add back check for if dir already exists

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1917583 13f79535-47bb-0310-9956-ffa450edef68

poi/src/main/java/org/apache/poi/util/DefaultTempFileCreationStrategy.java

@@ -77,15 +77,23 @@ private void createPOIFilesDirectory() throws IOException {
  // Create our temp dir only once by double-checked locking
  // The directory is not deleted, even if it was created by this TempFileCreationStrategy
  if (dir == null) {
+ final String tmpDir = System.getProperty(JAVA_IO_TMPDIR);
+ if (tmpDir == null) {
+ throw new IOException("System's temporary directory not defined - set the -D" + JAVA_IO_TMPDIR + " jvm property!");
+ }
  dirLock.lock();
  try {
  if (dir == null) {
- String tmpDir = System.getProperty(JAVA_IO_TMPDIR);
- if (tmpDir == null) {
- throw new IOException("System's temporary directory not defined - set the -D" + JAVA_IO_TMPDIR + " jvm property!");
- }
  Path dirPath = Paths.get(tmpDir, POIFILES);
- dir = Files.createDirectories(dirPath).toFile();
+ File fileDir = dirPath.toFile();
+ if (fileDir.exists()) {
+ if (!fileDir.isDirectory()) {
+ throw new IOException("Could not create temporary directory. '" + fileDir + "' exists but is not a directory.");
+ }
+ dir = fileDir;
+ } else {
+ dir = Files.createDirectories(dirPath).toFile();
+ }
  }
  } finally {
  dirLock.unlock();