在Java 7+中，你可以使用Files类。代码非常简单:

Path directory = Paths.get("/tmp");
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;
   }
});

Java 7通过符号链接处理增加了对遍历目录的支持:

import java.nio.file.*;

public static void removeRecursive(Path path) throws IOException
{
    Files.walkFileTree(path, new SimpleFileVisitor<Path>()
    {
        @Override
        public FileVisitResult visitFile(Path file, BasicFileAttributes attrs)
                throws IOException
        {
            Files.delete(file);
            return FileVisitResult.CONTINUE;
        }

        @Override
        public FileVisitResult visitFileFailed(Path file, IOException exc) throws IOException
        {
            // try to delete the file anyway, even if its attributes
            // could not be read, since delete-only access is
            // theoretically possible
            Files.delete(file);
            return FileVisitResult.CONTINUE;
        }

        @Override
        public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException
        {
            if (exc == null)
            {
                Files.delete(dir);
                return FileVisitResult.CONTINUE;
            }
            else
            {
                // directory iteration failed; propagate exception
                throw exc;
            }
        }
    });
}

我使用它作为特定于平台的方法(在这个未测试的代码中):

public static void removeDirectory(Path directory) throws IOException
{
    // does nothing if non-existent
    if (Files.exists(directory))
    {
        try
        {
            // prefer OS-dependent directory removal tool
            if (SystemUtils.IS_OS_WINDOWS)
                Processes.execute("%ComSpec%", "/C", "RD /S /Q \"" + directory + '"');
            else if (SystemUtils.IS_OS_UNIX)
                Processes.execute("/bin/rm", "-rf", directory.toString());
        }
        catch (ProcessExecutionException | InterruptedException e)
        {
            // fallback to internal implementation on error
        }

        if (Files.exists(directory))
            removeRecursive(directory);
    }
}

SystemUtils来自Apache Commons Lang。Processes是私有的，但是它的行为应该是明显的。)

rm -rf的性能比FileUtils.deleteDirectory要好得多。

经过大量的基准测试后，我们发现使用rm -rf比使用FileUtils.deleteDirectory快几倍。

当然，如果您有一个小的或简单的目录，这并不重要，但在我们的例子中，我们有多个gb和深度嵌套的子目录，使用FileUtils.deleteDirectory需要10分钟以上，使用rm -rf只需1分钟。

下面是我们粗略的Java实现:

// Delete directory given and all subdirectories and files (i.e. recursively).
//
static public boolean deleteDirectory( File file ) throws IOException, InterruptedException {

    if ( file.exists() ) {

        String deleteCommand = "rm -rf " + file.getAbsolutePath();
        Runtime runtime = Runtime.getRuntime();

        Process process = runtime.exec( deleteCommand );
        process.waitFor();

        return true;
    }

    return false;

}

如果您正在处理大型或复杂的目录，值得一试。

public void deleteRecursive(File path){
    File[] c = path.listFiles();
    System.out.println("Cleaning out folder:" + path.toString());
    for (File file : c){
        if (file.isDirectory()){
            System.out.println("Deleting file:" + file.toString());
            deleteRecursive(file);
            file.delete();
        } else {
            file.delete();
        }
    }
    path.delete();
}

使用符号链接和上面的代码失败的两种方式…也不知道怎么解决。

方法# 1

运行这个来创建一个测试:

echo test > testfile
mkdir dirtodelete
ln -s badlink dirtodelete/badlinktodelete

下面你可以看到你的测试文件和测试目录:

$ ls testfile dirtodelete
testfile

dirtodelete:
linktodelete

然后运行common -io deleteDirectory()。它崩溃，说文件没有找到。不知道其他例子是怎么做的。Linux的rm命令会简单地删除链接，目录上的rm -r也会删除链接。

Exception in thread "main" java.io.FileNotFoundException: File does not exist: /tmp/dirtodelete/linktodelete

方法# 2

运行这个来创建一个测试:

mkdir testdir
echo test > testdir/testfile
mkdir dirtodelete
ln -s ../testdir dirtodelete/dirlinktodelete

下面你可以看到你的测试文件和测试目录:

$ ls dirtodelete testdir
dirtodelete:
dirlinktodelete

testdir:
testfile

然后运行common -io deleteDirectory()或人们发布的示例代码。它不仅会删除目录，还会删除位于被删除目录之外的testfile。(它隐式地取消对目录的引用，并删除内容)。Rm -r只会删除链接。你需要使用类似这样的方法删除被解引用的文件:"find -L dirtodelete -type f -exec rm {} \;"

$ ls dirtodelete testdir
ls: cannot access dirtodelete: No such file or directory
testdir:

在遗留项目中，我需要创建本地Java代码。我创建了类似于Paulitex代码的代码。看到:

public class FileHelper {

   public static boolean delete(File fileOrFolder) {
      boolean result = true;
      if(fileOrFolder.isDirectory()) {
         for (File file : fileOrFolder.listFiles()) {
            result = result && delete(file);
         }
      }
      result = result && fileOrFolder.delete();
      return result;
   } 
}

单元测试:

public class FileHelperTest {

    @Before
    public void setup() throws IOException {
       new File("FOLDER_TO_DELETE/SUBFOLDER").mkdirs();
       new File("FOLDER_TO_DELETE/SUBFOLDER_TWO").mkdirs();
       new File("FOLDER_TO_DELETE/SUBFOLDER_TWO/TEST_FILE.txt").createNewFile();
    }

    @Test
    public void deleteFolderWithFiles() {
       File folderToDelete = new File("FOLDER_TO_DELETE");
       Assert.assertTrue(FileHelper.delete(folderToDelete));
       Assert.assertFalse(new File("FOLDER_TO_DELETE").exists());
    }

}