String path = "data/data/com.example.qqlogin/login.txt"; FileOutputStream fos = new FileOutputStream(path); String data = number + "##" + password; fos.write(data.getBytes()); fos.flush(); fos.close(); 或者 public class MainActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // /data/data/包名/files/aa.txt // openFileOutput("aa.txt", Context.mode) //私有文件 writeToLocal("private.txt",Context.MODE_PRIVATE); //可读文件 writeToLocal("readable.txt", Context.MODE_WORLD_READABLE); //可写文件 writeToLocal("writeable.txt", Context.MODE_WORLD_WRITEABLE); //可读可写 writeToLocal("readable_writeable", Context.MODE_WORLD_READABLE + Context.MODE_WORLD_WRITEABLE); } private void writeToLocal(String fileName,int mode){ try { FileOutputStream fos = openFileOutput(fileName, mode); fos.write(("第一个程序写的数据:"+fileName).getBytes()); fos.flush(); fos.close(); } catch (Exception e) { // TODO 自动生成的 catch 块 e.printStackTrace(); } } }