android 内置存储读写,Android App将数据写入内部存储和外部存储的示例

易采站长站为您分析Android App将数据写入内部存储和外部存储的示例,使用外部存储即访问并写入SD卡,需要的朋友可以参考下

File存储(内部存储)

一旦程序在设备安装后，data/data/包名/ 即为内部存储空间，对外保密。

Context提供了2个方法来打开输入、输出流

FileInputStream openFileInput(String name)

FileOutputStream openFileOutput(String name, int mode)

public class MainActivity extends Activity {

private TextView show;

private EditText et;

private String filename = "test";

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

show = (TextView) findViewById(R.id.show);

et = (EditText) findViewById(R.id.et);

findViewById(R.id.write).setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

try {

FileOutputStream fos = openFileOutput(filename, Context.MODE_PRIVATE);

//FileOutputStream是字节流，如果是写文本的话，需要进一步把FileOutputStream包装 UTF-8是编码

OutputStreamWriter osw = new OutputStreamWriter(fos, "UTF-8");

//写

osw.write(et.getText().toString());

osw.flush();

fos.flush();

osw.close();

fos.close();

} catch (FileNotFoundException e) {

e.printStackTrace();

} catch (UnsupportedEncodingException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

});

findViewById(R.id.read).setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

try {

FileInputStream fis = openFileInput(filename);

//当输入输出都指定字符集编码的时候，就不会出现乱码的情况

InputStreamReader isr = new InputStreamReader(fis, "UTF-8");

//获取文件的可用长度，构建一个字符数组

char[] input = new char[fis.available()];

isr.read(input);

isr.close();

fis.close();

String readed = new String(input);

show.setText(readed);

} catch (FileNotFoundException e) {

e.printStackTrace();

} catch (UnsupportedEncodingException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

});

}

}