Lost precision when do number format

[Ralph Ma]

I wanna convert a bigdecimal to a formated string. but, after conversion, I found the precision was lost. How can I handle it?
Thanks


eg:
String s="123456789123456789";
BigDecimal bd=new BigDecimal(s);
DecimalFormat df=new DecimalFormat();
System.out.println(df.format(bd));

The expected value is:123,456,789,123,456,789
While the acctal output is:123,456,789,123,456,784

[Kevin Huang]

The problem is that df.format(bd) casts bd into double, and the precision is lost.

[Ralph Ma]

Originally posted by Kevin Huang:
The problem is that df.format(bd) casts bd into double, and the precision is lost.

Would you mind to give me some advices to solve this problem?
Thanks

[Edwin Dalorzo]

What JDK and OS are you trying to run that program?

I ran this in JDK 1.5 under Linux (Ubuntu) and it worked as expected. Even this bigger number,printed just fine:

String s = "123456789123456789123456789";
BigDecimal bd = new BigDecimal(s);
DecimalFormat df = new DecimalFormat();
System.out.println(df.format(bd));

Prints 123,456,789,123,456,789,123,456,789

[Kevin Huang]

replace
System.out.println(df.format(bd));
by
System.out.println(df.format(bd.longValue()));
will get expected string.

I'm suprised that Linux will give different output (since overloading is done at the compile time, not run time). I'm using jdk 1.4 on Windows. Could anyone please try it on Linux using 1.4?

[Edwin Dalorzo]

On JDK 1.4.2_12 under Linux I got rounding problems.

This code:

String s = "123456789123456789123456789";
BigDecimal bd = new BigDecimal(s);
DecimalFormat df = new DecimalFormat();
System.out.println(df.format(bd));

Produces this output: 123,456,789,123,456,790,000,000,000

One more reason to give the jump and try to tame the Tiger.

[Campbell Ritchie]

Does the toString() method supply what you want?