java - Fastest way to generate all binary strings of size n into a boolean array?

Question

For example, if I wanted all binary strings of length 3 I could simply declare them like this:

boolean[] str1 = {0,0,0};
boolean[] str2 = {0,0,1};
boolean[] str3 = {0,1,0};
boolean[] str4 = {0,1,1};
boolean[] str5 = {1,0,0};
boolean[] str6 = {1,0,1};
boolean[] str7 = {1,1,0};
boolean[] str8 = {1,1,1};

What is the most efficient way to generate all possibly binary strings of length N into a boolean array?

I don't necessarily need the most efficient method, just one that's fairly efficient and easy for me to multithread.

EDIT: I should note that I will be storing them all in an ArrayList, if that matters.

Answer 1

Here's some code to generate a truth table... (works for only for 32 bits because of array size limits ( you can change the size variable to whatever and store booleans as 1/0 if you want):

int size = 3;
    int numRows = (int)Math.pow(2, size);
    boolean[][] bools = new boolean[numRows][size];
    for(int i = 0;i<bools.length;i++)
    {
        for(int j = 0; j < bools[i].length; j++)
        {
            int val = bools.length * j + i;
            int ret = (1 & (val >>> j));
            bools[i][j] = ret != 0;
            System.out.print(bools[i][j] + "");
        }
        System.out.println();
    }