Java Scanner用法案例详解

import java.util.*;
public class Example
{
public static void main(String args[])
{
System.out.println("请输入若干个数,每输入一个数用回车确认");
System.out.println("最后输入一个非数字结束输入操作");
Scanner reader=new Scanner(System.in);
double sum=0;
int m=0;
while(reader.hasNextDouble())
{
    double x=reader.nextDouble();
    m=m+1;
    sum=sum+x;
}
System.out.printf("%d个数的和为%f\n",m,sum);
System.out.printf("%d个数的平均值是%f\n",m,sum/m);
}
}

import java.util.Scanner;
import java.io.File;
import java.io.FileNotFoundException;
public class readhuman {
private static void readfile(String filename) {
try {
   Scanner scanner = new Scanner(new File(filename));
   scanner.useDelimiter(System.getProperty("line.separator"));
   while (scanner.hasNext()) {
      parseline(scanner.next());
   }
   scanner.close();
}catch (FileNotFoundException e) {
   System.out.println(e);
}
}
private static void parseline(String line) {
    Scanner linescanner = new Scanner(line);
    linescanner.www.gzlij.com useDelimiter(",");
    //可以修改usedelimiter参数以读取不同分隔符分隔的内容
    String name = linescanner.next();
    int age = linescanner.nextInt();
    String idate = linescanner.next();
    boolean iscertified = linescanner.nextBoolean();
    System.out.println("姓名："+name+" ，年龄："+ age+" ，入司时间："+ idate+" ，验证标记："+iscertified );
}
public static void main(String[] args) {
    if (args.length != 1) {
   System.err.println("usage: java readhuman file location");
   System.exit(0);
    }
   readfile(args[0]);
}
}

        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()); 
                } 
        }

String str1 = input1.nextLine();
input1.close();
Scanner input2 = new Scanner(System.in);
String str2 = input2.nextLine();
input2.close();

try {
            n = source.read(buf);
        } catch (IOException ioe) {
            lastException = ioe;
            n = -1;
        }
 
        if (n == -1) {
            sourceClosed = true;
            needInput = false;
        }

if (needInput)
    readInput();
else
    throwFor();

skipped = false;
if ((sourceClosed) && (position == buf.limit()))
    throw new NoSuchElementException();
else
    throw new InputMismatchException();