file存储

public void bt3(View v){

        try {
             //从内存写入文件
            //1.得到内部存储目录
                File file=getFilesDir();
        String s=file.getAbsolutePath();
        Toast.makeText(MainActivity.this, "path="+s, Toast.LENGTH_SHORT).show();

        //2.用输出流写入文件
        FileOutputStream fos=openFileOutput("test.txt",MODE_PRIVATE);

        //3.写入文件内容
        PrintStream ps=new PrintStream(fos);
        String ss=et.getText().toString();
        ps.println(ss);
        ps.print("测试");
        ps.close();
        fos.close();
        Toast.makeText(MainActivity.this, "保存成功", Toast.LENGTH_SHORT).show();}
        catch (Exception e){

        }
    }
    public  void bt4(View v){
        try {
        //输入流
        FileInputStream fis=openFileInput("test.txt");

            //定义byte[]
            byte []b=new byte[1024];
            int i;

            //循环读
            String str1="";
            while ((i=fis.read(b))>0){
                str1 =new String(b,0,i);
              }
            et2.setText(str1);
            fis.close();

    } catch (Exception e){

        }
    }