Example:
// Main.java
public class Main {
    public static void main(String[] args) {
        int[] ints = { 0x01020304, 0x05060708 };
        byte[] bytes = Test.castToByteArray(ints);
        System.out.println(bytes[0] + " " + bytes[1]);
    }
}

// Test.jasm
super class Test
version 52:0
{


public Method "<init>":"()V"
stack 1 locals 1
{
aload_0;
invokespecial Method java/lang/Object."<init>":"()V";
return;
}

public static Method castToByteArray:"([I)[B"
stack 1 locals 1
{
aload_0;
areturn;
}

} // end Class Test

Expected Output (Windows, x64):
4 3