Scanner类最实用的地方表现在获取控制台输入。当通过new Scanner(System.in)创建一个Scanner，控制台会一直等待输入，把所输入的内容传给Scanner，作为扫描对象。如果要获取输入的内容，则只需要调用Scanner的nextLine()方法即可。
1 如何判断控制台输入结束？
按回车键是输入下一行，多行输入，要有个结束符标志，如下例子中的“exit”
[plain]
public static void main(String[] args) {
Scanner s = new Scanner(System.in);
System.out.println("input files' name：");
while (true) {
String line = s.nextLine();
if (line.equals("exit")) break;
System.out.println(">>>" + line);
} //end while
}
public static void main(String[] args) {
Scanner s = new Scanner(System.in);
System.out.println("input files' name：");
while (true) {
String line = s.nextLine();
if (line.equals("exit")) break;
System.out.println(">>>" + line);
} //end while
}
2 Scanner默认使用空格作为分割符来分隔文本，但允许你指定新的分隔符
使用默认的空格分隔符：
[java]
public static void main(String[] args) throws FileNotFoundException {
Scanner s = new Scanner("123 asdf sd 45 789 sdf asdfl,sdf.sdfl,asdf ......asdfkl las");
// s.useDelimiter(" |,|\\.");
while (s.hasNext()) {
System.out.println(s.next());
}
}
public static void main(String[] args) throws FileNotFoundException {
Scanner s = new Scanner("123 asdf sd 45 789 sdf asdfl,sdf.sdfl,asdf ......asdfkl las");
// s.useDelimiter(" |,|\\.");
while (s.hasNext()) {
System.out.println(s.next());
}
}输出如下
[plain]
123
asdf
sd
45
789
sdf
asdfl,sdf.sdfl,asdf
......asdfkl
las
Process finished with exit code 0
123
asdf
sd
45
789
sdf
asdfl,sdf.sdfl,asdf
......asdfkl
las
Process finished with exit code 0将注释行去掉，使用空格或逗号或点号作为分隔符，输出结果如下：
[plain]
123
asdf
sd
45
789
sdf
asdfl
sdf
sdfl
asdf
asdfkl
las
Process finished with exit code 0
123
asdf
sd
45
789
sdf
asdfl
sdf
sdfl
asdf
asdfkl
las
Process finished with exit code 0