Question

我正在尝试重命名具有特定扩展名的所有文件。这样可以正常工作，但是，这个过程似乎很慢，有时会冻结设备一段时间。如何让它占用更少的内存？

setContentView(R.layout.transparent_ui);
    // getting SDcard root path
    File dir = new File(Environment.getExternalStorageDirectory()
            .getAbsolutePath());
    walkdir(dir);
    finish();
}

public static final String[] TARGET_EXTENSIONS = { "the_video_first",
        "webm", "mkv", "flv", "vob", "ogg", "drc", "gif", "gifv", "mng",
        "avi", "mov", "wmv", "yuv", "rm", "rmvb", "asf", "mp4", "mpg",
        "mpeg", "mpg", "mpeg", "m4v", "svi", "3gp", "3g2", "mxf",
        "now_the_audio", "wav", "mp3", "wma", "ogg", "m4a",
        "now_the_images", "jpg", "jpeg", "png", "bmp" };

public void walkdir(File dir) {
    File listFile[] = dir.listFiles();
    if (listFile != null) {
        for (int i = 0; i < listFile.length; i++) {
            if (listFile[i].isDirectory()) {
                walkdir(listFile[i]);
            } else {
                String fPath = listFile[i].getPath();

                for (String ext : TARGET_EXTENSIONS) {
                    fPath = fPath.replace("." + ext, ".xghost" + ext);
                }

                listFile[i].renameTo(new File(fPath));
            }
        }
    }
}

Answer 1

查看下面的链接，它有不同的实现

http://www.baeldung.com/java-how-to-rename-or-move-a-file

Answer 2

你想做什么？，你能详细说明你的逻辑吗？为什么这个内部FOR循环运行这么多次。它应该如何成为你的最终道路？

for (String ext : TARGET_EXTENSIONS) {
  fPath = fPath.replace("." + ext, ".xghost" + ext);
}

Answer 3

试试这段代码。

public void walkdir(File dir) {
    File listFile[] = dir.listFiles();
    if (listFile != null) {
        for (int i = 0; i < listFile.length; i++) {
            if (listFile[i].isDirectory()) {
                walkdir(listFile[i]);
            } else {
                String fPath = listFile[i].getPath();

                for (String ext : TARGET_EXTENSIONS) {
                    // use string builder avoid concatenation inside a loop
                    String oldExt = new StringBuilder().append(".").append(ext).toString();
                    if (fPath.contains(oldExt)) {
                        String newExt  = new StringBuilder().append(".xghost").append(ext).toString();
                        fPath = fPath.replace(oldExt, newExt);
                        listFile[i].renameTo( new File(fPath));
                        break; // no need to continue once we have replaced the extension.
                    }
                }

            }
        }
    }
}

重命名文件需要太多内存

3 个答案: