Rewrite ConfigGenerator.createClassName to Java.

- In new class ConfiggenUtil.
- This will allow using the function without loading classes
  from scala-xml in the future.
- Do not remove the original scala method, as it could still be
   used for a while by older config models.
  (By classes InstanceResolver and VespaModel.)

4 files changed, 55 insertions, 9 deletions

diff --git a/configgen/src/main/java/com/yahoo/config/codegen/ConfiggenUtil.java b/configgen/src/main/java/com/yahoo/config/codegen/ConfiggenUtil.java
new file mode 100644
index 00000000000..a7a3eb718a3
--- /dev/null
+++ b/configgen/src/main/java/com/yahoo/config/codegen/ConfiggenUtil.java
@@ -0,0 +1,43 @@
+package com.yahoo.config.codegen;
+
+import java.util.Arrays;
+import java.util.stream.Collectors;
+
+/**
+ * @author gjoranv
+ */
+public class ConfiggenUtil {
+
+    /**
+     * Create class name from def name
+     * @param defName The file name without the '.def' suffix
+     */
+    public static String createClassName(String defName) {
+        String className =  Arrays.stream(defName.split("-"))
+                .map(ConfiggenUtil::capitalize)
+                .collect(Collectors.joining())
+                + "Config";
+
+        if (! isLegalJavaIdentifier(className))
+            throw new CodegenRuntimeException("Illegal config definition file name '" + defName +
+                                                      "'. Must be a legal Java identifier.");
+
+        return className;
+    }
+
+    private static String capitalize(String in) {
+        StringBuilder sb = new StringBuilder(in);
+        sb.setCharAt(0, Character.toTitleCase(in.charAt(0)));
+        return sb.toString();
+    }
+
+    private static boolean isLegalJavaIdentifier(String name) {
+        if (name.isEmpty()) return false;
+        if (! Character.isJavaIdentifierStart(name.charAt(0))) return false;
+
+        for (char c : name.substring(1).toCharArray()) {
+            if (! Character.isJavaIdentifierPart(c)) return false;
+        }
+        return true;
+    }
+}
diff --git a/configgen/src/main/scala/com/yahoo/config/codegen/ConfigGenerator.scala b/configgen/src/main/scala/com/yahoo/config/codegen/ConfigGenerator.scala
index 7ea07762c01..f6876affe5d 100644
--- a/configgen/src/main/scala/com/yahoo/config/codegen/ConfigGenerator.scala
+++ b/configgen/src/main/scala/com/yahoo/config/codegen/ConfigGenerator.scala
@@ -2,11 +2,12 @@
 package com.yahoo.config.codegen
 
 
+import com.yahoo.config.codegen.BuilderGenerator.getBuilder
+import com.yahoo.config.codegen.JavaClassBuilder.Indentation
 import com.yahoo.config.codegen.LeafCNode._
 import com.yahoo.config.codegen.ReservedWords.{INTERNAL_PREFIX => InternalPrefix}
-import JavaClassBuilder.Indentation
-import BuilderGenerator.getBuilder
-import util.parsing.combinator.JavaTokenParsers
+
+import scala.util.parsing.combinator.JavaTokenParsers
 
 /**
  * @author gjoranv
@@ -409,7 +410,7 @@ object ConfigGenerator {
     node match {
       case emptyName: CNode if node.getName.length == 0 =>
         throw new CodegenRuntimeException("Node with empty name, under parent " + emptyName.getParent.getName)
-      case root: InnerCNode if root.getParent == null => createClassName(root.getName)
+      case root: InnerCNode if root.getParent == null => ConfiggenUtil.createClassName(root.getName)
       case b: BooleanLeaf   => "BooleanNode"
       case d: DoubleLeaf    => "DoubleNode"
       case f: FileLeaf      => "FileNode"
@@ -450,9 +451,10 @@ object ConfigGenerator {
   }
 
   /**
-   * Create class name from def name
-   * @param defName The file name without the '.def' suffix
-   */
+    * Deprecated!
+    * TODO: Remove when no longer used in config-model
+    */
+  @deprecated("Use ConfiggenUtil.createClassName() instead", "6.143")
   def createClassName(defName: String): String = {
     val className = defName.split("-").map (_.capitalize).mkString + "Config"
     val parser = new JavaTokenParsers {}
diff --git a/configgen/src/main/scala/com/yahoo/config/codegen/JavaClassBuilder.scala b/configgen/src/main/scala/com/yahoo/config/codegen/JavaClassBuilder.scala
index 518815d5a10..e03a6d3d04b 100644
--- a/configgen/src/main/scala/com/yahoo/config/codegen/JavaClassBuilder.scala
+++ b/configgen/src/main/scala/com/yahoo/config/codegen/JavaClassBuilder.scala
@@ -3,7 +3,8 @@ package com.yahoo.config.codegen
 
 import java.io.{File, FileNotFoundException, FileOutputStream, PrintStream}
 
-import com.yahoo.config.codegen.ConfigGenerator.{createClassName, indentCode}
+import com.yahoo.config.codegen.ConfigGenerator.indentCode
+import com.yahoo.config.codegen.ConfiggenUtil.createClassName
 import com.yahoo.config.codegen.DefParser.DEFAULT_PACKAGE_PREFIX
 
 import scala.collection.JavaConverters._
diff --git a/configgen/src/test/scala/com/yahoo/config/codegen/JavaClassBuilderTest.scala b/configgen/src/test/scala/com/yahoo/config/codegen/JavaClassBuilderTest.scala
index 4b35f3fb713..c1a5eb2dd6a 100644
--- a/configgen/src/test/scala/com/yahoo/config/codegen/JavaClassBuilderTest.scala
+++ b/configgen/src/test/scala/com/yahoo/config/codegen/JavaClassBuilderTest.scala
@@ -5,7 +5,7 @@ import org.junit.Assert.assertThat
 import org.junit.Assert.assertTrue
 import org.hamcrest.CoreMatchers.is
 import java.io.StringReader
-import ConfigGenerator.createClassName
+import ConfiggenUtil.createClassName
 import JavaClassBuilder.createUniqueSymbol
 import org.junit.{Ignore, Test}