String截取

1.str.substring(start,end)

end可以省略
eg
1.取字符串的前i个字符:str=str.Substring(0,i);
2.去掉字符串的前i个字符str=str.Substring(i)

2.replaceAll(resource,result)

支持正则
eg
String spec = "IP:".concat(sourceIp.replaceAll(":",":PORT").replaceAll(";:",";IP"));

3.String string2 = string.replace("old","new");

4.Object--json--String

    List<DeptDTO> list = (List<DeptDTO>)result.getResData().get("list");
    //list-->jsonArry
    JSONArray jsonArray= JSONArray.parseArray(JSON.toJSONString(list));
    //jsonArry-->String
    String string = jsonArray.toJSONString();
    String string2 = string.replace("childDeptList","childrenDeptList");
    //String-->jsonArry
    jsonArray= JSONArray.parseArray(string2);
    //jsonArry-->list
    List<DeptDTO2> list2 = JSONObject.parseArray(jsonArray.toJSONString(), DeptDTO2.class);