ヅラッシュ！ by NI-Lab.

ソースコード:

public class SplitTest {
  public static void main(String[] args) {
    String[] src = new String[]{
      "a,b,c",
      "a,b,",
      ",b,c",
      ",b,",
      ",",
      "a,,b,,c",
      "a,,b,,",
      ",,b,,c",
      ",,b,,",
      ",,",
    };
    for(int i=0; i<src.length; i++){
      System.out.println(
        src[i] +
        " -> " +
        src[i].split(",").length);
    }
    for(int i=0; i<src.length; i++){
      System.out.println(
        src[i] +
        " -> " +
        src[i].split(",", -1).length);
    }
  }
}

出力結果:

a,b,c -> 3
a,b, -> 2
,b,c -> 3
,b, -> 2
, -> 0
a,,b,,c -> 5
a,,b,, -> 3
,,b,,c -> 5
,,b,, -> 3
,, -> 0
a,b,c -> 3
a,b, -> 3
,b,c -> 3
,b, -> 3
, -> 2
a,,b,,c -> 5
a,,b,, -> 5
,,b,,c -> 5
,,b,, -> 5
,, -> 3