我在家庭预算申请方面遇到了一些问题。在我插入新的收入或账单，检查预算后，该程序甚至会在客户代码中添加以前的账单（或收入）。
public class Client {
public static void main(String[] args) {
Budget bud = new Budget();
Bills[] expenses = new Bills[10];
Income[] salary = new Income[4];
boolean toContinue = true;
String input = "";
int menuItem = 0;
int counter = 0;
int salCount = 0;
float budget = 0;
while (toContinue) {
input = JOptionPane
.showInputDialog("(1) Add an expense\n(2) Add the salary\n(3) Display Current Budget\n(4) Exit");
menuItem = Integer.parseInt(input);
switch (menuItem) {
case 1: //Add expense
String name = JOptionPane.showInputDialog("Enter the name of the expense");
double amount = Double.parseDouble(JOptionPane.showInputDialog("Enter the amount for " + name));
expenses[counter++] = new Bills(name, amount);
break;
case 2: //Add salary
String checkSal = JOptionPane.showInputDialog("Enter salary details");
double checkAm = Double.parseDouble(JOptionPane.showInputDialog("Enter the amount of " + checkSal));
salary[salCount++] = new Income(checkSal, checkAm);
break;
case 3: // display current budget
try {
String expDisplay = "Expenditure\t Amount\n";
String salDisplay = "Salary\t Amount\n";
float expenseSum = 0;
float salarySum = 0;
for (int i = 0; i < salary.length; i++) {
if (salary[i] != null)
salarySum += salary[i].Total();
}
for (int e = 0; e < expenses.length; e++) {
if (expenses[e] != null)
expenseSum += expenses[e].Total();
}
for (Bills e : expenses) {
if (e != null)
expDisplay += e.toString() + "\n";
}
for (Income p : salary) {
if (p != null)
salDisplay += p.toString() + "\n";
}
File fileBudget = new File("C:budget.txt");
if (!fileBudget.exists()) { //creating new txt
bud.setBudget(budget);
fileBudget.createNewFile();
System.out.println("TEXT File Created");
FileWriter fw = new FileWriter(fileBudget, false);
fw.write(bud.getBud() + "");
fw.flush();
fw.close();
budget = salarySum - expenseSum; //calculating budget
JOptionPane.showMessageDialog(null, expDisplay + "\n\n" + salDisplay + "\n\n" + "You spent: "
+ expenseSum + "\n" + "Budget: " + budget);
} else {
BufferedReader re = new BufferedReader(new FileReader("C:budget.txt")); //reading budget on txt file
while (true) {
String line = re.readLine();
if (line == null) {
break;
} else {
float d = Float.valueOf(line);
bud.setBudget(d); //store the read value
}
}
re.close(); //end reading
float c = bud.getBud(); //taking budget value
// problem...there are even previous sum values!!
budget = salarySum - expenseSum + c; // error
FileWriter fw = new FileWriter(fileBudget, false);
fw.write(budget + "\n");
fw.flush();
fw.close();
JOptionPane.showMessageDialog(null, expDisplay + "\n\n" + salDisplay + "\n\n" + "You spent: "
+ expenseSum + "\n" + "Budget: " + budget);
}
} catch (Exception e) {
System.err.println("Error: " + e.getMessage());
}
break;
case 4: //close program
JOptionPane.showMessageDialog(null, "You closed the Budget Program!");
System.exit(0); }}}}
//budget object
public class Budget implements Serializable {
private static final long serialVersionUID = 1L;
public float bud;
Budget()
{
}
public float getBud() {
return bud;
}
public void setBudget(float bud) {
this.bud = bud; }}
//Bill class
public class Bills {
private double amount;
private String name;
public Bills(double amount) {
this.amount = amount;
}
public Bills(String name, double amount) {
this.name = name;
this.amount = amount;
}
public Bills() {
this("New Expense", 0); }
public String toString() {
return name + "\t " + "\t " + amount; }
public double Total() {
return amount; }}
//Income class
public class Income {
private double amount;
private String Salary;
public Income(String Salary, double amount) {
this.Salary = Salary;
this.amount = amount;
}
public String toString() {
return Salary + "\t " + "\t " + amount;
}
public double Total() {
return amount; }}
答案 0 :(得分：1)
您的代码存在一些问题。
首先在这里：
for (int i = 0; i < salary.length; i++)
{
if (salary[i] != null)
{
salarySum += salary[i].Total();
}
}
for (int e = 0; e < expenses.length; e++)
{
if (expenses[e] != null)
{
expenseSum += expenses[e].Total();
}
}
每当您的用户输入[3]查看详细信息，添加这些数字，然后计算预算时，此预算就会添加到文件中。
现在在同一个会话中，用户再次单击[3]并重复上述步骤。
您应该找到一种方法来实际识别用户何时输入新费用或新工资，以避免重复计算预算，然后重复分配到文件。 （布尔变量可能？）
此外：
if (!fileBudget.exists()) { //creating new txt
bud.setBudget(budget);
fileBudget.createNewFile();
System.out.println("TEXT File Created");
FileWriter fw = new FileWriter(fileBudget, false);
fw.write(bud.getBud() + "");
fw.flush();
fw.close();
budget = salarySum - expenseSum; //calculating budget
JOptionPane.showMessageDialog(null, expDisplay + "\n\n" + salDisplay + "\n\n" + "You spent: "
+ expenseSum + "\n" + "Budget: " + budget);
}
您始终为文件指定零值。即使要创建文件，也许用户已经提供了一些预算，您将丢失此数字。我想你也必须在那里计算预算。
编辑：
一个可能的解决方案，也就是简化事情，就是在用户输入新工资时实际添加到文件中，并在用户输入费用时从文件中减去，因此这两个操作将在前两个案例中进行select语句的（1和2）。 （这两个操作都要求您首先读取文本值，然后添加新工资，或者然后减去新费用）。这样，您的文件将包含最新的计算预算，在第三种情况下，您只会读取文件中的值，该值将包含最新的计算预算，而不是每次都计算第3种情况下的预算！