new Integer(str);
Integer.parseInt(str);
Integer.valueOf(str);
https://www.cnblogs.com/wuxiangli/p/6066058.html
https://blog.youkuaiyun.com/qq_31807385/article/details/82693326
new Integer(str);
Integer.parseInt(str);
Integer.valueOf(str);
https://www.cnblogs.com/wuxiangli/p/6066058.html
https://blog.youkuaiyun.com/qq_31807385/article/details/82693326