java字符串寻找并替换的问题

Question

各位大婶们

 String columnName = "user_name";
// .....
// 最后想得到columnName = userName, 
// 如果是user_first_name 转换成userFirstName 

Answer 1

public static void main(String[] args) {
String columnName = "user_name_mmm";
//分组 根据_
String[] arr = columnName.split("_");
StringBuilder sb= new StringBuilder();
for(int i =0;i<arr.length;i++){
sb.append(arr[i]);
}
System.out.println(sb.toString());
//结果usernamemmm
}