The simple Apache Solr client for Scala

I pushed solr-scala-client into github. This is a simple Apache Solr client for Scala wrapping SolrJ.

• https://github.com/takezoe/solr-scala-client

The basic concept of solr-scala-client is providing fluent interface and wrapping SolrJ classes by Scala collection API. This is an example to register documents into the Solr server which is working at localhost:8983.

import jp.sf.amateras.solr.scala._

val client = new SolrClient("http://localhost:8983/solr")

client
  .add(Map("id"->"1", "name" -> "ThinkPad X201s"))
  .add(Map("id"->"2", "name" -> "ThinkPad X220"))
  .add(Map("id"->"3", "name" -> "ThinkPad X121e"))
  .commit

add() takes a variable-length argument. So an example above could be rewritten as follows:

client.add(
  Map("id"->"1", "name" -> "ThinkPad X201s"),
  Map("id"->"2", "name" -> "ThinkPad X220"),
  Map("id"->"3", "name" -> "ThinkPad X121e")
).commit

Next, see the following example to search document using the query.

// query
val result: List[Map[String, Any]] =
  client.query("name:%name%")
    .fields("id", "manu", "name")
    .sortBy("id", Order.asc)
    .getResult(Map("name" -> "ThinkPad"))

result.foreach { doc =>
  println("id: " + doc("id"))
  println("name: " + doc("name"))
  println("--")
}

%VARNAME% in the query is replaced by given parameters as Map and the result is returned as List[Map[String, Any]].

The current version of solr-scala-client does not support facet search yet. I wish to support it in the near future. And I'm also planning about using case class to specify document or parameters instead of Map.

mirage 1.1.5 and mirage-scala 0.0.4 is now available!

Today, we released Mirage 1.1.5 and mirage-scala 0.0.4!

Mirage is a simple SQL centric database access library and mirage-scala is the wrapper of Mirage for Scala. See the following URL to know about Mirage:

• http://amateras.sourceforge.jp/site/mirage/welcome.html

This release contains some important new features for mirage-scala. Mirage update is only small bug fix. So I introduce new features of mirage-scala 0.0.4 in this entry.

Improvement of SqlManager interface

Some methods of SqlManager had a java.lang.Class parameter which specifies the entity class in the previous version. But in mirage-scala 0.0.4, it modified to the generics type parameter.

// Until mirage-scala 0.0.3
val books = sqlManager.getResultList(
  classOf[Book], 
  Sql("SELECT * FROM BOOK"))

// In mirage-scala 0.0.4
val books = sqlManager.getResultList[Book](
  Sql("SELECT * FROM BOOK"))

Improvement of case class entity

mirage-scala can handle case class as the entity. But it required the default constructor as below:

@Table(name="BOOK")
case class Book(
  @(PrimaryKey @field)(generationType = IDENTITY)
  bookId: java.lang.Long,
  bookName: String,
  author: String,
  price: Option[Int]) {

  // This is not required in mirage-scala 0.0.4
  def this() = this(null, null, null, None)

}

The default constructor of case class is not required no longer in mirage-scala 0.0.4.

Wrapping primary key by Pk[T]

In mirage-scala 0.0.4, Pk[T], Id[T] and Auto are added. You can use Pk[T] to wrap the property which corresponds to the primary key. It is useful when the primary key is set by the database. For example, it's auto incremented column.

@Table(name="BOOK")
case class Book(
  @(PrimaryKey @field)(generationType = IDENTITY)
  bookId: Pk[Long],
  bookName: String,
  author: String,
  price: Option[Int])

val book = Book(
  Auto, 
  "Mirage in Action",
  "Naki Takezoe",
  25)

sqlManager.insertEntity(book)

If you have to set the value of the primary key, you can use Id[T] instead of Auto.

@Table(name="BOOK")
case class Book(
  @(PrimaryKey @field)(generationType = APPLICATION)
  bookId: Pk[Long],
  bookName: String,
  author: String,
  price: Option[Int])

val book = Book(
  Id(1), 
  "Mirage in Action",
  "Naki Takezoe",
  25)

sqlManager.insertEntity(book)

Anyway, mirage-scala became more scalanized database access library in 0.0.4. I hope mirage-scala will help your development with Scala!

Simple wrapper of PicoContainer for Scala

I tried SubCut to resolve dependency of components in Scala. However I think The Cake Pattern might be better than SubCut because it's so complex more than necessary and not transparent.It's similar to the service locator, not the DI container. I need a DI container which is more simple and intuitive. It's sufficient that supports constructor injection.

There are PicoContainer in Java World. So I wrote a simple wrapper of PicoContainer for Scala:

It does not cover all features of PicoContainer. But it might be enough for my current use :-)