doubts in SingleThreadModel
naresh govindaswmay
Ranch Hand
Posts: 90
posted 9 years ago
hi,
Which statement is TRUE regarding the following code?
Please select one correct answer.
import javax.servlet.*;
import javax.servlet.http.*;
public class MyHttpServlet extends HttpServlet
implements SingleThreadModel {
StringBuffer bufferOne = new StringBuffer(); //1
static StringBuffer bufferTwo = new StringBuffer(); //2
protected void doGet(HttpServletRequest req, //3
HttpServletResponse res) throws java.io.IOException{
HttpSession session = req.getSession(); //4
res.setContentType("text/html");
java.io.PrintWriter out = res.getWriter();
out.println("<html>");
out.println("<head>");
out.println("<title>This is my servlet!</title>");
out.println("</head>");
out.println("<body>");
out.println("</body>");
out.println("</html>");
out.close();
}
A.Variable bufferOne at //1 is NOT thread-safe.
B.Variable bufferTwo at //2 is NOT thread-safe
C.Both A and B
D.Variable req at //3 is NOT thread-safe
E.Variable session at //4 is NOT thread-safe
F.Both D and E
I have selected c is the answer, because class variable are not thread safe.But they tole "B" is the rite answer. anybody please clear this doubt.
Which statement is TRUE regarding the following code?
Please select one correct answer.
import javax.servlet.*;
import javax.servlet.http.*;
public class MyHttpServlet extends HttpServlet
implements SingleThreadModel {
StringBuffer bufferOne = new StringBuffer(); //1
static StringBuffer bufferTwo = new StringBuffer(); //2
protected void doGet(HttpServletRequest req, //3
HttpServletResponse res) throws java.io.IOException{
HttpSession session = req.getSession(); //4
res.setContentType("text/html");
java.io.PrintWriter out = res.getWriter();
out.println("<html>");
out.println("<head>");
out.println("<title>This is my servlet!</title>");
out.println("</head>");
out.println("<body>");
out.println("</body>");
out.println("</html>");
out.close();
}
A.Variable bufferOne at //1 is NOT thread-safe.
B.Variable bufferTwo at //2 is NOT thread-safe
C.Both A and B
D.Variable req at //3 is NOT thread-safe
E.Variable session at //4 is NOT thread-safe
F.Both D and E
I have selected c is the answer, because class variable are not thread safe.But they tole "B" is the rite answer. anybody please clear this doubt.
Thanks and Regards<br />Naresh govindaswamy
Remko Strating
Ranch Hand
Posts: 893
posted 9 years ago
With the single thread model you know for sure that only one thread per instance of the servlet will run. This means that instance variables are thread safe.
You should not use the single thread model because it's depreciated and considered evil.
You should not use the single thread model because it's depreciated and considered evil.
Remko (My website)
SCJP 1.5, SCWCD 1.4, SCDJWS 1.4, SCBCD 1.5, ITIL(Manager), Prince2(Practitioner), Reading/ gaining experience for SCEA,
James Mark
Ranch Hand
Posts: 115
Rhett Wang
Greenhorn
Posts: 12
Ulf Dittmer
Rancher
Posts: 42970
73
raja ram
Ranch Hand
Posts: 169
posted 9 years ago
Hi,
as it is a single thread model all the variables are thread safe but even though HttpSession session = req.getSession(); session variable is also thread safe but the data with in the session scope are not since when some other thread executing code paralley it can get same session in that case it can still modify the values in session scope.
Thanks
as it is a single thread model all the variables are thread safe but even though HttpSession session = req.getSession(); session variable is also thread safe but the data with in the session scope are not since when some other thread executing code paralley it can get same session in that case it can still modify the values in session scope.
Thanks
