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Spring MVC: How to perform validation?
...lem/context better.
Let's have a User :
public class User {
private String name;
...
}
Method 1 : If you have Spring 3.x+ and simple validation to do, use javax.validation.constraints annotations (also known as JSR-303 annotations).
public class User {
@NotNull
private Strin...
Calling Java varargs method with single null argument?
...le. See the example below:
public class Temp{
public static void main(String[] args){
foo("a", "b", "c");
foo(null, null);
foo((Object)null);
Object bar = null;
foo(bar);
}
private static void foo(Object...args) {
System.out.println("foo called, args: ...
__FILE__ macro shows full path
...
Try
#include <string.h>
#define __FILENAME__ (strrchr(__FILE__, '/') ? strrchr(__FILE__, '/') + 1 : __FILE__)
For Windows use '\\' instead of '/'.
share
...
Java: What is the difference between and ?
...low code to see it in debug.
public class ByteCodeParent
{
public static String name="ByteCode";
public ByteCodeParent()
{
System.out.println("In Constructor");
}
static
{
System.out.println("In Static");
}
{
System.out.println("In Instance");
}
To test, use
Class<B...
Cleaner way to do a null check in C#? [duplicate]
... return visitor.IsNull;
}
}
class Program
{
static void Main(string[] args)
{
Person nullPerson = null;
var isNull_0 = nullPerson.IsNull(p => p.contact.address.city);
var isNull_1 = new Person().IsNull(p => p.contact.address.city);
var isNull_2...
Format a datetime into a string with milliseconds
I want to have a datetime string from the date with milliseconds. This code is typical for me and I'm eager to learn how to shorten it.
...
Better way to cast object to int
...t conversion defined.
int.Parse()/int.TryParse() — For converting from a string of unknown format.
int.ParseExact()/int.TryParseExact() — For converting from a string in a specific format
Convert.ToInt32() — For converting an object of unknown type. It will use an explicit and implicit conve...
“Unicode Error ”unicodeescape" codec can't decode bytes… Cannot open text files in Python 3 [duplica
...
The problem is with the string
"C:\Users\Eric\Desktop\beeline.txt"
Here, \U in "C:\Users... starts an eight-character Unicode escape, such as \U00014321. In your code, the escape is followed by the character 's', which is invalid.
You either nee...
Get generic type of java.util.List
...a.util.ArrayList;
import java.util.List;
public class Test {
List<String> stringList = new ArrayList<String>();
List<Integer> integerList = new ArrayList<Integer>();
public static void main(String... args) throws Exception {
Field stringListField = Test...
Is there any significant difference between using if/else and switch-case in C#?
... which is O(1).
C# (unlike many other languages) also allows to switch on string constants - and this works a bit differently. It's obviously not practical to build jump tables for strings of arbitrary lengths, so most often such switch will be compiled into stack of IFs.
But if number of conditi...