Addressed Scalastyle errors.

Author: LorenzBuehmann

sansa-inference-common/src/main/scala/net/sansa_stack/inference/data/JenaOps.scala

@@ -1,10 +1,10 @@
 package net.sansa_stack.inference.data
 
+import scala.collection.JavaConverters._
+
 import org.apache.jena.datatypes.{BaseDatatype, RDFDatatype, TypeMapper}
 import org.apache.jena.graph.{Graph => JenaGraph, Node => JenaNode, Triple => JenaTriple, _}
-import org.apache.jena.rdf.model.{Literal => JenaLiteral, Seq => _}
-
-import scala.collection.JavaConverters._
+import org.apache.jena.rdf.model.{Seq => _}
 
 class JenaOps extends RDFOps[Jena]  {
 
@@ -33,10 +33,12 @@ class JenaOps extends RDFOps[Jena]  {
     val s = t.getSubject
     val p = t.getPredicate
     val o = t.getObject
-    if (p.isInstanceOf[Jena#URI])
-      (s, p.asInstanceOf[Jena#URI], o)
-    else
-      throw new RuntimeException("fromTriple: predicate " + p.toString + " must be a URI")
+    p match {
+      case uri: Node_URI =>
+        (s, uri, o)
+      case _ =>
+        throw new RuntimeException("fromTriple: predicate " + p.toString + " must be a URI")
+    }
   }
 
   // node
@@ -52,10 +54,11 @@ class JenaOps extends RDFOps[Jena]  {
   def makeUri(iriStr: String): Jena#URI = { NodeFactory.createURI(iriStr).asInstanceOf[Node_URI] }
 
   def fromUri(node: Jena#URI): String =
-    if (node.isURI)
+    if (node.isURI) {
       node.getURI
-    else
+    } else {
       throw new RuntimeException("fromUri: " + node.toString() + " must be a URI")
+    }
 
   // bnode
 
@@ -67,17 +70,18 @@ class JenaOps extends RDFOps[Jena]  {
   }
 
   def fromBNode(bn: Jena#BNode): String =
-    if (bn.isBlank)
+    if (bn.isBlank) {
       bn.getBlankNodeId.getLabelString
-    else
+    } else {
       throw new RuntimeException("fromBNode: " + bn.toString + " must be a BNode")
+    }
 
   // literal
 
   // TODO the javadoc doesn't say if this is thread safe
   lazy val mapper = TypeMapper.getInstance
 
-  def jenaDatatype(datatype: Jena#URI) = {
+  private def jenaDatatype(datatype: Jena#URI) = {
     val iriString = fromUri(datatype)
     val typ = mapper.getTypeByName(iriString)
     if (typ == null) {
@@ -94,20 +98,21 @@ class JenaOps extends RDFOps[Jena]  {
   val __rdfLangStringURI: Jena#URI = makeUri("http://www.w3.org/1999/02/22-rdf-syntax-ns#langString")
 
   def makeLiteral(lexicalForm: String, datatype: Jena#URI): Jena#Literal =
-    if (datatype == __xsdStringURI)
+    if (datatype == __xsdStringURI) {
       NodeFactory.createLiteral(lexicalForm, null, null).asInstanceOf[Node_Literal]
-    else
+    } else {
       NodeFactory.createLiteral(lexicalForm, null, jenaDatatype(datatype)).asInstanceOf[Node_Literal]
+    }
 
   def makeLangTaggedLiteral(lexicalForm: String, lang: Jena#Lang): Jena#Literal =
     NodeFactory.createLiteral(lexicalForm, fromLang(lang), null).asInstanceOf[Node_Literal]
 
 
   // lang
 
-  def makeLang(langString: String) = langString
+  def makeLang(langString: String): String = langString
 
-  def fromLang(lang: Jena#Lang) = lang
+  def fromLang(lang: Jena#Lang): String = lang
 
 
 

sansa-inference-common/src/main/scala/net/sansa_stack/inference/data/RDF.scala

@@ -39,4 +39,4 @@ trait RDF {
   // types for the graph traversal API
   type NodeMatch
   type NodeAny <: NodeMatch
-}
+}

sansa-inference-common/src/main/scala/net/sansa_stack/inference/data/RDFTuple.scala

@@ -8,6 +8,7 @@ package net.sansa_stack.inference.data
   * @author Lorenz Buehmann
   */
 case class RDFTuple(s: String, o: String) extends Product2[String, String] {
-    override def _1: String = s
-    override def _2: String = o
-  }
+  override def _1: String = s
+
+  override def _2: String = o
+}

sansa-inference-common/src/main/scala/net/sansa_stack/inference/data/SimpleRDFOps.scala

@@ -17,10 +17,12 @@ class SimpleRDFOps extends RDFOps[SimpleRDF]  {
         val s = t.s
         val p = t.p
         val o = t.o
-        if (p.isInstanceOf[SimpleRDF#URI])
-            (s, p.asInstanceOf[SimpleRDF#URI], o)
-        else
-            throw new RuntimeException("fromTriple: predicate " + p.toString + " must be a URI")
+        p match {
+            case uri: String =>
+                (s, uri, o)
+            case _ =>
+                throw new RuntimeException("fromTriple: predicate " + p.toString + " must be a URI")
+        }
     }
 
     // node

sansa-inference-common/src/main/scala/net/sansa_stack/inference/rules/minimizer/MinimizationRule.scala

@@ -18,4 +18,4 @@ abstract class MinimizationRule extends Logging {
 
   def apply(graph: RuleDependencyGraph): RuleDependencyGraph
 
-}
+}

sansa-inference-common/src/main/scala/net/sansa_stack/inference/rules/plan/SimplePlanGenerator.scala

@@ -1,30 +1,20 @@
 package net.sansa_stack.inference.rules.plan
 
-import java.io.PrintWriter
-import java.util.Collections
+import scala.collection.JavaConverters._
+import scala.util.Try
 
-import com.google.common.collect.ImmutableList
 import org.apache.calcite.config.Lex
+import org.apache.calcite.interpreter.{BindableConvention, Bindables}
 import org.apache.calcite.plan.{RelOptUtil, _}
+import org.apache.calcite.rel.`type`.RelDataTypeSystem
+import org.apache.calcite.rel.rules._
 import org.apache.calcite.rel.{RelCollationTraitDef, RelNode}
 import org.apache.calcite.schema.SchemaPlus
 import org.apache.calcite.sql.parser.SqlParser
 import org.apache.calcite.tools._
-import collection.JavaConverters._
-import scala.util.Try
-
-import org.apache.calcite.rel.`type`.RelDataTypeSystem
-import org.apache.calcite.rel.externalize.RelWriterImpl
-import org.apache.calcite.rel.rules._
 import org.apache.jena.reasoner.rulesys.Rule
 
 import net.sansa_stack.inference.utils.{Logging, RuleUtils}
-import org.apache.calcite.adapter.enumerable.{EnumerableConvention, EnumerableRules}
-import org.apache.calcite.interpreter.{BindableConvention, Bindables}
-import org.apache.calcite.plan.RelOptPlanner.CannotPlanException
-import org.apache.calcite.plan.hep.{HepMatchOrder, HepPlanner, HepProgramBuilder}
-import org.apache.calcite.plan.volcano.VolcanoPlanner
-import org.apache.calcite.sql2rel.{RelDecorrelator, SqlToRelConverter}
 
 /**
   * @author Lorenz Buehmann
@@ -37,7 +27,7 @@ class SimplePlanGenerator(schema: SchemaPlus) extends Logging {
     BindableConvention.INSTANCE.getTraitDef
   )
 
-  val optRuleSet = RuleSets.ofList(
+  val optRuleSet: RuleSet = RuleSets.ofList(
     FilterJoinRule.FILTER_ON_JOIN,// push a filter into a join
     FilterJoinRule.JOIN,// push filter into the children of a join
     ProjectJoinTransposeRule.INSTANCE// push a projection to the children of a join
@@ -68,13 +58,13 @@ class SimplePlanGenerator(schema: SchemaPlus) extends Logging {
 //      // Context provides a way to store data within the planner session that can be accessed in planner rules.
 //      .context(Contexts.EMPTY_CONTEXT)
 //      // Rule sets to use in transformation phases. Each transformation phase can use a different set of rules.
-////      .ruleSets(optRuleSet)
+// //      .ruleSets(optRuleSet)
 //      .ruleSets(RuleSets.ofList(Bindables.BINDABLE_TABLE_SCAN_RULE, Bindables.BINDABLE_PROJECT_RULE, Bindables.BINDABLE_JOIN_RULE, Bindables.BINDABLE_FILTER_RULE, FilterJoinRule.FILTER_ON_JOIN))
 //      .programs(Programs.ofRules(Bindables.BINDABLE_TABLE_SCAN_RULE, Bindables.BINDABLE_PROJECT_RULE, Bindables.BINDABLE_JOIN_RULE, Bindables.BINDABLE_FILTER_RULE, FilterJoinRule.FILTER_ON_JOIN))
 //
 //      // Custom cost factory to use during optimization
 //      .costFactory(null)
-////      .programs(program)
+// //      .programs(program)
 //      .typeSystem(RelDataTypeSystem.DEFAULT)
 //      .build()
 

sansa-inference-common/src/main/scala/net/sansa_stack/inference/utils/JenaTripleToNTripleString.scala

@@ -9,7 +9,7 @@ import org.apache.jena.graph.Triple
   * @author Lorenz Buehmann
   */
 class JenaTripleToNTripleString
-    extends ((Triple) => String)
+    extends Function[Triple, String]
     with java.io.Serializable {
   override def apply(t: Triple): String = {
     val subStr =
@@ -27,7 +27,7 @@ class JenaTripleToNTripleString
       } else {
         s"<${t.getObject}>"
       }
-    s"${subStr} <${t.getPredicate}> ${objStr} ."
+    s"$subStr <${t.getPredicate}> $objStr ."
   }
 }
 

sansa-inference-common/src/main/scala/net/sansa_stack/inference/utils/Logging.scala

@@ -11,7 +11,7 @@ import scala.language.implicitConversions
   */
 trait Logging {
 
-  @transient private var log_ : Logger = null
+  @transient private var log_ : Logger = _
 
   // Method to get or create the logger for this object
   protected def log: Logger = {
@@ -22,7 +22,7 @@ trait Logging {
   }
 
   // Method to get the logger name for this object
-  protected def logName = {
+  protected def logName: String = {
     // Ignore trailing $'s in the class names for Scala objects
     this.getClass.getName.stripSuffix("$")
   }

sansa-inference-common/src/main/scala/net/sansa_stack/inference/utils/NTriplesStringToJenaTriple.scala

@@ -11,7 +11,7 @@ import org.apache.jena.riot.{Lang, RDFDataMgr}
   * @author Lorenz Buehmann
   */
 class NTriplesStringToJenaTriple
-    extends Function1[String, Triple]
+    extends Function[String, Triple]
     with java.io.Serializable {
   override def apply(s: String): Triple = {
     RDFDataMgr.createIteratorTriples(new ByteArrayInputStream(s.getBytes), Lang.NTRIPLES, null).next()

sansa-inference-common/src/main/scala/net/sansa_stack/inference/utils/RDFTripleToNTripleString.scala

@@ -8,7 +8,7 @@ import net.sansa_stack.inference.data.RDFTriple
   * @author Lorenz Buehmann
   */
 class RDFTripleToNTripleString
-    extends Function1[RDFTriple, String]
+    extends Function[RDFTriple, String]
     with java.io.Serializable {
   override def apply(t: RDFTriple): String = {
     val objStr =
@@ -17,6 +17,6 @@ class RDFTripleToNTripleString
       } else {
         t.o
       }
-    s"<${t.s}> <${t.p}> ${objStr} ."
+    s"<${t.s}> <${t.p}> $objStr ."
   }
 }