Java Enterprise in a Nutshell, Third Edition

Basic Data Types

IDL supports the basic data types shown in Table G-2. The table also shows the Java type that each is mapped to according to the standard IDL Java mapping. Note that there isn’t a standard mapping defined for the long double IDL type, because Java doesn’t have a basic data type that supports the precision required. Another important thing to note is that Java doesn’t support unsigned types, such as unsigned short. So you’ll see in the table that IDL short and unsigned short are both mapped to the Java short data type. You should be aware of this when writing implementations of IDL-generated Java interfaces, since it is up to you to either ensure that their values remain positive or deal with the fact that their values may in fact be set to negative values.

Table G-2. IDL basic data types, sizes, and Java mappings

IDL type specifier	Required size	Java data type
short	16 bits	short
long	32 bits	int
long long	64 bits	long
unsigned short	16 bits	short
unsigned long	32 bits	int
unsigned long long	64 bits	long
char	8 bits	char
wchar	Implementation-dependent	char
string	Unlimited	java.lang.String
string<size>	size chars	java.lang.String
wstring	Unlimited	java.lang.String
wstring<size>	size wchars	java.lang.String
boolean	Implementation-dependent	boolean
octet	8 bits	byte
Any	Implementation-dependent	org.omg.CORBA.Any
float	IEEE single precision	float
double	IEEE double precision	double
long double	IEEE double extended	Not supported
fixed	31 decimal digits	java.math.BigDecimal

Strings and Characters

There are two character types ...