Avitek Medical Records Development Tutorials

Developing the MedRec Applications

Tutorial 5: Creating the MedRec Project Directory

This tutorial describes how to create the main project directory that holds the MedRec source files and compiled classes. The tutorial also explains the high-level directory structure and contents for the MedRec application suite components.

Tutorials that follow provide more detail about the development directory structure and WebLogic Server Ant tasks that help you easily build and deploy Enterprise Applications and their subcomponents—Web applications, EJBs, and Web services.

The preferred BEA method for building applications with WebLogic Server is Apache Ant. Ant is a Java-based build tool. One of the benefits of Ant is that is it is extended with Java classes, rather than with shell-based commands. BEA provides numerous Ant extension classes to help you compile, build, deploy, and package applications in the WebLogic Server split development directory environment.

This tutorial includes the following sections:

Prerequisites

Before starting this tutorial:

Create the MedRec domain and MedRec server, and start the MedRec administration server. See Tutorial 1: Creating a WebLogic Domain and Server Instance for Development.
Start the PointBase database management system. See Tutorial 2: Starting the PointBase Development Database.
Use the Administration Console to configure the resources needed to run the MedRec applications. See Tutorial 3: Configuring WebLogic Server Resources with the Administration Console.

Procedure

To create the source directory structure for the MedRec application suite:

Step 1: Create the tutorial project directory.

Begin by creating a top-level project directory in which you will store source and output files for the MedRec Enterprise Applications and client programs. Name the directory medrec_tutorial:

prompt> mkdir c:\medrec_tutorial

Step 2: Unpack the project subdirectories.

BEA provides a .zip file that contains the entire source code of the MedRec application; the source code files are used in these tutorials. This .zip file also contains a build directory that contains some pre-compiled classes of the MedRec application, as well as the XML files that correspond to procedures in these tutorials.

To populate your project directory with the necessary files and directories:

Download the medrec_tutorial.zip (MD5 checksum) file. Save the downloaded file to the c:\medrec_tutorial directory.

Open up a command window and set your command shell environment with the MedRecDomain environment script:

prompt> c:\bea\user_projects\domains\MedRecDomain\bin\setDomainEnv.cmd

Move to the MedRec project directory and unpack the downloaded .zip file:

prompt> cd c:\medrec_tutorial

prompt> jar xvf medrec_tutorial.zip

Step 3: Verify the project directory contents.

Verify that the following files and subdirectories were created:

prompt> dir

 Directory of C:\medrec_tutorial

12/09/2005  11:39 AM    <DIR>          .
12/09/2005  11:39 AM    <DIR>          ..
12/09/2005  11:39 AM    <DIR>          build
12/09/2005  11:39 AM    <DIR>          dist
12/09/2005  11:39 AM               493 install.properties
12/09/2005  11:39 AM    <DIR>          lib
12/09/2005  11:39 AM         6,799,498 medrec_tutorial.zip
12/09/2005  11:39 AM    <DIR>          META-INF
12/09/2005  11:39 AM    <DIR>          src
12/09/2005  11:39 AM               996 substitute.xml

The \build directory contains the classes generated by the various MedRec build scripts. It does not contain editable source files or deployment descriptors, which reside in \src. Each subdirectory in \build represents the compiled classes for MedRec clients (\clients) or for a MedRec application (\medrecEar, \physicianEar, \initEar, and \startBrowserEar applications).

If you look at the contents of the \build directory, you'll notice that many of the classes that make up the MedRec application have already been built for you. In particular, all medrecEar and startBrowserEar applications, and the Web Services in the physicianEar application, have been pre-compiled. The parts of the physicianEar application that have not been pre-compiled are those that you will be working with in these tutorials, namely EJBs and Web applications. This pre-compilation is for your convenience, so you can browse many of the directories and compiled classes of the MedRec application right away without having to build it yourself. Later tutorials demonstrate how to re-compile parts, and then all, of the MedRec application using the WebLogic Ant tasks, such as wlcompile and jwsc, as part of the normal development process.

The \src directory contains the full source for all MedRec applications. You will be working in this directory for most remaining tutorials. Step 4: Verify the source directory contents. describes the subdirectories in \src.

\build and \src together represent a WebLogic Server split development directory. You can deploy individual MedRec applications to a development server by targeting an application subdirectory in \build (such as \build\medrecEar) using weblogic.Deployer or the wldeploy Ant task described in Tutorial 9: Deploying MedRec from the Development Environment. WebLogic Server locates the necessary deployment descriptors (available in \src) by examining the .beabuild.txt file located in the appropriate \build subdirectory.

The \dist directory is also an output directory—it will store the archived .ear files or exploded .ear directories created by the wlpackage task in Tutorial 14: Packaging MedRec for Distribution. Right now it contains only a few JAR files corresponding to some of the pre-compiled classes in the \build directory. The \dist directory will eventually store complete, exploded .ear directories for the different MedRec applications. The \dist directory is not considered part of the split development directory structure, because it is not required for compiling or deploying applications during development. It is used only for storing final, completed applications—.ear files or exploded .ear directories—that you generate after completing the development process.

The \lib directory contains precompiled, third-party .jar files that several of the MedRec applications require. This includes supporting .jars for struts and log4j.

Step 4: Verify the source directory contents.

The \src subdirectory contains the full application source for the MedRec applications, and it is the subdirectory in which you will spend the most time during the remaining tutorials. Take a look at the installed \src directory:

prompt> dir src

 Directory of C:\medrec_tutorial\src

12/09/2005  11:39 AM    <DIR>          .
12/09/2005  11:39 AM    <DIR>          ..
12/09/2005  11:39 AM            19,736 build.html
12/09/2005  11:39 AM             2,938 build.xml
12/09/2005  11:39 AM    <DIR>          clients
12/09/2005  11:39 AM    <DIR>          common
12/09/2005  11:39 AM    <DIR>          initEar
12/09/2005  11:39 AM             4,550 medrec.properties
12/09/2005  11:39 AM    <DIR>          medrecEar
12/09/2005  11:39 AM    <DIR>          physicianEar
12/09/2005  11:39 AM    <DIR>          security
12/09/2005  11:39 AM    <DIR>          startBrowserEar

The build.xml file in the top level of the medrec_tutorial directory is a project-wide build file. It:

Cleans up previously-built versions of MedRec before compiling
Builds the contents of each application subdirectory into the \build directory by calling each application's build.xml file
Packages each application as an exploded .ear file into the \dist directory

You will use this project-level build.xml before moving the WebLogic Server instance into production mode in Tutorial 13: Compiling the Entire MedRec Project. However, do not try to use it yet—you need to complete the next few tutorials to create the application-level build.xml files that this script calls.

The \src directory also contains a medrec.properties file that defines property values used by the project-level build.xml file, as well as the build.xml files used in each applications subdirectory.

The subdirectories of \src represent either deployable MedRec applications or MedRec components that are used by those applications:

\clients holds source files for the Java and C# clients of MedRec Web Services.
\common holds source files for Java classes shared between the MedRec Enterprise Applications. These include:

Shared constants and JNDI names
The ServiceLocator class, used to access MedRec services in the service tier
Factories for creating EJBs and JMS connections
Value objects, which represent data passed between tiers of the MedRec application
Image files and Struts action classes shared across MedRec web components

The \initEar subdirectory contains an application that implements and registers a custom MBean that polls the database every 6 seconds to check for new users to be added to the system. You can use this application to register your own custom MBean.
The \medrecEar and \physicianEar subdirectories store the main Enterprise Applications that make up the MedRec application suite. These subdirectories use the WebLogic Server 9.1 Development Directory structure and Ant tasks for building and deploying, and are described in detail in the next tutorials.
The \security subdirectory contains the MedRec authentication provider shared across applications.
The \startupBrowserEar subdirectory contains the listener class that automatically boots the browser and loads MedRec's main index JSP when you start MedRec on a Windows machine. You do not work directly with this application in the tutorials that follow. However, the application is compiled as part of the overall MedRec build process.

Step 5: Edit the install.properties file and run substitute.xml.

The top-level project directory into which you unzipped the ZIP file contains a file called install.properties that specifies information local to your environment, such as the name of the computer which hosts WebLogic Server and the MedRec domain directory. After editing this file with information specific to your environment, run the substitute.xml Ant file which uses this properties file to substitute your local values for the place-holders in the files you unzipped.

Use a text editor to open the properties file:

prompt> notepad c:\medrec_tutorial\install.properties

Edit the SERVER_HOSTNAME property to point to the computer that hosts WebLogic Server:

SERVER_HOSTNAME=myhost.mycompany.com

If you did not use 7101 and 7102 as the administration server port numbers when creating the MedRecDomain in Tutorial 1: Creating a WebLogic Domain and Server Instance for Development, edit the SERVER_PORT and SERVER_SSL_PORT properties to point the appropriate ports:

SERVER_PORT=7101
SERVER_SSL_PORT=7102

Edit the WL_HOME property to point to your WebLogic Server installation directory (c:/bea/weblogic91 by default):

WL_HOME=c:/bea/weblogic91

Edit the MEDREC_HOME_DIR property to point to your new project directory:

MEDREC_HOME_DIR=c:/medrec_tutorial

Edit the MEDREC_DOMAIN_DIR property to point to the MedRecDomain directory you created (c:/bea/user_projects/domains/MedRecDomain by default):

MEDREC_DOMAIN_DIR=c:/bea/user_projects/domains/MedRecDomain

Save and close the install.properties file.

Go to the c:\medrec_tutorial directory and run the substitute.xml script:

prompt> cd c:\medrec_tutorial

prompt> ant -f substitute.xml

The substitution script may take a few seconds to complete, at the end of which you should see output similar to the following: Buildfile: substitute.xml replace: BUILD SUCCESSFUL Total time: 23 seconds

Best Practices

Smaller J2EE projects may not require the nested subdirectories found in the MedRec project directory. For example, a project that produces a single Enterprise application file can have minimal subdirectories such as:

\myProject—top-level project directory
\myProject\myEarBuild—output directory for storing compiled and generated files
\myProject\myEarSrc—source files and editable content for the Enterprise Application

This minimal directory structure still allows you to develop your application by using the WebLogic split development directory structure and Ant tasks described in Tutorial 6: Understanding the WebLogic Server Split Directory Structure.

The Big Picture

The MedRec application suite consists of three separate applications for the patient, physician, and administrator user roles. Using a separate application for each user role allows you to distribute each application function across different WebLogic Server instances as needed. For example, the MedRec sample domain (optionally installed with WebLogic Server) deploys all three applications on a single server instance for easy demonstration purposes. The MedRec tutorials also deploy the applications in a single-server domain, which is typical for development environments. However, you can also deploy the MedRec and Physician applications on two different server instances (in separate domains) to illustrate the use of Web Services between the applications.

The MedRec project directory also contains subdirectories for compiling the client applications that access MedRec via Web Services.