Java如何替换第一个和最后一个字符串

package com.jeff.json;
import com.alibaba.fastjson.JSONObject;
public class JsonDemo1 {
 public static void main(String[] args) {
  String ret = "\"{\"success\":true,\"msg\":\"success\",\"data\":{}}\"";
  System.out.println(ret);
  if (ret.startsWith("\"")) {
   ret = replaceFirst(ret, "\"", "");
   System.out.println("去除前引号：" + ret);
  }
  if (ret.endsWith("\"")) {
   ret = replaceLast(ret, "\"", "");
   System.out.println("去除后引号：" + ret);
  }
  JSONObject result = JSONObject.parseObject(ret);
  System.out.println(result);
 }
 private static String replaceFirst(String ret, String strToReplace, String replaceWithThis) {
  return ret.replaceFirst(strToReplace, replaceWithThis);
 }
 public static String replaceLast(String text, String strToReplace, String replaceWithThis) {
  return text.replaceFirst("(?s)" + strToReplace + "(?!.*?" + strToReplace + ")", replaceWithThis);
 }
}

String s = "#y*#test*#txt";
String s1 = s.replaceFirst("\\*#", "_");
String s1_2 = s.replaceFirst(".#", "_");
String s2 = s.replace("\\*#", "_");
String s2_2 = s.replace(".#", "_");
String s3 = s.replaceAll("\\*#", "_");
String s3_2 = s.replaceAll(".#", "_");