java - 将目录、子目录和文件复制到 SD 卡 - android

Question

我使用以下代码将特定目录及其内容复制到 SD 卡。该目录位于 res/raw 文件夹中。

以下是我使用的代码:

public class CopyActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    copyFilesToSdCard();
}

static String extStorageDirectory =  Environment.getExternalStorageDirectory().toString();
final static String TARGET_BASE_PATH = extStorageDirectory+"/Android/data/";

private void copyFilesToSdCard() {
    copyFileOrDir("");
}

private void copyFileOrDir(String path) {
    AssetManager assetManager = this.getAssets();
    String assets[] = null;
    try {
        Log.i("tag", "copyFileOrDir() "+path);
        assets = assetManager.list(path);
        if (assets.length == 0) {
            copyFile(path);
        } else {
            String fullPath =  TARGET_BASE_PATH + path;
            Log.i("tag", "path="+fullPath);
            File dir = new File(fullPath);
            if (!dir.exists())
                if (!dir.mkdirs());
                    Log.i("tag", "could not create dir "+fullPath);
            for (int i = 0; i < assets.length; ++i) {
                String p;
                if (path.equals(""))
                    p = "";
                else 
                    p = path + "/";

                    copyFileOrDir( p + assets[i]);
            }
        }
    } catch (IOException ex) {
        Log.e("tag", "I/O Exception", ex);
    }
}

private void copyFile(String filename) {
    AssetManager assetManager = this.getAssets();

    InputStream in = null;
    OutputStream out = null;
    String newFileName = null;
    try {
        Log.i("tag", "copyFile() "+filename);
        in = assetManager.open(filename);
        if (filename.endsWith(".jpg")) // extension was added to avoid compression on APK file
            newFileName = TARGET_BASE_PATH + filename.substring(0, filename.length()-4);
        else
            newFileName = TARGET_BASE_PATH + filename;
        out = new FileOutputStream(newFileName);

        byte[] buffer = new byte[1024];
        int read;
        while ((read = in.read(buffer)) != -1) {
            out.write(buffer, 0, read);
        }
        in.close();
        in = null;
        out.flush();
        out.close();
        out = null;
    } catch (Exception e) {
        Log.e("tag", "Exception in copyFile() of "+newFileName);
        Log.e("tag", "Exception in copyFile() "+e.toString());
    }

}
}

---

异常:

 Exception in copyFile() of /mnt/sdcard/Android/data/raw/edu/anees.txt
 Exception in copyFile() java.io.FileNotFoundException:
 /mnt/sdcard/Android/data/raw/edu/anees.txt: open failed: ENOENT (No such file or directory)

---

谁能告诉我导致此问题的原因及其解决方案。

引用:How to copy files from 'assets' folder to sdcard?

编辑

我可以通过在此处作为一个答案发布的有关权限的提示之一解决异常。

现在又遇到一个问题，如下:

以下日志显示我无法在以下路径中创建文件夹:

Log.i("tag", "could not create dir "+fullPath);// fullPath = /mnt/sdcard/Android/data/raw

我不想将数据存储在/mnt/sdcard/Android/data/raw 中，而是希望将 assets 中 raw 文件夹的内容复制到路径/mnt/sdcard/我从我提供的引用链接中使用的代码段没有发生 Android/data 。有什么明显的原因可能导致我提供的代码出现这种情况？

Answer 1

您可能忘记在 list 中设置权限

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />