Java Reference
In-Depth Information
CLDC APIs
Packages included in CLDC are
java.io
,
java.lang
,
java.util
, and
javax.microedition.io
, where
javax.microedition.io
is mainly a replacement for
the missing
java.net
package. Here, we will give only a short overview of the classes available.
Please note that most classes do not provide all the methods of their J2SE counterparts. For
detailed information, please consult the CLDC API documentation.
In
Appendix B
,
"Comparison Charts," you can find a table with hints for mapping functionality of
J2SE classes and methods omitted in CLDC. The following classes are available in CLDC 1.1
only: Float, Double, java.lang.ref.Reference, java.lang.ref.Reference, and
java.lang.ref.
WeakReference.
The
java.lang
Package
Supported classes from
java.lang
are
Object
, the wrapper classes for the built-in data types,
Math
,
Runtime
,
String
,
StringBuffer
,
System
,
Thread
, and
Throwable
.
Depending on the CLDC version
java.lang.Math
might not contain operations for floating
point numbers.
java.lang.Class
provides only very limited support for reflection.
The following classes are available in CLDC 1.1 only:
Float
,
Double
,
java.lang.ref.
Reference, java.lang.ref.Reference, and java.lang.ref.WeakReference.
The
java.util
Package
Supported classes from
java.util
are
Calendar
,
Date
,
Hashtable
,
Random
,
Stack
,
TimeZone
, and
Vector
.
The Java 2 collection framework is not supported at all. The
Vector
class contains only the old
access methods
elementAt()
,
setElementAt()
, and
addElement()
, instead of the
get(),
set(),
and
add()
methods introduced with the Java 2 collection framework. The only time
zone required is GMT.
The
java.io
Package
Supported classes from
java.io
are
ByteArrayInputStream
,
ByteArrayOutputStream
,
DataInputStream
,
DataOutputStream
,
InputStream
,
InputStreamReader
,
OutputStream
,
OutputStreamWriter
,
PrintStream
,
Reader
, and
Writer
. As you can
infer from the list, all file-related classes are missing. The CLDC does not provide any
replacement, but MIDP provides the package
javax.microedition.rms
for persistent storage,
and PDAP adds a
FileConnection
interface to the
javax.microedition.io
package.
The
javax.microedition.io
Package
The package
javax.microedition.io
is mainly a compact replacement for the
java.net
"Networking: The Generic Connection Framework"). It provides a set of classes and interfaces
that let you establish different kinds of network connections.
Search WWH ::
Custom Search