//讀寫文件函數調用
writeFileData(filename,datas);
String result=readFileData(filename);
Toast.makeText(Main2Activity.this,result.getClass().toString(),Toast.LENGTH_SHORT).show();

下面是讀寫代碼的實現：

//文件寫入
    public void writeFileData(String filename, String content){
        try {
            FileOutputStream fos = this
 
.openFileOutput(filename, MODE_PRIVATE);//獲得FileOutputStream
            //將要寫入的字符串轉換為byte數組
            byte[]  bytes = content.getBytes();
            fos.write(bytes);//將byte數組寫入文件
            fos.close();//關閉文件輸出流

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    //文件讀取
 

    public String readFileData(String fileName){
        String result="";
        try{
            FileInputStream fis = openFileInput(fileName);
            //獲取文件長度
            int lenght = fis.available();
            byte[] buffer = new byte[lenght];
            fis.read(buffer);
            //將byte數組轉換成指定格式的字符串
 

            result = new String(buffer, "UTF-8");

        } catch (Exception e) {
            e.printStackTrace();
        }
        return  result;
    }

android文件寫入和讀取