Load File Content and Save it back in a Servlet : File Save Read « Servlet « Java Tutorial

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Java Tutorial » Servlet » File Save Read   25.20.2.Load File Content and Save it back in a Servlet import java.io.*; import javax.servlet.*; import javax.servlet.http.*; import java.util.*; public class MyServlet  extends HttpServlet {   int count;   public void init() throws ServletException {     FileReader fileReader = null;     BufferedReader bufferedReader = null;     try {       fileReader = new FileReader("InitDestroyCounter.initial");       bufferedReader = new BufferedReader(fileReader);       String initial = bufferedReader.readLine();       count = Integer.parseInt(initial);       bufferedReader.close();        return;     }     catch (Exception ignored) { }     String initial = getInitParameter("initial");                         try {                                                                   count = Integer.parseInt(initial);                                    return;                                                             }                                                                     catch (NumberFormatException ignored) { }  // null or non-integer value     count = 0;                                                          }                                                                                                                                           public void doGet(HttpServletRequest req, HttpServletResponse res)                                 throws ServletException, IOException {     res.setContentType("text/plain");                                     PrintWriter out = res.getWriter();                                    count++;                                                              out.println("Since the beginning, this servlet has been accessed " +                 count + " times.");                                     }                                                                                                                                           public void destroy() {                                                 super.destroy();     saveState();                                                        }                                                                                                                                           public void saveState() {                                               FileWriter fileWriter = null;     PrintWriter printWriter = null;     try {                                                                   fileWriter = new FileWriter("InitDestroyCounter.initial");       printWriter = new PrintWriter(fileWriter);                printWriter.println(count);                                         printWriter.close();       return;                                                             }                                                                     catch (IOException e) {     }   } } <?xml version="1.0" encoding="ISO-8859-1"?> <!DOCTYPE web-app     PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.2//EN"     "http://java.sun.com/j2ee/dtds/web-app_2_2.dtd"> <web-app>     <servlet><servlet-name>MyServletName</servlet-name>              <servlet-class>MyServlet</servlet-class>     </servlet>          <servlet-mapping><servlet-name>MyServletName</servlet-name>         <url-pattern>/index.html</url-pattern>     </servlet-mapping> </web-app>   Download:  ServletLoadFileContentAndSaveBack.zip( 89 k) 25.20.File Save Read 25.20.1. Read File in a Servlet 25.20.2. Load File Content and Save it back in a Servlet