.split(",", -1);和.split(",")的区别

.split(",", -1);和.split(",")的区别在于：//eg:String a="河南省，，金水区".//a.split(",")=[河南省,金水区 ]，而a.split(",",-1)=[河南省, ,金水区 ]。.split(",", -1);会保存空值。