WebLogic for IBM AS/400e Technical FAQ
- AS/400-specific differences in WebLogic
-
In general, how does WebLogic on the AS/400 differ from WebLogic on Windows or UNIX?
- WebLogic installation directory
- How do you run WebLogic utility programs on a client?
- Working with example files
- weblogicaux.jar is three files on AS/400 V4R3
- General questions about Java on AS/400
- How do you edit stream files on the AS/400?
- How do I set the WebLogic classpath on the AS/400?
- How do I set the WebLogic classpath on a client workstation?
- Why does the WebLogic Server still not find classes
when I've set the classpath?
- Can I use Qshell with Java and WebLogic on the AS/400?
- How can I improve Java performance on my AS/400?
- How do you create direct executable Java programs?
- How do you run an AS/400 program or CL command from Java?
- How should I set the STRWEBL command garbage collection parameters?
- Questions about installation
- How do I give WLADMIN privileges to an existing user?
- Installation failed. How can I find the problem?
- How do I uninstall WebLogic?
- Questions about using DB2 with WebLogic
- How do I set up DB2 to work with the WebLogic Server?
- What are the JDBC drivers for AS/400 DB2?
- More resources
AS/400-specific differences in WebLogic
In general, how does WebLogic on the AS/400 differ from WebLogic
on Windows or UNIX?
The WebLogic Java code is the same on all platforms. IBM has created a
Java environment for the AS/400 that is highly compatible with the
Java standard and at the same time able to exploit the strengths of
the AS/400. WebLogic is packaged for the AS/400 by creating
direct executables for all class files, adding AS/400 installation
commands, and creating a save file that you restore on your AS/400.
If you use WebLogic on Windows NT or UNIX, you will notice some
differences when you run WebLogic on the AS/400. The differences are
environmental, resulting from the Java virtual machine on the AS/400,
the powerful security system on the AS/400, or the design of the
OS/400 operating system. Also, since the AS/400 is designed as a
business server, you cannot run the graphical interfaces provided with
the WebLogic Server on the AS/400 -- you must run them from a client computer.
One of the primary features of the AS/400 Java environment is the
direct executable. The AS/400 JVM transforms Java class files into
AS/400 direct executables, resulting in faster execution than a
standard Java byte code interpreter. Although this conversion happens
automatically, it can be time-consuming and produce noticeable pauses
in execution. Also, the AS/400 CRTJVAPGM command that creates direct executables is
capable of various levels of optimization. The WebLogic classes are
transformed to direct executables with maximum optimization. We
recommend that you also transform your own Java classes before you
place your application into production on an AS/400.
WebLogic installation directory
WebLogic for IBM AS/400 installs in the AS/400 IFS in the /weblogic/version
directory, where version is the
three-digit WebLogic release number. For example, WebLogic release 4.5.0 installs
into the /weblogic/450 IFS
directory.
On UNIX and Windows, the installation location can be selected at
installation time. The WebLogic documentation often refers to the
weblogic/ directory as the
WebLogic installation directory. For AS/400, you can map this
to /weblogic/version.
How do you run WebLogic utility programs on a client?
The WebLogic Server runs on the AS/400. Other WebLogic utility programs
and example programs can also run on the AS/400 if they do not require
a windowing system. However, some WebLogic programs, such as the
WebLogic Console and the ZAC must be run on a Windows NT client
workstation. The programs can be loaded from the AS/400 and executed
in a JVM on the workstation.
Working with example files
The example files in the /weblogic/version/examples directory cannot be
altered without special permissions.
To try the examples out, first
copy them to another directory. You can use the build scripts for
Windows NT to build the examples on a workstation.
weblogicaux.jar is three files on AS/400 V4R3
The V4R3 JVM restricts .jar
files to 2MB. Therefore, in the V4R3 version, the weblogicaux.jar file is provided as four .jar files named weblogicaux0.jar, weblogicaux1.jar,
and weblogicaux2.jar. You must place each of these files in the
AS/400's CLASSPATH and in any client CLASSPATH that executes WebLogic
programs from the AS/400 file system.
The limit on .jar file size does
not exist on V4R4, so the weblogicaux.jar file is a single .jar file in the
WebLogic release for V4R4.
General questions about Java on AS/400
How do you edit stream files, such as Java program files, on the AS/400?
Java source code (.java files)
and other files such as the WebLogic properties file (/weblogic/version/weblogic.properties) are ASCII
stream files in the AS/400 IFS. You can't use the source entry
utility (SEU) to edit these files directly. Here are four alternatives
for editing these files:
- Map the IFS structure as a network drive on your PC using Client
Access. Then use your favorite PC editor to create and edit stream
files.
- Use FTP to move stream files between the AS/400 IFS directories
and your using PC. You can edit these files with your favorite editor
on the PC.
- There are two utilities that allow you to update stream files
directly on your AS/400. These utilities are EDTF (to create and edit
stream files) and DSPSTMF (to display stream files). These utilities
are available in V4R3 with the 5769SS1-SF49052 PTF. Applying the
PTF is not sufficient. Follow the instructions found in the cover
letter to finish installing the utilities.
- You can use STRSEU to edit a file as a source file member. Use
CPYTOSTMF to copy to an IFS ASCII stream file and CPYFMSTMF to copy
from an IFSASCII stream file.
How do I set the WebLogic classpath on the AS/400?
Before you start the WebLogic Server, or run any of the WebLogic utility programs on
the AS/400, you must add the WebLogic classes to your classpath. The
classpath must contain these directories and .jar files:
- OS/400 V4R3
-
- /weblogic/version/classes
- /weblogic/version/lib/weblogicaux0.jar
- /weblogic/version/lib/weblogicaux1.jar
- /weblogic/version/lib/weblogicaux2.jar
- /weblogic/version/license
- OS/400 V4R4
-
- /weblogic/version/classes
- /weblogic/version/lib/weblogicaux.jar
- /weblogic/version/license
The version directory is
the WebLogic release number. For example, WebLogic version 4.5.0 installs
into the /weblogic/450
directory.
There are a number of ways to set your classpath on the AS/400:
- Enter the classpath value as a parameter when you run the STRWEBL command. (Type WEBLOGIC/STRWEBL at the
prompt and press F4 instead of
ENTER.) The default value is
*ENVVAR, which means the
classpath is taken from the CLASSPATH environment variable. If the environment
variable is not set, you must type the path in the Classpath field.
- Use the ADDENVVAR command
to add the CLASSPATH variable
to your environment.
- If the CLASSPATH variable
is already in your environment, use CHGENVVAR to change it.
- You can use the WRKENVVAR
command to add new environment variables or modify existing
environment variables.
Here is the command to set the classpath on a V4R3 AS/400 using the ADDENVVAR command. (The command
is displayed on several lines here for clarity, but you should type
it without line breaks when you enter it.)
===> ADDENVVAR ENVVAR(CLASSPATH) VALUE(
'.:/weblogic/version/classes:
/weblogic/version/license:
/weblogic/version/lib/weblogicaux0.jar:
/weblogic/version/lib/weblogicaux1.jar:
/weblogic/version/lib/weblogicaux2.jar')
On a V4R4 AS/400, substitute /weblogic/version/lib/weblogicaux.jar for the
four .jar files.
How do I set the WebLogic classpath on a client workstation?
To run WebLogic utility programs on a client workstation, you first add
the WebLogic classes to the workstation's CLASSPATH environment variable. The workstation must
have Client Access installed, or a similar utility that allows the
client to have network access to the AS/400 file system.
Your classpath also needs to include the Java runtime classes.
In the following example, drive F: is mapped to the AS/400 file system, and the JDK is
installed in the c:\jdk
directory. The command, for a V4R3 system, is shown on multiple lines
for readability, but you should type it as a single command with no
breaks:
C:\>SET CLASSPATH=c:\jdk\lib\classes.zip;
f:\weblogic\version\classes;
f:\weblogic\version\license;
f:\weblogic\version\lib\weblogicaux0.jar;
f:\weblogic\version\lib\weblogicaux1.jar;
f:\weblogic\version\lib\weblogicaux2.jar
Why does the WebLogic Server still not find classes when I've set the classpath?
If you are having trouble with CLASSPATH on the AS/400, here are a couple of
things to look for:
-
The CLASSPATH must
not contain any spaces. Check that there are no spaces at the
beginning, end, or anywhere in the middle of the value.
- If you use Client Access, be very careful with Windows copy
and paste. When you paste the value at the AS/400 prompt, it may
be corrupted. It looks correct after you paste, but when you go
back and look at it later, you will notice missing characters.
For more help on setting your classpath, check our Administrators Guide, Setting classpath.
Can I use Qshell with Java and WebLogic on the AS/400?
You can use Qshell to run Java programs and WebLogic utilities, such as
utils.t3dbping and utils.licenses.
Warning. Never start
the WebLogic Server on the AS/400 with java
commands described in the WebLogic documents. Always use the WEBLOGIC/STRWEBL command to start
the WebLogic Server because it runs the server as the WEBLOGIC user. If you run the WebLogic Server
using a java command, the
server runs under your current user profile. Depending on your
profile, the WebLogic Server will have security problems when you run this way, or
in subsequent sessions that start with the
WEBLOGIC/STRWEBL command.
Your classpath must include the WebLogic classes. With Qshell, you
must also set the QIBM_MULTI_THREADED environment variable to 'Y' before you run the JAVA or RUNJAVA commands.
If you set environment variables in your AS/400 command session before
you start Qshell, the variables remain set in Qshell, unless a .profile file in your home directory
or the /etc/profile file
resets environment variables.
You can set environment variables for every interactive Qshell shell
you start with STRQSH or QSH by setting the CLASSPATH in the
.profile file in your home
directory.
An administrator can set environment variables globally by adding them
to the /etc/profile file,
which is executed whenever any user starts a Qshell shell with
the STRQSH or QSH commands.
To set the environment variables in Qshell, use the following commands at
the prompt, or add them to one of the profile files mentioned above:
$ export -s CLASSPATH=.:/weblogic/version/classes:
/weblogic/version/license:
/weblogic/version/lib/weblogicaux0.jar:
/weblogic/version/lib/weblogicaux1.jar:
/weblogic/version/lib/weblogicaux2.jar
$ export -s QIBM_MULTI_THREADED=Y
If you have a V4R4 system, substitute weblogicaux.jar for the four .jar files.
How can I improve Java performance on my AS/400?
The most important factor contributing to the performance of AS/400
Java applications is the use of the CRTJVAPGM command. This command transforms Java class
and jar files to program objects that contain fully compiled 64-bit
RISC machine instructions. The resulting object is called a DE
(Direct Executable). If a DE exists before the JVM executes a class,
there is a dramatic increase in performance. On the other hand, if
the DE does not exist, the JVM creates a DE on the fly, and performance
suffers. The next question has information about creating a DE.
There are many other ways to improve and analyze performance of AS/400
Java applications. A good starting place is AS/400e
series Java Information on the Web, particularly Building
AS/400 Applications with Java. This is the IBM Redbook titled
"AS/400 Appls with Java-Version 2". It covers many topics including
performance analysis and enhancement.
How do you create direct executable Java programs?
If you install or modify Java class files called by the WebLogic Server, you can
boost performance by creating an AS/400 direct executable for the
class with the CRTJVAPGM
command. Running this command once prevents the AS/400 JVM from
compiling the class every time it is loaded.
In particular, when you Install a
WebLogic license, you modify the WebLogicLicense.java file and run
the JAVA command to create a new class file. On the AS/400,
you should then run the CRTJVAPGM command on the
WebLogicLicense.class file so that the class is
not recompiled whenever it is loaded.
Here is the command to create a direct executable for the WebLogic license class:
===> CRTJVAPGM
CLSF('/weblogic/version/classes/WebLogicLicense.class')
OPTIMIZE(40)
You can choose an optimization level of 0, 10, 20, 30, or 40. A
higher level spends more time, but produces a faster direct
executable. The WebLogic direct executables are produced at optimization
level 40.
How do you run an AS/400 program from Java?
The AS/400 Toolbox for Java includes Access classes that provide
access to various AS/400 services, including the ability to run AS/400
programs and CL commands, and access AS400 files and objects. In
Java, you create an AS400 object for a specified AS/400 Server and
then use methods on that object to access AS/400 facilities. See the
AS/400
Toolbox for Java web page for examples and more information.
How should I set the STRWEBL command garbage collection parameters?
The WEBLOGIC/STRWEBL
command's default value for the "Garbage collection initial size"
parameter is 65536 (64MB). The default for the "Garbage collection
maximum size" is *NOMAX.
If you change these parameters, you should allocate at least 65536
kilobytes for the garbage collection initial size parameter. If you
choose to change *NOMAX to a
specific value for the maximum garbage collection size, make sure that
you use a size greater than the initial size, because the
AS/400 JVM's garbage collection mechanism performance degrades when
the initial and maximum garbage collection memory sizes are equal. The
STRWEBL command will not
permit a maximum smaller than the initial size.
Questions about installation
How do I give WLADMIN privileges to a user?
WebLogic administrative users have *ALL authority for the commands in
the WEBLOGIC library and *RWX authority on certain files in the /weblogic directory. To allow a
user to start and stop the server or to modify any of these files, you
can add GRPPRF(WLADMIN) to
their profiles.
To create a new user with authority to administer the WebLogic Server, use this
command:
===> CRTUSRPRF USRPRF(USERNAME) GRPPRF(WLADMIN)
To add authority to administer the WebLogic Server to an existing user, use this command:
===> CHGUSRPRF USRPRF(USERNAME) GRPPRF(WLADMIN)
Installation failed. How can I find the problem?
If the WEBLOGIC/INSWEBL command fails, follow this procedure to
retry the installation and identify the failure:
-
If the /weblogic IFS directory
exists, make sure that it belongs to the WEBLOGIC user, which is true
if the directory was created with the INSWEBL command. If the directory was created with
another user profile, INSWEBL is unable to set permissions in the
directory.
- Delete the WEBLOGIC library:
===> DLTLIB WEBLOGIC
- Restore from the save file:
===> RSTLIB SAVLIB(WEBLOGIC) DEV(*SAVF) SAVF(QGPL/WEBLversion)
- Request detailed command output:
===> CALL QCMD
- Run INSWEBL again:
===> WEBLOGIC/INSWEBL
If the installation fails again, the additional information displayed
when you use the CALL QCMD command
will help technical support diagnose the problem.
How do I uninstall WebLogic?
Follow these steps to uninstall WebLogic:
- Make sure that the WebLogic Server is not running. Run the WRKACTJOB command and look for STRWEBL. If the WebLogic Server is running,
shut it down before you continue.
- Delete the WEBLOGIC library:
===> DLTLIB WEBLOGIC
- Delete the save file:
===> DLTF WEBLversion.SAVF
- Save any custom files you want to save from the /WEBLOGIC directory to another
directory. Otherwise, you will lose these file when you delete the
/WEBLOGIC directory in next
step.
- Remove the /WEBLOGIC
directory. If you have Qshell, you can carefully use this command to remove the
directory:
$ rm -r /WEBLOGIC
If you do not have Qshell, use Windows Explorer from a client machine.
In either case, it takes a very long time to remove the /WEBLOGIC directory from the AS/400
file system.
- Remove the WLADMIN and WEBLOGIC profiles:
===> DLTUSRPRF USRPRF(WLADMIN)
===> DLTUSRPRF USRPRF(WEBLOGIC)
Questions about using DB2 with WebLogic
How do I set up DB2 for use with WebLogic?
You can use the WebLogic Server in a multitier JDBC connection to DB2 -- the client
application connects to the WebLogic Server using WebLogic JDBC, and the WebLogic Server connects
to DB2 using one of IBM's JDBC drivers for
DB2.
You can define a connection pool in the weblogic.properties file. The connection pool specifies
a number of database connections that the WebLogic Server opens and allocates to
clients that request them. Opening a database connection is a fairly
expensive operation, and setting up a pool of shared connections
minimize the number of open operations. A pool is especially beneficial
when a large number of clients execute short-duration transactions.
Before the WebLogic Server can connect to DB2, there must be an entry in the AS/400
Relational Database Directory. You can use the
DSPRDBDIRE command to see if the entry has been
made. If there is no entry, use the ADDRDBDIRE entry to add the entry.
the WebLogic Server also requires a JDBC driver for DB2. The next question
describes the JDBC drivers available from IBM.
To define a connection pool, you add a weblogic.jdbc.connectionPool property to the weblogic.properties file. Here is the
syntax for the property:
weblogic.jdbc.connectionPool.virtualName=\
url=jdbc:db2:rdbdire/defCollection,\
driver=jdbcDriver,\
initialCapacity=initialN,\
maxCapacity=maxN,\
capacityIncrement=incrementInterval,\
props=jdbcConnectionProps
| Parameter |
Description |
| virtualName |
A name for the connection pool. Although this is an
optional parameter, you need it to reference in the Access Control Lists (ACLs)
that control access to the connection pool. |
| rdbdire |
The name of local database in the
Relational Database Directory. You can see this name with the DSPRDBDIRE command. |
| defCollection |
The default collection is "QGPL".
You can specify a different default collection with this parameter.
|
| driver |
The full package name of the JDBC driver for
DB2. The JDBC drivers that IBM provides for DB2 are described in
the next question. |
| initialCapacity |
The number of database connections to
open initially. Use 0 if you want to wait until a client requests
a connection. Otherwise, the WebLogic Server opens the connections when it starts up. |
| maxCapacity |
The maximum number of connections to
open. When all connections in a pool are in use, the WebLogic Server opens more
connections until the maximum number are open. When no more connections
are available in the pool and no more can be opened, client requests are
refused. |
| capcityIncrement |
The number of connections to open at a time. When
all connections in the pool are in use the WebLogic Server adds this many connections to
the pool, up to the maximum specified
|
| props |
Properties to pass to the JDBC
driver, in a semicolon-separated list. The properties needed for
DB2 include the database username and password, and the server
name.
|
If you have problems with a DB2 JDBC connection, this AS/400
JDBC FAQ is a good place to look for help.
Here is an example connection pool, with the virtual name "finance",
that uses the Type 2 JDBC driver. The database name
(displayed by the
DSPRDBDIRE command) is "FIN400E". The pool is defined so that
the WebLogic Server does not open any connections until one is requested, and then
opens 3 connections at a time until a maximum of 12 connections are in
the pool. The connections are opened by user "nick" with the password
"HedGe!HoG89".
weblogic.jdbc.connectionPool.finance=\
url=jdbc:db2://FIN400E,\
driver=com.ibm.db2.jdbc.app.DB2Driver,\
initialCapacity=0,\
maxCapacity=12,\
capcityIncrement=3,\
props=user=nick;password=HedGe!HoG89;server=LOCALHOST
A connection pool also requires an ACL to allow clients to obtain
a connection from the pool, and an ACL that allows someone to
reset the connection pool if needed:
weblogic.allow.reserve.weblogic.jdbc.connectionPool.virtualName=list
weblogic.allow.reset.weblogic.jdbc.connectionPool.virtualName=list
For example, the following ACLs allow anyone (group "everyone") to use a
connection from the "finance" pool, but only users "nick" and "tracey"
can reset the connection pool:
weblogic.allow.reserve.weblogic.jdbc.connectionPool.finance=everyone
weblogic.allow.reset.weblogic.jdbc.connectionPool.finance=nick tracey
What are the JDBC drivers for AS/400 DB2?
IBM provides type 2 and type 4 JDBC drivers for AS/400 DB2. The type
2 driver is native AS/400 code, appropriate when a Java application
(such as the WebLogic Server) and DB2 are executing on AS/400 machines.
The type 4 driver is pure Java and can execute on the AS/400 or on
another platform running Java. If you run WebLogic on a non-AS/400
computer, you must use the type 4 driver on that computer. Also, if
you write applets that are served by WebLogic on the AS/400 computer,
you must install the type 4 driver so that browsers on any platform
can access DB2 on the AS/400.
The type 2 driver is packaged with the AS/400 Developer Kit for Java
(5769-JV1). The type 4 driver is packaged with AS/400 Toolbox for Java
(5769-JC1).
When you use a JDBC driver, whether in a two-tier or three-tier
configuration, you need to know the full pathname to the driver class
file and the connect URL for the driver. Here is the information you
need for the AS/400 type 2 and type 4 drivers:
| Type 2 driver |
| Package |
5769-JV1 |
Driver class |
com.ibm.db2.jdbc.app.DB2Driver |
Driver URL |
jdbc:db2://hostname/database |
| Type 4 driver |
| Package |
5769-JC1 |
Driver class |
com.ibm.as400.access.AS400JDBCDriver |
Driver URL |
jdbc:as400://hostname/database |
