blob: f2ccfcc7e13a0806c9aee929019aab2326e0df74 (
plain) (
tree)
|
|
<?xml version="1.0" encoding="latin1" ?>
<!DOCTYPE chapter SYSTEM "chapter.dtd">
<chapter>
<header>
<copyright>
<year>1997</year><year>2009</year>
<holder>Ericsson AB. All Rights Reserved.</holder>
</copyright>
<legalnotice>
The contents of this file are subject to the Erlang Public License,
Version 1.1, (the "License"); you may not use this file except in
compliance with the License. You should have received a copy of the
Erlang Public License along with this software. If not, it can be
retrieved online at http://www.erlang.org/.
Software distributed under the License is distributed on an "AS IS"
basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
the License for the specific language governing rights and limitations
under the License.
</legalnotice>
<title>Orber Examples</title>
<prepared></prepared>
<docno></docno>
<date>1997-05-20</date>
<rev>A</rev>
<file>ch_example.xml</file>
</header>
<section>
<title>A Tutorial on How to Create a Simple Service</title>
<section>
<title>Interface Design</title>
<p>This example uses a very simple stack server. The specification
contains two interfaces: the first is the Stack itself and the
other is the StackFactory which is used to create new stacks.
The specification is in the file <c>stack.idl</c>.</p>
<codeinclude file="../../examples/Stack/stack.idl" tag="" type="c"></codeinclude>
</section>
<section>
<title>Generating Erlang Code</title>
<p>Run the IDL compiler on this file by calling the <c>ic:gen/1</c> function </p>
<code type="erl">
1> ic:gen("stack").
</code>
<p>This will produce the client stub and server skeleton. Among other files a stack API module named <c>StackModule_Stack.erl</c>
will be produced.
This will produce among other files a stack API module called
<c>StackModule_Stack.erl</c> which contains the client stub and
the server skeleton. </p>
</section>
<section>
<title>Implementation of Interface</title>
<p>After generating the API stubs and the server skeletons it is time to
implement the servers and if no special options are sent
to the IDL compiler the file name should be
<c><![CDATA[<global interface name>_impl.erl]]></c>, in our case
<c>StackModule_Stack_impl.erl</c>.</p>
<codeinclude file="../../examples/Stack/StackModule_Stack_impl.erl" tag="" type="erl"></codeinclude>
<p>We also have the factory interface which is used to create new stacks
and that implementation is in the file
<c>StackModule_StackFactory_impl.erl</c>.</p>
<codeinclude file="../../examples/Stack/StackModule_StackFactory_impl.erl" tag="" type="erl"></codeinclude>
<p>To start the factory server one executes the function
<c>StackModule_StackFactory:oe_create/0</c> which in this
example is done in the module <c>stack_factory.erl</c> where
the started service is also registered in the name service.</p>
<codeinclude file="../../examples/Stack/stack_factory.erl" tag="" type="erl"></codeinclude>
</section>
<section>
<title>Writing a Client in Erlang</title>
<p>At last we will write a client to access our service.</p>
<codeinclude file="../../examples/Stack/stack_client.erl" tag="" type="erl"></codeinclude>
</section>
<section>
<title>Writing a Client in Java</title>
<p>To write a Java client for Orber you must have another
ORB that uses IIOP for client-server communication and supports a
Java language mapping. It must also have support for
<c>IDL:CosNaming/NamingContext</c> or <c>IDL:CosNaming/NamingContextExt</c>.
If the client ORB support Interoperable Naming Service the Java Client
can look like:</p>
<codeinclude file="../../examples/Stack/StackClient.java" tag="" type="c"></codeinclude>
<note>
<p>If an ORB does not support CosNaming at all the <c>cos_naming.idl</c>
file must be compiled and imported.</p>
</note>
</section>
<section>
<title>Building the Example</title>
<p>To build the example for access from a Java client you need a Java
enabled ORB (e.g. JavaIDL). The example below is based on JDK-1.4.</p>
<code type="none">
fingolfin 127> erl
Erlang (BEAM) emulator version 5.5.4.3 [async-threads:0] [hipe] [kernel-poll:false]
Eshell V5.5.4.3 (abort with ^G)
1> ic:gen(stack).
Erlang IDL compiler version 4.2.12
ok
2> make:all().
Recompile: StackModule_EmptyStack
Recompile: StackModule_Stack
Recompile: StackModule_StackFactory
Recompile: StackModule_StackFactory_impl
Recompile: StackModule_Stack_impl
Recompile: oe_stack
Recompile: stack_client
Recompile: stack_factory
up_to_date
3>
BREAK: (a)bort (c)ontinue (p)roc info (i)nfo (l)oaded
(v)ersion (k)ill (D)b-tables (d)istribution
a
fingolfin 128> idlj stack.idl
fingolfin 129> javac StackModule/*.java
fingolfin 130> javac *.java
fingolfin 131> cp StackClient.class StackModule/
</code>
</section>
<section>
<title>How to Run Everything</title>
<p>Below is a short transcript on how to run Orber.</p>
<code type="none">
fingolfin 143> erl
Erlang (BEAM) emulator version 5.5.4.3 [async-threads:0] [hipe] [kernel-poll:false]
Eshell V5.5.4.3 (abort with ^G)
1> orber:jump_start([{interceptors, {native, [orber_iiop_tracer_silent]}}]).
ok
2> oe_stack:oe_register().
ok
3> stack_factory:start().
ok
4> stack_client:run().
1
1
7
4
ok
5>
</code>
<p>Before testing the Java part of this example generate and compile Java classes for
<c>orber/examples/stack.idl</c> as seen in the build example.
To run the Java client use the following command:</p>
<code type="none">
fingolfin 38> java StackModule.StackClient "corbaname::localhost:4001#StackFactory"
1
1
7
4
Empty stack
fingolfin 39>
</code>
</section>
</section>
</chapter>
|
