I have a constructor like as follows:
public Agent(){
this.name = "John";
this.id = 9;
this.setTopWorldAgent(this, "Top_World_Agent", true);
}
I'm getting a null pointer exception here in the method call. It appears to be ... |
In some of our projects, there's an class hierarchy that adds more parameters as it goes down the chain. At the bottom, some of the classes can have up to 30 ... |
In general, what is the maximum number of parameters a class constructor should accept? I'm developing a class that requires a lot of initialization data (currently 10 parameters). However, a constructor ... |
I have the following class in a common jar:
public class Common
{
public Common(List list)
{
...
}
}
I then change the ... |
normally I implement my Runnables as follows (directly implemented inner class):
Runnable updateRunnable = new Runnable() {
public void run() {
}
}
Is there any working ... |
What are the best practices if you have a class which accepts some parameters but none of them are allowed to be null?
The following is obvious but the exception is a ... |
Here is my object constructor
static class Edge {
int source; // source node
int destination; // destination node
int weight; // weight ...
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Possible Duplicate:
What's the best way to refactor a method that has too many (6+) parameters?
If a constructor has a long parameter list, should we ... |
I have a base class that have to be constructed with parameter. In child class I need to prepare this parameter before constructing base class but in Java super must be ... |
I've defined an object in Java - as far as the Java is concerned, they're the same thing, but as far as the data which populates them is concerned, they can ... |
Currently I have a class, TransactionData, which is just a little bit more than a POJO. I build the object from an HTTPServletRequest. What I do:
public class TransactionData
{
...
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New to Java...
I have a name class that has:
private String firstName;
private String middleInitial;
private String lastName;
as its instance variables.
If I had certain data that had only firstName and lastName, no middleInitial, how ... |
I'm trying to use ClassParser to get method parameter names, ClassParser constructor takes class name as parameter for example:
ClassParser parser = new ClassParser("Main.class");
I 'm trying to set the parameter to String ... |
I know that in PHP if you want to call a function with less parameters you declare the function like:
function foo(int param1, int param2 = "2");
and now I can call foo(2) ... |
If I have the following class:
public class ObjectDAOMongoDBImpl<T> extends GenericDAOMongoDBImpl<T, ObjectId> implements ObjectDAO<T> {
public ObjectDAOMongoDBImpl(Class<T> entityClass, Mongo mongo, Morphia morphia, String dbName) {
...
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I'm using Guice (v 3.0) and have a value that is being injected into a constructor. This value can be null, so I have annotated the parameter in the constructor with ... |
P: 6 eraserwars I really cannot find anything wrong with this, I have checked it at least 5 times, and there is nothing I see that can make the driver not ... |
Set them through setters. Generally, its a bad practice to have a method with more than 5 or 6 variables. Think of supportability. You write both version of the code and add a 16th variable. In the first technique where you set them via the constructor, you would add a 16th parameter to the constructor variable lists, whereas in the second ... |
I am seeking advice on what should happen if constructor passed invalid data and unable to create new object. Is this responsibility of object class or calling class to manage this? This best illustrated with simple example below. Say have simple class called DayOfWeek. It only has once instance variable that stores day of week as number (1=Sunday,..7=Saturday). It simply stores ... |
The soul is dyed the color of its thoughts. Think only on those things that are in line with your principles and can bear the light of day. The content of your character is your choice. Day by day, what you do is who you become. Your integrity is your destiny - it is the light that guides your way. - ... |
"h" is defined within the try block, inside the { } braces. It goes out of scope at the close brace, so the compiler can't "see" it any more. This is one bit of syntax that annoys me because it forces us to declare the variable before the try block, before we use it. This makes "h" visible to the try ... |
public DelaunayPoint (double... coords) { coordinates = new double[coords.length]; System.arraycopy(coords, 0, coordinates, 0, coords.length); } what is the meaning of this 3 dots ? This is a code which is related to my assignment .I'm trying to understand this ! Can we have this kind of parameters in the method also ? what i noticed here was when I can call ... |
In this ElementK training I'm doing on the section on constructors it enumerates the steps involved in constructing an object. The first step says "Bind Constructor Parameters". Not understanding what this means I googled it and found out that it is from the Sun (Now Oracle) tutorials. Still not clear what it means. Would appreciate any insight... |
Lalit Mehra wrote:for your question: Is it Possible ??? you should try and run it yourself secondly, an object of the same class as the reference can be used in many cases... most common one might be to initialize the new object with the same values as that of the passed one. Yes but lets imagine this to create an object ... |
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I am currently taking a class in Java. I have an assignment that requires me to create 4 employee types. I have an Employee superclass and four subclasses. First, I need to figure out the best way to pass parameters to the appropriate constructors using some sort of user input. I am planning on using the Scanner class to receive my ... |
Hi, I am a novice Java programmer using BlueJ. Below is a link to a screen dump which demonstrates the error I can't figure out (copy and paste into address bar). http://img.photobucket.com/albums/v462/theff7obsession/scrndump.png In the if statement highlighted in yellow (and others further down), I am asking the program to evaluate whether the variable screenCapacity is 0, but it says it doesn't ... |
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Another thing, there is a Point class in the Java API. Are you supposed to use this class or write your own. If you must write your own it would be a good idea to give it a different name to avoid confusion (unless it is a stoopid requirement by your teacher). |
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Now, the above doesn't print out "10". Why not? Because the value "0" was passed into the method giveMeTen, not the variable itself. Exactly the same is true of reference variables - the value of the reference is passed in, not the variable itself. It's the same kind of copying that happens on variable assignment. |
} How could I call/initialize the Sudoku constructor in the SudokuSolver class main method? If it was without parameters would be like above Sudoku Sudoku1 = new Sudoku();, but when I put the value like Sudoku Sudoku1 = new Sudoku( {{1,2}}); it does not work. I would be very happy if anyone could help me out with this noob question. 7runks.net ... |
Hello, As part of my research project I need to find the "constructor" of a given parameter object. For example: Suppose we have the following method - public void int pop(Stack st) { //some code... } I want to generate code that calls this method and its parameter with its constructor. Like - pop(new Stack(10)); As you can see I need ... |
Stefan, Sorry mate, I don't think the argument names are accessible via reflections... I guess the only way you'll get the names is by parsing the original source code... which might be doable in an open source product, but is definitely butt ugly. Why do you need the names anyway? why not just generate names like "int1" and "int2" ? Or ... |
I guess it depends on the Object, you must have some idea how many values should be available most/all of the time, and how many values will be initialized later on. Are some of the null values ever going to be used? if not then maybe your class should have a super type which is more basic, with less variables. You ... |