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How to display an integer value instead of a decimal value

I have this string:
$V{Formatter}.format(new Double($F{quantita}.replaceAll(",",".")))+" " + $F{unitaDiMisura}
that serves to display a number on a document, based on the value that the user digits on his control panel.
With this string, if the user digits "1", in the document appears "1,00".
What do I need to do if I don't want the decimals to be displayed?
Example: if the user digits "1", I want that in the document is displayed "1".
Sorry if something is not understandable, I'm not a developer...
Thanks in advance to everyone who will help.

You have to convert the double value to integer type.
I assume $F{quantita} contains the double value (in String) then,
String.valueOf(Double.valueOf($F{quantita}).intValue())
Above line can be split down like below.
Create a Double value from String.
Double value = Double.valueOf($F{quantita});
extract the Integer portion from double value.
Integer intValue = value.intValue();
Convert to String using toString().
intValue.toString();

Thanks guys! I was in need of the same exact thing :D I guess we are having troubles editing the same software (Fattura24).
I wanted to ask #Dinesh how would I then divide this integer by a set number?
E.g. I have $F{quantita} (which contains the double value if not converted to integer) and I need to display the result of its division by 4. So the output has to be the integer result of $F{quantita} /4. How can I achieve this? Thank you for your help

In Java, how do you print out an anwer in a different literal?

I know that you add an L to a value if it exceeds the scope of an integer but you still have to print it as such. I understand the concept of doing it when you're just printing out a plain number.
What about when you're using a defined variable instad?
Say I have something like.
double a = 2.5;
System.out.println(a);
I want "a" to be printed out as a integer.
Thanks for any answers in advance :)

You can use Math.round for instance.
System.out.println(Math.round(a));
or you can format it as an integer as follows:
System.out.printf("%.0f%n", a);

cast double a to Double and use a.intValue()
Double a = new Double("2.5");
System.out.println(a.intValue());

You could use a NumberFormat. There are predefined formats available which you could use for your particular use-case.
NumberFormat format = NumberFormat.getIntegerInstance();
double a = 2.5;
System.out.println( format.format( a ) );
But it also allows to create one for more difficult output, like with a specified number of decimals. That would be much harder using Math.round or the other suggestions made here.

How to keep n decimal places in Java

Hi All it might be a trivial question but as for now I could not find any solution.So asking for your help!
What I am trying to get is a specific encoding table that looks like this:
0.000
0.100
0.200
I need to keep track of zeroes as I will use them to reconstruct a part of an specific array. Original loop that was creating those numbers is:
for(int k=0;k<m_0;k++){
for(int l=0;l<m_1;l++){
for(int a=0;a<a1;a++){
Y[x-1]=0.1*k+0.01*l+0.001*a;
x++;
}
}
}
Problem! I could not fix zeros after decimal place and rather then getting table described above I am getting following:
0.0
0.1
0.2
As a solution I have tried to use BigDecimal and DecimalFormat but no success. Any suggestions?
UPD Few words what I am trying to do. I am encoding specific array to array and back index correspondence. For example 0.100 will be decomposed into 1 and 0 and 0 and used as array index labeling like:
Array1[Method(1,0,0,Y(i)][Method(1,0,0,Y(i))]=Array2[1][0][0]
So that I need an output suitable for assigning array index and string will not do the deal.

The DecimalFormat class is the correct place to look. You just need the correct format.
DecimalFormat df = new DecimalFormat("0.000");
System.out.println(df.format(0.1));
Output:
0.100

As an alternative to the DecimalFormat class, I would like to propose the following (which I use quite regularly):
Step 1: Create a function that allows me to specify the number of units to keep. Here is a copy of this function.
public static String format(Number n) {
NumberFormat format = DecimalFormat.getInstance();
format.setRoundingMode(RoundingMode.FLOOR);
format.setMinimumFractionDigits(0);
format.setMaximumFractionDigits(2);
return format.format(n);
}
Step 2: Call the function whenever you have any output to format. Below is a simple example using this function to set the appropriate decimal place length:
System.out.println("Based on this, the wind chill index was calculated to be " + format(chill));
Note that you could simply change the line:
format.setMaximumFractionDigits(2);
to
format.setMaximumFractionDigits(n);
depending on your desired decimal length.

When you are printing the numbers, you can use this:
System.out.format("%.3f", yourDecimalNumber);

How to format numbers on Android

i am learning to program mobile aplications on Android. My first app is a unit converter. Everithing is working for now, but i have a question about formating numbers. I hava this code to get text from buttons and to convert the appropriet output:
if (bPrevodZ.getText() == "milimeter"){
if (bPrevodDo.getText()=="kilometer"){
String PomocnaPremenna = jednotkaZ.getText().toString();
double cisloNaPrevod = Double.parseDouble(PomocnaPremenna);
cisloNaPrevod = cisloNaPrevod*0.0000001;
vysledok.setText(Double.toString(cisloNaPrevod));
}
The final result is "cisloNaPrevod", but i have problems to show a good format of that number. For example:
12345 mm = 0,0012345 km this is good right ? :)
but if i convert:
563287 mm = 0.05632869999999995 this is bad :) i need it to show 0.0563287
Thx for any help

Use String.format:
String.format("%.6f", cisloNaPrevod);

If you want your number to always have 6 significant figures, use
vysledok.setText(String.format("%.6g", cisloNaPrevod));
giving the result 0.0563287.
If you want to round to 6 numbers after the decimal place, use
vysledok.setText(String.format("%.6f", cisloNaPrevod));
giving the result 0.056329.
Here's some good resources that cover number formatting:
Floating-point cheat sheet for Java
java.util.Formatter

If it's something you're going to do often, perhaps you should use DecimalFormat.
DecimalFormat df = new DecimalFormat("#.#######");
Then call:
df.format(someDoubleValue);

Retain formatting of a Double value - Java

I am using Poi to create Excel workbooks in Java. My raw data comes in as a string. I need to format the data to enter two decimal places into the cell where the number is being written. I use Double.parseDouble() to convert the string to numeric and then use DecimalFormat to format the numeric as a string. Another call to Double.parseDouble() to return the value to numeric (the cell where it is going is formatted numeric, so I can't use the string value) and I should be good. Problem is, that second call to Double.parseDouble() truncates any trailing zeroes off from the right of the decimal point. Anybody have an idea as to how I can coerce this value to read as, say, 1.50 rather than 1.5?

I always want two decimals.
Solution: Always apply specific decimal format pattern.
Sample code snippet:
//java.text.DecimalFormat df = new java.text.DecimalFormat( "###0.00" );
java.text.DecimalFormat df = new java.text.DecimalFormat();
df.applyPattern( "###0.00" ); // always two decimals
double dbl = 1.50d ;
// prints: dbl = 1.5
System.out.println( "dbl = " + dbl );
// prints: df.format( 1.5 ) = 1.50
System.out.println ( "df.format( " + dbl + " ) = " + df.format( dbl ) );
UPDATE:
OK, from your posting, I understand that you are trying to fill the numeric formatted cell only to print or show up with two decimal positions. You know by default all numeric fields are interpreted omitting trailing zeros. To achieve your requirement, you may require to use CellFormat and/or DataFormatter on your contextual Cell object, but when said Format, it is a String again.
I didn't try the following code but may help you.
DataFormatter dataFormatter = new DataFormatter();
dataFormatter.setDefaultNumberFormat( instanceOfDesiredDecimalFormat );
// or
// dataFormatter.setExcelStyleRoundingMode( instanceOfDesiredDecimalFormat );
// apply this format on the cell you want
dataFormatter.formatCellValue( instanceOfNumericCellInContext );

You are actually doing nothing in most part of the code you described. You might as well just return Double.parseDouble(inputString). Doubles are stored in binary format and the leadin/trailing zeros make no sense. Perhaps the BigDecimal class is something for you.

It appears we are at an impasse. As Mario pointed out, doubles are managed as binary and there is no way to format the binary as a double, except to convert it to a string with DecimalFormat, which is no longer a double. I explained this to my boss and he's ok with the solution of taking the raw double, so I'm closing this issue. Thanks to all for your help and support.
regards,
Mike