一、方式一(IO流)
BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); //InputStreamReader转换流
String line = br.readLine();
System.out.println(line);
br.close();
二、方式二(Scanner)
Scanner sc = new Scanner(System.in);
String line = sc.nextLine();
System.out.println(line);
sc.close();