I'm training myself with the EJB 3 technology. I would like to create a stateless bean that instead of returning a String, it returns an object. I tried in the same way I did with the first exercise, but I'm getting several errors.
So I'm pretty sure this is correct, as it follows most examples I can find online, but I keep getting an error that my return variable cannot be resolved. The error is on the return conn; statement. It says conn cannot be resolved. If I place it above within the try block it allows it but then I receive an error saying the method getDBConnection must return type Connection.
I don't want to create this method. Basically I want to connect to the database in the main program, but I do want methods that can access the DB too. But however I place it, it doesn't let me touch any of the DB variables outside of the Try block.
So i have used the "remove()" method in conjunction with an iterator to remove an object from a HashSet in my program, and part of my exercise requires me to return said object. What I can do to return an object that has been removed using "remove()" method?
I've been assigned to create a Black Jack game with a gui. In this game I've created a seperate Player and Dealer class, and both initiated them, however when I try to call a Player object in a certain way I get a null pointer reference. (It should be noted that the Player object is an array)
public void runGame(){ while(running){ while(dealer.getPoints() <=19){ int count=0;
[Code] .....
And this is how I've initilized the Player class in the constructor
Player[] players = new Player[numberofplayers]; for(int i=0; i<numberofplayers; i++){ players[i] = new Player(i); players[i].setDeck(d1); gui.add(players[i].getPanel()); }
What I don't get is if I change players[i] to dealer, it works fine.
The question pretty much says it all, but I tasked myself with creating a program about lemurs. There are multiple class files in this program. In the below code snippet, I have my TreeLemur.class which extends to the Lemur.class which extends to the Mammal.class. However, when I create a Tree Lemur object in the main program, it is returning null consistently from certain methods. What am I doing wrong here?
TreeLemur.class :
public class TreeLemur extends Lemur { private String groupSize; private String diet; private String fur; public void setGroupSize() { groupSize = " Group Size: Large"; }
[Code]...
As of yet, I'm just trying to get Tree Lemur working properly to continue with creating the other if-branches within the main program.
I am writing a code where in the first method the question will ask whats your favorite website. for example www.javaprogrammingforums.com...when it outputs it will read just "javaprogrammingforums" without the www. and the .com.
Because the program will ask a series of questions in the main, I would like website question to be returned to the main. Here is my code, and what can I do?
import java.util.Scanner; public class chapter3 { public static String website(Scanner kb) { String website; System.out.println("What is your favorite website?"); website = kb.next();
public class Lab07 { public static void main (String[] args) { System.out.println(convertToInt("123")); } public static int convertToInt(String str) { int conversion = 0; int i;
[Code] ....
The only methods I am aloud to use is length and charAt, which I have done. I see why it is returning a 0 at the end of the value returned, its because I set my int conversion = 0. If I just declare it I get a compiler error that it must be initialized.
Task:The main method of the class Things below creates an object called printer deriving from the class PrintingClass and uses that object to print text. Your task is to write the PrintingClass class.
Program to complete: import java.util.Scanner; public class Things { public static void main(String args[]) { String characterString; Scanner reader = new Scanner(System.in); PrintingClass printer = new PrintingClass(); System.out.print("Type in the character string for printing: "); characterString = reader.nextLine(); printer.Print(characterString); } }
// Write the missing class here
Note: In this exercise the solution is part of a conversion unit where many classes have been declared. Because of this the classes are not declared as public using the public attribute.
Example output
Type in the character string for printing: John Doe
John Doe
My Class: class PrintingClass { public void print(){ System.out.println(characterString); } }
I have problem with writing objects to file. The thing i want to do is write object(Measur) and then read it from Notepad++. Not from program, but normally from computer. When i'm opening my file i see patterns(i dont how to call this). I think, that I need write it as a string in some way. There is my code:
I want to create a program where I need to create an object of list type such as text file will contain nos like 1,2,3,4,5 and write into text file and delete the in FIFO order i.e 1,2,3,4,5...how i can achieve to write a program? I tried bt everytime got concurrent modification exception or Array out of bound exception.
I am trying to get a price of a certain show in a theatre but the problem is that i don't know how to use the method's String parameter:
/** * Gives the price of the show with a given place in the room * * @param place the place in the room (VIP, average seating, in the back) * @return price */ public double getPlaceprice(String place) { if (place !=null) { double p = place.getPrice(); // price= Double.parseDouble("place.getPrice()"); return p;
} return 0; }
Now I have a class called Place which has an attribute double price and a getter for price
public double getPrice() { return price;
So I somehow have to alter the String parameter Place to the object(class) Place, on which i can call the method getPrice()
At least, that's what i think i have to do. Where i go wrong?
this is part of a larger project but i figure if i can figure out this first step i can work the rest. I need to get a title from the user add it to a object array (i think thats what it is) and then when i call listAllItems(), items[] should be copied into a string array called listAllItems, and then printed, but currently im jusst having trouble i think making it an object and then make it an item in the items[], if i run case 3 the list it says null...
public class MediaItem { String title; MediaItem(){ } MediaItem(String title){
I have the following method that I need to implement:
{ // YOUR CODE HERE File file = new File(filename); int counter = 0; String tempArtist, tempName; Album tempAlbum; Track tempTrack;
[code]....
Ok so I updated my code from the initial post since I made some progress on my own. I guess now I'm just stuck on how to scan in the file of strings and stock it into the type Track. (I've tried using both the initial linked list for this and a temporary variable with no luck).
I am converting String to date object while converting this i am getting Run time Exception. Here in this code i am using String tokennizer reading a data from a text file. Here is my code
public static void main(String[] args)throws Exception { FileReader fr = new FileReader("g:abc.txt"); BufferedReader br = new BufferedReader(fr); String line = br.readLine();
I am making a function to search through the whole inventory to see if any of the Lamborghini object has a certain model name such as aventador, diablo, etc....
This is what I have but I figured there's a big mistake when I make it true / false; it's making it going through the list and what's return is the last one instead of saying there's such match in the whole list or not.
public boolean hasCarModel(String modelName){ boolean exist = false; for (Lamborghini lambo : inventory){ String carModelName = lambo.getModelName(); if(carModelName.equalsIgnoreCase(modelName)){
[Code] ....
I figured if I add break; under exist = true; it'll work because as soon as it found one match then it'll turn to true and break out the loop but I don't think this is the best way to do it right?
why my sub class object just gives me a blank when it comes to the String. It works just fine for the super class but when I get to the sub class the program just gives me a blank. I won't let me input anything for the String. On line 24 of the client I attempt to input a new String but it doesn't ever let me enter one so then any call to getName is just a blank.
I have altered my super and sub class as well as the client to try to get it to work. I tried a local variable in the client, I tried using protected in the super class, I tried a handful of other things.
import java.util.*; public class TryingItOutClient { public static void main(String[] args) { Scanner input = new Scanner(System.in);
//Scanner Test String stream2 = "ab34ef 56"; // create a new scanner with the specified String Object Scanner scanner = new Scanner(stream1); // find a string "World"
[Code] ....
Matched expression found by findInLine: 34
ef56
is new line? right?
The java.util.Scanner.nextLine() method advances this scanner past the current line and returns the input that was skipped. This method returns the rest of the current line, excluding any line separator at the end.
then 56 is in new line and it must return ef.What is the problem?
Suppose that you have an ArrayList and that it contains String objects. Which declaration of the ArrayList requires that objects retrieved using the get method be cast to Strings before calling a String method?
I. ArrayList a = new ArrayList(); II. ArrayList<Object> a = new ArrayList<Object>; III. ArrayList<String> a = new ArrayList<String>;
A. I only B. II only C. III only D. I and II only E. I, II, and III
I know that all of these are ways to declare an Array List, but I am unfamiliar with the last two since I usually just declare my Array Lists with the first option.
I have a little a problem with String object in this class ....
public class Personne { private String nom; private String prenom; private int age; public Personne(){ this(null, null, 0);
[Code] ....
When i call the class personne with the Personne() i get these errors in compiling-time :
Exception in thread "main" java.lang.NullPointerException at java.lang.String.<init>(Unknown Source) at Personne.setNom(Personne.java:18) at Personne.<init>(Personne.java:12) at Personne.<init>(Personne.java:8) at Main.main(Main.java:4) // The line wich i inisialize my object in my main method.