java io 追加字符

第一種方式

 File file=new File("c://RHDSetup.log"); 
    if (!file.exists()) {
        file.mkdirs();
    }
    File files=new File("D://1.log");

    FileOutputStream fos=new FileOutputStream(files);
    StringBuffer sb=new StringBuffer();
    RandomAccessFile raf=new RandomAccessFile(file, "rw");//也可以使用FileinputStream去讀取文件
    byte[] buffer = new byte[1];
    while (raf.read(buffer)!=-1) {
        sb.append(new String(buffer));

        System.out.println(raf.getFilePointer());
    }
     sb.append("xxx");//拼接字符
    fos.write(sb.toString().getBytes());//轉換成Byte寫入到文件
    System.out.println(sb.toString());


    fos.flush();
    fos.close();

第二種方式

    public static void main(String[] args) throws Exception {
            iotest in = new iotest();
            in.getFile("C://Rule.txt");
        }

        public void getFile(String path) throws Exception {
            StringBuffer sbf = new StringBuffer();

            BufferedReader fr =new BufferedReader(new FileReader(path));


            String s;
            while ((s=fr.readLine())!=null) {
                sbf.append(s);
            }



            System.out.println(Integer.parseInt(sbf.toString()));
        }

}

        public static void main(String[] args) throws Exception {
            iotest in = new iotest();
            in.getFile("C://Rule.txt");
        }

        public void getFile(String path) throws Exception {
            StringBuffer sbf = new StringBuffer();

            FileInputStream fr = new FileInputStream(path);



            byte [] b=new byte[1024];
            while (fr.read(b)!=-1) {
                String ss =new String(b);
               sbf.append(ss);
            }



            System.out.println(sbf.toString());
        }