Question

Java初学者在这里，但我真诚地尝试。此程序的目标是从Realtor11.txt文件中读取两个值并将它们分配给变量。

Realtor11.txt的内容是（无空格）：

约翰

100

参见//阅读Realtor11.txt部分不确定我做错了但目前错误是

Realtor11.java:48：错误：不兼容的类型 price = in.readLine（）; ^ 要求：双倍发现：字符串 1错误错误：无法找到或加载主类Realtor11 [在1.1s完成]

// java class for keyboard I/O
import java.util.Scanner;
// java class for JOption GUI
import javax.swing.JOptionPane;
// File reader
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;

public class Realtor11
{
    public static void main(String[] args)
    {
    // Keyboard and file input
        Scanner console = new Scanner(System.in); 
        Scanner inputStream = null;
    // price of the house, the cost to sell the house and the commission
        double price, cost, commission;
    // seller’s name
        String seller; 

    // GUI diplay message declaration
        String display_message = "This program calculates the cost to sell a home\n" 
        + "and the commission paid to an individual sales agent.\n\n"
        + "The user is asked for the last name of the seller and the\n"
        + "sales price.\n\n";

    // Output descriptive messages
        JOptionPane.showMessageDialog(null, display_message, "Lab 1 Description", JOptionPane.INFORMATION_MESSAGE);

    // Read Realtor11.txt
        try {
            BufferedReader in = new BufferedReader(new FileReader("Realtor11.txt"));
            while (in.read()!= -1);
            seller = in.readLine();
            price = in.readLine();
            in.close();
            } 
            catch (IOException e) {}

    // calculate the cost and the commission
        cost = 0.06 * price;
        commission = 0.015 * price;
    // display the input and results
        String 
            out1 = String.format("%nThe " + seller + "’s" + " home sold for $%.2f%n", price),
            out2 = String.format("The cost to sell the home was $%.2f%n", cost),
            out3 = String.format("The selling or listing agent earned $%.2f%n", commission);

        JOptionPane.showMessageDialog(null, out1 + out2 + out3, seller + "'s Home Sale", JOptionPane.INFORMATION_MESSAGE);

    // Output to file
    // still writing this. 

    }
}

Answer 1

方法readLine()会返回String值，您希望double值（see API）。您必须将String值转换为double，如下所示：

price = Double.parseDouble(in.readLine());

Answer 2

readline（）函数返回一个字符串。您需要做的是手动将该价格字符串转换为double double price = Double.parseDouble（价格的字符串版本）;

读取文本文件并为变量赋值

2 个答案: