NAME
idlj - The IDL-to-Java Compiler
idlj generates Java bindings from a given IDL file.
Synopsis
idlj [ options ] idl-file
where idl-file is the name of a file containing Interface Definition
Language (IDL) definitions. Options may appear in any order, but must
precede the idl-file.
Description
The IDL-to-Java Compiler generates the Java bindings for a given IDL
file. For binding details, see the OMG IDL to Java Language Language
Mapping Specification. Some previous releases of the IDL-to-Java
compiler were named idltojava.
Emitting Client and Server Bindings
To generate Java bindings for an IDL file named My.idl: idlj My.idl
This generates the client-side bindings and is equivalent to: idlj
-fclient My.idl
The client-side bindings do not include the server-side skeleton. If
you want to generate the server-side bindings for the interfaces:
idlj -fserver My.idl
Server-side bindings include the client-side bindings plus the
skeleton, all of which are POA (that is, Inheritance Model) classes.
If you want to generate both client and server-side bindings, use
one of the following (equivalent) commands: idlj -fclient -fserver
My.idl
idlj -fall My.idl
There are two possible server-side models: the Inheritance Model and
the Tie Delegation Model.
The default server-side model is the Portable Servant Inheritance
Model. Given an interface My defined in My.idl, the file MyPOA.java
is generated. You must provide the implementation for My and it must
inherit from MyPOA.
MyPOA.java is a stream-based skeleton that extends
org.omg.PortableServer.Servant and implements the InvokeHandler
interface and the operations interface associated with the IDL
interface the skeleton implements.
The PortableServer module for the Portable Object Adapter (POA)
defines the native Servant type. In the Java programming language,
the Servant type is mapped to the Java
org.omg.PortableServer.Servant class. It serves as the base class
for all POA servant implementations and provides a number of methods
that may be invoked by the application programmer, as well as
methods which are invoked by the POA itself and may be overridden by
the user to control aspects of servant behavior.
Another option for the Inheritance Model is to use the -oldImplBase
flag in order to generate server-side bindings that are compatible
with versions of the Java programming language prior to J2SE 1.4.
Note that using the -oldImplBase flag is non-standard: these APIs
are being deprecated. You would use this flag ONLY for compatibility
with existing servers written in J2SE 1.3. In that case, you would
need to modify an existing MAKEFILE to add the -oldImplBase flag to
the idlj compiler, otherwise POA-based server-side mappings will be
generated. To generate server-side bindings that are backwards
compatible:
idlj -fclient -fserver -oldImplBase My.idl
idlj -fall -oldImplBase My.idl
Given an interface My defined in My.idl, the file _MyImplBase.java
is generated. You must provide the implementation for My and it must
inherit from _MyImplBase.
The other server-side model is called the Tie Model. This is a
delegation model. Because it is not possible to generate ties and
skeletons at the same time, they must be generated separately. The
following commands generate the bindings for the Tie Model:
idlj -fall My.idl
idlj -fallTIE My.idl
For the interface My, the second command generates MyPOATie.java.
The constructor to MyPOATie takes a delegate. In this example, using
the default POA model, the constructor also needs a poa. You must
provide the implementation for delegate, but it does not have to
inherit from any other class, only the interface MyOperations. But
to use it with the ORB, you must wrap your implementation within
MyPOATie. For instance:
ORB orb = ORB.init(args, System.getProperties());
// Get reference to rootpoa & activate the POAManager
POA rootpoa = (POA)orb.resolve_initial_references("RootPOA");
rootpoa.the_POAManager().activate();
// create servant and register it with the ORB
MyServant myDelegate = new MyServant();
myDelegate.setORB(orb);
// create a tie, with servant being the delegate.
MyPOATie tie = new MyPOATie(myDelegate, rootpoa);
// obtain the objectRef for the tie
My ref = tie._this(orb);
You might want to use the Tie model instead of the typical
Inheritance model if your implementation must inherit from some
other implementation. Java allows any number of interface
inheritance, but there is only one slot for class inheritance. If
you use the inheritance model, that slot is used up . By using the
Tie Model, that slot is freed up for your own use. The drawback is
that it introduces a level of indirection: one extra method call
occurs when invoking a method.
To generate server-side, Tie model bindings that are compatible with
versions of the IDL to Java language mapping in versions prior to
J2SE 1.4.
idlj -oldImplBase -fall My.idl
idlj -oldImplBase -fallTIE My.idl
For the interface My, this will generate My_Tie.java. The
constructor to My_Tie takes a impl. You must provide the
implementation for impl, but it does not have to inherit from any
other class, only the interface HelloOperations. But to use it with
the ORB, you must wrap your implementation within My_Tie. For
instance:
ORB orb = ORB.init(args, System.getProperties());
// create servant and register it with the ORB
MyServant myDelegate = new MyServant();
myDelegate.setORB(orb);
// create a tie, with servant being the delegate.
MyPOATie tie = new MyPOATie(myDelegate);
// obtain the objectRef for the tie
My ref = tie._this(orb);
Specifying Alternate Locations for Emitted Files
If you want to direct the emitted files to a directory other than
the current directory, invoke the compiler as:
idlj -td /altdir My.idl
For the interface My, the bindings will be emitted to
/altdir/My.java, etc., instead of ./My.java.
Specifying Alternate Locations for Include Files
If My.idl included another idl file, MyOther.idl, the compiler
assumes that MyOther.idl resides in the local directory. If it
resides in /includes, for example, then you would invoke the
compiler with the following command: idlj -i /includes My.idl
If My.idl also included Another.idl that resided in /moreIncludes,
for example, then you would invoke the compiler with the following
command: idlj -i /includes -i /moreIncludes My.idl
Since this form of include can become irritatingly long, another
means of indicating to the compiler where to search for included
files is provided. This technique is similar to the idea of an
environment variable. Create a file named idl.config in a directory
that is listed in your CLASSPATH. Inside of idl.config, provide a
line with the following form: includes=/includes;/moreIncludes
The compiler will find this file and read in the includes list. Note
that in this example the separator character between the two
directories is a semicolon (;). This separator character is platform
dependent. On the Windows platform, use a semicolon, on the Unix
platform, use a colon, etc. For more information on includes, read
the CLASSPATH (Solaris) or CLASSPATH (Windows) documentation.
Emitting Bindings for Include Files
By default, only those interfaces, structs, etc, that are defined in
the idl file on the command line have Java bindings generated for
them. The types defined in included files are not generated. For
example, assume the following two idl files: My.idl
#include <MyOther.idl>
interface My
{
};
MyOther.idl
interface MyOther
{
};
The following command will only generate the java bindings for My:
idlj My.idl
To generate all of the types in My.idl and all of the types in the
files that My.idl includes (in this example, MyOther.idl), use the
following command: idlj -emitAll My.idl
There is a caveat to the default rule. #include statements which
appear at global scope are treated as described. These #include
statements can be thought of as import statements. #include
statements which appear within some enclosing scope are treated as
true #include statements, meaning that the code within the included
file is treated as if it appeared in the original file and,
therefore, Java bindings are emitted for it. Here is an example:
My.idl
#include <MyOther.idl>
interface My
{
#include <Embedded.idl>
}; MyOther.idl
interface MyOther
{
}; Embedded.idl
enum E {one, two, three};
Running the following command: idlj My.idl
will generate the following list of Java files: ./MyHolder.java
./MyHelper.java
./_MyStub.java
./MyPackage
./MyPackage/EHolder.java
./MyPackage/EHelper.java
./MyPackage/E.java
./My.java
Notice that MyOther.java was not generated because it is defined in
an import-like #include. But E.java was generated because it was
defined in a true #include. Also notice that since Embedded.idl was
included within the scope of the interface My, it appears within the
scope of My (that is,in MyPackage).
If the -emitAll flag had been used in the previous example, then all
types in all included files would be emitted.
Inserting Package Prefixes
Suppose that you work for a company named ABC that has constructed
the following IDL file:
Widgets.idl
module Widgets
{
interface W1 {...};
interface W2 {...};
};
Running this file through the IDL-to-Java compiler will place the
Java bindings for W1 and W2 within the package Widgets. But there is
an industry convention that states that a company's packages should
reside within a package named com.<company name>. The Widgets
package is not good enough. To follow convention, it should be
com.abc.Widgets. To place this package prefix onto the Widgets
module, execute the following: idlj -pkgPrefix Widgets com.abc
Widgets.idl
If you have an IDL file which includes Widgets.idl, the -pkgPrefix
flag must appear in that command also. If it does not, then your IDL
file will be looking for a Widgets package rather than a
com.abc.Widgets package.
If you have a number of these packages that require prefixes, it
might be easier to place them into the idl.config file described
above. Each package prefix line should be of the form:
PkgPrefix.<type>=<prefix>
So the line for the above example would be:
PkgPrefix.Widgets=com.abc
The use of this option does not affect the Repository ID.
Defining Symbols Before Compilation
You may need to define a symbol for compilation that is not defined
within the IDL file, perhaps to include debugging code in the
bindings. The command idlj -d MYDEF My.idl
is the equivalent of putting the line #define MYDEF inside My.idl.
Preserving Pre-Existing Bindings
If the Java binding files already exist, the -keep flag will keep
the compiler from overwriting them. The default is to generate all
files without considering if they already exist. If you've
customized those files (which you should not do unless you are very
comfortable with their contents), then the -keep option is very
useful. The command idlj -keep My.idl
emit all client-side bindings that do not already exist.
Viewing Progress of Compilation
The IDL-to-Java compiler will generate status messages as it
progresses through its phases of execution. Use the -v option to
activate this "verbose" mode: idlj -v My.idl
By default the compiler does not operate in verbose mode.
Displaying Version Information
To display the build version of the IDL-to-Java compiler, specify
the -version option on the command-line:
idlj -version
Version information also appears within the bindings generated by
the compiler. Any additional options appearing on the command-line
are ignored.
Options
-d symbol
This is equivalent to the following line in an IDL file:
#define symbol
-emitAll
Emit all types, including those found in #include files.
-fside
Defines what bindings to emit. side is one of client, server,
serverTIE, all, or allTIE. The -fserverTIE and -fallTIE options
cause delegate model skeletons to be emitted. Assumes -fclient if
the flag is not specified.
-i include-path
By default, the current directory is scanned for included files.
This option adds another directory.
-keep
If a file to be generated already exists, do not overwrite it. By
default it is overwritten.
-noWarn
Suppresses warning messages.
-oldImplBase
Generates skeletons compatible with pre-1.4 JDK ORBs. By default,
the POA Inheritance Model server-side bindings are generated.
This option provides backward-compatibility with older versions
of the Java programming language by generating server-side
bindings that are ImplBase Inheritance Model classes.
-pkgPrefix type prefix
Wherever type is encountered at file scope, prefix the generated
Java package name with prefix for all files generated for that
type. The type is the simple name of either a top-level module,
or an IDL type defined outside of any module.
-pkgTranslate type package
Whenever the module name type is encountered in an identifier,
replace it in the identifier with package for all files in the
generated Java package. Note that pkgPrefix changes are made
first. type is the simple name of either a top-level module, or
an IDL type defined outside of any module, and must match the
full package name exactly.
If more than one translation matches an identifier, the longest
match is chosen. For example, if the arguments include:
-pkgTranslate foo bar -pkgTranslate foo.baz buzz.fizz
The following translations would occur:
foo => bar
foo.boo => bar.boo
foo.baz => buzz.fizz
foo.baz.bar => buzz.fizz.bar
The following package names cannot be translated:
o org
o org.omg or any subpackages of org.omg
Any attempt to translate these packages will result in uncompilable
code, and the use of these packages as the first argument after
-pkgTranslate will be treated as an error.
-skeletonName xxx%yyy
Use xxx%yyy as the pattern for naming the skeleton. The defaults
are:
o %POA for the POA base class (-fserver or -fall)
o _%ImplBase for the oldImplBase class (-oldImplBase and
(-fserver or -fall))
-td dir
Use dir for the output directory instead of the current
directory.
-tieName xxx%yyy
Name the tie according to the pattern. The defaults are:
o %POATie for the POA tie base class (-fserverTie or -fallTie)
o %_Tie for the oldImplBase tie class (-oldImplBase and
(-fserverTie or -fallTie))
-nowarn, -verbose
Verbose mode.
-version
Display version information and terminate.
See the Description section for more option information.
Restrictions:
o Escaped identifiers in the global scope may not have the same
spelling as IDL primitive types, Object, or ValueBase. This is
because the symbol table is pre-loaded with these identifiers;
allowing them to be redefined would overwrite their original
definitions. (Possible permanent restriction).
o The fixed IDL type is not supported.
Known Problems:
o No import generated for global identifiers. If you invoke on an
unexported local impl, you do get an exception, but it seems to be
due to a NullPointerException in the ServerDelegate DSI code.
07 Aug 2006 idlj(1)