Avoid Deadlock While Coding
Jul 25, 2014is it possible to avoid deadlock while coding..
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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).
Deadlock 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] ....
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?
View Replies View RelatedDeadlock 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
How To Avoid NullPointerException
May 3, 2014I have been playing around with my code, but how to avoid NullPointerexception.. So my program's point is simple, use Jsoup to scrape html of certain webpage, then i search the things i want and print them out. Problem is, when scraped html doesnt contain even 1 thing on my search list, i get NullPointerException... i understand why, Heres part of my code:
Java Code:
//Things i need to search from html
String[] MySearchArray = new String[]{"138","146","474"};
//Search things contained in MySearchArray and print them out
for (String Ml : MySearchArray) {
Element flights = doc.select(String.format("tr:contains(%s)", Ml)).first();
Elements flights2 = flights.select("td");
System.out.println(flights2.get(4).text() + " " + flights2.get(0).text()+ " " + flights2.get(3).text());
} mh_sh_highlight_all('java');
Coding A Coinage
Sep 26, 2014Listed below is the program I put together for class. I followed all of the instructions ....
import java.util.Scanner;
public class coinageJones{
int quarter = 0;
int dime = 0;
int nickel = 0;
int penny = 0;
int current = 0;
int original = 0;
int remainder1 = 0;
int remainder2 = 0;
int remainder3 = 0;
int remainder4 = 0;
[code]...
What Is The Coding For Udp Port Scanning
Feb 3, 2014what is the coding for udp port scanning?
View Replies View RelatedHow To Avoid Empty Map Value In A List
Apr 24, 2014I have a HashMap with multiple values at runtime. In that map one key has empty value , how to avoid this value to add in a list. some code sample is below:
public HashMap getLoop2Map(Map map, String xslFile , int sheetNo){
HashMap hashMap = new HashMap();
try{
ArrayList list = new ArrayList();
System.out.println("-------Map : " +map);
list.add(map.values());
//System.out.println("------- boolean : " +val);
System.out.println("------List : " +list);
}
I do not want to add the empty value in a list ...
result in map
-------Map : {Free Text Entry={},
Mouth / Throat={Free Text Entry={Free Text Entry=<FORMFILENAME>EditChartPhysicalExamText.form
</FORMFILENAME><TAG>"<MUSCULOSKELETAL.PE>"</TAG>},
Salivary Glands Condition={Salivary Glands Condition=MouthAttribute},
Examination Overview- Mouth / Throat={Examination Overview- Mouth / Throat=MouthAttribute},
Tonsils={Tonsils=MouthAttribute},
[Code] ....
Avoid Duplicates On ArrayList
Nov 5, 2014I'm struggling with that piece of code, my intention is to check for the object I want to add before adding it, so there won't be any duplicate on my list. I'm not sure how could I do that, since I'm working with objects.
Person is a class with few parameters such as id, name, and few others.
I guess I should search for a person with the same id, since that has be unique, but can't get it right.
private ArrayList<person> model= new ArrayList<>();
//...
if (model.contains(person))throw new IllegalArgumentException("duplicate");
else model.addElement(person);
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.
Coding AI Game Through Java
Apr 10, 2015The game has two players: x and o. The players take alternate turns, with player x moving first at the beginning of each game.
Player x starts at position (1,1) while o starts at (8,8).
Each turn, a player can move like a queen in chess (in any of the eight directions) as long as her path does not cross a square already filled in or occupied. After moving, the space vacated by the player is designated as filled and cannot be moved to again. Notice that only the space that was occupied is filled, not the entire path.
The game ends when one player can no longer move, leaving the other player as the winner.
The coordinate (1 1) indicates the top left hand side of the board.
The board is specified as a list of rows. Each row is a list of entries:
- is an empty square * is a filled in square x is the current position of the x player o is the current position of the o player
The board will always be 8 by 8.
Your player function should take in the parameters as described above and return a move as a list in the format (row column) within 1 minute. If you cannot move, return (nil nil). The Tournament Referees will check for this. If you return an illegal move, the other player (and the Tournament Referees) will detect it and you will lose.
Additionally if your time expires you will lose.
How To Avoid Hardcoded Href URL In JSP
Feb 12, 2014How to avoid hard coded href url .
For example a href="www.yahoo.com">
How To Avoid Keyboard Auto-repeat
Oct 8, 2014I wanted to make a small program to move a small rectangle by pressing the WASD keys. The program works, except that when I hold a key to move the rectangle, after a second, auto-repeat starts up, and the rectangle motion accelerates. I want to prevent automatic repeat to activate, so that the rectangle moves at a constant speed when I hold a key and stops when I released. Here is the ButtonMotion classe :
import java.awt.event.ActionEvent;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.JButton;
import javax.swing.KeyStroke;
[code]....
Java Coding For Block Division
Feb 7, 2014I'm doing project in area of "Cryptography and Network security". I'm having a file with binary Unicode (mean file contain Unicode value of corresponding data (text file)), want to divide that as blocks with the size of 144bits.
View Replies View RelatedHow To Avoid Getting Negative Numbers Of Coins
Oct 18, 2014how to avoid getting negative numbers of coins, use casting and mod to show how many quarters, dimes, nickels, and pennies there are?
import java.util.Scanner;
public class VM
{
public static void main(String[] args)
{
//money deposit
Scanner input = new Scanner(System.in);
[code]....
Eclipse - Coding Multiple If / Else Statements
Apr 22, 2015What I am attempting to program is a simple Boss battle. I would like the user to have 2 options (for now): Run, or Attack. I got the portion completed and working, but once I tried to implement the Run feature (the way that it's supposed to work is you can either attack OR run), both Attack and Run will happen. Also, for some reason, the running always fails (it will always return the else statement, then move onto the attack.) Here's my code:
import java.util.*;
public class AdvancedBossBattle {
public static void main (String[] args) {
Scanner scan = new Scanner (System.in);
Random gen = new Random();
int bosshp, bossdmg, playerhp, playerdmg, runChance;
String answer;
bosshp = 100;
[Code] ....
How To Avoid Hard Coded Values
Jun 17, 2014I have code which query value from database,the use case is the user can enter value as 1,01,11 in database but when the user enter value in xml file he can only enter 11,01,12 in database there is two columns lets say column test1=1 and test2=2 combination of this is 12,which is the value the use will enter in xml, but sometime the use can enter test1=04 than column test2=00 ....
View Replies View RelatedElectric Bandit Machine Coding
Jan 8, 2015I am required to create an electronic bandit machine that can display all images and buttons, user can input money, random display of images, machine stop when money runs out, user can put money in and start again and also a display of winnings. So far The user can input money and this is added to their bank however when the spin button is clicked no shapes appear despite their being a selection of images. My code is below.
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
import java.util.*;
import javax.swing.Timer;
[code]....
Make A Circle With Java Coding
Aug 12, 2014i want to make a circle with java coding.... i tried but i am grtting some error...
View Replies View RelatedJava Coding For Constructors And Input
Oct 25, 2014I was required to make a program that contains 3 data fields, 2 constructors, and 4 methods. I'm having a hell of a time trying to put some input into this, where the user would choose from 1 of the 3 data fields I made up for car prices and choose their vehicle. As far as the constructors go, I made a default one but I'm not sure on how to A) implement another constructor and how do I involve the input into this and C) where the methods go in that.
I'm thinking of putting the input first but that ruins my constructors? I realize I asked a lot, but this is an online class without a text, and I'm basically starving for knowledge. [code]
public class Vehicle{
int truck;
int car;
int van;
[code]....
EJB / EE :: Avoid Persist Entity On Set Methods
Dec 9, 2014I'm using EclipseLink, WildFly, EJB, postgresSQL and JSF.I'm trying to persist some countries and their localities.So I've:
- Two entities Countries and Localities in which I specify respective columns and relations.
- Abstract Session beans for entity classes: AbstractFacade providing basic crud methods and entity manager.
- Two concrete session bean for entity classes: CountriesFacade and LocalitiesFacade.
- A JSF managed bean named geoJSF.
- A JSF page with a form allowing to insert new country and localities.
In geoJSF I'm injecting via EJB CountriesFacade as property named cf and LocalitiesFacade as property named lf.For the actual inserting country and locality I'm using geoJSF.country and geoJSF.locality. When the form is submitted I'm simply doing:
this.cf.create(this.country);
this.locality.setCountry(this.country); //<- this throw an exception (unique constraint violation) due to the attempt to reinsert this.country
this.lf.create(this.locality);
I disabled all cascade among relations definitions.Based on what I know this.country should appear detached to entity manager so, setting relation the entity manager try to re-persist it.
Sieve Coding Not Pairing In Output
Apr 1, 2015When I compile the code, it goes through fine in the compiler. However after entering the boundaries for the lower an upper it doesn't produce the prime pairs between the two boundaries that the user sets. I have tried changing some of my integers that i initialized no luck. I looked at the last section of public void showPrimes() . However I can't seem to see where it has gone wrong there. I have included the entire code, plus the section again that I think is wrong. I have also posted the final output of what it looks like and what else should be included to make it easier to see what I am missing. Basically it keeps giving me zero primes even when the boundary is 100 and 200, or so and so forth.
import java.util.Scanner;
public class kbeaudry_xSieve
{
public static void main (String args[]){
kbeaudry_xSieve i = new kbeaudry_xSieve();
}
boolean primes[] = new boolean [50001];
int upper;
int lower;
[code]....
This is what i get when I actually run the program. However in the section where I have added *****, this is where it should put the prime pairs in.
Please enter a lower boundary and an upper boundary and I will print all of the sexy prime pairs between those boundaries.
Please enter the lower boundary (between 1 and 50000): 200
Please enter the upper boundary (between 1 and 50000): 600
There were 0 sexy pairs displayed between 200 and 600.. I am still working on another code for my that I had issues with, however I had to go out of the country for a few days to take care of some work.
Copy File From C To Another Drive And Avoid Duplication?
Jan 12, 2014Write a program to copy file from c: drive to another drive and avoid duplication??????????
View Replies View RelatedHow To Avoid Flickering When Calling Another Swing Frame
Jul 28, 2014I am trying to call another swing frame from my current frame. And after calling second frame i dispose the current frame.
But while second frame coming on the screen, current frame gets dispose and second frame takes some seconds to appear on screen.
So its creating a bad flickering effect on screen and its not suitable for my application.
I want that first frame will call sencond frame and it will not look like second frame is called. I just want to cancel flickering effect.
Here is my source code.
1st Frame:
public class Welcome extends JFrame {
JFrame f;
JTextArea nameField,nameField1;
JLabel lable;
[Code] .....
How To Avoid String Index OutOfBounds Exception
Feb 16, 2015The method I am trying to successfully write is startsWith(String s1, String s2)
The intention of the code is to return true if s2 starts with the string s1, and false otherwise. For example,
x.startsWith("Maplestory","Maple"); Should return true.
This code partially works, depending on the values entered into it. When it is supposed to return true, it does do this. When it is meant to return false, I get a StringIndex OutOfBounds Exception.
public class CC02{
String remove1(char c, String s){
String to_return="";
while(true){
if(s.equals(""))
return to_return;
[Code] ....
The method I have written uses one other method from my code, which is "reverse". Any way to return false without getting this error.