有很多答案，但我决定加上我自己的，因为它有点不同。它是基于OOP的;)

我创建了DirectoryCleaner类，每当我需要清理某个目录时，它都会帮助我。

public class DirectoryCleaner {
    private final File mFile;

    public DirectoryCleaner(File file) {
        mFile = file;
    }

    public void clean() {
        if (null == mFile || !mFile.exists() || !mFile.isDirectory()) return;
        for (File file : mFile.listFiles()) {
            delete(file);
        }
    }

    private void delete(File file) {
        if (file.isDirectory()) {
            for (File child : file.listFiles()) {
                delete(child);
            }
        }
        file.delete();

    }
}

可以用下面的方法来解决这个问题:

File dir = new File(Environment.getExternalStorageDirectory(), "your_directory_name");
new DirectoryCleaner(dir).clean();
dir.delete();

如果你不需要递归删除东西，你可以尝试这样做:

File file = new File(context.getExternalFilesDir(null), "");
    if (file != null && file.isDirectory()) {
        File[] files = file.listFiles();
        if(files != null) {
            for(File f : files) {   
                f.delete();
            }
        }
    }

你可以像这样递归地删除文件和文件夹:

void deleteRecursive(File fileOrDirectory) {
    if (fileOrDirectory.isDirectory())
        for (File child : fileOrDirectory.listFiles())
            deleteRecursive(child);

    fileOrDirectory.delete();
}

public static void deleteDirectory( File dir )
{

    if ( dir.isDirectory() )
    {
        String [] children = dir.list();
        for ( int i = 0 ; i < children.length ; i ++ )
        {
         File child =    new File( dir , children[i] );
         if(child.isDirectory()){
             deleteDirectory( child );
             child.delete();
         }else{
             child.delete();

         }
        }
        dir.delete();
    }
}

有很多答案，但我决定加上我自己的，因为它有点不同。它是基于OOP的;)

我创建了DirectoryCleaner类，每当我需要清理某个目录时，它都会帮助我。

public class DirectoryCleaner {
    private final File mFile;

    public DirectoryCleaner(File file) {
        mFile = file;
    }

    public void clean() {
        if (null == mFile || !mFile.exists() || !mFile.isDirectory()) return;
        for (File file : mFile.listFiles()) {
            delete(file);
        }
    }

    private void delete(File file) {
        if (file.isDirectory()) {
            for (File child : file.listFiles()) {
                delete(child);
            }
        }
        file.delete();

    }
}

可以用下面的方法来解决这个问题:

File dir = new File(Environment.getExternalStorageDirectory(), "your_directory_name");
new DirectoryCleaner(dir).clean();
dir.delete();

根据文档:

如果此抽象路径名不表示目录，则此方法返回null。

所以你应该检查listFiles是否为空，如果不是则继续

boolean deleteDirectory(File path) {
    if(path.exists()) {
        File[] files = path.listFiles();
        if (files == null) {
            return false;
        }
        for (File file : files) {
            if (file.isDirectory()) {
                deleteDirectory(file);
            } else {
                boolean wasSuccessful = file.delete();
                if (wasSuccessful) {
                    Log.i("Deleted ", "successfully");
                }
            }
        }
    }
    return(path.delete());
}