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about servlet variable  RSS feed

 
haoxiang guo
Greenhorn
Posts: 3
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import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class HolisticCounter extends HttpServlet {

static int classCount = 0; // shared by all instances
int count = 0; // separate for each servlet
static Hashtable instances = new Hashtable(); // also shared

public void doGet(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
res.setContentType("text/plain");
PrintWriter out = res.getWriter();

count++;
out.println("Since loading, this servlet instance has been accessed " +
count + " times.");

// Keep track of the instance count by putting a reference to this
// instance in a hashtable. Duplicate entries are ignored.
// The size() method returns the number of unique instances stored.
instances.put(this, this);
out.println("There are currently " +
instances.size() + " instances.");

classCount++;
out.println("Across all instances, this servlet class has been " +
"accessed " + classCount + " times.");
}
}

can anyonn expalin the result
 
Bear Bibeault
Author and ninkuma
Marshal
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Please read this.
 
William Brogden
Author and all-around good cowpoke
Rancher
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At first glance I would say you got bit by one of the invoker servlet traps. Read the Invoker servlet FAQ here at the ranch
Bill
 
It is sorta covered in the JavaRanch Style Guide.
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