java - 输入文本文件上的正则表达式 float

Question

我需要做一份工资报告。您必须键入包含文本信息的文件。程序检查文件是否存在。然后创建程序的输出文件。该程序在文本文件中打印 worker 的姓名、工作时间和工资。我的程序只运行最后一组数字。

 import java.text.NumberFormat;
 import javax.swing.JTextArea;
 import java.awt.Font;
 import javax.swing.JOptionPane;
 import java.util.Scanner;
 import java.io.*;

 public class Homework {

/**
 * @param args the command line arguments
 */
public static void main(String[] args) throws IOException {

    String answer, filename;


    filename = JOptionPane.showInputDialog("Enter the Input File Path:");

    File input = new File(filename);
    if (!input.exists()) {
        JOptionPane.showMessageDialog(null, "The input file:\n" + filename + "\ndoes not exist!");
        System.exit(0);
    }
    filename = JOptionPane.showInputDialog("Enter the Output File Path:");

    File output = new File(filename);
    if (output.exists()) {
        answer = JOptionPane.showInputDialog("The output file alaready exist!\nDo you want to overwrite it?");
        if (!answer.toLowerCase().equals("yes")) {
            System.exit(0);
        }
    }






    PrintWriter outFile = new PrintWriter(filename);
    Scanner in = new Scanner(input);

    double numberWords = 0, countNumber = 0;


   double value;

    String num, words, message;
    String amtStr, line = "";

    String alphaRegex = ".*[A-Za-z].*";
    String numRegex = ".*[0-9].*";



    while (in.hasNext()) {
        words = in.next();

        if (words.matches(alphaRegex)) {

            numberWords++;
            message = "The name is "+words+"\n"; //The Line is but leave +line+

     JOptionPane.showMessageDialog (null, message);



        } else if (words.matches(numRegex)) {
            countNumber++;
           num = in.next();


           message = "The number is "+num+"\n"; //The Line is but leave +line+

     JOptionPane.showMessageDialog (null, message);

             }



}
}

}

Answer 1

导致问题的不是您的正则表达式。这是 while 循环中的 if 语句。当单词与 numRegex 匹配时，您将 in.next() 分配给 num，导致扫描器跳过当前单词并选择下一个单词，在您的情况下，该单词恰好也是一个 num。

用这个替换 while 循环，它将起作用(我已经测试了代码):

while (in.hasNext()) {
    words = in.next();

    if (words.matches(alphaRegex)) {
        numberWords++;
        message = "The name is "+words+"\n";
        JOptionPane.showMessageDialog (null, message);

    } else if (words.matches(numRegex)) {
        countNumber++;
        num = words; // instead of num = in.next()
        message = "The number is "+num+"\n";
        JOptionPane.showMessageDialog (null, message);
    }
}