s"))
// => name:("ThinkPad" AND "X201s")
result.documents.foreach { doc: Map[String, Any] =>
...
}](https://image.slidesharecdn.com/scalafrustrations-130306104041-phpapp02/85/Scala-Frustrations-27-320.jpg)
![scalaquery-magic
https://github.com/shimamoto/scalaquery-magic
• Extends ScalaQuery.
• Make a Magic (like old Anorm’s Magic) by code
generation using scalagen.
val userInfoDao = new UserInfoDao()
// SELECT by ID
val userInfo = userInfoDao.selectById(1)
// INSERT
userInfoDao.insert(UserInfo(DEFAULT[Int], 'userName', 'password'))
// UPDATE
userInfoDao.update(userInfo.copy(userName = 'newName'))
// DELETE by ID
userInfoDao.deleteById(1)](https://image.slidesharecdn.com/scalafrustrations-130306104041-phpapp02/85/Scala-Frustrations-29-320.jpg)
![play2-httpsession
https://github.com/takezoe/play2-httpsession
• Provide HttpSession for Play2 applications.
• Work with play2-war-plugin.
import jp.sf.amateras.play2.httpsession.HttpSessionSupport._
def index = Action { implicit request =>
// retrieve the object from HttpSession
val value: Option[String] = HttpSession[String]("key")
Ok(value).withHttpSession {
// store objects into HttpSession
"key" -> "value"
}
}](https://image.slidesharecdn.com/scalafrustrations-130306104041-phpapp02/85/Scala-Frustrations-31-320.jpg)
Scala Frustrations
- 1. Scala Frustrations in Real Development Naoki Takezoe @takezoen NTT-DATA INTELLILINK
- 2. Abstract • Scala is pretty good for real development. • However Scala has also some bad points. • Please note for these points when you introduce Scala into real development.
- 3. Scala 300 Recipes from Shoeisha • Includes 300 Practical Scala Recipes. • from Basic Scala topics to frameworks and tools. Covers Play2, Akka, sbt, scaladoc, ScalaIDE, ScalaTest, Specs2, Scalatra, ScalaQuery, Anorm, Casbah, spray, scala-io, scala-time, sjson, util-eval, scalaxb, Dispatch and more.
- 4. Why we are using Scala? • Decrease costs of system development. • We felt the limit of Java several years ago. • Scala might be a breakthrough?
- 5. About Our Project • Porting Java based web application to Scala. • Over 170 HTMLs and 40,000 lines. • 5 members on 6 months. Before After Seasar2 Play2 (Customized) Apache Click ScalaQuery (Cuztomized) S2JDBC PostgreSQL PostgreSQL + Tsearch Apache Solr Raw JavaScript jQuery + jQuery UI
- 6. Benefits of Scala • Decrease amount of source code ▫ 40%-50% OFF ▫ Better abstraction techniques • Decrease bugs ▫ More type safe ▫ Immutable data types • Java Interoperability ▫ Many Java based Frameworks and Libraries are available ▫ Easy to port existing Java software
- 7. Benefits of Scala • Decrease amount of source code ▫ 40%-50% OFF ▫ Better abstraction techniques Flexibility and Safety • Decrease bugs ▫ More type safe ▫ Immutable data types • Java Interoperability ▫ Many Java based Frameworks and Libraries are available ▫ Easy to port existing Java software
- 9. Long compilation time • Compilation is so much heavy. • Painful for large application development.
- 10. Solution Buy high spec machines Asynchronous and automated build
- 11. ScalaIDE is heavy • We meet a sandglass frequently.
- 12. Solution 1. Turn off the incremental builder 2. Turn off the code completion 3. Try other IDE or text editor
- 13. sbt is NOT Simple Build Tool • When we get a trouble, difficult to find a reason. • Rapid version up causes compatibility problem of sbt plugins.
- 14. Solution We really need SBT in Action!
- 16. Long compilation time • Many code generation and template compilation. • Development mode is slow also.
- 17. Solution Buy high spec machines Divide large project play2-fastassets decreases request
- 18. Inflexible Validation • Client-side validation is not provided. • Error Message can’t be contained field name.
- 19. Solution Original client-side validation framework based on Play2’s form definition Original helper to display error messages
- 20. Anorm is too simple • We have to write all SQL. • Magic does not already exist. • SQL is not type safe. • No support for dynamic SQL.
- 21. Solution Use other ORMs such as ScalaQuery. We used a combination of scalaquery-magic scalagen and mirage-scala.
- 22. Function22 Problem in form definition • a.k.a. Tuple22 Problem • Form can not have over 18 properties. val userForm = Form( mapping( "firstName“ -> text, "lastName“ -> text, "mailAddress“ -> email, "password“ -> text, ... Max 18 properties "tel“ -> text, "mobile“ -> text, "company“ -> text, "department“ -> text )(UserInfo.apply)(UserInfo.unapply) )
- 23. Solution Nested definition, BUT it’s not expectable. val userForm = Form( mapping( "firstName" -> text, "lastName" -> text, "mailAddress" -> email, "password" -> text, "companyInfo" -> mapping( "company" -> text, "department" -> text )(CompanyInfo.apply)(CompanyInfo.unapply) )(UserInfo.apply)(UserInfo.unapply) )
- 24. No Servlet and HttpSession • Hard to port existing Java based web apps. • We want to run Play2 on the servlet container by un-technical reasons.
- 25. Solution play2-war-plugin packs Play2 apps to war. play2-httpsession provides HttpSession by using with play2-war-plugin.
- 27. solr-scala-client https://github.com/takezoe/solr-scala-client • Simple wrapper of SolrJ for Scala. • Query converter using parser combinator. import jp.sf.amateras.solr.scala._ val client = new SolrClient("http://localhost:8983/solr") val result = client.query("name: ?name?") .getResultAsMap(Map("name" -> "ThinkPad & X201s")) // => name:("ThinkPad" AND "X201s") result.documents.foreach { doc: Map[String, Any] => ... }
- 28. scalagen https://github.com/takezoe/scalagen • Code Generator from RDBMS. • Supports Anorm and ScalaQuery in the current version. • Easy to add support for other ORMs. • Work as CLI and sbt plugin. seq(jp.sf.amateras.scalagen.ScalagenPlugin.scalagenSettings: _*) scalagenConfiguration := jp.sf.amateras.scalagen.Settings( // for ScalaQuery generator = new jp.sf.amateras.scalagen.ScalaQueryGenerator(), // for Anorm //generator = new jp.sf.amateras.scalagen.ScalaQueryGenerator(), driver = "org.hsqldb.jdbcDriver", url = "jdbc:hsqldb:hsql://localhost/", username = "sa", password = "" )
- 29. scalaquery-magic https://github.com/shimamoto/scalaquery-magic • Extends ScalaQuery. • Make a Magic (like old Anorm’s Magic) by code generation using scalagen. val userInfoDao = new UserInfoDao() // SELECT by ID val userInfo = userInfoDao.selectById(1) // INSERT userInfoDao.insert(UserInfo(DEFAULT[Int], 'userName', 'password')) // UPDATE userInfoDao.update(userInfo.copy(userName = 'newName')) // DELETE by ID userInfoDao.deleteById(1)
- 30. mirage-scala https://github.com/takezoe/mirage-scala • SQL Centric ORM similar to Anorm. • Executable SQL template called 2waySQL. SLEECT USER_ID, USER_NAME, PASSWORD FROM USER_INFO /*BEGIN*/ WHERE /*IF userId != null*/ USER_ID = /*userId*/1 /*END*/ /*IF userId != null*/ USER_NAME = /*userName*/ 'takezoe' /*END*/ /*END*/
- 31. play2-httpsession https://github.com/takezoe/play2-httpsession • Provide HttpSession for Play2 applications. • Work with play2-war-plugin. import jp.sf.amateras.play2.httpsession.HttpSessionSupport._ def index = Action { implicit request => // retrieve the object from HttpSession val value: Option[String] = HttpSession[String]("key") Ok(value).withHttpSession { // store objects into HttpSession "key" -> "value" } }
- 32. play2-fastassets https://github.com/takezoe/play2-fastassets • Decrease amount of request to external CSS, JavaScript and images by browser cache. @(title: String)(content: Html) @import jp.sf.amateras.play2.fastassets.FastAssets <!DOCTYPE html> <html> <head> <title>@title</title> <link rel="stylesheet" media="screen" href="@FastAssets.at("stylesheets/main.css")"> <link rel="shortcut icon" type="image/png" href="@FastAssets.at("images/favicon.png")"> <script src="@FastAssets.at("javascripts/jquery-1.7.1.min.js")" type="text/javascript"></script> </head> <body> @content </body> </html>
- 34. Scala is practical • You are evangelists of Scala. • Please introduce Scala in your work. • But so carefully, especially in the large project.
- 35. Scala is now glowing up! • This way along which Java passed. • Time will solve these problems. • We can contribute Scala glowing.