1.数据持久化-SDCard//数据持久化-SDCard

findViewById(R.id.button1).setOnClickListener(new OnClickListener()

{

@Override

public void onClick(View v)

{

//判断SDCard是否正常加载

if(Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState()))

{

//获取SDCard根目录

File sdcardPath = Environment.getExternalStorageDirectory();

//获取SDCard可用空间

long freeSpace = sdcardPath.getFreeSpace();

Log.e("space", freeSpace + "");

}

}

});

2.SharedPreferences：(data/data/包名/shared_prefs/)private void btn2Click()

{

// SharedPreferences sp = getPreferences(0);

SharedPreferences sp = getSharedPreferences("filename", MODE_PRIVATE);//私有模式

String str = sp.getString("value", "noread");

boolean bol = sp.getBoolean("flag", true);

textView.setText(str + " " + bol);

}

private void btn1Click()

{

// SharedPreferences sp = getPreferences(MODE_WORLD_READABLE | MODE_WORLD_WRITEABLE);//全局可读可写

SharedPreferences sp = getSharedPreferences("filename", MODE_APPEND);//指定文件名，(内容)追加模式

Editor editor = sp.edit();

String value = editText.getText().toString();

editor.putString("value", value);

editor.putBoolean("flag", false);

editor.commit();

}

3.内部存储internalStorage:(data/data/包名/files/)private void btn2Click()

{

try

{

FileInputStream fis = openFileInput("fos1.txt");//读取文件

int length = 0;

byte[] buffer = new byte[1024];

while(-1 != (length = fis.read(buffer)))

{

textView.setText(new String (buffer,0,length));

}

}

catch (FileNotFoundException e)

{

e.printStackTrace();

}

catch (IOException e)

{

e.printStackTrace();

}

}

private void btn1Click()

{

FileOutputStream fos = null;

try

{

fos = openFileOutput("fos1.txt",MODE_PRIVATE);//写入文件

String str = editText.getText().toString();

fos.write(str.getBytes());

fos.flush();

}

catch (FileNotFoundException e)

{

e.printStackTrace();

}

catch (IOException e)

{

e.printStackTrace();

}

finally

{

if( null != fos )

{

try

{

fos.close();

}

catch (IOException e)

{

e.printStackTrace();

}

}

}

}