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Get type of a generic parameter in Java with reflection
... I get this exception : Exception in thread "main" java.lang.ClassCastException: java.lang.Class cannot be cast to java.lang.reflect.ParameterizedType not sure what is the constraint .
– Dish
Feb 29 '16 at 14:25
...
How do I check for nulls in an '==' operator overload without infinite recursion?
...
Cast to object in the overload method:
public static bool operator ==(Foo foo1, Foo foo2) {
if ((object) foo1 == null) return (object) foo2 == null;
return foo1.Equals(foo2);
}
...
Java: Instanceof and Generics
...(Object o) {
try {
abstractMethod((T) o);
} catch (ClassCastException e) {
//...
You are casting the object to T (your generic type), just to fool the compiler. Your cast does nothing at runtime, but you will still get a ClassCastException when you try to pass the wrong type of...
How to get the caller's method name in the called method?
...ccessing.
import inspect
from types import FrameType
from typing import cast
def caller_name() -> str:
"""Return the calling function's name."""
# Ref: https://stackoverflow.com/a/57712700/
return cast(FrameType, cast(FrameType, inspect.currentframe()).f_back).f_code.co_name
if...
Run a string as a command within a Bash script
...rameters so I ended up with something like:
my_exe ()
{
mysql -sN -e "select $1 from heat.stack where heat.stack.name=\"$2\";"
}
This is something I use to monitor openstack heat stack creation. In this case I expect two conditions, an action 'CREATE' and a status 'COMPLETE' on a stack named ...
Should you choose the MONEY or DECIMAL(x,y) datatypes in SQL Server?
...@num2 DECIMAL(19,4),
@num3 DECIMAL(19,4),
@num4 DECIMAL(19,4)
SELECT
@mon1 = 100, @mon2 = 339, @mon3 = 10000,
@num1 = 100, @num2 = 339, @num3 = 10000
SET @mon4 = @mon1/@mon2*@mon3
SET @num4 = @num1/@num2*@num3
SELECT @mon4 AS moneyresult,
@num4 AS numericresult...
How can I return an empty IEnumerable?
...rExists) yield break; foreach(var descendant in doc.Descendants("user").Select(user => new Friend { ID = user.Element("id").Value, Name = user.Element("name").Value, URL = user.Element("url").Value, Photo = user.Element("photo").Value })) { yield r...
Comparing boxed Long values 127 and 128
...val4); // true
(Proper null checking is necessary, even for castings)
IMO, it's always a good idea to stick with .equals() methods when dealing with Object comparisons.
Reference links:
https://today.java.net/pub/a/today/2005/03/24/autoboxing.html
https://blogs.oracle.com/darcy/en...
ThreadStart with parameters
...
+1: Even though the currently selected answer is absolutely correct, this one by JaredPar is the better one. It simply is the best solution for most practical cases.
– galaktor
Oct 10 '09 at 10:27
...
Why is “int i = 2147483647 + 1;” OK, but “byte b = 127 + 1;” is not compilable?
...t has to do with Java not supporting coercions (*). You have to add a typecast
byte b = (byte)(127 + 1);
and then it compiles.
(*) at least not of the kind String-to-integer, float-to-Time, ... Java does support coercions if they are, in a sense, non-loss (Java calls this "widening").
And no,...