Java Split注意事项

String string = ",1,,3,";
String separator = ",";
System.out.println("1:"+string.split(separator).length);
System.out.println("2:"+string.split(separator, 0).length);
System.out.println("3:"+string.split(separator, -1).length);
System.out.println("4:"+StringUtils.split(string, separator).length);
System.out.println("5:"+StringUtils.splitByWholeSeparator(string, separator).length);
System.out.println("6:"+StringUtils.splitPreserveAllTokens(string, separator).length);

1:4
2:4
3:5
4:2
5:3
6:5

java.lang.String
split(String regex) //查看源码，调用的是split(String regex, 0)，会忽略尾部的分隔符
split(String regex, int limit)  //limit为0时，忽略尾部的分隔符；limit为-1时，不忽略

org.apache.commons.lang.StringUtils
split(String str, String separatorChars)    //忽略所有的
splitByWholeSeparator(String str, String separatorChars)    //忽略首尾的
splitPreserveAllTokens(String str, String separatorChars)   //不忽略