Code example of java read and write operations

This article brings you code examples about Java read and write operations. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to you.

java code:

Write:

public void getNotice(HttpServletRequest request, String notice){
     String message = JSON.toJSONString(notice);
     File file = new File(request.getRealPath("/text/history.txt"));//这里是绝对路径。括号内的路径自己根据自己存放的路径来写。
     try(OutputStreamWriter op = new OutputStreamWriter(new FileOutputStream(file , true), "utf-8")){
         if(!file.exists()){
            file.createNewFile();
         }
         op.append(message);
         op.write("\r\n");//这里是换行，根据自己需求加与不加。
         op.flush();
         op.close();
     }catch(IOException e){
         e.printStackTrace();
     }
}

Read:

public void postNotice (HttpServletRequest request, HttpServletResponse response){
      JSONObject json = new JSONObject();
      String message ="";
      File file = new File(request.getRealPath("/text/history.txt"));
      try{
             FileInputStream in = new FileInputStream(file);
             int len = 0;
             byte[] buff = new byte[1024];
             while((len = in.read(buff))!= -1){
                 message = new String(buff,0 ,len, "utf-8);
             }
      }catch(IOException e){

      }
      String str1 = JSONObject.toJSONString(message.replaceAll("\r|\n", ""));//如果上述的换行未写，这句可以不用
      json.put("str", str1);
      returnMessage(response ,json);
}

1. When reading, the callback function should print console.log(JSON.parse(data.str)) ;

2. In order to ensure that there are no encoding format errors, it is recommended that the txt of the saved text should be set to the format of UTF-8.

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