rmic

You use the rmic compiler to generate stub and skeleton class files using the Java Remote Method Protocol (JRMP) and stub and tie class files (IIOP protocol) for remote objects. The rmic compiler generates Object Management Group (OMG) Interface Definition Language (IDL).

Synopsis

rmic [ options ] package-qualified-class-names
options

This represent the command-line options for thermic compiler. See Options for the rmic Compiler.

package-qualified-class-names

Class names that include their packages, for example, java.awt.Color.

Description

Deprecation Note: Support for static generation of Java Remote Method Protocol (JRMP) stubs and skeletons has been deprecated. Oracle recommends that you use dynamically generated JRMP stubs instead, eliminating the need to use this tool for JRMP-based applications.

The rmic compiler generates stub and skeleton class files using the JRMP and stub and tie class files (IIOP protocol) for remote objects. These class files are generated from compiled Java programming language classes that are remote object implementation classes. A remote implementation class is a class that implements the interface java.rmi.Remote. The class names in the rmic command must be for classes that were compiled successfully with the javac command and must be fully package qualified. For example, running the rmic command on the class file name HelloImpl as shown here creates the HelloImpl_Stub.class file in the hello subdirectory (named for the class's package):

rmic hello.HelloImpl

A skeleton for a remote object is a JRMP protocol server-side entity that has a method that dispatches calls to the remote object implementation.

A tie for a remote object is a server-side entity similar to a skeleton, but communicates with the client with the IIOP protocol.

A stub is a client-side proxy for a remote object that’s responsible for communicating method invocations on remote objects to the server where the actual remote object implementation resides. A client's reference to a remote object, therefore, is actually a reference to a local stub.

By default, the rmic command generates stub classes that use the 1.2 JRMP stub protocol version only, as though the -v1.2 option were specified. See Options for the rmic Compiler.

A stub implements only the remote interfaces, and not local interfaces that the remote object also implements. Because a JRMP stub implements the same set of remote interfaces as the remote object, a client can use the Java programming language built-in operators for casting and type checking. For IIOP, the PortableRemoteObject.narrow method must be used.

Options for the rmic Compiler

-bootclasspath path

Overrides the location of bootstrap class files.

-classpath path

Specifies the path the rmic command uses to look up classes. This option overrides the default or the CLASSPATH environment variable when it is set. Directories are separated by colons or semicolons, depending on your operating system. The following is the general format for path:

  • Oracle Solaris, Linux, and OS X: .:your_path, for example: .:/usr/local/java/classes

  • Windows: .;your_path, for example: .;/usr/local/java/classes

-d directory

Specifies the root destination directory for the generated class hierarchy. You can use this option to specify a destination directory for the stub, skeleton, and tie files.

  • Oracle Solaris, Linux, and OS X: For example, the following command places the stub and skeleton classes derived from MyClass into the directory /java/classes/exampleclass:

    rmic -d /java/classes exampleclass.MyClass
    
  • Windows: For example, the following command places the stub and skeleton classes derived from MyClass into the directory C:\java\classes\exampleclass:

    rmic -d C:\java\classes exampleclass.MyClass
    

If the -d option isn’t specified, then the default behavior is as though -d was specified. The package hierarchy of the target class is created in the current directory, and stub/tie/skeleton files are placed within it.

-g

Enables the generation of all debugging information, including local variables. By default, only line number information is generated.

-idl

Causes the rmic command to generate OMG IDL for the classes specified and any classes referenced. IDL provides a purely declarative, programming language-independent way to specify an API for an object. The IDL is used as a specification for methods and data that can be written in and called from any language that provides CORBA bindings. This includes Java and C++ among others.

When the -idl option is used, other options also include:

  • The -always or -alwaysgenerate options force regeneration even when existing stubs/ties/IDL are newer than the input class.

  • The -factory option uses the factory keyword in generated IDL.

  • The -idlModule from JavaPackage[.class] toIDLModule specifies IDLEntity package mapping, for example: -idlModule my.module my::real::idlmod.

  • -idlFile fromJavaPackage[.class] toIDLFile specifies IDLEntity file mapping, for example: -idlFile test.pkg.X TEST16.idl.

-iiop

Causes the rmic command to generate IIOP stub and tie classes, rather than JRMP stub and skeleton classes. A stub class is a local proxy for a remote object and is used by clients to send calls to a server. Each remote interface requires a stub class, which implements that remote interface. A client reference to a remote object is a reference to a stub. Tie classes are used on the server side to process incoming calls, and dispatch the calls to the proper implementation class. Each implementation class requires a tie class.

If you call the rmic command with the -iiop, then it generates stubs and ties that conform to this naming convention:

_implementationName_stub.class
_interfaceName_tie.class

When you use the -iiop option, other options also include:

  • The -always or -alwaysgenerate options force regeneration even when existing stubs/ties/IDL are newer than the input class.

  • The -nolocalstubs option means don’t create stubs optimized for same-process clients and servers.

  • The -noValueMethods option must be used with the -idl option. The -noValueMethods option prevents the addition of valuetype methods and initializers to emitted IDL. These methods and initializers are optional for value types, and are generated unless the -noValueMethods option is specified with the -idl option.

  • The -poa option changes the inheritance from org.omg.CORBA_2_3.portable.ObjectImpl to org.omg.PortableServer.Servant. 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 can be called by the application programmer, and methods that are called by the POA and that can be overridden by the user to control aspects of servant behavior. This behavior is based on the OMG IDL to Java Language Mapping Specification, CORBA V 2.3.1 ptc/00-01-08.pdf .

-Jargument

Used with any Java command, the -J option passes the argument that follows it (no spaces between the -J and the argument) to the Java interpreter.

-keep or -keepgenerated

Retains the generated .java source files for the stub, skeleton, and tie classes and writes them to the same directory as the .class files.

-nowarn

Turns off warnings. When the -nowarn options is used, the compiler doesn’t print warnings.

-nowrite

Doesn’t write compiled classes to the file system.

-vcompat (deprecated)

Generates stub and skeleton classes that are compatible with both the 1.1 and 1.2 JRMP stub protocol versions. This option was the default in releases before 5.0. The generated stub classes use the 1.1 stub protocol version when loaded in a JDK 1.1 virtual machine and use the 1.2 stub protocol version when loaded into a 1.2 (or later) virtual machine. The generated skeleton classes support both 1.1 and 1.2 stub protocol versions. The generated classes are relatively large to support both modes of operation. Note: This option has been deprecated. See Description.

-verbose

Causes the compiler and linker to print messages about what classes are being compiled and what class files are being loaded.

-v1.1 (deprecated)

Generates stub and skeleton classes for the 1.1 JRMP stub protocol version only. The -v1.1 option is useful only for generating stub classes that are serialization-compatible with existing, statically deployed stub classes generated by the rmic command from JDK 1.1 that can’t be upgraded (and dynamic class loading isn’t being used). Note: This option has been deprecated. See Description.

-v1.2 (deprecated)

(Default) Generates stub classes for the 1.2 JRMP stub protocol version only. No skeleton classes are generated because skeleton classes aren’t used with the 1.2 stub protocol version. The generated stub classes don’t work when they’re loaded into a JDK 1.1 virtual machine. Note: This option has been deprecated. See Description.

Environment Variables

CLASSPATH

Used to provide the system a path to user-defined classes.

  • Oracle Solaris, Linux, OS X: Directories are separated by colons, for example: .:/usr/local/java/classes.

  • Windows: Directories are separated by colons, for example: .;C:\usr\local\java\classes.