java - 程序终止时遇到问题

Question

我正在为类做一个程序。基本上，该程序会遍历当天的一些销售信息并在最后打印一份报告。

我唯一的问题是程序似乎并没有在最后退出。当我为员工姓名键入“完成”时，它会打印报告，但程序会循环返回并继续运行，再次询问员工今年迄今的销售额。

我无法弄清楚为什么程序会这样做。如果有人可以帮助我指出导致它循环而不是退出的原因，以便我可以修复它，将不胜感激。谢谢!

import java.io.*;
import java.text.DecimalFormat;

public class Project04Driver {
    public static void main(String args[]) throws IOException {
        Project04 app;
        app = new Project04();
        app.appMain();
    }
}

class Project04 {
private static DecimalFormat df2 = new DecimalFormat ("$#,###.00");
BufferedReader stdin;   
int trans, tCount;
double ytd, amount, empTotal, empBonus, totA, totF, totS, totSales, totYtd, hiTrans, ytdSales;
String date, hiEmp, name, type;
public void appMain() throws IOException {
    rptInit();
    displayHeader();
    getDate();
    while (!name.equalsIgnoreCase("Done")) {
        salesData();
    }
}

void rptInit() {
    name = "f";
    trans = 1;
    amount = totF = totA = totS = totSales = totYtd = hiTrans = ytdSales = 0;
    stdin = new BufferedReader(new InputStreamReader(System.in));
}

void displayHeader() {
    System.out.println("--------------------------------------------");
    System.out.println("Project #04 Solution");
    System.out.println("Written by Jordan Hawkes");
    System.out.println("--------------------------------------------");
    System.out.println("");
}

void getDate() throws IOException {
    System.out.print("Enter Date: ");
    date = stdin.readLine();
}

void salesData() throws IOException {
    System.out.print("Enter Name: ");
    name = stdin.readLine();
    if (name.equalsIgnoreCase("done")) {
        rptOut();
        return;
    }

    System.out.print("Enter Year to Date Sales: ");
    ytd = Double.parseDouble(stdin.readLine());
    ytdSales = ytdSales + ytd;
    totYtd = totYtd + ytdSales;

    trans();

}

void trans() throws IOException {
    while (trans != 0) {
    System.out.print("Enter Transaction Number: ");
    trans = Integer.parseInt(stdin.readLine());

    if (trans == 0) {
        outputSalesData();
        empTotal = 0;
        empBonus = 0;
        ytdSales = 0;
        trans = 1;
        salesData();
    } else {
        System.out.print("Enter Transaction Type: ");
        type = stdin.readLine();
        System.out.print("Enter Transaction Amount: ");
        amount = Double.parseDouble(stdin.readLine());

        totSales = totSales + amount;
        totYtd = totYtd + amount;
        ytdSales = ytdSales + amount;
        empTotal = empTotal + amount;
        empBonus = empBonus + (amount * 0.05);

        outputUpdate();

        calcSalesData();
        tCount++;
    }
}
}

void calcSalesData() {
    if (type.equalsIgnoreCase("F")) {
        totF = totF + amount;
    }
    if (type.equalsIgnoreCase("A")) {
        totA = totA + amount;
    }
    if (type.equalsIgnoreCase("S")) {
        totS = totS + amount;
    }

    hiTrans();
}

void hiTrans() {
    if (amount > hiTrans) {
        hiTrans = amount;
        hiEmp = name;
    }
}

void outputUpdate() {
    System.out.println("");
    System.out.println("--------------------------------------------");
    System.out.println(name + "'s Total Sales for Day: " + df2.format(empTotal));
    System.out.println("--------------------------------------------");
    System.out.println("");
}

void outputSalesData() {
    System.out.println("");
    System.out.println("--------------------------------------------");
    System.out.println("Employee Name: \t\t" + name);
    System.out.println("YTD Sales: \t\t" + df2.format(ytdSales));
    System.out.println("Employee Bonus: \t" + df2.format(empBonus));
    System.out.println("--------------------------------------------");
    System.out.println("");
}

void rptOut() {
     System.out.println("Total Food & Soft Drink Sales: \t" + df2.format(totF));
    System.out.println("Total Alcohol Sales: \t\t" + df2.format(totA));
    System.out.println("Total Sundries Sales: \t\t" + df2.format(totS));
    System.out.println("--------------------------------------------");
    System.out.println("Total Sales for Day: \t\t" + df2.format(totSales));
    System.out.println("Total YTD: \t\t\t" + df2.format(totYtd));
    System.out.println("--------------------------------------------");
    System.out.println("Highest Trans Amount: \t\t" + df2.format(hiTrans));
    System.out.println("Employee w/ Highest Trans: \t" + hiEmp);
    System.out.println("--------------------------------------------");
    return;
}

Answer 1

为了让程序自然退出，你不应该在循环中调用方法，而是让方法从主循环中退出并控制流程。

这是重新设计的方法:

新的主循环成对调用 salesData() 和 trans()(假设 name 不是“done”)

while (!name.equalsIgnoreCase("Done")) {
    salesData();
    if (!name.equalsIgnoreCase("Done"))
        trans();
}

现在，方法 salesData() 不能调用 trans():

void salesData() throws IOException {
    System.out.print("Enter Name: ");
    name = stdin.readLine();
    if (name.equalsIgnoreCase("done")) {
        rptOut();
        return;
    }
    // ... processing ...
 }

而且 trans() 不能调用 salesData():

void trans() throws IOException {
   while (trans != 0) {
   System.out.print("Enter Transaction Number: ");
   trans = Integer.parseInt(stdin.readLine());

   if (trans == 0) {
     outputSalesData();
     empTotal = 0;
     empBonus = 0;
     ytdSales = 0;
   } else {
     System.out.print("Enter Transaction Type: ");
     type = stdin.readLine();
     System.out.print("Enter Transaction Amount: ");
     amount = Double.parseDouble(stdin.readLine());
     // ... processing ...
     outputUpdate();
     calcSalesData();
     tCount++;
   }
 }
}

总结:现在方法salesData()和trans()不会相互调用(完成方法后自然返回)，并且由于控件现在从主循环中，您的应用程序将按预期退出。