I have application written in rest with Jersey-Jackson for JSON processing. All the resources produce and consume JSON. Now, the problem is, it is a server intensive application and large number of request will be hitting the server with large JSON request object. Now, because of this reason, when the JSON object gets converted in to Java object with String fields in it mapping to JSON request values large number of string objects are getting created which is resulting in frequent GC.
I'm having a hard time with this problem, this is what I have, but I can not use two integers, I have to use one integer and a string...
This is the question:
Write a method called printStrings that accepts a String and a number of repetitions as parameters and prints that String the given number of times. For example, the call:
printStrings("abc", 5);
will print the following output: abcabcabcabcabc
This is what I attempted:
public class printStringsproject { public static void printStrings(int abc, int number) { for (int i = 1; i <= number; i++) { System.out.print("abc"); } } public static void main(String[] args) { printStrings(1, 5); } }
We are doing a visualisation tool for point cloud research project. We use 3d sphere to represent each single point and when we have large number of points to display (~40,000), the rotation becomes very lagging.
What we have tried:
set JVM flag -Djavafx.animation.fullspeed=true, this worked a bit, but not significant.set JVM flag -Djavafx.autoproxy.disable=true, this did not work.
set Cache to true and CacheHint to Cache.SPEED, this did not make much difference.create another thread to do the rotation, and sync back after calculation, this did not work neither.
I am creating an apointment application. This programm will have the ability to book apointments for a number of different services, such as doctors, hairdressers, teachers etc for a number of cities.
These information will be placed on a combo box and ideally i would like to provide only the options available acording to the choices made so far.
So, for example we have A Pediatric in London A Vet in London A Sergeon in Berlin A Barber in Berlin A Heardresser in Rome A Programmer teacher in London An English teacher in Rome
My thinking is that the user choses the city, for example London, then there will be a type of service combo box. In this case (of London) it will hold Doctors and Teachers. If Doctors is chosen, the next field will hold the available Medical specialty, i.e. Pediatrics and Vets and according to that choice the apropriate doctor will pop up.
My problem is not how to programm that. i havent got there yet.
My problem is how to design it! I am thinking that each individual will be an object. each having the same fields, city, type of service etc. But in such a way i am not sure how i can manage to get all the appropriate information in order to poppulate the combo boxes.
I would have to search all the objects for each combo box? From a rough testing i did, i think i could easily get all the individuals that resign in London, but that would give me two records for the doctors(for example).
I have a Database with Data of people (name, adress, phone number).
If a user enters a phone number (CLIENT) -> the correct person with the name and adress should appear.
I build up the infrastructure and now I'm at the point that I have to create a Webmethod for it. I just worked on projects like addition of two integers, hello "name", ... I think this example now is harder, BUT i can learn a lot!
I have a large text file of 1 GB size. I need to print the line when a matching word is found in a particular line. Below is the code I am using. But if there are many lines that has the matching word, it's taking lot of time. Any solution to print the lines much faster.
Scanner scanner = new Scanner(file); while (scanner.hasNextLine()) { String line = scanner.nextLine(); if(line.contains("xyz")) { System.out.println(line); } }
how String objects are different from other objects
part 1:
// creating two objects Dog mydog1 = new Dog(); Dog mydog2 = new Dog(); // comparing the reference variables if( mydog1 == mydog2){ System.out.println(" The reference variables refer the same object "); } else { System.out.println(" They refer to different objects "); }
The above code works as I understand objects , it prints "They refer to different objects " to the screen.
Part - 2
// creating two objects ( I beleive, pls correct me if i am wrong ) String a = "haai"; String b = "haai";
if( a == b){ System.out.println(" Reference variables refer to same object");
When i run the above code it prints that a and b refer same object , I don't understand how they refer to same object when i didn't assign " String b = a; ". My question is did java just create one object and stored the same reference values to a and b .
//read the file //make the numbers 1 string line //count the number of repetitiveness in the string for the numbers //display four lowest ones
import java.io.*; import java.util.*; public class Lottery2
[Code] ....
when I run it the array gets sorted but how do i keep the data in other words
what it is supposed to do is grab numbers from a file, and give me the lowest 4 numbers back. I know the numbers using the array but how do i pull out the lowest 4 and keep the data true no matter what numbers or how many of them are in the file.
I am trying to find a concise way to write the sort methods for my class. I am supposed to make a program that can sort objects by a number of fields: year, rank, artist and title.
I used an idea from this thread : java - Sorting a collection of objects - Stack Overflow
And I am trying to use the custom comparator for my sort methods. However for some reason, the sortingBy variable fails to recognize any of the enum types.
Whenever I try to set the sortingBy variable equal to one of them, for example:
Java Code:
private Order sortingBy = Year; mh_sh_highlight_all('java');
I get a "Year cannot be resolved to a variable" error.
What I want to be able to do is make it so every time a specific method is called, say, for example sortTitle(), sortingBy will change to Title, then the SongComparator will sort using the case Title.
Is it possible to do this? I can't figure out how to modify SongComparator's object variables that way.
Java Code:
import java.util.Comparator; public class SongComparator implements Comparator<Song> { public enum Order {Year, Rank, Artist, Title} public Order sortingBy;
Which is the best way to keep track of the number of the objects I've created?Is is a good practice to have a static variable, which will be incremented everytime I call a contructor?
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];
Part of my program requires writing a function that determines the number of subsets of k items that can be chosen from a set of n distinct objects ("n choose k" or n!/((n-k)! n!)). The only errors I am getting are from the first line of the function:
// n choose k: distinct subsets of k items chosen from n items public static int choose (int n, int k) { if (k <= 0) return 1; else return choose(n--, k--) * (n/k); }
I am little confused about String creation in java.
Doubt 1: How String objects assigned to Pool area:
1. String s="in pool"; 2. String s1= new String("not in pool");
How many objects created in statement 1 and 2. According to recent discussion with my colleague, one object created in String pool in case 1. And in case 2, two objects are created, one as literal goes to String pool and other with new() opr goes to Heap.
If above is correct, Ain't we wasting double memory for same object ? Really need clear understanding on this
Doubt 2: How does intern() work: Please see if my below explanation is correct
1. If String literal is already present in String pool , and i create a same string with new operator, reference to object is changed to pool area.
2. If String object is created using new operator and intern is called on it. If same string object is not present in the String Pool, Its moved to String pool and reference to this in Pool is returned.
I want to clarify it whether this below code, when running this loop, will it create separate string objects as strings are immutable or else, will it keep the same reference(as each time inside loop, we use the same name 'rslt') and assign new string value for this?
I have a school assignment that involves me sorting an array of objects based on one of the class String variables. I am using as the title says a simple selection sort method. The problem I'm having is that when I run the program in debug mode, it never seems to enter the if statement in the inner loop. I would like to say I've tried a number of things to figure it out, but honestly I'm just stumped as to why it's not working.
Here is the code:
public static void sortTransactions(Transaction[] oTransaction){// This is the sorting method, obviously it's not done so it currently just prints to screen. System.out.println("Successful call to sortTransaction()"); String min = ""; int curInd = 0; Transaction[] temp = new Transaction[1];
[Code] ....
The output when I check to see if the array is sorted verifies that the array never does get sorted.
I'm trying to come up with a method that would validate each turn a player makes. For a turn to be valid, it has to only contain numbers from 0 to 3(inclusive) and at least one digit must not be 0. Here is what I`ve come up with so far. For example, with "303" as the number and "101" as the turn, the turn would be valid and my method should return true, but it does not.
public static boolean turnIsValid (String number, String turn ){ boolean rep=false; int pos1=0; char min='0'; char max='3'; while(number.length()==turn.length()&&pos1<turn.length()){
In the above example number 123456789012 is masked to 12XXXXXX01 but the number 55555 remains same as length of 55555 is 5 and we will only mask the number whose length is between 10 to 12 .
I've to return some value as a string and some as a int, how is this possible? Here's my code:
public class Card { public void start(){ String [] suit = {"Spade","Club","Diamond","Heart"}; int [] number = {1,2,3,4,5,6,7,8,9,10,11,12,13};} public String getColour(){ String [] suit = {"Spade","Club","Diamond","Heart"};
[Code] .....
So at the top, i've set it to return value as string because of the King Jack Queen and Ace, but i also have to return as numbers(int). And also i'm using a loop to read all the numbers, is there any other way?
I am trying to write a regular expression for a text which has both String and number... like abc1234, xyz987, gh1052 etc. And the string usually contains 2 or 3 characters.
What I need is two Strings one containing the text (abc, xyz, gh etc) and other containing number (1234, 987, 1052, etc.). Have written the code below. but doesn't seem to work.
Some of the numbers can be converted from int to string , other cant. My problem is in if (input.length() == 3) and if (input.length() == 4. Basically having problems printing the 3 digit and 4 digit
public static void main(String[] args) { System.out.print("Skriv: "); Scanner console = new Scanner(System.in); String input = console.nextLine(); int firstDigit = 0; int secondDigit = 0; int thirdDigit = 0; int lastDigit = 0;
the number of occurrences of a specified character in a string...i tried to do the program occurrences in a given string and i tried the code as below.
code:
import java.util.*; public class Occurrence { public static void main(String[] args) { Scanner input = new Scanner(System.in);
I'm trying to write a method that returns a number, given an uppercase letter as follows:
public static int getNumber(char uppercaseLetter)
The program is supposed to prompt the user to enter a phone number as a string. The input number may contain letters. The program translates a letter (upper- or lowercase) to a digit and leaves all other characters intact.
My code is below:
import java.util.*; public class PhoneKeypad { public static void main(String[] args){ System.out.print("Enter a string: "); Scanner input = new Scanner(System.in); String phNumber = input.next();
[Code] ....
I am getting these errors: java.lang.ClassFormatError: Duplicate field name&signature in class file Chapter9/PhoneKeypad at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:791) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
Working on my java skills. The is Delimiter function is suppose to return true if there is a delimiter in the string and false otherwise. The main is suppose to call this function and count the number of words in the string:
Here is what I came up with:
import java.util.*; public class NumberOfWordsInString { public static void main (String[] args){ Scanner in= new Scanner (System.in); String s;
[Code] ....
Somehow my method isn't being successfully called by my main and the following error msg was received:
Exception in thread "main" java.lang.Error: Unresolved compilation problems:
length cannot be resolved or is not a field
The method isDelimiter(char) in the type NumberOfWordsInString is not applicable for the arguments (char[])
at javaimprovements.NumberOfWordsInString.main(Number OfWordsInString.java:10)
line 10: char ch [] = new char [s.length];
and the main doesn't call the isDelimiter function
