java--Scanner

public class test{    public static void main(String args[]) throws Exception {        //System.in 是InputStrema对象        //BufferedReader构造接受Reader对象        //InputStreamReader将字节流变为字符流        BufferedReader buf = new BufferedReader(new InputStreamReader(System.in));        System.out.print("请输入数据:");        String str = buf.readLine(); //以回车作为换行        System.out.println("输入的内容:" + str + ",长度:"+ str.length());        //没长度限制    }   }