RFR: 8208227: tools/jdeps/DotFileTest.java fails on Win-X64

[Jonathan Gibbons]

Please review a simple fix for a P2 (tier1) langtools test failure.

It's Yet Another Example of using Files.delete on Windows and expecting 
it to work.
The fix is to replace the usage with more robust library code, such as 
that provided
in the ToolBox test-utility class.

Webrev: http://cr.openjdk.java.net/~jjg/8208227/webrev.00/
JBS: https://bugs.openjdk.java.net/browse/JDK-8208227

The diff is small enough to also include inline:

--- old/test/langtools/tools/jdeps/DotFileTest.java	2018-07-25 14:51:38.032332248 -0700
+++ new/test/langtools/tools/jdeps/DotFileTest.java	2018-07-25 14:51:37.644315078 -0700
@@ -27,7 +27,8 @@
   * @summary Basic tests for jdeps -dotoutput option
   * @modules java.management
   *          jdk.jdeps/com.sun.tools.jdeps
- * @build Test p.Foo p.Bar
+ * @library /tools/lib
+ * @build toolbox.ToolBox Test p.Foo p.Bar
   * @run main DotFileTest
   */
  
@@ -43,6 +44,8 @@
  import java.util.regex.*;
  import java.util.stream.Collectors;
  
+import toolbox.ToolBox;
+
  public class DotFileTest {
      public static void main(String... args) throws Exception {
          int errors = 0;
@@ -51,9 +54,11 @@
              throw new Exception(errors + " errors found");
      }
  
+    final ToolBox toolBox;
      final Path dir;
      final Path dotoutput;
      DotFileTest() {
+        this.toolBox = new ToolBox();
          this.dir = Paths.get(System.getProperty("test.classes", "."));
          this.dotoutput = dir.resolve("dots");
      }
@@ -169,12 +174,10 @@
  
      Map<String,String> jdeps(List<String> args, Path dotfile) throws IOException {
          if (Files.exists(dotoutput)) {
-            try (DirectoryStream<Path> stream = Files.newDirectoryStream(dotoutput)) {
-                for (Path p : stream) {
-                    Files.delete(p);
-                }
-            }
-            Files.delete(dotoutput);
+            // delete contents of directory, then directory,
+            // waiting for confirmation on Windows
+            toolBox.cleanDirectory(dotoutput);
+            toolBox.deleteFiles(dotoutput);
          }
          // invoke jdeps
          StringWriter sw = new StringWriter();