Java Double to String conversion without formatting

Question

I have the number 654987. Its an ID in a database. I want to convert it to a string. The regular Double.ToString(value) makes it into scientific form, 6.54987E5. Something I dont want.

Other formatting functions Ive found checks the current locale and adds appropriate thousand separators and such. Since its an ID, I cant accept any formatting at all.

How to do it?

[Edit] To clarify: Im working on a special database that treats all numeric columns as doubles. Double is the only (numeric) type I can retrieve from the database.

See the top answer in, http://stackoverflow.com/questions/47045/sprintf-equivalent-in-java Answers the same question. — Dana the Sane, Oct 27 '09 at 14:13
654987 is an integer, not a double. Did you mean something else? — Kai, Oct 27 '09 at 14:14
check this: http://stackoverflow.com/questions/1521122/java-converting-a-double-to-a-string/1521324#1521324 — JuanZe, Oct 27 '09 at 14:47
@JuanZe: Setting a locale causes thousand separators to be added, which I dont want. — Mizipzor, Oct 27 '09 at 15:18

score 33 · Answer 1 · answered Oct 27 '09 at 14:15

33

Use a fixed NumberFormat (specifically a DecimalFormat):

double value = getValue();
String str = new DecimalFormat("#").format(value);

alternatively simply cast to int (or long if the range of values it too big):

String str = String.valueOf((long) value);

But then again: why do you have an integer value (i.e. a "whole" number) in a double variable in the first place?

answered Oct 27 '09 at 14:15

Joachim Sauer

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Reason for double is that Im working with a database that treats all numeric columns as doubles. – Mizipzor Oct 27 '09 at 14:20
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If you cast double to long, sometimes the value changes. For ex: `((long) ((double)25891000000002001L))` becomes `25891000000002000L` – Vigneshwaran Dec 28 '15 at 10:22

score 20 · Accepted Answer · answered Oct 27 '09 at 14:16

20

Use Long:

long id = 654987;
String str = Long.toString(id);

answered Oct 27 '09 at 14:16

alphazero

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score 6 · Answer 3 · answered Oct 27 '09 at 14:13

6

If it's an integer id in the database, use an Integer instead. Then it will format as an integer.

answered Oct 27 '09 at 14:13

Ned Batchelder

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In a perfect world, of course, but the reason for the question is that Im trying to work around limits in the database; the only (numeric) type it can store is a double. – Mizipzor Oct 28 '09 at 07:48

score 6 · Answer 4 · answered Oct 27 '09 at 14:14

6

How about String.valueOf((long)value);

answered Oct 27 '09 at 14:14

rsp

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Eemeli Kantola · Answer 5 · 2009-10-28T11:35:39.753

2

What about:

Long.toString(value)

or

new String(value)

edited Oct 28 '09 at 11:35

answered Oct 27 '09 at 14:14

Eemeli Kantola

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Please don't suggest `""+value`! It's a hack and doesn't convey the intent in any way. I'd say it's bad style at the very least. – Joachim Sauer Oct 27 '09 at 15:03
Ok :) Replaced that with "new String(value)". – Eemeli Kantola Oct 28 '09 at 11:36
new String(value) will have the same problem as the question mentions, if value is a `double`. – Joachim Sauer Oct 28 '09 at 11:39
`new String(long)` does not exist in Java – Sean Owen Jan 02 '14 at 07:43

score 2 · Answer 6 · answered Sep 09 '13 at 10:16

2

Also you can use

double value = getValue();

NumberFormat f = NumberFormat.getInstance();
f.setGroupingUsed(false);

String strVal = f.format(value);

answered Sep 09 '13 at 10:16

Bob

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score 1 · Answer 7 · answered Oct 27 '09 at 15:30

1

If what you are storing is an ID (i.e. something used only to identify another entity, whose actual numeric value has no significance) then you shouldn't be using Double to store it. Precision will almost certainly screw you.

If your database doesn't allow integer values then you should stored IDs as strings. If necessary make the string the string representation of the integer you want to use. With appropriate use of leading zeros you can make the alphabetic order of the string the same as the numeric order of the ints.

That should get you round the issue.

answered Oct 27 '09 at 15:30

DJClayworth

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Sadly, both the database and its datatypes are set. The column I am to handle is a double and there is nothing I can do about it. When the database is read I of course quickly convert it into an int for internal use (or a string as you suggest). It doesnt really matter since the problem is the actual conversion, as I cant change the content or layout of the database. – Mizipzor Oct 27 '09 at 15:52

score 0 · Answer 8 · answered Nov 05 '14 at 08:04

0

What about Long.toString((long)value) ?

answered Nov 05 '14 at 08:04

Yotam Abramson

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score -3 · Answer 9 · answered Oct 27 '09 at 16:36

-3

    double d = 56789;
    String s = d+"";

answered Oct 27 '09 at 16:36

amit.bhayani

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Doesnt that call Double.toString(d)? Which by default, if Im not mistaken, adds both scientific notation and thousand separators (if necessary). – Mizipzor Oct 28 '09 at 07:52

Java Double to String conversion without formatting

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