在Android下创建文件夹

时间:2022-04-23 12:32:05

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由于工作的需要,今天研究了在android下创建文件夹和修改其权限的方法,需要了解的是每个应用程序包都会有一个私有的存储数据的目录(类似文件夹),只有属于该包的应用程序才能写入该目录空间,每个包应用程序的私有数据目录位于Android绝对路径/data/data/<包名>/目录中。除了私有数据目录应用程序还拥有/sdcard目录(即SD Card的写入权限,但不可以修改sd card下文件的访问权限)。文件系统中其他系统目录,第三方应用程序是不可写入的。

代码如下两种:

1、

//创建文件夹

File destDir = new File(“/data/data/[your path]/temp”);
if (!destDir.exists()) {
destDir.mkdirs();
}

//修改权限

FileOutputStream fos;

fos = openFileOutput("filename" , MODE_WORLD_READABLE);


备注:可用的mode 参数如下:

/**
* 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、

//创建文件夹

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,最好先判断sdcard是否插入,代码如下
//首先判断sdcard是否插入
String status = Environment.getExternalStorageState();
if (status.equals(Environment.MEDIA_MOUNTED)) {
return true;
} else {
return false;
}


注意:AP只能在自己所在的包目录下穿件文件夹