String.split()1つ以上のスペース分割文字列

区切り文字列

//        ,    ,  tab   
String str = "a b  c    d";

効果

//     
String[] arr1 = str.split(" ");
String[] arr2 = str.split("s");
String[] arr3 = str.split("\t");
String[] arr4 = str.split("\\s+");

//  
for (String s : arr1) {
    System.out.print(s+",");
}
System.out.println("");
for (String s : arr2) {
    System.out.print(s+",");
}
System.out.println("");
for (String s : arr3) {
    System.out.print(s+",");
}
System.out.println("");
for (String s : arr4) {
    System.out.print(s+",");
}

ブログ参照
[1]https://blog.csdn.net/xueqinmax/article/details/81748034