I have to use a long primitive type for the input of a credit card number and ID the credit card by using the first number of the input; however, the only way I know for that is to use charAt, which is used for a String. Is there a way to convert long to String, or am I missing a better solution? (There's no code because I'm still doing the pseudocode).
I have a java string 0001 and I want to convert this to a Long object , I use Long.parseLong("0001") , the value returned is 1 ( stripping off the 0's ), how do I convert String "0001" to Long 0001 in java?
I am looking for a program to generate a unique alphanumerical identifier that is not too long; for example would start out with 6 digits like a licence plate or a postal code ex: AAA001 and use up all the possible combinations until 999ZZZ (just an example) and then when the possibilities are exhausted a 7th digit is added and so on. It matters not if they are sequential, the identifier just needs to be unique and not be too hard to remember (also i don't want to use ip adress or any personal identification). How I can accomplish this using java.
I have about 100,000 (N) random long variables in an array. I'd like to find if any two longs are equal; they're not expected to be. At this size, should I use the Hashtable or brute force it at a cost of N^2/2?
Taking two input strings that are integers such as "1234" and "567" then multiplying as you would do by hand. Trying to get them saved in the n3 new string but something is going wrong. You also need to account for the zeroes that have to be added just like on paper.
String mulN(String n1, String n2) { int p = 0, tmp = 0; int zeros = 0; String n3= ""; String r = ""; for(int i = n2.length()-1; i >= 0; i--) {
import java.io.File; import java.io.FileNotFoundException; import java.util.Scanner; public class PrintALongFile{ public static void main(String[] args) throws FileNotFoundException{ File inFile = new File("C:VeryLongFile.txt");
[Code] .....
When I try to read from a file that's 4,075,904 lines long and 41,646KB in size, it wont go past line 1,266,471. The above code is simplified from my actual program, which actually prints out the results to another file. However, the console (Eclipse IDE) and the output file, both show that it's stopping at the same line.
I want to develop a Java EE application for the following scenario.
Webapp takes a file from a user and analyze the file. This analysis could take hours. User should be able to check if the analysis is finished via AJAX. When the analysis is finished user should be able to view the analysis report that has been generated by the analyzer.
I checked what are the possibles ways I could achieve this but couldn't get a clear idea. I heard about JMS, Work Manager API and servlet asynchronous processing. But still not sure what to use and how to use.I'm not very much familiar with EJB.
I have a problem with my application. It supposed to store 4 different Room objects but when I entered one only it stores tat object variables into all my Array elements. I just need it to store any number of objects as long as it is less than 4.
Java Code:
import java.util.Arrays; import java.util.Scanner; import javax.swing.JOptionPane; class TestRoom { public static void main(String [] args) { String[] roomsInHouse = new String[4];
I've built up an unreasonably large and unreasonably complicated JPanel. Unfortunately, when I use setViewportView to add it to a JScrollPane, a get an extended UI freeze—that operation takes several seconds. I'm trying to figure out what's taking so long. I've tried some fairly extreme things, like overriding the paintComponent, PaintComponents, paintChildren, paint, repaint, validate, revalidate, and validateTree methods in the panel with no-ops to try to figure out what's taking so long, but to no avail. I've tried validating the JPanel before adding it, but that has no effect. If I override the addImpl method of the scroll pane, that makes things quick, but it doesn't really narrow things down much.
I'm trying to output a ten digit phone number as a string on one file, and write another program to write it as a long because I don't know what value I need to use in order to get the code to run properly on either one.
I have in my application a button that when it is pressed, runs a long running task (usually takes a couple of seconds....).
My problem is that while the task runs, I want to stop the button from receiving clicks. Unfortunately this is something I have not achieved.
I have tried creating a new thread and calling the long running method, and using the Display.geCurrent().asyncExec...
Examples of what I have tried so far:
myButton.addSelectionListener(new SelectionAdapter() { @Override public void widgetSelected(SelectionEvent e) { if (myList.size() > 0) { myButton.setEnabled(false); myButton.setGrayed(true);
[Code] .....
In both cases, while the button is disabled and the cursor busy, if the user clicks the button, the long running method is ran several times - and this is what I want to avoid.
I have created an application using hibernate and struts.In which a form is created where the user will enter all its personal details(for e.g name ,phone no. and address).
Here for address I have used textarea and whenever user enters the address, sometimes it can be a long string also.
So the problem is if a long string is entered then while displaying that ,address comes on single line and the page is stretched.
how to break this single string into mutiple lines in java class?
I have a primefaces datatable with about 52000 records to be fetched.Since it is a large dataset,i tried using live scrolling feature of primefaces with scroll rows equal to 20.THe number of columns is 53.The table also has filtering and sorting feature on its each column.Still i am not satisfied with the performance of the table.It takes about 15 secs for the page to load,worst thing is that it takes about 65 secs for the next set of 20 records to be loaded on reaching the end of scrolling.
Just for testing i reduced the total number of records to 25000 and the preformance improves with scroll time of 29 secs.I am really not able to understand why it is taking this much time when i am displaying only 20 records at a time.The total number of records should not have affected the performance.
Currently, my program converts Long values to String. And when I test it out, it do print out the correct output. However, when the converted String value is passed over to be written in a text file, it seems that BufferedWriter isn't printing out the outcome that it's supposed to be.
saltVs = Long.toString(saltV); System.out.print(saltVs); //will print out 79723172
Now the problem is here...It only prints out the last digit of the String value (instead of 79723172).
Here is my FileWriter/BufferedWriter part.
Why is that when I run my program using command prompt, it prints out the output that I wanted, but however when it comes to writing to the file, it doesn't come out right.
Can we cance/stop a long running database query execution instantly so that we can do any another task.
As i know swing uses a single thread i,e Event Dispatch Thread (EDT), But at the same time we can use Swingworker class for better use of UI. When we use Swingworker class the process goes to a different thread and our basic UI is not Frozen. Infact we can do another task. But what I want is I want to stop of cancel the execution of swingworker thread ( Because I that thread takes long time to execute). How can I do that??
I used ProgressMonitor and in the cancel option i canceled the task ( worker.cancel(true) also i closed the connection and statement for executing the database query using stmt.close() and conn.close() methods.
But it does not work. How to cancel a long running database background process in a Java Swing Program.
I tried to create file and write the output of my program in it in java when i use WriteLong then the file does not contain long value, how I create this file my program is to print prime numbers between 500000 to 10000000
public class primenumber { public static void main(String[] args) { long start = 5000000; long end = 10000000; System.out.println("List of prime numbers between " + start + " and " + end); for (long i = start; i <= end; i++) { if (isPrime(i)) { System.out.println(i);
If you have final int i = 1; short s = 1; switch(s) { case i: System.out.println(i); }
it runs fine. Note that the switch expression is of type short (2 bytes) and the case constant is of type int (4 bytes).My question is: Is the type irrelevant as long as the value is within the boundaries of the type of the switch expression?I have the feeling that this is true since:
byte b = 127; final int i = 127; switch(b) { case i: System.out.println(i); }
This runs fine again, but if I change the literal assigned to i to 128, which is out of range for type byte, then the compiler complains.Is it true that in the first example the short variable and in the second example the byte variable (the switch expressions) are first implicitly converted to an int and then compared with the case constants?
I can understand result 3 is because of an upcast from short to int, since FunWithOverloading will not have a overloaded method with short now. However, what is happening with result 4? Shouldn't it call methodA of the subclass with the argument type short? If its because I have declared the reference variable, derived, of the type FunWithOverloading, then how come the first result correctly picks the overloaded method of the sub class?
class FunWithOverloading{ void methodA(int x){System.out.println("Integer method " + x);} void methodA(short x){System.out.println("Short method " + x);} //line 3 } class OverloadedSubClass extends FunWithOverloading{ void methodA(short x){System.out.println("Sub class short method " + x);}
I have having some trouble on counting the primitive operations on the pseudocode given below:
Algorithm 4. MaximumArray(Arr) Input: A 1-D numerical array Arr of size n 1) Let CurrentMax = a0 2) For i = 1 to n-1 3)If ai > CurrentMax Then CurrentMax = ai 4) End For Output: CurrentMax, the largest value in Arr
As of now, I know that for Line 1 there are 2 operations (one set and one read). I don't know how to figure out the for loop and If statement (line 2 and line 3 too).
public class AutoBoxingExample { public void add(Integer intVal){ System.out.println("Wrapper"); } public void add(int value){ System.out.println("Primitive"); } public static void main(String[] args) { AutoBoxingExample auto = new AutoBoxingExample(); auto.add(12); } }
The output is "Wrapper". What would be the reason behind it?
