From Linux Man Pages
NAME
idlj - The IDL-to-Java Compiler (RMI-IIOP version)
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 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 bind-
ings 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, Inheri-
tance 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 Inneritance Model and the Tie Model.
NEW in 1.4! 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 InvokeHan-
dler interface and the operations interface associated with the IDL interface the skeleton implements.
The PortableServer module for the PortableObjectAdapter (POA) defines the native Servant type. In the Java pro-
gramming 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 appli-
cation 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 bind-
ings that are compatible with older version of the Java programming language (prior to J2SE 1.4). 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 _MyImpleBase.java is generated. You must provide the implemen-
tation 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.
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:
MyImpl myImpl = new MyImpl ();
My POATie tie = new MyPOATie (myImpl);
orb.connect (tie);
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 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 older version of the IDL to Java language
mapping in versions of J2SE before 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 HelloOpera-
tions. But to use it with the ORB, you must wrap your implementation within My_Tie. For instance:
MyImpl myImpl = new MyImpl ();
My_Tie tie = new My_Tie (myImpl);
orb.connect (tie);
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 com-
mand:
idlj -i /includes My.idl
If My.idl also included Another.idl that resided in /moreIncludes, for example, then you would invoke the com-
piler 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 NT it is a
semicolon, on Solaris it is a colon, etc. For more information on includes, read the CLASSPATH 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 fol-
lowing 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:
Notice that MyOther.java was not generated because it is defined in an import-like #include. But E.java was gen-
erated 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 emit-
ted.
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.<companyname>. The Widgets package is not good enough. To follow convention, it should be com.abc.Wid-
gets. 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.con-
fig 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 options 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
Supresses warning messages.
-oldImplBase
Generates skeletons compatible with old (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
Wherever the type or module name type is encountered, replace it in the 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. Also note that the following package names cannot be translated:
� org
� 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
� %POA for the POA base class (
-fserver or -fall)
� %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:
� %POATie for the POA tie base class (
-fserverTie or -fallTie)
� %_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
� 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).
� The fixed IDL type is not supported.
Known Problems
None at this time.
CATEGORY