Question

How do i add all charAcro[] to create a string? example
charAcro[0] = a, charAcro[1] = b, charAcro[2] = c, which makes the string abc

 while(resultSet.next()){
                    String Name = rs.getString(1);
                    String Acro=Name;
                    String delimiterAcro = " ";
                    String[] temp =null;
                    char[] charAcro = null;
                    temp = Name.split(delimiterAcro);
                    for(int i = 0;i<temp.length;++i){
                    charAcro[i] = temp[i].charAt(0);
                    //SOME CODE HERE?
                    }

      }

Answer 1

There is a String constructor available that takes a char array,

char data[] = {'a', 'b', 'c'};
String str = new String(data);

While I’m at it, look into Java Naming Conventions. Class names should be nouns, in mixed case with the first letter of each internal word capitalized. Whereas variables are in mixed case with a lowercase first letter. Internal words start with capital letters.

For example in your code snippet you have,

String Name = rs.getString(1);

which is bad, if not wrong.

Moreover, you are likely to have a NullPointerException at line,

charAcro[i] = temp[i].charAt(0);

as you didn’t initialise the array. Below is the code which should work for you.

String name = rs.getString(1);
String[] temp = name.split(" ");
char[] charAcro = new char[temp.length];
for (int i = 0; i < temp.length; ++i) {
    charAcro[i] = temp[i].charAt(0);
}
System.out.println(new String(charAcro));