由於工作的需要,今天研究了在android下建立檔案夾和修改其許可權的方法,需要瞭解的是每個應用程式套件組合都會有一個私人的儲存資料的目錄(類似檔案夾),只有屬於該包的應用程式才能寫入該目錄空間,每個包應用程式的私人資料目錄位 於Android絕對路徑/data/data/<包名>/目錄中。除了私人資料目錄應用程式還擁有/sdcard目錄(即SD Card的寫入許可權,但不可以修改sd card下檔案的存取權限)。檔案系統中其他系統目錄,第三方應用程式是不可寫入的。
代碼如下兩種:
1、
//建立檔案夾
File destDir = new File(“/data/data/[your path]/temp”);
if (!destDir.exists()) {
destDir.mkdirs();
}
//修改許可權
FileOutputStream fos;
fos = openFileOutput("filename" , MODE_WORLD_READABLE);
備忘:可用的mode 參數如下:
/**
* File creation mode: the default mode, where the created file can only
* be accessed by the calling application (or all applications sharing the
* same user ID).
* @see #MODE_WORLD_READABLE
* @see #MODE_WORLD_WRITEABLE
*/
public static final int MODE_PRIVATE = 0x0000;
/**
* File creation mode: allow all other applications to have read access
* to the created file.
* @see #MODE_PRIVATE
* @see #MODE_WORLD_WRITEABLE
*/
public static final int MODE_WORLD_READABLE = 0x0001;
/**
* File creation mode: allow all other applications to have write access
* to the created file.
* @see #MODE_PRIVATE
* @see #MODE_WORLD_READABLE
*/
public static final int MODE_WORLD_WRITEABLE = 0x0002;
/**
* File creation mode: for use with {@link #openFileOutput}, if the file
* already exists then write data to the end of the existing file
* instead of erasing it.
* @see #openFileOutput
*/
public static final int MODE_APPEND = 0x8000;
2、
//建立檔案夾
File destDir = new File(“/data/data/[your path]/temp”);
if (!destDir.exists()) {
destDir.mkdirs();
}
Process p;
int status;
try {
p = Runtime.getRuntime().exec("chmod 777 " + destDir );
status = p.waitFor();
if (status == 0) {
//chmod succeed
Toast.makeText(this, "chmod succeed", Toast.LENGTH_LONG).show();
} else {
//chmod failed
Toast.makeText(this, "chmod failed", Toast.LENGTH_LONG).show();
}
}
友情提醒:
如果是在sdcard下插入,最好先判斷sdcard是否插入,代碼如下//首先判斷sdcard是否插入String status = Environment.getExternalStorageState();
if (status.equals(Environment.MEDIA_MOUNTED)) {
return true;
} else {
return false;
} 參考:http://www.devdiv.net/blog/space-28742-do-blog-id-1956.html http://www.phpfans.net/article/htmls/201009/MzAzNjMz.html