在指定的字符串前拼接字符串

   String sql = "INSERT INTO   TABLEName(id int)";
        StringBuilder stringBuilder = new StringBuilder(sql);
//
        int index = stringBuilder.indexOf("TABLEName");//字符第一次出现的位置
        while (index != -1) {
            stringBuilder.insert(index, "dbName.");
            index = stringBuilder.indexOf("TABLEName", index + "dbName".length() + "TABLEName".length());
            //下一次出现的位置， } return stringBuilder.toString();
        }
        int table = stringBuilder.indexOf("INTO");
        if (table<0){
            table = stringBuilder.indexOf("into");
            System.out.println("ceshi");
        }
//        if (table==0)
        String dbName = stringBuilder.insert(table+4, " dbName.").toString();

//        String s = stringBuilder.append("123").toString();
        System.out.println(dbName);
        

        System.out.println(sql);
        System.out.println(stringBuilder.toString());