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();
}

刚刚看到我的解决方案或多或少与埃里克森的相同，只是包装成一个静态方法。把它放到某个地方，它的重量比安装所有Apache Commons要轻得多，因为(如您所见)非常简单。

public class FileUtils {
    /**
     * By default File#delete fails for non-empty directories, it works like "rm". 
     * We need something a little more brutual - this does the equivalent of "rm -r"
     * @param path Root File Path
     * @return true iff the file and all sub files/directories have been removed
     * @throws FileNotFoundException
     */
    public static boolean deleteRecursive(File path) throws FileNotFoundException{
        if (!path.exists()) throw new FileNotFoundException(path.getAbsolutePath());
        boolean ret = true;
        if (path.isDirectory()){
            for (File f : path.listFiles()){
                ret = ret && deleteRecursive(f);
            }
        }
        return ret && path.delete();
    }
}

下面的代码递归删除给定文件夹中的所有内容。

boolean deleteDirectory(File directoryToBeDeleted) {
    File[] allContents = directoryToBeDeleted.listFiles();
    if (allContents != null) {
        for (File file : allContents) {
            deleteDirectory(file);
        }
    }
    return directoryToBeDeleted.delete();
}

番石榴21.0及以上版本

有一个void deleterecursive (Path Path, RecursiveDeleteOption…)options)会抛出从Guava 21.0开始可用的MoreFiles类的IOException静态方法。

请参阅Javadoc文档:

public static void deleteRecursively(Path path, RecursiveDeleteOption... options) throws IOException Deletes the file or directory at the given path recursively. Deletes symbolic links, not their targets (subject to the caveat below). If an I/O exception occurs attempting to read, open or delete any file under the given directory, this method skips that file and continues. All such exceptions are collected and, after attempting to delete all files, an IOException is thrown containing those exceptions as suppressed exceptions.

public static void deleteDirectory(File path) 
{
    if (path == null)
        return;
    if (path.exists())
    {
        for(File f : path.listFiles())
        {
            if(f.isDirectory()) 
            {
                deleteDirectory(f);
                f.delete();
            }
            else
            {
                f.delete();
            }
        }
        path.delete();
    }
}