OnJava8-Examples/strings/UsingStringBuilder.java

// strings/UsingStringBuilder.java
// (c)2021 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
import java.util.*;
import java.util.stream.*;

public class UsingStringBuilder {
  public static String string1() {
    Random rand = new Random(47);
    StringBuilder result = new StringBuilder("[");
    for(int i = 0; i < 25; i++) {
      result.append(rand.nextInt(100));
      result.append(", ");
    }
    result.delete(result.length()-2, result.length());
    result.append("]");
    return result.toString();
  }
  public static String string2() {
    String result = new Random(47)
      .ints(25, 0, 100)
      .mapToObj(Integer::toString)
      .collect(Collectors.joining(", "));
    return "[" + result + "]";
  }
  public static void main(String[] args) {
    System.out.println(string1());
    System.out.println(string2());
  }
}
/* Output:
[58, 55, 93, 61, 61, 29, 68, 0, 22, 7, 88, 28, 51, 89,
9, 78, 98, 61, 20, 58, 16, 40, 11, 22, 4]
[58, 55, 93, 61, 61, 29, 68, 0, 22, 7, 88, 28, 51, 89,
9, 78, 98, 61, 20, 58, 16, 40, 11, 22, 4]
*/