读数据：

public static String txt2String(){        File file = new File("G:/data/swf/data.txt");        StringBuilder result = new StringBuilder();        try{            InputStreamReader isr = new InputStreamReader(new FileInputStream(file), "UTF-8");            BufferedReader br = new BufferedReader(isr);//构造一个BufferedReader类来读取文件            String s = null;            while((s = br.readLine())!=null){
   //使用readLine方法，一次读一行                result.append(System.lineSeparator()+s);            }            br.close();        }catch(Exception e){            e.printStackTrace();        }        return result.toString();    }

写入数据：

public static void writeFile(String str) throws IOException {        //写入中文字符时解决中文乱码问题        FileOutputStream fos=new FileOutputStream(new File("G:/data/swf/data.txt"),true);        OutputStreamWriter osw=new OutputStreamWriter(fos, "UTF-8");        BufferedWriter  bw=new BufferedWriter(osw);        bw.write(str+",");        //注意关闭的先后顺序，先打开的后关闭，后打开的先关闭        bw.close();        osw.close();        fos.close();    }