package com.oreilly.jent.servlets;
/**
* In general, you may use the code in this book in your programs and
* documentation. You do not need to contact us for permission unless
* you're reproducing a significant portion of the code. For example,
* writing a program that uses several chunks of code from this book does
* not require permission. Selling or distributing a CD-ROM of examples
* from O'Reilly books does require permission. Answering a question by
* citing this book and quoting example code does not require permission.
* Incorporating a significant amount of example code from this book into
* your product's documentation does require permission.
*
* We appreciate, but do not require, attribution. An attribution usually
* includes the title, author, publisher, and ISBN. For example:
*
* "Java Enterprise in a Nutshell, Third Edition,
* by Jim Farley and William Crawford
* with Prakash Malani, John G. Norman, and Justin Gehtland.
* Copyright 2006 O'Reilly Media, Inc., 0-596-10142-2."
*
* If you feel your use of code examples falls outside fair use or the
* permission given above, feel free to contact us at
* permissions@oreilly.com.
*/
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class LifeCycleServlet extends HttpServlet {
int timesAccessed;
public void init(ServletConfig conf) throws ServletException {
super.init(conf);
// Get initial value
try {
timesAccessed = Integer.parseInt(getInitParameter("defaultStart"));
}
catch(NullPointerException e) {
timesAccessed = 0;
}
catch(NumberFormatException e) {
timesAccessed = 0;
}
// Try loading from the disk
DataInputStream ds = null;
try {
File r = new File("./data/counter.dat");
ds = new DataInputStream(new FileInputStream(r));
timesAccessed = ds.readInt( );
}
catch (FileNotFoundException e) {
// Handle error
}
catch (IOException e) {
// This should be logged
}
finally {
if (ds != null)
try {
ds.close();
} catch (IOException ignored) {}
}
}
public void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
resp.setContentType("text/html");
PrintWriter out = resp.getWriter( );
timesAccessed++;
out.println("<html>");
out.println("<head>");
out.println("<title>Life Cycle Servlet</title>");
out.println("</head><body>");
out.println("I have been accessed " + timesAccessed + " time[s]");
out.println("</body></html>");
}
public void destroy( ) {
// Write the Integer to a file
File r = new File("./data/counter.dat");
DataOutputStream dout = null;
try {
dout = new DataOutputStream(new FileOutputStream(r));
dout.writeInt(timesAccessed);
}
catch(IOException e) {
// This should be logged
}
finally {
try { dout.close( ); } catch (IOException ignored) {}
}
}
}
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