Fixes GenClass exception when the temp directory does not exists.

--
Change-Id: Ie4236fbadc63ef38f08783acc0162cf0dd4fe872
Reviewed-on: https://bazel-review.googlesource.com/3422
MOS_MIGRATED_REVID=120146252

1 files changed, 18 insertions, 12 deletions

diff --git a/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/genclass/GenClass.java b/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/genclass/GenClass.java
index 7e6a5404ff..a0e053c107 100644
--- a/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/genclass/GenClass.java
+++ b/src/java_tools/buildjar/java/com/google/devtools/build/buildjar/genclass/GenClass.java
@@ -43,19 +43,25 @@ public class GenClass {
    * Recursively delete a directory.
    */
   private static void deleteTree(Path directory) throws IOException {
-    Files.walkFileTree(directory, new SimpleFileVisitor<Path>() {
-      @Override
-      public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
-        Files.delete(file);
-        return FileVisitResult.CONTINUE;
-      }
+    if (directory.toFile().exists()) {
+      Files.walkFileTree(
+          directory,
+          new SimpleFileVisitor<Path>() {
+            @Override
+            public FileVisitResult visitFile(Path file, BasicFileAttributes attrs)
+                throws IOException {
+              Files.delete(file);
+              return FileVisitResult.CONTINUE;
+            }
 
-      @Override
-      public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {
-        Files.delete(dir);
-        return FileVisitResult.CONTINUE;
-      }
-    });
+            @Override
+            public FileVisitResult postVisitDirectory(Path dir, IOException exc)
+                throws IOException {
+              Files.delete(dir);
+              return FileVisitResult.CONTINUE;
+            }
+          });
+    }
   }
 
   public static void main(String[] args) throws IOException {