java 从指定行读 java 读一行

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import java.util.Stack;
import java.util.Vector;

public class Main {

	public static void main(String[] args) throws IOException {
		String S;
		int n;
		Scanner sc = new Scanner(System.in);
		//String s = sc.next();读入一行字符串，遇见空格或者换行就停，相当于C的scanf("%s", s)
		int n1 = sc.nextInt();
		BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));//重点
		String s = stdin.readLine();//读入一行完整的字符串，只在遇见换行符时终止
		System.out.println(s+"长度"+s.length());
	}
}