Mit jelent az alábbi hiba javaban?

Exception in thread "main" java.lang.StackOverflowError

at java.lang.StringBuffer.setLength(Unknown Source)

at java.text.DecimalFormat.expandAffix(Unknown Source)

at java.text.DecimalFormat.expandAffixes(Unknown Source)

at java.text.DecimalFormat.applyPattern(Unknown Source)

at java.text.DecimalFormat.<init>(Unknown Source)

at sun.util.locale.provider.NumberFormatProviderImpl.getInstance(Unknown Source)

at sun.util.locale.provider.NumberFormatProviderImpl.getNumberInstance(Unknown Source)

at java.text.NumberFormat.getInstance(Unknown Source)

at java.text.NumberFormat.getInstance(Unknown Source)

at java.text.NumberFormat.getNumberInstance(Unknown Source)

at java.util.Scanner.useLocale(Unknown Source)

at java.util.Scanner.<init>(Unknown Source)

at java.util.Scanner.<init>(Unknown Source)

at Number2.<init>(Number2.java:4)

at Number2.<init>(Number2.java:5)

at Number2.<init>(Number2.java:5)

at Number2.<init>(Number2.java:5)

at Number2.<init>(Number2.java:5)