how to create a temporary directory inside a Java application using java 1.6 ?

Question

I have a java application where i'm using javaMail API to send attachments generated by other utilities java class. IS there any way to create a temporary folder where to save these attachments before sending it using java 1.6 version ?

Answer 1

You can use File.createTempFile to create temp files which go to a temp directory (depending on your platform), but there's no way to create a temp dir in a similar way.

You should modify your generating code to create temp files instead, and then pass the File objects around.

Answer 2

Google Guava has a Files.createTempDir() method, explained here .

  /** Maximum loop count when creating temp directories. */
  private static final int TEMP_DIR_ATTEMPTS = 10000;

public static File createTempDir() {
    File baseDir = new File(System.getProperty("java.io.tmpdir"));
    String baseName = System.currentTimeMillis() + "-";

    for (int counter = 0; counter < TEMP_DIR_ATTEMPTS; counter++) {
        File tempDir = new File(baseDir, baseName + counter);
        if (tempDir.mkdir()) {
            return tempDir;
        }
    }
    throw new IllegalStateException("Failed to create directory within " + TEMP_DIR_ATTEMPTS + " attempts (tried " + baseName + "0 to " + baseName + (TEMP_DIR_ATTEMPTS - 1) + ')');
}

Answer 3

The standard way is to create a temp file, then delete it, then recreate it as a directory. For example, this is how JUnit's TemporaryFolder Rule does it:

    File folder= File.createTempFile("junit", "");
    folder.delete();
    folder.mkdir();

However, this isn't threadsafe since something else can create the same file in the time between the delete() and mkdir() calls which will cause this code to fail.