How to Split Fixed Size with Java

Splitting a Java String into a series of smaller Strings with a fixed width is helpful when you need to copy the data to a source that has limited space, such as a table with a specific column width. A Java String is an object that contains a series of characters, such as a name or a sentence from a book. Splitting up a String is done by looping through the String, repeatedly calling the "substr" function and storing the new list of Strings.

Instructions

1. Open your Java file in an editor such as Netbeans, Eclipse or JBuilder X.

2. Create a function to split a String into smaller Strings of a fixed size by adding the following code in your file:

   public static List<String> split_str_fixed_size(String str, int fixed_size)

   {

   int pos = 0;

   String tmp = "";

   List<String> ret_value = new ArrayList<String>((str.length() + fixed_size - 1) / fixed_size);

   for (pos = 0; pos < str.length(); pos += fixed_size)

   {

   tmp = str.substring(pos, Math.min(str.length(), pos + fixed_size));

   ret_value.add(tmp);

   }

   return ret_value;

   }

   The function creates a "List" of Strings that have the specified fixed size. It then loops through the String, calling the "substring" function to copy fixed size sections of the String into the "List."

3. Call the "split_str_fixed_size" function to split your String into fixed size parts by adding the following code in another function:

   String str = "example string of characters";

   int fixed_size = 3;

   List<String> str_split = new ArrayList<String>();

   str_split = split_str_fixed_size(str,3);

   The "str_split" will contain the Strings "exam", "ple ", "stri", "ng o", "f ch", "arac" and "ters."

4. Save the Java file, compile and run your program to split up the String.

References

• Oracle: Class String
• Oracle: Class List