Java文本的输入处理

深碍√TFBOYSˉ_ 2021-09-30 00:30 332阅读 0赞

**一 读入文本单词**

1 代码

import java.util.Scanner;
    public class InputWordsDemo
    {
        public static void main(String[] args)
        {
            Scanner console = new Scanner(System.in);
            // console.useDelimiter("[^A-Za-z]+");  // 默认以空格作为分割符
            while (console.hasNext())
            {
                String input = console.next();
                System.out.println(input);
            }
            console.close();
        }
    }

2 运行

I Love Java 我爱Java
    I
    Love
    Java
    我爱Java

**二 读入单个字符**

1 代码

import java.util.Scanner;
    public class InputWordsDemo
    {
        public static void main(String[] args)
        {
            Scanner console = new Scanner(System.in);
            console.useDelimiter("");  // 过滤参数必须是空字符串
            while (console.hasNext())
            {
                char input = console.next().charAt(0);
                System.out.println(input);
            }
            console.close();
        }
    }

2 运行

I love java
    I
    
    l
    o
    v
    e
    
    j
    a
    v
    a

**三 读入单行**

1 代码

import java.io.File;
    import java.io.FileNotFoundException;
    import java.util.Scanner;
    
    public class InputLineDemo {
        public static void main( String[] args ) throws FileNotFoundException {
            File inputFile = new File("share.txt");
            Scanner in = new Scanner(inputFile);
    
            while (in.hasNextLine()) {
                String line = in.nextLine();
                int i = 0;
                while (Character.isDigit(line.charAt(i)) == false) i++;
                String shareName = line.substring(0, i);
                String shareValue = line.substring(i);
                shareName = shareName.trim();
                shareValue = shareValue.trim();
                double share = Double.parseDouble(shareValue);
                System.out.printf("%s\t:\t%-10.4f\n", shareName, share);
            }
            in.close();
        }
    }

2 运行

E:\Java\Java编程技术大全\范例源码、实战练习答案、赠送资源\范例源码\chap16\范例16-6>java InputLineDemo
    每股收益      (元)      :       0.7480
    目前流通    (万股)      :       970810.7800
    每股净资产    (元)      :       9.1000
    总 股 本    (万股)      :       1103915.2000