diff --git a/src/Pure/General/file_watcher.scala b/src/Pure/General/file_watcher.scala
--- a/src/Pure/General/file_watcher.scala
+++ b/src/Pure/General/file_watcher.scala
@@ -1,136 +1,136 @@
 /*  Title:      Pure/General/file_watcher.scala
     Author:     Makarius
 
 Watcher for file-system events.
 */
 
 package isabelle
 
 
 import java.io.{File => JFile}
 import java.nio.file.FileSystems
 import java.nio.file.{WatchKey, WatchEvent, Path => JPath}
 import java.nio.file.StandardWatchEventKinds.{ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY}
 
-import scala.collection.JavaConversions
+import scala.collection.JavaConverters
 
 
 class File_Watcher private[File_Watcher]  // dummy template
 {
   def register(dir: JFile) { }
   def register_parent(file: JFile) { }
   def deregister(dir: JFile) { }
   def purge(retain: Set[JFile]) { }
   def shutdown() { }
 }
 
 object File_Watcher
 {
   val none: File_Watcher = new File_Watcher
   {
     override def toString: String = "File_Watcher.none"
   }
 
   def apply(handle: Set[JFile] => Unit, delay: => Time = Time.seconds(0.5)): File_Watcher =
     if (Platform.is_windows) none else new Impl(handle, delay)
 
 
   /* proper implementation */
 
   sealed case class State(
     dirs: Map[JFile, WatchKey] = Map.empty,
     changed: Set[JFile] = Set.empty)
 
   class Impl private[File_Watcher](handle: Set[JFile] => Unit, delay: Time) extends File_Watcher
   {
     private val state = Synchronized(File_Watcher.State())
     private val watcher = FileSystems.getDefault.newWatchService()
 
     override def toString: String =
       state.value.dirs.keySet.mkString("File_Watcher(", ", ", ")")
 
 
     /* registered directories */
 
     override def register(dir: JFile): Unit =
       state.change(st =>
         st.dirs.get(dir) match {
           case Some(key) if key.isValid => st
           case _ =>
             val key = dir.toPath.register(watcher, ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY)
             st.copy(dirs = st.dirs + (dir -> key))
         })
 
     override def register_parent(file: JFile): Unit =
     {
       val dir = file.getParentFile
       if (dir != null && dir.isDirectory) register(dir)
     }
 
     override def deregister(dir: JFile): Unit =
       state.change(st =>
         st.dirs.get(dir) match {
           case None => st
           case Some(key) =>
             key.cancel
             st.copy(dirs = st.dirs - dir)
         })
 
     override def purge(retain: Set[JFile]): Unit =
       state.change(st =>
         st.copy(dirs = st.dirs --
           (for ((dir, key) <- st.dirs.iterator if !retain(dir)) yield { key.cancel; dir })))
 
 
     /* changed directory entries */
 
     private val delay_changed = Standard_Thread.delay_last(delay)
     {
       val changed = state.change_result(st => (st.changed, st.copy(changed = Set.empty)))
       handle(changed)
     }
 
     private val watcher_thread = Standard_Thread.fork("File_Watcher", daemon = true)
     {
       try {
         while (true) {
           val key = watcher.take
           val has_changed =
             state.change_result(st =>
               {
                 val (remove, changed) =
                   st.dirs.collectFirst({ case (dir, key1) if key == key1 => dir }) match {
                     case Some(dir) =>
                       val events =
-                        JavaConversions.collectionAsScalaIterable(
+                        JavaConverters.collectionAsScalaIterable(
                           key.pollEvents.asInstanceOf[java.util.List[WatchEvent[JPath]]])
                       val remove = if (key.reset) None else Some(dir)
                       val changed =
                         (Set.empty[JFile] /: events.iterator) {
                           case (set, event) => set + dir.toPath.resolve(event.context).toFile
                         }
                       (remove, changed)
                     case None =>
                       key.pollEvents
                       key.reset
                       (None, Set.empty[JFile])
                   }
                 (changed.nonEmpty, st.copy(dirs = st.dirs -- remove, changed = st.changed ++ changed))
               })
           if (has_changed) delay_changed.invoke()
         }
       }
       catch { case Exn.Interrupt() => }
     }
 
 
     /* shutdown */
 
     override def shutdown()
     {
       watcher_thread.interrupt
       watcher_thread.join
       delay_changed.revoke
     }
   }
 }
diff --git a/src/Pure/System/isabelle_charset.scala b/src/Pure/System/isabelle_charset.scala
--- a/src/Pure/System/isabelle_charset.scala
+++ b/src/Pure/System/isabelle_charset.scala
@@ -1,52 +1,52 @@
 /*  Title:      Pure/System/isabelle_charset.scala
     Author:     Makarius
 
 Charset for Isabelle symbols.
 */
 
 package isabelle
 
 
 import java.nio.Buffer
 import java.nio.{ByteBuffer, CharBuffer}
 import java.nio.charset.{Charset, CharsetDecoder, CharsetEncoder, CoderResult}
 import java.nio.charset.spi.CharsetProvider
 
+import scala.collection.JavaConverters
+
 
 object Isabelle_Charset
 {
   val name: String = "UTF-8-Isabelle-test"  // FIXME
   lazy val charset: Charset = new Isabelle_Charset
 }
 
 
 class Isabelle_Charset extends Charset(Isabelle_Charset.name, null)
 {
   override def contains(cs: Charset): Boolean =
     cs.name.equalsIgnoreCase(UTF8.charset_name) || UTF8.charset.contains(cs)
 
   override def newDecoder(): CharsetDecoder = UTF8.charset.newDecoder
 
   override def newEncoder(): CharsetEncoder = UTF8.charset.newEncoder
 }
 
 
 class Isabelle_Charset_Provider extends CharsetProvider
 {
   override def charsetForName(name: String): Charset =
   {
     // FIXME inactive
     // if (name.equalsIgnoreCase(Isabelle_Charset.name)) Isabelle_Charset.charset
     // else null
     null
   }
 
   override def charsets(): java.util.Iterator[Charset] =
   {
-    import scala.collection.JavaConversions._
     // FIXME inactive
     // Iterator(Isabelle_Charset.charset)
-    Iterator()
+    JavaConverters.asJavaIterator(Iterator())
   }
 }
-
diff --git a/src/Tools/jEdit/src/keymap_merge.scala b/src/Tools/jEdit/src/keymap_merge.scala
--- a/src/Tools/jEdit/src/keymap_merge.scala
+++ b/src/Tools/jEdit/src/keymap_merge.scala
@@ -1,259 +1,259 @@
 /*  Title:      Tools/jEdit/src/keymap_merge.scala
     Author:     Makarius
 
 Merge of Isabelle shortcuts vs. jEdit keymap.
 */
 
 package isabelle.jedit
 
 
 import isabelle._
 
 import java.lang.Class
 import java.awt.{Color, Dimension, BorderLayout}
 import javax.swing.{JPanel, JTable, JScrollPane, JOptionPane}
 import javax.swing.table.AbstractTableModel
 
-import scala.collection.JavaConversions
+import scala.collection.JavaConverters
 
 import org.gjt.sp.jedit.{jEdit, View, GUIUtilities}
 import org.jedit.keymap.{KeymapManager, Keymap}
 
 
 object Keymap_Merge
 {
   /** shortcuts **/
 
   private def is_shortcut(property: String): Boolean =
     (property.endsWith(".shortcut") || property.endsWith(".shortcut2")) &&
     !property.startsWith("options.shortcuts.")
 
   class Shortcut(val property: String, val binding: String)
   {
     override def toString: String = property + "=" + binding
 
     def primary: Boolean = property.endsWith(".shortcut")
 
     val action: String =
       Library.try_unsuffix(".shortcut", property) orElse
       Library.try_unsuffix(".shortcut2", property) getOrElse
       error("Bad shortcut property: " + quote(property))
 
     val label: String =
       GUIUtilities.prettifyMenuLabel(jEdit.getProperty(action + ".label", ""))
 
 
     /* ignore wrt. keymap */
 
     private def prop_ignore: String = property + ".ignore"
 
     def ignored_keymaps(): List[String] =
       space_explode(',', jEdit.getProperty(prop_ignore, ""))
 
     def is_ignored(keymap_name: String): Boolean =
       ignored_keymaps().contains(keymap_name)
 
     def ignore(keymap_name: String): Unit =
       jEdit.setProperty(prop_ignore,
         Library.insert(keymap_name)(ignored_keymaps()).sorted.mkString(","))
 
     def set(keymap: Keymap): Unit = keymap.setShortcut(property, binding)
     def reset(keymap: Keymap): Unit = keymap.setShortcut(property, null)
   }
 
 
   /* content wrt. keymap */
 
   def convert_properties(props: java.util.Properties): List[Shortcut] =
     if (props == null) Nil
     else {
       var result = List.empty[Shortcut]
-      for (entry <- JavaConversions.mapAsScalaMap(props)) {
+      for (entry <- JavaConverters.mapAsScalaMap(props)) {
         entry match {
           case (a: String, b: String) if is_shortcut(a) =>
             result ::= new Shortcut(a, b)
           case _ =>
         }
       }
       result.sortBy(_.property)
     }
 
   def get_shortcut_conflicts(keymap_name: String, keymap: Keymap): List[(Shortcut, List[Shortcut])] =
   {
     val keymap_shortcuts =
       if (keymap == null) Nil
       else convert_properties(Untyped.get[java.util.Properties](keymap, "props"))
 
     for (s <- convert_properties(jEdit.getProperties) if !s.is_ignored(keymap_name)) yield {
       val conflicts =
         keymap_shortcuts.filter(s1 =>
           s.property == s1.property && s.binding != s1.binding ||
           s.property != s1.property && s.binding == s1.binding && s1.binding != "")
       (s, conflicts)
     }
   }
 
 
 
   /** table **/
 
   private def conflict_color: Color =
     PIDE.options.color_value("error_color")
 
   private sealed case class Table_Entry(shortcut: Shortcut, head: Option[Int], tail: List[Int])
   {
     override def toString: String =
       if (head.isEmpty) "<html>" + HTML.output(shortcut.toString) + "</html>"
       else
         "<html><font style='color: #" + Color_Value.print(conflict_color) + ";'>" +
           HTML.output("--- " + shortcut.toString) +
         "</font></html>"
   }
 
   private class Table_Model(entries: List[Table_Entry]) extends AbstractTableModel
   {
     private val entries_count = entries.length
     private def has_entry(row: Int): Boolean = 0 <= row && row <= entries_count
     private def get_entry(row: Int): Option[Table_Entry] =
       if (has_entry(row)) Some(entries(row)) else None
 
     private val selected =
       Synchronized[Set[Int]](
         (for ((e, i) <- entries.iterator.zipWithIndex if e.head.isEmpty) yield i).toSet)
 
     private def is_selected(row: Int): Boolean =
       selected.value.contains(row)
 
     private def select(head: Int, tail: List[Int], b: Boolean): Unit =
       selected.change(set => if (b) set + head -- tail else set - head ++ tail)
 
     def apply(keymap_name: String, keymap: Keymap)
     {
       GUI_Thread.require {}
 
       for ((entry, row) <- entries.iterator.zipWithIndex if entry.head.isEmpty) {
         val b = is_selected(row)
         if (b) {
           entry.tail.foreach(i => entries(i).shortcut.reset(keymap))
           entry.shortcut.set(keymap)
         }
         else
           entry.shortcut.ignore(keymap_name)
       }
     }
 
     override def getColumnCount: Int = 2
 
     override def getColumnClass(i: Int): Class[_ <: Object] =
       if (i == 0) classOf[java.lang.Boolean] else classOf[Object]
 
     override def getColumnName(i: Int): String =
       if (i == 0) " " else if (i == 1) "Keyboard shortcut" else "???"
 
     override def getRowCount: Int = entries_count
 
     override def getValueAt(row: Int, column: Int): AnyRef =
     {
       get_entry(row) match {
         case Some(entry) if column == 0 => java.lang.Boolean.valueOf(is_selected(row))
         case Some(entry) if column == 1 => entry
         case _ => null
       }
     }
 
     override def isCellEditable(row: Int, column: Int): Boolean =
       has_entry(row) && column == 0
 
     override def setValueAt(value: AnyRef, row: Int, column: Int)
     {
       value match {
         case obj: java.lang.Boolean if has_entry(row) && column == 0 =>
           val b = obj.booleanValue
           val entry = entries(row)
           entry.head match {
             case None => select(row, entry.tail, b)
             case Some(head_row) =>
               val head_entry = entries(head_row)
               select(head_row, head_entry.tail, !b)
           }
           GUI_Thread.later { fireTableDataChanged() }
         case _ =>
       }
     }
   }
 
   private class Table(table_model: Table_Model) extends JPanel(new BorderLayout)
   {
     private val cell_size = GUIUtilities.defaultTableCellSize()
     private val table_size = new Dimension(cell_size.width * 2, cell_size.height * 15)
 
     val table = new JTable(table_model)
     table.setShowGrid(false)
     table.setIntercellSpacing(new Dimension(0, 0))
     table.setRowHeight(cell_size.height + 2)
     table.setPreferredScrollableViewportSize(table_size)
     table.setFillsViewportHeight(true)
     table.getTableHeader.setReorderingAllowed(false)
 
 		table.getColumnModel.getColumn(0).setPreferredWidth(30)
 		table.getColumnModel.getColumn(0).setMinWidth(30)
 		table.getColumnModel.getColumn(0).setMaxWidth(30)
 		table.getColumnModel.getColumn(0).setResizable(false)
 		table.getColumnModel.getColumn(1).setPreferredWidth(table_size.width - 30)
 
     val scroller = new JScrollPane(table)
 		scroller.getViewport.setBackground(table.getBackground)
 		scroller.setPreferredSize(table_size)
 
     add(scroller, BorderLayout.CENTER)
   }
 
 
 
   /** check with optional dialog **/
 
   def check_dialog(view: View)
   {
     GUI_Thread.require {}
 
     val keymap_manager = jEdit.getKeymapManager
     val keymap_name = jEdit.getProperty("keymap.current", KeymapManager.DEFAULT_KEYMAP_NAME)
     val keymap =
       keymap_manager.getKeymap(keymap_name) match {
         case null => keymap_manager.getKeymap(KeymapManager.DEFAULT_KEYMAP_NAME)
         case keymap => keymap
       }
 
     val all_shortcut_conflicts = get_shortcut_conflicts(keymap_name, keymap)
     val no_shortcut_conflicts = for ((s, cs) <- all_shortcut_conflicts if cs.isEmpty) yield s
     val shortcut_conflicts = all_shortcut_conflicts.filter(_._2.nonEmpty)
 
     val table_entries =
       for {
         ((shortcut, conflicts), i) <- shortcut_conflicts zip
           shortcut_conflicts.scanLeft(0)({ case (i, (_, cs)) => i + 1 + cs.length })
         entry <-
           Table_Entry(shortcut, None, ((i + 1) to (i + conflicts.length)).toList) ::
           conflicts.map(Table_Entry(_, Some(i), Nil))
       } yield entry
 
     val table_model = new Table_Model(table_entries)
 
     if (table_entries.nonEmpty &&
         GUI.confirm_dialog(view,
           "Pending Isabelle/jEdit keymap changes",
           JOptionPane.OK_CANCEL_OPTION,
           "The following Isabelle keymap changes are in conflict with the current",
           "jEdit keymap " + quote(keymap_name) + ":",
           new Table(table_model),
           "Selected shortcuts will be applied, unselected changes will be ignored.",
           "Results are stored in $JEDIT_SETTINGS/properties and $JEDIT_SETTINGS/keymaps/.") == 0)
     { table_model.apply(keymap_name, keymap) }
 
     no_shortcut_conflicts.foreach(_.set(keymap))
 
     keymap.save()
     jEdit.saveSettings()
     jEdit.propertiesChanged()
   }
 }