How do I generate a random integer between min and max in Java?

What method returns a random int between a min and max? Or does no such method exist?

What I'm looking for is something like this:

NAMEOFMETHOD (min, max) 

(where min and max are ints), that returns something like this:

8

(randomly)

If such a method does exist could you please link to the relevant documentation with your answer.

Thanks.


UPDATE

Attempting to implement the full solution and I get the following error message:

class TestR
{
    public static void main (String[]arg) 
    {   
        Random random = new Random() ;
        int randomNumber = random.nextInt(5) + 2;
        System.out.println (randomNumber) ; 
    } 
} 

I'm still getting the same errors from the compiler:

TestR.java:5: cannot find symbol
symbol  : class Random
location: class TestR
        Random random = new Random() ;
        ^
TestR.java:5: cannot find symbol
symbol  : class Random
location: class TestR
        Random random = new Random() ;
                            ^
TestR.java:6: operator + cannot be applied to Random.nextInt,int
        int randomNumber = random.nextInt(5) + 2;
                                         ^
TestR.java:6: incompatible types
found   : <nulltype>
required: int
        int randomNumber = random.nextInt(5) + 2;
                                             ^
4 errors


What's going wrong here?


Solution 1:

Construct a Random object at application startup:

Random random = new Random();

Then use Random.nextInt(int):

int randomNumber = random.nextInt(max + 1 - min) + min;

Note that the both lower and upper limits are inclusive.

Solution 2:

You can use Random.nextInt(n). This returns a random int in [0,n). Just using max-min+1 in place of n and adding min to the answer will give a value in the desired range.

Solution 3:

public static int random_int(int Min, int Max)
{
     return (int) (Math.random()*(Max-Min))+Min;
}

random_int(5, 9); // For example

Solution 4:

As the solutions above do not consider the possible overflow of doing max-min when min is negative, here another solution (similar to the one of kerouac)

public static int getRandom(int min, int max) {
    if (min > max) {
        throw new IllegalArgumentException("Min " + min + " greater than max " + max);
    }      
    return (int) ( (long) min + Math.random() * ((long)max - min + 1));
}

this works even if you call it with:

getRandom(Integer.MIN_VALUE, Integer.MAX_VALUE)