ADDITIONAL SYSTEM INFORMATION :
OSX, JDK 12,8

A DESCRIPTION OF THE PROBLEM :
Wrong rounding in formatter:
      double v3 = 0.00024649999999999997d;
       System.out.println(String.format("%.6f", v3));
       System.out.println(String.format("%.7", v3));
0.000247 (incorrect)
0.0002465

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
double v3 = 0.00024649999999999997d;
       System.out.println(String.format("%.6f", v3));
       System.out.println(String.format("%.7f", v3));

double v2 = .0002755d;
System.out.println(new DecimalFormat("#.######").format(v2));

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
0.000246
ACTUAL -
0.000247

---------- BEGIN SOURCE ----------
double v3 = 0.00024649999999999997d;
System.out.println(String.format("%.6f", v3));
System.out.println(String.format("%.7f", v3));
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
BigDecimal maybe, but it's slow

FREQUENCY : always