36,051 Topics
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| | Hi, I have a problem that is shortest path problem. I use dijkstra algorithm but query has a time that is an hour on 280.000 node-graph. I have to reduce query time to 1 second. I try to find these way but I can not found any implementation of these … |
| | hey guys , i'am just new to java EE , well i am pretty good at java SE , so please i want to know where i can start learning jsp and servlets and if there were books that is pretty simple to understand as i mentioned that i am … |
| | Can someone work with me on this program. I will put the instructions first, then my code, then the errors [B]INSTRUCTIONS: [/B] Create a program to enter grades and calculate averages and letter grades. 1. Need a class which will contain: a. Student Name b. Student Grades (an array of … |
| | I have been working with my final project for about 3 weeks now and its due by 10am tuesday. Currently I am receiveing cannot find symbol errors. I know this is something simple. Please help. [B]INSTRUCTIONS[/B] Create a program to enter grades and calculate averages and letter grades. 1. Need … |
| | Once again, I found some code that seems to be doing something that I would like to try, but I get a Static Error when I try to run the code (apparently, I may be the only one). By the way, the code comes from the book, "Swing Hacks" By … |
| | I am using eXist-db for storing xml documents for my website, build on JSP. I have to provide a upload box, in my website, so that any outsider can upload the xml document and that will get stored in the eXist db. I know how to register eXist db inside … |
| | Hello, I'm a bit new here, and also quite new to java. I'm wondering how I would insert a print statement into the do while loop, if the while is false. [CODE] do { System.out.println("Enter number of years for the loan an in integer: "); numberOfYears = input.nextDouble(); System.out.println("Enter the …  |
| | Hello to all, I did not know how to entitle this post,since it is more of a logical problem,but it's connected to the writing of my objects to a file. So, my server expects connections from multiple clients. The clients vote for the candidates offered to them by a menu, … |
 | I am trying to build a very quick invoice type program, and I can't seem to get the final total to print. I am calling the function for it, but it's not printing anything to the screen...any suggestions? [code] public class Invoice { private double Total; //Constructor public Invoice( double … |
| | Hi people, i was wondering If you could help me. I have a personal project as a java program, and I wish to develop my own Look and Feel. It will be rather simplistic (like a metro ui). Is a Look and Feel the right way to be going about … |
| | Please help with this problem... I'm still learning java and i got stuck with a problem posted through our school campus... this is the one....and it's supposed to be the sequential structure.. Write a program that classifies a given amount of money in dollars. The program outputs a report listing … |
| | [CODE] import java.util.*; public class Employee{ private String emplo []; private int count; private int size=10; private String emp; public Employee(int size){ String [] emplo=new String [10]; count=0; } public Employee(){ this(10); } public boolean isFull(){ return count== emplo.length; } public boolean isEmpty(){ return count==0; } public void add(int x){ …  |
| | i read this on the net. and i cant understand why i have this mistake? [QUOTE]Thrown when an application attempts to use null in a case where an object is required. These include: * Calling the instance method of a null object. * Accessing or modifying the field of a … |
| | Hi! I've spent 4 hours trying to read the data from file to ArrayList and then to JTable, but still cannot solve one problem. I have the following class UserDataRow, where the data about a user is described. [CODE] public class UserDataRow { public String regnumber; public String firstname; public … |
| | Hi Everyone! I have a problem with reading data from the txt file into the 2d array. In general, the above code is workable. The only thing that doesn't work is: userdata[row][j] = tokens[j]; The problem is that my array "userdata" gets values "null". However, if I replace this code … |
| | [CODE] import java.util.*; public class sSone { public static void main ( String[] args ) { Scanner scan = new Scanner ( System.in ); System.out.print ( "Enter an integer number from 0-128" ); int inInt = scan.nextInt [/CODE] PURPOSE: program that receives an integer number from 0-128 and displays the … |
| | I need to create a list which contains objects of a particular class. I am having problem in retrieving the objects back from the list. Here is my code for insertion into list- import java.util.LinkedList; import java.util.ListIterator; public class listchek { int i; String name; public listchek(int k, String n) … |
| | Hi! I have a code that generates the table with 6 columns, and 6 textfields. Textfields are used to filter the table, and they are assigned to columns. Everything works normally, but looks badly. Attached you will find a picture to see what I mean. I don't like that textfields … |
| | (BEGINNER) problem: i need a program that reads a 4 digit integer and adds all the digits in the integer. example: input=1234, output==10 |
| | hey am creating a quiz(examination) which randomly selects questions from a database,and each question has 4 options,out of which 1 is correct.....also i need to show the final result of the number of ques correctly answered,wrong and those not attempted.... im at loss at MySql...don't know how the design of … |
| | I have completed a program and it compiles fine. When I run it, it seems to run fine. The only thing is that I am missing element data for two of the objects I am printing out in the text area of this JFrame. I an array called printerProduct[5], that … |
| | Hello Im going to make a program that is much like a calender. I havent started coding anything yet because I would like some advice on how to make the program "alive". - I wont it to be able to start up automatically when windows starts. - Run in the … |
| | I know how to write messages and save it as a .txt file (using Input/Output streams). What I want to do now is to be able to click a button and have notepad open the .txt file. How can I do this? |
| | I have written some code that compares two "BufferedImage" rectangles by doing a pixel by pixel comparison. These BufferedImages are of "playing cards" with rounded corners so I would like to exclude those corner areas during the image comparison process since the varied background could cause the comparison to be … |
| | I am writing a Java application that "passively" interacts with a Windows Desktop Application. What I mean when I say that it interacts "passively" is that I perform screen captures to determine the location of "buttons" displayed by this Desktop Application and I use "absolute" x and y coordinates to … |
| | hi every1 i m able to print the first record of the database on the page. but i m not able to go to next record which i want to show on click of a button. i dont want to use while(rs.next) as i dont want to show all the … |
| | I am given dates in string format- Eg. 11/09/2010. (11-09-2010 not allowed) How can I convert it into integer dates? I am given two such dates in string format only and I want to find the no of days between them. |
| | class Stars { public static void main(String args[]) { int c=1; for(int i=1;i<=10;i++) { for(int k=1;k<=c;k++) { if(k%2==0) System.out.print("*"); // else // System.out.print("*"); } System.out.println(); c+=2; } output: * ** *** **** ***** ****** ******* ******** ********* i cannot understand that what the function of variable "c" and how it … |
| | Hi all, I saved my connector/j jar file into this location C:\ ... \Java\jre6\lib\ext as well as in $CATALINA_HOME/common/lib and i am using this code in the JSP : Class.forName("com.mysql.jdbc.Driver").newInstance(); I am getting below driver error message. Somebody please help me out. javax.servlet.ServletException: java.lang.ClassNotFoundException: com.mysql.jdbc.Driver My jar file name is …  |
| | HI ,how can i get the size of a JBUtton JLabel . I always get 0 when i use the getHeight or getWidth method .  |
| | public class DebugFour3 // This class uses a FixDebugBox class to instantiate two Box objects { public static void main(String[] args) { int width = 12; int length = 10; int height = 8; FixDebugBox box1 = new FixDebugBox FixDebugBox box2 = new FixDebugBox(width, length, height); System.out.println("The dimensions of the … |
| | Okay, so i need help getting a value from a variable in one class's method. I want to use that data in another Class's method. Heres what i mean... [code=java] public class RoomType{ public String N(String[] args){ Scanner scan = new Scanner(System.in); String opt = ""; int x=1; do{ opt … |
| | Hello. Anyone familiar with the Halstead product metrics? we are going to implement it. and again i need some help. here is our algorithm: 1. The user runs the program. 2. The program will ask the user to browse the file he/she wants to be evaluated using the programer's own … |
| | so, lets say I have a thread that looks like this: [CODE=java] public run() { boolean active = true; while (active) { //do some action that takes a really long time } } [/CODE] Is there any way I can directly stop and destroy this thread in the middle of …  |
| | The question is: Write a code that will take and inches input and convert it to mm. Then display the same result using m, cm, and mm. Example would be: Input: 53 inches Output: 1346 mm OR 1 m 34 cm and 6 mm Something is happening with the remainder … |
| | I found some code that does something that interests me, but I don't fully understand the implementation. The part I am struggling with is where the author "overrides" an "actionPerformed" method. I have a vague idea of why someone would want to override a method that is inherited from the … |
| | Just because security holes and vulnerabilities get reported to software vendors doesn't mean they are actually patched. A new report from IBM's X-Force security team found that of all the software holes reported in the first half of this year, more than half are still unpatched. IBM's X-Force report is … |
| | here is the java script where i used window.close() function but it's not working. <script language="javascript"> var answer = confirm("Session expired! Want to go to the home page?") if (answer){ window.location = "index.jsp" } else{ window.close(); }  |
| | Goodeve guys... please help me on how to start a java game.. we have a proposed game and mine is a song lyrics game.. this is our project for the finals and honestly, i'm not that good in java.. :C what should be the first step? what is the best … |
| | Hi all, I saved my connector/j rar file into this location C:\ ... \Java\jre6\lib\ext and i am using this code in the JSP : Class.forName("com.mysql.jdbc.Driver").newInstance(); I am getting below driver error message. Somebody please help me out. javax.servlet.ServletException: java.lang.ClassNotFoundException: com.mysql.jdbc.Driver |
| | I tried a lot to open a JAR file but it is not opening.I typed in command prompt javaw -jar MyJar.jar but it is not open. It makes some error sound bt not open. Please help me regard this  |
| | this error was displayed after i package and deployed my jsp file. i dont know any help? [CODE] HTTP Status 500 - -------------------------------------------------------------------------------- type Exception report message description The server encountered an internal error () that prevented it from fulfilling this request. exception org.apache.jasper.JasperException: Unable to compile class for JSP … |
| | Hey guys, I'm a newbie programmer and I'm trying to create a program which calculates BMI. Weight is in lbs and height is in inches. I've compiled this and its got quite a bit of errors, so I could really use some help. The final result that I'm trying to … |
| | the class is the same. but there are two methods: first method: if simply returns a string. [CODE]public String FindPiece(String chessPiece) { return name; } [/CODE] name. is a constructor variable. it is a name of the chess piece [CODE]public Pawn(String name){ this.name=name; }[/CODE] second method public boolean isMoveValid(ChessPiece[][] pieces, … |
| | Hello All, I am student just starting Java. I do need help with swing - GUI. I am creating 4 textfield that accepts input from 3 user and will display as a 2D Array in the text area. As well as calculate the average of one column from the input. … |
| | im tyinh to writ a program to calculate nd display the volum ,area as well as the area of 6 sides of the rectangular prism but im stuck lol im a beginners import java.util.Scanner; public class RectangularPrism { public static void main(String[] args) { int length; int width; int height; … |
| | OK, so I want to thank all of you that helped me with my little problems within the past few days,I have almost come to the end of this project thanks to your suggestions. Now the thing is, I used ObjectInputStream & ObjectOutputStream to write down whole objects to a … |
 | private static void randomNumber() { int rand; int min = -10; int max = 10; System.out.println(" "); for (int i = 0; i < 10; i++) { rand = (int) (Math.random() * (max - min + 1) ) + min; System.out.print(" " + rand); } System.out.println("\n"); } can anyone explain … |
| | Hi guys, I have this assignment to do: Synchronize access to the instance variable, accBalance. Because accBalance is a double and not an object, it cannot be used as the monitor. Use synchronized methods or synchronized blocks of code, as appropriate. Simultaniously test two threads. Because the threads can complete … |
| | I have a problem outputting the contents of a text file. Whenever I try to display the contents of a file a "null" word is printed at the end of the output. Any help would be deeply appreciated. [code] import java.io.*; import java.lang.*; public class prog1 { public static void … |
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