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"main" java.util.InputMismatchException [duplicate]

This question already has answers here:
Why am I getting InputMismatchException?
(5 answers)
Closed 6 years ago.
Whenever I try to compile it, it keeps giving me an exception:
This is my source code:
Scanner input = new Scanner(System.in);
DecimalFormat df = new DecimalFormat("#.##");
System.out.print("Gaji Pokok (x 10.000) : ");
double gaji = input.nextDouble();
System.out.print("Lama Tahun Kerja : ");
int th = input.nextInt();
System.out.print("Lama Bulan Kerja : ");
float bl = input.nextFloat();
if ( bl > 12)
{
System.out.println("Inputan bulan anda salah");
System.out.print("Masukkan kembali bulan yang benar : ");
float blnnew = input.nextFloat();
float tukar = blnnew;
bl = tukar;
}
float fak_peng;
fak_peng = Float.valueOf(df.format((th+(bl/12))*2.5));
System.out.print("Jumlah Faktor Penghargaan : " );
System.out.println(fak_peng + " %");
System.out.println("Nilai Sekarang : 1.0000000 " );
float per_mppeg;
per_mppeg = Float.valueOf(df.format(gaji*(fak_peng/100)*1));
System.out.print("Perhitungan MP Pegawai : " );
System.out.println(gaji + " x " + fak_peng + "% x " + " 1.0000000 = Rp." + (per_mppeg) + "(x 10.000)");
System.out.print("MP Perbulan : " );
System.out.println(per_mppeg + " + 100% = Rp." + (per_mppeg) + "(x 10.000)");
System.out.println("MP sekaligus 100% : ");
float peserta;
peserta = Float.valueOf(df.format(100.6650*per_mppeg));
float jd;
jd = Float.valueOf(df.format(14.4820*per_mppeg*0.8));
float anak;
anak = Float.valueOf(df.format(0.6090*per_mppeg*0.8));
float jml;
jml = Float.valueOf(df.format(peserta+jd+anak));
System.out.println(" Peserta = 100.6650 x "+ per_mppeg + " = " + peserta + "(x 10.000)");
System.out.println(" Jd/Dd = 14.4820 x "+ per_mppeg + " x 80% = " + jd + "(x 10.000)" );
System.out.println(" Anak = 0.6090 x "+ per_mppeg + " x 80% = " + anak + "(x 10.000)");
System.out.println("Jumlah Total = "+ jml);
float mpdua;
mpdua = Float.valueOf(df.format (jml*0.2)) ;
float mpdel;
mpdel = Float.valueOf(df.format(per_mppeg*0.8)) ;
System.out.println("MP Sekaligus 20% = "+ mpdua + "(x 10.000)");
System.out.println("MP sekaligus 80% = "+ mpdel + "(x 10.000)");

Your exception is not a compile-time error/exception; it is a runtime exception. It is thrown because the thing the scanner is reading cannot be converted to the type you are asking for (e.g., the next thing the scanner should read is "hello" but you are using scanner.nextInt(), as "hello" cannot be converted to an integer it will raise a InputMismatchException).
In your case the exception is raised when asking for a double. Probably you are using the wrong syntax. You should check which syntax your system uses to represent doubles. On some systems, for example, the fractional and the integer part of a double should be separated with a , and on other systems with a .. So one-half on the first type of system should be written as 0,5 but on the second as 0.5.
In Java the syntax the scanner uses is defined with a Locale instance.
You can check which-one your scanner uses with the locale() method and change it with useLocale() method.
So you should recheck what you give as input.
Besides your problem with the format of double you are creating your DecimalFormat on a discommanded way (see last quote below) and there is another line that may rise an exception ( NumberFormatException ), if you do not pay attention to the Locale instance you are using:
fak_peng = Float.valueOf(df.format((th+(bl/12))*2.5));
As you are using your own format to parse the decimal (new DecimalFormat("#.##");) the string that will be passed to the Float.valueOf method will depend on the Locale instance used to create the DecimalFormat object df (in the code sample you didn't use a specific Locale instance so your systems default Locale instance is used). But Float.valueOf expects its argument to use a specific syntax defined by The Java™ Language Specification regardless to your system as written in the Java API for Float.valueOf:
[...] where Sign, FloatingPointLiteral, HexNumeral, HexDigits, SignedInteger and FloatTypeSuffix are as defined in the lexical structure sections of The Java™ Language Specification, except that underscores are not accepted between digits. If s does not have the form of a FloatValue, then a NumberFormatException is thrown.
(The complete text was too big too include here. Follow this link or the one above to have more info about what Sign, FloatingPointLiteral, HexNumeral, HexDigits, SignedInteger, FloatTypeSuffix and FloatValue exactly represent)
If you want to change the Locale instance used in your DecimalFormat object, read the API for the DecimalFormat class.
To obtain a NumberFormat for a specific locale, including the default locale, call one of NumberFormat's factory methods, such as getInstance(). In general, do not call the DecimalFormat constructors directly, since the NumberFormat factory methods may return subclasses other than DecimalFormat.
In the API (follow link just before quote) they give an example of how you should correctly create an instance of a NumberFormat.
Good luck!

Java - If statement required to display the value as 0.00 instead of 0.0 [duplicate]

This question already has answers here:
Show padding zeros using DecimalFormat
(8 answers)
Closed 7 years ago.
I created this code to display a certain output however the output is displayed with as so:
First Class Parcel - Cost is £3.3
John Smith, 1 Downing Street, SQ13 9DD
Weight = 1.342kg.
This piece of code is the part of the output about(First Class Parcel - Cost is £3.3) However instead of displaying 3.3 I want to display 3.30.
#Override
public String toString() {
String str = "";
double cost = 0.00;
if (this.isFirstClass()){
cost = 3.30;
str = "First Class Parcel";
} else {
cost = 2.80;
str = "Second Class Parcel";
}
return str + " - Cost is £" + cost + "\n" + super.toString() + "\n";
}

This will help you :
DecimalFormat df = new DecimalFormat("#.00");
double d= 23.2;
System.out.println(df.format(d));

Use DecimalFormat. Something on the lines like following
double cost = 3.30;
DecimalFormat df = new DecimalFormat("#.00");
System.out.println("Cost is £" + df.format(cost) );

Have you tried:
String.format( "%.2f", cost);
http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#format(java.lang.String,%20java.lang.Object...)

Java Methods and return statement

I am trying to test a class i'm working on. I want to run a print statement that takes a monthly salary for an employee multiply it by 12 to give me the annual salary then adds 10%. I have gotten everything to work except for the last part
Here is my code so far (This is just partial code)
constructors
public double findSal(){
return this.monthlySalary * 12;
}
public double giveRaise(){
return this.monthlySalary * 12 * 0.10;
}
System.out.printf("The yearly salary for " +employee1.getfirstName()+" " + employee1.getlastName()+" " + "With a 10% raise is: $" +employee1.giveRaise()+ "\n");
System.out.printf("The yearly salary for " +employee2.getfirstName()+" " + employee2.getlastName()+" " + "With a 10% raise is: $" +employee2.giveRaise()+ "\n");
This is the error I am getting when I run
Exception in thread "main" java.util.UnknownFormatConversionException: Conversion = 'r'
at java.util.Formatter$FormatSpecifier.conversion(Formatter.java:2691)
at java.util.Formatter$FormatSpecifier.(Formatter.java:2720)
at java.util.Formatter.parse(Formatter.java:2560)
at java.util.Formatter.format(Formatter.java:2501)
at java.io.PrintStream.format(PrintStream.java:970)
at java.io.PrintStream.printf(PrintStream.java:871)
at labex4oop.employeeTest.main(employeeTest.java:35)
Java Result: 1

Your code suffers from a minor oversight:
Public double giveRaise(){
return this.monthlySalary * 12.0 * 1.10; // was 0.10
}
You also need to convert from double When printing the values and you have to escape the percent sign in your literals (since you use printf where % has placeholder semantics):
System.out.printf("The yearly salary for " +employee2.getfirstName()+" " + employee2.getlastName()+" " + "With a 10%% raise is: $" +String.valueOf(employee2.giveRaise())+ "\n");

System.out.printf("With [...] a 10% raise [...]");
^ // your problem is here
printf() is for formatted output. Placeholders in the format string are introduced via %. 10% raise in your code is interpreted as a %r formatting specifier. Since you neither have any arguments to format nor is %r a valid printf format specifier, you get the error message telling you that your format string is wrong.
To include a literal % you must use %%. Or stop using printf() at all because you are not using its capabilities:
System.out.println("The yearly salary for "
+ employee2.getfirstName()
+ " " + employee2.getlastName()
+ " with a 10% raise is: $"
+ employee2.giveRaise() + "\n"
);

This should give you the correct answer.
I have tried it.public double giveRaise(){
return this.monthlySalary * 12 * 1.10;
}

New line in JTextArea?

This is the question of the program:
Write a Java Application program that will determine the gross pay for each of several employees (Use either ‘while’, ‘for’, or ‘do/while’ loop to input several employees). The company pays "straight time" for the first 40 hours worked by each employee and pays "time-and-a-half" for all hours worked in excess of 40 hours. Your program should ask the user to input the hours worked and the rate per hour.
Put all output in one window. Format your gross pay in two decimal places.
This is what I have coded:
/*
* This is a program that determines the gross pay for employees of a
* company that pays "straight time" for the first 40 hours and "time
* and a half" for all hours excess. The program asks the user to
* input the hours worked and the rate per hour.
*/
// Imports.
import java.text.DecimalFormat;
import javax.swing.*;
public class SalaryCalculator
{
public static void main( String[] args )
{
// Ask for number of employees.
String num = JOptionPane.showInputDialog( "How many employees?" );
int employees = Integer.parseInt( num );
for (int counter = 0; counter != employees; counter++)
{
// Ask for employee info.
String name = JOptionPane.showInputDialog ( "Enter employee name:" );
String rate = JOptionPane.showInputDialog( "Enter standard rate per hour in $:" );
String hours = JOptionPane.showInputDialog( "Enter number of hours worked:" );
// Convert string to double.
double money = Double.parseDouble( rate );
double time = Double.parseDouble( hours );
// Create number format and text area.
DecimalFormat noDecimal = new DecimalFormat( "0.00" );
JTextArea outputArea = new JTextArea( 30, 30 );
// Format text area.
outputArea.append( "Name \t Rate \t Hours \t Total \n\n" );
// Calculations and all.
if ( time <= 40 )
{
outputArea.append( name + "\t" + "$"
+ money + "\t"
+ hours + "\t" + "$"
+ noDecimal.format( money * time ) + "\n" );
}
else if( time > 40 )
{
outputArea.append( name + "\t" + "$"
+ money + "\t"
+ hours + "\t" + "$"
+ noDecimal.format( ( money * 1.5 ) * time ) + "\n" );
}
// Output.
JOptionPane.showConfirmDialog( null,
outputArea, "Gross Pay", JOptionPane.DEFAULT_OPTION,
JOptionPane.PLAIN_MESSAGE );
}
}
}
When the code is executed, it asks for the number of employees. Say I enter 2, for example. The program then proceeds to ask the employee name, pay per hour, and number of hours worked. When I enter all of these, it shows the output nicely in a window like I want.
Picture: Data set 1.
After that, it again asks for employee name, pay, and hours (since I said there are 2 employees). This is where my problem is. When I input the second set of data, it replaces the first in the result window.
Picture: Data set 2 replaces set 1.
I want it to be displayed in a new line below the first on the same window, without having the first omitted.
This is my first time posting on stack overflow. Any help will be greatly appreciated!

You're creating a new JTextArea with each iteration of the loop. Don't do that. Create the JTextArea before the loop, and use the same one.

NumberFormatException occurs with different regional settings

I'm developing an application in Java and found this strange behaviour:
if the regional settings format is set to Hungarian (system default) via the Control Panel, I get this exception, but if I set it to an English one, it works perfectly. Also works on a virtual Mandriva where I'm developing the program in the first place.
This is the code snippet that causes the problem:
public String stattxt(){
double dt = time_avg();
double bpm = (Double.compare(dt, 0) == 0) ? 0 : msec2bpm(dt);
String s = "<html>Number of control points: " + timestamps.size() + "<br>Average dt: " +
Double.valueOf(new DecimalFormat("#.####").format(dt).toString()) + " ms<br>" +
"Average BPM: " + Double.valueOf(new DecimalFormat("#.####").format(bpm).toString()) + "<br>&nbsp</html>";
return s;
}
where both time_avg() and msec2bpm return double (not Double by any chance) values.
How could I make this work regardless to regional settings? Any help would be appreciated.

It seems like you're using
Double.valueOf(new DecimalFormat("#.####").format(dt).toString())
to round a number to 4 decimal places, but this looks like a hack to me and will fail due to regionalization settings (Hungary probably uses a decimal comma, not a decimal point.)
So, instead round doubles using something like:
rounded = Math.round(original * 10000)/10000.0;
And, if you want to create a string which is a double rounded to 4 decimal places, use String.format()
String.format("%.4f", original);

It looks like you should just skip the Double.valueOf:
public String stattxt(){
double dt = time_avg();
double bpm = (Double.compare(dt, 0) == 0) ? 0 : msec2bpm(dt);
String s = "<html>Number of control points: " + timestamps.size() + "<br>Average dt: " +
new DecimalFormat("#.####").format(dt) + " ms<br>" +
"Average BPM: " + new DecimalFormat("#.####").format(bpm) + "<br>&nbsp</html>";
return s;
}

Why are you converting String to Double and then again to String? Do it like this:
public String stattxt(){
double dt=time_avg();
double bpm=(Double.compare(dt, 0)==0)?0:msec2bpm(dt);
String s="<html>Number of control points: "+timestamps.size()+"<br>Average dt: "+
new DecimalFormat("#.####").format(dt).toString()+" ms<br>"+
"Average BPM: "+Double.valueOf(new DecimalFormat("#.####").format(bpm).toString())+"<br>&nbsp</html>";
return s;
}