idlj(1)idlj(1)Nameidlj - The IDL-to-Java Compiler
idlj generates Java bindings from a given IDL file.
Synopsisidlj [ 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 @
http://docs.oracle.com/javase/7/docs/technotes/guides/idl/map‐
ping/jidlMapping.html. Some previous releases of the IDL-to-Java com‐
piler 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 skele‐
ton, 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.Portable‐
Server.Servant @
http://docs.oracle.com/javase/7/docs/api/org/omg/PortableServer/Ser‐
vant.html 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) @
http://docs.oracle.com/javase/7/docs/technotes/guides/idl/POA.html
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 dep‐
recated. 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 delega‐
tion model. Because it is not possible to generate ties and skeletons
at the same time, they must be generated separately. The following com‐
mands 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 implementa‐
tion. 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 indi‐
rection: 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 inter‐
face 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 vari‐
able. 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 directo‐
ries is a semicolon (;). This separator character is platform depen‐
dent. On the Windows platform, use a semicolon, on the Unix platform,
use a colon, etc. For more information on includes, see the Setting the
Classpath @
http://docs.oracle.com/javase/7/docs/technotes/tools/index.html#gen‐
eral.
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 fol‐
lowing 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:
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 follow‐
ing:
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
emits 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 bind‐
ings 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 direc‐
tory.
-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 defi‐
nitions. (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.
16 Mar 2012 idlj(1)
