问题
Please help. I get this error after the prompts from the Scanner are displayed to the console:
Exception in thread "main" java.util.IllegalFormatPrecisionException: 2
at java.util.Formatter$FormatSpecifier.checkInteger(Unknown Source)
at java.util.Formatter$FormatSpecifier.<init>(Unknown Source)
at java.util.Formatter.parse(Unknown Source)
at java.util.Formatter.format(Unknown Source)
at java.io.PrintStream.format(Unknown Source)
at java.io.PrintStream.printf(Unknown Source)
at Project6.main(Project6.java:56)
Is the problem coming from the printf? I've checked the formatting, and it looks right.
Here is the program:
import javax.swing.JOptionPane; // allows for message dialog
import java.util.Scanner; // allows for Scanner object to be used
import java.text.DecimalFormat; // allows for formatting numbers
public class Project6 {
public static void main (String[] args) {
final double LUXURYRATE = .2; // rate of luxury tax
final double STATERATE = .1; // rate of state tax
final double LABORRATE = .05; // rate of labor cost
double diamondCost; // cost of diamond, value comes from the Scanner
double settingCost; // cost of setting, value comes from the Scanner
int numOrdered; // quantity ordered, value comes from the Scanner
double baseCost ; //sum of the values in the variables for diamond and setting
double totalCost; // total cost including tax
double laborCost; // cost of labor
double stateTax; // cost of state tax
double luxuryTax; // cost of luxury tax
double finalAmountDue; // total cost times quantity ordered
DecimalFormat formatter = new DecimalFormat("$#,##0.00"); // money format
Scanner input = new Scanner (System.in); // creates Scanner object
System.out.print("Enter diamond cost:"); // prompts user
diamondCost = input.nextDouble(); // converts input to double
System.out.print("Enter setting cost:"); // prompts user
settingCost = input.nextDouble(); // converts input to double
System.out.print("Enter quantity:"); // prompts user
numOrdered = input.nextInt(); // converts input to integer
baseCost = diamondCost + settingCost; // calculates the cost before multiplication
laborCost = calcExtraCost(LABORRATE , baseCost); // calls method calcExtraCost for calculation
stateTax = calcExtraCost(STATERATE, baseCost); // calls method calcExtraCost for calculation
luxuryTax = calcExtraCost(LUXURYRATE, baseCost); // calls method calcExtraCost for calculation
totalCost = baseCost + laborCost + stateTax + luxuryTax; // total cost including tax and labor costs
finalAmountDue = totalCost * numOrdered; // calculates total
System.out.printf("Diamond Cost: $%,.2d \n", diamondCost); // displays bill to console
System.out.printf("Setting Cost: $%,.2f \n", settingCost);
System.out.printf("State Tax @ 10%: $%,.2f \n", stateTax);
System.out.printf("Luxury Tax @ 20%: $%,.2f \n", luxuryTax);
System.out.printf("Labor Charge @ $5% %,.2f \n", laborCost);
System.out.printf("Total Price: $%,.2f \n" , totalCost);
System.out.printf("Number Ordered: $%,.2d \n", numOrdered);
System.out.printf("Amount Due: $%,.2f \n", finalAmountDue);
JOptionPane.showMessageDialog(null, "Diamond Cost: " + formatter.format(diamondCost) + "\n" +
"Setting Cost: " + formatter.format(settingCost) + "\n" +
"State Tax @ 10%: " + formatter.format(stateTax) + "\n" +
"Luxury Tax @ 20%: " + formatter.format(luxuryTax) + "\n" +
"Labor Charge @ 5% " + formatter.format(laborCost) + "\n" +
"Total Price: " + formatter.format(totalCost) + "\n" +
"Number Ordered: " + formatter.format(numOrdered) + "\n" +
"Amount Due: " + formatter.format(finalAmountDue) ); // displays bill in message dialog
} // end method main
public static double calcExtraCost (double RATE, double bcost) {
double cost = RATE * bcost; // calculates extra cost
return cost; // returns value of extra cost
} // end method calcExtraCost
} // end class Project6
回答1:
A: Because your format specifiers don't match input arguments used in the printf method.
Use %f rather than %d as the format specifier character for double values
System.out.printf("Diamond Cost: $%,.2f \n", diamondCost);
^
In addition % requires an additional % to escape that character
System.out.printf("State Tax @ 10%%: $%,.2f \n", stateTax);
Finally, remove the unnecessary dot character
System.out.printf("Number Ordered: $%,.2d \n", numOrdered);
^
Read: Formatter javadoc
来源：https://stackoverflow.com/questions/19775242/why-am-i-getting-an-exception