HttpServlet: destroy() : HttpServlet « javax.servlet.http « Java by API

1. Java by API
2. javax.servlet.http
3. HttpServlet

HttpServlet: destroy()

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class MainServlet 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);
      return;
    } catch (Exception ignored) {
    }  
    finally {
      try {
        if (bufferedReader != null) {
          bufferedReader.close();
        }
      } catch (IOException ignored) {
      }
    }
    String initial = getInitParameter("initial");
    try {
      count = Integer.parseInt(initial);
      return;
    } catch (NumberFormatException ignored) {
    } 
    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() {
    saveState();
  }

  public void saveState() {
    // Try to save the accumulated count
    FileWriter fileWriter = null;
    PrintWriter printWriter = null;
    try {
      fileWriter = new FileWriter("InitDestroyCounter.initial");
      printWriter = new PrintWriter(fileWriter);
      printWriter.println(count);
      return;
    } catch (IOException e) { // problem during write
      // Log the exception. See Chapter 5.
    } finally {
      // Make sure to close the file
      if (printWriter != null) {
        printWriter.close();
      }
    }
  }
}

           
       

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