Java

Statistics of visits to Java web website

When the client visits the site, read the file, read in the pre-restart count, add 1 to it, and then write the new count to the file.

The reference code is as follows:

< html >

<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Insert title here</title>
</head>
<body>
  <%!
    int number = 0;
    File file = new File("count.txt");
    synchronized void countPeople()
    {
      if(!file.exists())
      {
        number++;
        try{
          file.createNewFile();
          FileOutputStream out = new FileOutputStream("count.txt");
          DataOutputStream dataOut = new DataOutputStream(out);
          dataOut.writeInt(number);
          dataOut.close();
        }catch(IOException ex){}
      }
      else
        try{
          FileInputStream in = new FileInputStream("count.txt");
          DataInputStream dataIn = new DataInputStream(in);
          number = dataIn.readInt();
          number++;
          in.close();
          dataIn.close();
          FileOutputStream out = new FileOutputStream("count.txt");
          DataOutputStream dataOut = new DataOutputStream(out);
          dataOut.writeInt(number);
          out.close();
          dataOut.close();
        }catch(IOException ex){}
    }
  %>
  <%
    countPeople();
  %>
  <p>
     You are the first
    <%=number %>
     Five customers who visit the site.
  </p>
</body>
</html>