Android内存和SD卡的数据存取

Android内存和SD卡的数据存取

内存

存

private String fileName = "test.txt";

public void saveToROM(View view) {
File file = new File(getFilesDir(), fileName);
try {
FileOutputStream fos = new FileOutputStream(file);
String str = "这是我写入内存的数据";
fos.write(str.getBytes());
fos.close();
Toast.makeText(this, "保存到内存成功", Toast.LENGTH_SHORT).show();
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(this, "保存到内存失败", Toast.LENGTH_SHORT).show();
}
}

取

private String fileName = "test.txt";

public void readFromROM(View view) {
File file = new File(getFilesDir(), fileName);
try {
BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(file)));
String text = br.readLine();
br.close();
Toast.makeText(this, "读取:\n" + text, Toast.LENGTH_SHORT).show();
} catch (Exception e) {
e.printStackTrace();
}
}

data/data/包名/files

SD卡

权限

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

存

private String fileName = "test.txt";

public void saveToSD(View view) {
if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
// sd卡可用
File file = new File(Environment.getExternalStorageDirectory(), fileName);
try {
FileOutputStream fos = new FileOutputStream(file);
String str = "这是我写入SD卡的数据";
fos.write(str.getBytes());
fos.close();
Toast.makeText(this, "保存到SD卡成功", Toast.LENGTH_SHORT).show();
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(this, "保存到SD卡失败", Toast.LENGTH_SHORT).show();
}
} else {
// 当前不可用
Toast.makeText(this, "SD卡不可用", Toast.LENGTH_SHORT).show();
}
}

取

private String fileName = "test.txt";

public void readFromSD(View view) {
if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
// SD卡可用
File file = new File(Environment.getExternalStorageDirectory(), fileName);
try {
BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(file)));
String text = br.readLine();
br.close();
Toast.makeText(this, "读取:\n" + text, Toast.LENGTH_SHORT).show();
} catch (Exception e) {
e.printStackTrace();
}
} else {
// SD卡不可用
Toast.makeText(this, "SD卡不可用", Toast.LENGTH_SHORT).show();
}
}