[{"sl":239,"sc":-1,"el":239,"ec":-1,"m":"Dead store to e in Boolean.getBoolean(String)","p":5,"t":"DLS_DEAD_LOCAL_STORE","a":"DLS","c":"STYLE"}]
I am learning GoF Java Design Patterns and I want to see some real life examples of them. Can you guys point to some good usage of these Design Patterns.(preferably in Java's core libraries).
Thank you
I was recently trying to convert a string literal into a boolean, when the method boolean Boolean.getBoolean(String name) popped out of the auto-complete window. There was also another method (boolean Boolean.parseBoolean(String s)) appearing right after, which led me to search to find out what were the differences between these two, as they both seemed to do the same.
It turns out that what B...
I have a class with a private static final field, that unfortunately i need to change at run time.
using reflection i get this error: java.lang.IllegalAccessException: Can not set static final boolean field
is there any possibility to change it anyway?
Field hack = WarpTransform2D.class.getDeclaredField("USE_HACK");
hack.setAccessible(true);
hack.set(null, true);
I have a quick and straighforward question:
I have this simple class:
public class A
{
public void m(Object o)
{
System.out.println("m with Object called");
}
public void m(Number n)
{
System.out.println("m with Number called");
}
public static void main(String[] args)
{
A a = new A();
// why will m(Number) be called?
a.m(null...
the following code throws NPE for me:
int num = Integer.getInteger("123");
is my compiler invoking getInteger on null since it's static? that doesn't make any sense!
can someone explain what's happening?
thanks.
While I know that by definition a boolean consists of only two states, true or false. I was wondering what value does a boolean have before it is initialized with one of these states.
I would like to understand the difference between the Boolean and boolean types in Java, specifically as they relate to GWT.
I know that methods are not supported but I want more info if it is available.
Title basically says it all. I've tried Googling but return a load of false positives. I guess I'm just wondering if there was a certain rationale behind these two specific numbers or could they have easily been many other sets of numbers?
Edit: And, since the source of the numbers has been answered, any reason why writers of the Boolean hashCode method used those numbers (besides that they're...
I have this code
public static Boolean freq[] = new Boolean[Global.iParameter[2]];
freq[Global.iParameter[2]] = false;
could someone tell me what exactly i'm doing wrong here and how would i correct it? I just need to initialize all the array elements to Boolean false.
thank you
I have this behaviour I do not really understand
${requestScope.rs_redirectFacade}
${requestScope.rs_redirectFacade.class.name}
${requestScope.rs_redirectFacade == 'error'}
outputs
false
java.lang.Boolean
true
How can it be exlpained?
What it the correct way to write the test in order to first test if the two 'things' have the same type and then if their value is the same?
I have a custom button class called ImageButton that extends JButton. In it i have a setEnabled method that I want to be called rather than the JButton's setEnabled method.
My code is below. In my other class I create a new instance of ImageButton, but when I try to use the setEnabled method, it goes straight to the JButton's setEnabled method. Even before I run the code, my IDE is telling me ...
I need a mutable boolean field in Java (I will return this field via get* method later and it should be possible to modify this field).
Boolean doesn't work because there are no set* methods in the Boolean class (I would say that Boolean is immutable, you can only change the reference, but you can't change the object itself).
I guess I can use Boolean array of size 1. But probably there are m...
Possible Duplicate:
Java Boolean Question
Good afternoon
What is the default value of Boolean (primitive wrapper) in Java
I am curious. Why do I have to type String myStr with a capital letter whereas I type int aNumba with a lower-case letter?
I have a question about the meaning (evaluation) of Boolean variables in return statements in Java.
I know that:
if (var) { ... }
is the same as:
if (var==true) { ... }
In the second case we explicitly say var==true, but we don't need to do this, because Java evaluates var as true anyway. I hope I have understood this right.
My question is: is it the same when Boolean variables are retu...
I am surprised to know that getBoolean() and valueOF() method returns diff output for the same string input.
I have tried to pass the
String str = "true"
to both the methods. But getBoolean() gives me false output whereas valueOF() gives me right output that is true. why??
Guys need your comments?
Regards,
Mahendra
There are discussion around Integer vs int in Java. The default value of the former is null while in the later it's 0. How about Boolean vs boolean?
A variable in my application can have 0/1 values. I would like to use boolean/Boolean and prefer not to use int. Can I use Boolean/boolean instead?
Thanks.
I've been learning Java in my spare time and have a quick question I can't seem to figure out. This code returns true:
Boolean testBool = true;
Boolean test = testBool instanceof Object;
System.out.println(test);
However, I thought Boolean was a primitive type and when I try this same logic with any other primitive type I get a compiler error that says:
unexpected type required: reference ...
is there any reason why java booleans take only true or false why not 1 or 0 also?
I did a little search on this but couldn't find anything useful.
The point being that if String value is either "true" or "false" the return value should be true. In every other value it should be false.
I tried these:
String value = "false";
System.out.println("test1: " + Boolean.parseBoolean(value));
System.out.println("test2: " + Boolean.valueOf(value));
System.out.println("test3: " + Boo...
PS: I understand the difference between "true" and true.
Edit:
I also understand that Boolean.TRUE is a wrapper for the primitive true, my question then is - why does the primitive boolean accept Boolean.TRUE as a value?
For instance,
boolean boolVar = Boolean.TRUE;
seems to be a valid statement.
