正如本RFE及其注释中所讨论的，您可以首先调用tempDir.delete()。或者你可以使用System.getProperty("java.io.tmpdir")并在那里创建一个目录。无论采用哪种方法，都应该记得调用tempDir.deleteOnExit()，否则在完成操作后文件将不会被删除。

这是我决定为我自己的代码所做的:

/**
 * Create a new temporary directory. Use something like
 * {@link #recursiveDelete(File)} to clean this directory up since it isn't
 * deleted automatically
 * @return  the new directory
 * @throws IOException if there is an error creating the temporary directory
 */
public static File createTempDir() throws IOException
{
    final File sysTempDir = new File(System.getProperty("java.io.tmpdir"));
    File newTempDir;
    final int maxAttempts = 9;
    int attemptCount = 0;
    do
    {
        attemptCount++;
        if(attemptCount > maxAttempts)
        {
            throw new IOException(
                    "The highly improbable has occurred! Failed to " +
                    "create a unique temporary directory after " +
                    maxAttempts + " attempts.");
        }
        String dirName = UUID.randomUUID().toString();
        newTempDir = new File(sysTempDir, dirName);
    } while(newTempDir.exists());

    if(newTempDir.mkdirs())
    {
        return newTempDir;
    }
    else
    {
        throw new IOException(
                "Failed to create temp dir named " +
                newTempDir.getAbsolutePath());
    }
}

/**
 * Recursively delete file or directory
 * @param fileOrDir
 *          the file or dir to delete
 * @return
 *          true iff all files are successfully deleted
 */
public static boolean recursiveDelete(File fileOrDir)
{
    if(fileOrDir.isDirectory())
    {
        // recursively delete contents
        for(File innerFile: fileOrDir.listFiles())
        {
            if(!FileUtilities.recursiveDelete(innerFile))
            {
                return false;
            }
        }
    }

    return fileOrDir.delete();
}

即使稍后显式删除它，也不要使用deleteOnExit()。

谷歌'deleteonexit is evil'获取更多信息，但问题的要点是:

deleteOnExit()只删除正常的JVM关闭，不删除崩溃或杀死JVM进程。 deleteOnExit()只在JVM关闭时删除-不适合长时间运行的服务器进程，因为: 最糟糕的是deleteOnExit()为每个临时文件条目消耗内存。如果您的进程运行了几个月，或者在短时间内创建了大量临时文件，那么您将消耗内存，直到JVM关闭才释放内存。

这是Guava库的Files.createTempDir()的源代码。它没有你想象的那么复杂:

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) + ')');
}

默认情况下:

private static final int TEMP_DIR_ATTEMPTS = 10000;

在这里看到的

谷歌Guava库有大量有用的实用程序。这里需要注意的是Files类。它有很多有用的方法，包括:

File myTempDir = Files.createTempDir();

这正是您在一行中要求的。如果您阅读这里的文档，您将看到File的建议改编。createTempFile("install"， "dir")通常会引入安全漏洞。

如果您使用的是JDK 7，请使用新的Files。类创建临时目录。

Path tempDirWithPrefix = Files.createTempDirectory(prefix);

在JDK 7之前，应该这样做:

public static File createTempDirectory()
    throws IOException
{
    final File temp;

    temp = File.createTempFile("temp", Long.toString(System.nanoTime()));

    if(!(temp.delete()))
    {
        throw new IOException("Could not delete temp file: " + temp.getAbsolutePath());
    }

    if(!(temp.mkdir()))
    {
        throw new IOException("Could not create temp directory: " + temp.getAbsolutePath());
    }

    return (temp);
}

如果你愿意，你可以创建更好的异常(子类IOException)。