Servlets :: How To Create Deadlock Condition
Mar 2, 2014How can we create deadlock condition on our servlet? Does calling doGet() from doPost() and vice versa really cause a deadlock? Or, does it cause a StackOverflowException?
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How To Create A New Array For Each Numbers That Are Passing Through Condition
May 26, 2014how to translate it into Java language due to lack of experience (2 weeks). My solution I've formed in my head is: create a new array for the numbers that are in improvement and then declare a "max" variable. Check which array's length is higher and print that length. What I don't know to do is: I don't know how to create a new array for each numbers that are passing through the condition.
Note: I couldn't find anything on internet about my problem so that's why I'm here.
My code is this one:
class MyClass {
static int progresie=0;
public static void longest_improvement(Integer[] grades) {
for(int i=0;i<grades.length-1;i++){
if(grades[i]<=grades[i+1]){
progresie ++;
}
}
System.out.println(progresie);
}
}
How To Construct A Minimalistic Deadlock
Jan 7, 2015i'm trying to construct a deadlock deliberately by coding this scenario:
1) Thread A enters a synchronized method of object foo
2) Thread A goes to sleep (thus still holding the key of foo)
3) Thread B enters a synchronized method of object bar
4) Thread B tries to enter a synchronized method of foo (, but cant)
5) Thread A wakes up and tries to enter a synchronized method of bar => deadlock
I'm trying to keep the code really minimalistic, i.e. just 2 threads and 2 objects.
I also dont want to use this syntax:
synchronized(a){
...
}
but would like to achieve this just by calling synchronized methods of 2 different objects (as stated above).
Avoid Deadlock While Coding
Jul 25, 2014is it possible to avoid deadlock while coding..
View Replies View RelatedDeadlock In Java Multithreading
Aug 24, 2014This is my own coding for understanding deadlock in multithreading . But my doubt is whether this program mirrors the concept of deadlock perfectly or not. If not what should i do to make this code a perfect deadlock.
import java.io.*;
class A
{
B bc;
synchronized void funcA(B b)
{
bc=b;
System.out.println("INSIDE FIRST OBJECTS MONITOR");
[Code] ....
Deadlock Detected While Waiting For Resource
Jan 27, 2015In my project i am getting this error, i couldn't investigating this error :
..java.sql.SQLException: ORA-00060: deadlock detected while waiting for resource
Servlets :: How To Create A New Instance For Each New Request
Sep 26, 2014I want to create a new instance of a Java model class for each new request coming to a servlet.
How to do that without doing that in doGet() or doPost().
Servlets :: Create Corresponding Java Object?
Sep 18, 2014I get an json from http request. I want to create a corresponding Java object.
is there any automated mapping? Something called pojo or something else?
Servlets :: How To Create One Login And Have Other WARs Reference It
May 6, 2014I'm trying to design a website that will require users to register and login before they use it. In order to keep things separate, I was thinking it might be useful to create a single web archive that just handles the user signup and login. That way I could work on my other web archive apps independently and have them just check to see if the user has logged in and posted a token somewhere, and if not redirect to the login webpage.
View Replies View RelatedServlets :: How To Create Dynamic Table In View Page
Mar 28, 2014What i have done till now is i make a table in html explicitly (by assigning fixed rows and columns) . Now what i want is to show a table of whose number of rows and columns are generated dynamically according to the table in the database.
View Replies View RelatedServlets :: Disabling Cookies In Firefox Does Not Create Session
Mar 4, 2014I'm experimenting the basic concepts of Servlet technology with my below simple setup.
I have a welcome.jsp defined under webContent in eclipse and my welcome.jsp looks like
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1" [b]session="false"[/b]%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
[Code] ....
Now I have few questions based on the above setup
1) As you see session="false" in jsp, and when I used scriptlet like <%= request.getSession(false) %>, I see "null" being printed but if I use pageContext.request.session.id, the session is not null. How does session = "false" influences scriptlets and implicit objects and why the behavior is different
2) If session really exists, even when session=false is used, when I disabled cookies in FireFox browser and click on "click Me" hyperlink, the control goes to Controller, but in the servlet, I see 'No Session Created" being displayed. Which means session was not created and probably because I used false is getSession(false). But if I enable cookies, with the same setup, I get Session ID = << some value>> being printed and this is same as the session what printed through pageContext.request.session.id in the jsp.
So when cookies disabled, how can pageContext.request.session.id actually printed session id , but not in servlet and when cookies enabled, the same session id is displayed in both cases.
My question is why there is no impact in jsp, when cookies are disabled.
Servlets :: Create A Session After Login And Invalid It After Logout
Apr 1, 2014How can i create a session when i loged in and how can i invalid it when i logout?
View Replies View RelatedServlets :: Create A Service To Embed Widgets On Any Foreign Website
Jan 22, 2015Its required to create a service to embed widgets on any foreign website(server), using servlets where i'll pass encrypted widgetId and in turn i will get html for displaying it on screen. Also a refresh button with the embedded widget is to be provided so as to fetch updated computed data. The point is that user should copy some html/script code and place it on his website.
I am thinking of following approach.An empty span with id, followed by a js script to make ajax call to the server to get widget HTML.
Ending The Run After If A Condition Is Not Met?
May 24, 2014For an assignment
-I am too write a program that checks if 3 numbers (scannerinputted) are three sides of a triangle if not just ignore it.
-If they are the 3 sides to a triangle tell what kinda triangle it is Right/scalene/equilateral etc.
-ignore the 3 numbers if they are <=0
if(side1+side2>side3 && side1+side3>side2 && side2+side3>side1)
System.out.println("This is a Triangle.");
else
System.out.println("Not a Triangle.");
How can I make the program stop immediately if the else statement is checked. I have more "if statements afterward.
so it would say.
"This not a triangle"
"This is scalene or isosceles"
how can I get this output.
"This is not a triangle" and stop there.
Simplify If Condition
May 24, 2014I m trying to simplify an if condition as much as possible and i m curious if it can be made more short then i managed to .The problem is simple , a integer number with 3 digits is generated and the user is asked to input another 3 digits integer number ... One of the conditions that need to be verified is if all the digits in each number match but not exactly ( aka 123 and 132 ) .Using only an if statement to verify this what is the most short condition that can be checked to identify when the digits in a 3 digits number match the digits of another 3 digits integer number (not interested if they match exactly) .
The simplest condition i managed to find is :
else if (guessDigit1 + guessDigit2 + guessDigit3
== lotteryDigit1 + lotteryDigit2 + lotteryDigit3
&& (guessDigit1 == lotteryDigit1 || guessDigit1
== lotteryDigit2 || guessDigit1 == lotteryDigit3)
&& (guessDigit2 == lotteryDigit1 || guessDigit2
== lotteryDigit2 || guessDigit2 == lotteryDigit3)) {
System.out.println("Match all digits: you win $3,000");}
Is there a better(shorter ) condition that can be used ?
For Loop With Condition
May 11, 2014[public static void PrintNum () {
int i;
int j = 0;
for (i =100; j<5; i=i)j=100-(i-=1);
System.out.println(i);
} ]
I'm not following how it calculated to 95 since I'm confused with this
part i=i)j = 100-(i-=1);
JSF :: How To Check Condition In Xhtml
Mar 26, 2014I need to display button based on the condition in xhtml page.
using JSF2 & richface 4.0
<c:forEach items="#{empList}" var="emp">
How to check condition like empList.size > 0 in xhtml?
if list is having value, need to show buttons.
Coding Own Classes - If Condition?
Jun 9, 2014public int getIndexOfAMonster(String nameToGet){
int retValue = -1; //default is not found
for (int i = 0; i <= numberOfMonsters - 1; i++)
if (monsters[i].getName().equals(nameToGet))
retValue = i;
return retValue;
}
1.What does the if-condition do?If the name of a monster in the array is equal to the name stored in the variable, return the monster's assigned value.
2.What does the for loop do? The loop condition simply loops through the whole arraylists. (In other words, it simply checks each Monster contained in the lists).
3.Assuming that the driver code compiles, explain what it’s use is? If the name of the monster is the same as the variable passed unto this method, return the number assigned to that Monster.
If Condition Matches Multiple Times
Feb 16, 2015I'm working on a problem that requires me to generator all possible word combinations based on a 7-digit number as input. Many of the generated "words" will be nonsense, but some with be "NEWCARS", "TAKEOUT", etc... This problem mimics the phone number a company would use to support clients remember that number.
I completed the exercise, but I would like to explore more elegant solutions. Specifically, I've used an IF-THEN-ELSE condition inside of a FOR loop. Here is my working code:
package com.johnny_v.exercises.telephone;
public class WordGenerator {
public static void main(String[] args) {
int numOfTimes = 2187;
String two = "ABC";
String three = "DEF";
String four = "GHI";
[code].....
I receive StringIndexOutOfBoundsException exceptions. I it's because multiple conditions are matched. For example, the indexSix is reset to 0 when row is a multiple of 9. Because row is also a multiple of 3, this condition also executes and then increments "indexSix".
Why If Condition Not Working When Compare Two Strings
May 11, 2014Is there a different logic in Java for if statements when it comes to conditions? I mean my attempt to compare a String variable and a String attribute of a class that is on an array of objects was frustrated someway. It will not enter the if block. The two strings are equal. I displayed the values of each strings before the if evaluation and they are equal. The simbol I used was the ==, and I also tried the string.equals(string variable) as well as the compareTo() == 0 option but none of those worked. I wish I knew what it is the way to compare two strings.
View Replies View RelatedWhile Getting Input From User Check A Second Condition
Apr 22, 2015Is it possible to wait for an input for a user and check in the meantime if something else is true?
Now if the server in the meantime says: there is no input needed and tells it the client.
Could the client now somehow change from
input.readLine() to another Method say: quit() ?
I am stuck there because I know the server sends: quit to the client1 but the client2 cannot react because it still waits for an input for the user.
Maybe something with Thread.sleep ?
Search Algorithm Not Reaching End Condition
Apr 29, 2015I am using what is known as a Depth First Search to solve a maze using my own Stack created class for an assignment. The reason I believe I am getting this error is because my program is never meeting the `finishSpot` condition. I have used the debugger and it looks like it is infinitely stuck at the Point before the `finishSpot`. My logic seems to be mostly correct except until the point where my maze solver tries to finish the maze, so i just need meeting that last condition that is causing my program to crash.
This is a sample maze:
*****
*s* *
* * *
* f*
*****
Here is my Main which uses my created Stack class.
//Creates a Stack and determines the start and endpoints.
public static void solveDFS( char [][] maze ){
LinkedStack stack = new LinkedStack();
Point currentSpot = findPoint( maze,'s' );
Point finishSpot = findPoint( maze, 'f' );
findPath( maze,currentSpot, finishSpot,stack );
[Code] ....
I made a mistake it says my program is crashing which it is not, but simply not meeting the condition.
Validate Postal Code Based On Condition
Feb 18, 2014How can I validate the postal code based on this condition...
9999 may not be used for US province .
If the street province is Mexico or Argentina or Brazil the street postal code must be 9999 ....
Changing Background Image Of JPanel When Certain Condition Meets?
Apr 22, 2015In my program one of the panel has a background image and I need that background image to be updated/refresh or changed whenever the panel reaches certain number of clicks
here's the code
Constructor/gui
import java.awt.*;
import javax.swing.*;
import javax.swing.text.*;;
public class demo {
JFrame frame = new JFrame ("Idle Game Test!");
JPanel backGroundPanel = new JPanel ();
[code].....
also is there other way to access those static variables? the way i implemented them works but i do think there are other ways that are more suitable or better but i cant figure out.
Instance Of Operator - No Output Generated Since If Condition Fails
Feb 2, 2014As per my knowledge, the instance of operator compiles only if the reference type compared to class type are in the same inheritance tree. According to that, below code should not compile but it compiles FINE!!.
Output:No output generated since the if condition fails
public class InstanceOfTest implements Inter{
public static void main(String arg[]){
Inter iot = new InstanceOfTest();
if(iot instanceof Someone) //here Inter(interface) and Someone(class) are not in the same inheritance tree.
System.out.println("iot is a Someone");
}
}
interface Inter{}
class Someone{}
Running Java Application - Analyze Traffic Condition
Jun 18, 2014I have a java application which uses Google Maps to analyze the traffic condition. But sometimes it can be run and work properly, sometimes not. On some computers on which there is installed java, the program can be run, and on some, again with installed java (jre), exactly the same version, the program can not be run. For example the application first run well on my desktop computer, connected in a LAN, and then stopped working well when run. But when I use laptop which uses the WiFi and run the same computer using VMWare, if I connect to the desktop on which the program can not be run, on the laptop the same program can be run well, in the same room, but using the Wifi.
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