1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
|
$Id$
This is a simple CORBA example that has a module Bank with two
interfaces Account and AccountManager. The Account interface has
operations for balance, deposit and withdraw. It has a readonly
attribute for the Account Holder's name. It also has a user defined
exception which is raised for withdrawing more moneythen the current
balance. The AccountManager interface has methods to create and close
Accounts. It also has a method to shutdown the server.
run_test.pl : This is a perl script to run the server and client as :
------------
server -o ior_file
client -f ior_file
Passing the Server IOR to Clients:
---------------------------------
To keep this example simple, the server advertises its IOR in the
following manner - The server program writes its server object's IOR
to a ior_file. Later on, the client reads this IOR from the specified
ior_file and uses the <string_to_object> method to obtain a reference
to the server object.
For this mechanism to work, the file must be readable and writable. If
it doesn't exist, a new file is created by the server. Moreover, the
file path must be accessible to both the client and server.
If the client and server are on different machine, then there must be
a shared directory accessible by both. On UNIX system's this is
typically done via the NFS mount command. On Windows, the 'explorer'
application provides an option to share drives.
In general if no such file sharing option is available, then using the
the Naming Service mechanism is the only alternative, as described by
the -n option below. There are other command line options available
for the server and client which are also explained below.
server:
-------
server [-d] [-o IOR_file_name] [-n]
Options:
-------
-d Debug flag (It is additive more -d flags will give debugging).
When the server is started, you should see as the first line of output
something that looks like
iiop:1.0//danzon.cs.wustl.edu:10015/P35ad159600081a38/child_poa/server
(-ORBobjrefstyle url)
or
IOR:000000000000001649444c3a43756269745...
(-ORBobjrefstyle ior)
Using -d turns on debugging messages. This option is additive, i.e.,
the more -d options provided, the more debugging you can get. At the
moment, only 2 levels of debugging are implemented, and more than 2 -d
options are ignored.
-o This option creates an ior file for the server with the name ior_filename.
-n Use naming service
The file can be used by clients who wish to access the server directly
using this ior file. This obviates the need for the client to use the
naming service for getting the server ior. The client can use the -f
option to specify the file which contains the ior of the server (the
same file that was written by the server using the -o option).
client:
-------
client [-d] [-x] [-n iterations] [-b initial_balance] [-o Name_of_account_holder]
[-f IOR_file_name ] [-k IOR]
Options:
-------
-d Debug flag
-x Tells the server to shutdown at the end of the test.
-n Use naming service
-b initial balance
-o Name of the Account Holder
-k Read IOR from the command line. If this option is specified the client does not use
the Naming Service for locating the server. It just uses the ior file supplied with
this option.
-f Read IOR from the specified file. If this option is specified the client does not use
the Naming Service for locating the server. It just uses the ior file supplied with
this option.
The client executes the following tests :
1. Creating accounts with the same name to make sure the Account is
created only once and he gets back the same object reference each
time. This is confirmed by the server printing the message for
Creation of an account only once.
2. Creating accounts with different name to make sure a different
Account is created and a different IOR returned each time.
3. Creating an Account with some initial balance and then withdrawing
more than the current balance. The server throws an exception which is
passed to the client and the client displays the reason for the
exception.
|
