MyEclipse Web Project Tutorial http://www.myeclipseide.com/documentation/quickstarts/webprojects/[8/5/2009 12:31:51 PM] MyEclipse Web Project Tutorial Outline 1. Preface 2. Introduction 3. Web project concepts and terminology 4. Creating a web project 5. Overview of web development productivity tools 6. Creating a JSP document 1. Creating a JSP 2. Editing JSP 3. Using code completion 4. Validating JSP 7. Deploy, test, and debug web project 1. Deploy web project 2. Test application 3. JSP debugging 8. Working with an existing web project 9. Customizing web project preferences 10. Advanced Features 1. Dependent Java project setup and deployment 2. Library deployment policy configuration 3. Adding Advanced Capabilities... to your Web Project 11. Summary 12. User Feedback 1. Preface This document was written using Sun JDK 1.4.2, Eclipse 3.1 and MyEclipse 4.0. All screenshots were taken using the default settings for Eclipse, MyEclipse, and Windows XP. If you experience difficulty with the instruction of this document, please see the User Feedback section for how to provide feedback to the MyEclipse documentation team. 2. Introduction This tutorial presents the basic and advanced features, concepts, and techniques for rapidly getting started in the development of J2EE web applications using MyEclipse Web Tools. Specifically, this document presents how to: Create a MyEclipse Web Project Create a JSP using the JSP Wizard Editing a JSP using the JSP Editor Deploy, test and debug a Web Project as a web application Add web project capabilities to an existing Java project Create dependent Java projects and configure their deployment policy Add an external library to a Web Project and configure its deployment policy Customize Web Project preferences 3. Web Project Concepts and Terminology This section introduces the key Web Project concepts and terminology used throughout the MyEclipse product. Having a basic understanding of these concepts will enable you to work with MyEclipse Web Projects and productivity tools proficiently and intuitively. In simplest terms: A MyEclipse Web Project is an Eclipse Java Project that includes metadata that defines the project's web nature and a directory structure patterned after the J2EE web archive (WAR) structure . Figure 1 presents an annotated view of the structure of an example HelloWorld web project. Note that MyEclipse web projects are decorated with a small globe icon in the top-right corner of a project folder, . Within this example project, two special subfolders are shown: " src" and " WebRoot" The " src " folder contains Java source code such as Java packages and their classes and interfaces. The " WebRoot " folder is the root or base folder of a directory structure patterned after the J2EE web archive (WAR) structure . The root directory is formally known as the web-root and it contains 3 subdirectories. Web content and resources such as JSP and HTML files, tag libraries, and JAR files are located under the web-root directory and its subdirectories. Table-1 defines the role of the web-root subdirectories and resources.
1. Preface2. Introduction3. Web project concepts and terminology4. Creating a web project5. Overview of web development productivity tools6. Creating a JSP document
1. Creating a JSP2. Editing JSP3. Using code completion4. Validating JSP
7. Deploy, test, and debug web project1. Deploy web project2. Test application3. JSP debugging
8. Working with an existing web project9. Customizing web project preferences
10. Advanced Features1. Dependent Java project setup and deployment2. Library deployment policy configuration3. Adding Advanced Capabilities... to your Web Project
11. Summary 12. User Feedback
1. Preface
This document was written using Sun JDK 1.4.2, Eclipse 3.1 and MyEclipse 4.0. All screenshots were taken using the default settings for Eclipse, MyEclipse,and Windows XP. If you experience difficulty with the instruction of this document, please see the User Feedback section for how to provide feedback tothe MyEclipse documentation team.
2. Introduction
This tutorial presents the basic and advanced features, concepts, and techniques for rapidly getting started in the development of J2EE web applicationsusing MyEclipse Web Tools. Specifically, this document presents how to:
Create a MyEclipse Web ProjectCreate a JSP using the JSP WizardEditing a JSP using the JSP Editor Deploy, test and debug a Web Project as a web applicationAdd web project capabilities to an existing Java projectCreate dependent Java projects and configure their deployment policyAdd an external library to a Web Project and configure its deployment policyCustomize Web Project preferences
3. Web Project Concepts and Terminology
This section introduces the key Web Project concepts and terminology used throughout the MyEclipse product. Having a basic understanding of theseconcepts will enable you to work with MyEclipse Web Projects and productivity tools proficiently and intuitively.
In simplest terms:
A MyEclipse Web Project is an Eclipse Java Project that includes metadata that defines the project's web nature and a directorystructure patterned after the J2EE web archive (WAR) structure .
Figure 1 presents an annotated view of the structure of an example HelloWorld web project. Note that MyEclipse web projects are decorated with a small
globe icon in the top-right corner of a project folder, . Within this example project, two special subfolders are shown: " src" and " WebRoot" The "src " folder contains Java source code such as Java packages and their classes and interfaces. The "WebRoot" folder is the root or base folder of adirectory structure patterned after the J2EE web archive (WAR) structure . The root directory is formally known as the web-root and it contains 3subdirectories. Web content and resources such as JSP and HTML files, tag libraries, and JAR files are located under the web-root directory and itssubdirectories. Table-1 defines the role of the web-root subdirectories and resources.
Note: While the actual name of the web-root directory and its location within the project are user definable, its subdirectory structuremust include the layout shown in Table 1.
Table 1. Web-root Description
WAR Dir. Layout WAR Elements Description
<project web-root>
WEB-INF/
classes/
lib/
web.xml
web-root
The root or base directory within a Web Project under which all webcontent, executable and support resources resides. Any folder within theproject including the project folder itself (see Figure 2 for anexample) that includes the subdirectory structure may serve as the web-root. Publicly accessible web content such as JSP and HTML files andtheir organizing subdirectories typically reside directly under this folder.
WEB-INF/
A direct child directory of the web-root directory (e.g., <web-rootfolder>/WEB-INF). This directory and its subdirectories contain the non-public application resources such as deployment descriptors, taglibraries, compiled java classes, etc.
WEB-INF/classes
A child directory of WEB-INF that serves as the output location of theproject's compiled Java classes from the "src" folder(s) . Contains*.class files and other non-Java resources from the source tree. Atruntime these resources are accessible from the System classpath.
WEB-INF/lib A child directory of WEB-INF that contains the project's JAR files
web.xml
The J2EE web deployment descriptor that defines the J2EE web entitiessuch as servlets and tag libraries. This file is required by J2EE webprojects for deployment and execution. The web.xml file resides in the<web-root>/WEB-INF directory. MyEclipse web tools interpret andmaintains this file.
Additionally, MyEclipse includes two special project members, the .mymetadata file and the optional .myeclipse folder. The .mymetadata file is an XMLformatted file that defines MyEclipse-specific information such as the location of the web-root folder and other important details required by MyEclipse webtools for their proper operation. This file should be treated with equal importance as the project's corresponding Eclipse . project and .classpathfiles. If you are maintaining your project within a source management system, e.g., CVS, include the .mymetadata file under version control.
The optional .myeclipse folder is MyEclipse's transient work area for storing temporary data such as compiled JSPs. Since it is a temporary work area itmay be created and deleted dynamcially by MyEclipse Web Tools. You do not need to maintain this folder under your source code control system. Forexample, if you are maintaining your project under CVS we recommend adding .myeclipse it the project's.cvsignore file.
The default names for the Java source and web-root folders are defined by the Web Project template. See Section 9 to learn more about customizing WebProject preferences. Figure 2, illustrates a Web Project for which the project folder serves as the web-root folder.
Figure 2. Web Project serves as web-root folder
4. Creating a Web Project
This section introduces the steps for creating an example Web Project named "HelloWorld".
Step-1: Open the new Web Project Wizard by selecting File > New > Project > MyEclipse > J2EE Projects > Web Project as shown in Figure3.
Step-2: Enter HelloWorld into the Project Name field.
The remaining fields are prepopulated from the MyEclipse Web Project Template. This template is defined under the MyEclipse J2EE Project preferencesand is described in more detail in Section 9 . Table-2 describes each of the fields for the New J2EE Web Project wizard shown in Figure 4.
Projectname The project's name. Must be a valid Eclipse Java project name.
Location Enable checkbox to specify a custom file-system location for the new project and its resources.
DirectoryThe default file-system location for the project is under the workspace directory for which MyEclipse was started. You may choosean alternative file location outside of the workspace directory. Note: You may not choose an alternate directory under theworkspace directory as this is not allowed by Eclipse.
Sourcefolder
The Java source folder - will contain Java packages and *.java files. The contents of this folder are added to the project's Java buildpath.
Web rootfolder
The folder that will contain the web content, WEB-INF and its required subfolders. If this field is empty or "/" then the project folderwill serve as the web-root folder.
Contextroot URL
This is the context under which the MyEclipse Deployment Serivce will use when deploying the new Web Project. The default valueof the context-root field is the name of the project. If you are unfamiliar with the purpose of the context-root, it is the root portionof a URL that is used to access this application when deployed, e.g., http://localhost:8080/HelloWorld . You may change thecontext-root field to any alpha-numeric value that you prefer.
J2EEspecificationlevel
Specifies the J2EE specification compliance level. Please ensure that you select the proper specification level for the J2EE featuresyour application requires and that your target deployment application server(s) support this specification level. For example, if youare working with Tomcat 5.x or JBoss 4.x, choose J2EE 1.4 specification for the latest J2EE capabilities. Check with your applicationserver vendor for information regarding J2EE specification level compliance.
Add JSTL1.0 libraries
Enabling this option will result in the Java Standard Template Library (ver. 1.0) JAR's to be added to the new project's <web-root>/WEB-INF/lib directory.
Step 3: Select Finish
Completing the wizard creates and configures the HelloWorld Web Project. Figure 5 depicts the structure of the new project from the MyEclipse perspective.To open the MyEclipse perspective select from the MyEclipse menubar Window > Open Perspective > Other and select . The Java Package Explorer isopened by selecting Window > Show View > Java > Package Explorer.
In Figure 4, note the J2EE 1.4 Library Container . This is a library of J2EE API Jars provided by MyEclipse to your project for compilation and codecompletion support. These API JAR files are placed only on the project's build path. Note: No J2EE JAR files or other resources are physicallycopied into your project.
Congratulations on the creation of a MyEclipse Web Project!!! The next step is to create the project's web content and functionality. Section 5provides a brief overview of the tools you will want to be familiar with as you develop your web application. Go to Section 6 to begin creating webcontent.
5. Web Development Productivity Tools - Overview
MyEclipse provides a number of productivity tools for the development of web applications. This section outlines the key tools and their use.
All editors support user customizable syntax color highlighting, font, layout and formatting. The HTML, JSP, and XML editors provide real-timevalidation and error marking similar to the Eclipse Java editor.
WizardsWeb Project creationHTML creationJSP creation includes Strutsweb.xml document creation and maintenanceXML creation
ValidationJSP including custom tags, and Java scriptletsHTMLCSSXML/XSLDeployment descriptors
Deploy, Test, and DebugDeploy directly from MyEclipse to test application server environmentSupport for over 20 different application serversLaunch and control an application server Hot-swap/update debugging of JSP and Java code
Advanced CapabilitiesStruts Designer and WizardsXDoclet supportJava Server Faces support
This section introduces the process for creating a simple helloworld.jsp JSP file using the MyEclipse wizards and JSP Editor. We will continue working with theHelloWorld Web Project created in Section 4 .
6.1 Creating a helloworld.jsp
Begin by creating a JSP named helloworld.jsp using the MyEclipse JSP wizard. Access this wizard as follows:
Select the " WebRoot " folder.From the context-menu (e.g., right-click menu) select New > Other > MyEclipse > Web > JSP
Alternatively you may select New > JSP from the tools as shown in Figure 6b or from menubar File > New action.
Figure 6a. Opening JSP creation wizard from context-menu action
Note that the specified JSP location was under the WebRoot folder of the project. A location under the web-root folder is required toenable the JSP Editor to fully provide code completion and validation features and for the MyEclipse Deployment Service to deploy theJSP.
6.2 Editing helloWorld.jsp
Open helloWorld.jsp in the MyEclipse JSP editor by double-clicking the file or from the "Open with..." context-menu action if you have a customized JSPeditor associated for .jsp extension files. Scroll to line 27 and enter the text, <% out . Followed by the ctrl->space key sequence to invoke MyEclipsecode completion suggestions. Figure 8 illustrates an example JSP code completion for Java scriptlets.
Figure 8. Invoking JSP code completion
6.3 JSP and HTML Tag Completion
In the previous step you learned how to invoke the java scriplet code completion feature. In addition to scriplet completion, MyEclipse JSP editor providescode completion for JSP directives, e.g., <%@ %>, custom JSP tags, e.g., <x:if>, and HTML tags. The ctl+space sequence is used to invoke all relevantforms of code completion. Figures 9 and 10 illustrate JSP directive completion and HTML tag completion examples respectively.
MyEclipse JSP validation capabilities can help identify JSP coding errors early in the development cycle at their precise point of occurance. This section
introduces the two levels of JSP validation and how problems are identified in the JSP Editor and elsewhere in the workbench. The first level, or type, of JSPvalidation applies to the JSP editor. This editor is patterned after the Java editor and provides real-time type-in validation on the editor's contents. The secondlevel of validation is a build-time action that is performed automatically on JSP files whenever they are modified and saved, or when a workspace "Clean"operation is performed on the project. Lastly, manual JSP validation may be activated from the context-menu on a single JSP file or recursively starting ata project or subfolder level.6.4.1 JSP Editor Real-time Type-in Problem Detection
The JSP editor can detect a wide range of syntax and potential compilation problems as you enter source text. Warnings and errors that are detected in thismanner are displayed in the JSP editor's overview column (right-hand side annotation column). You may enable/disable this behavior as well as modify theannotation colors from the Workbench>Editor>Annotations preference page.
Note: Real-time type-in problems will not appear in the Problems View.
To enable automatic JSP validation when saving the contents of a JSP Editor or performing a "Project clean..." operation ensure that the following settingsare defined accordingly:
1. Launch MyEclipse with a full JDK JVM in order for the the JSP validator to have access to the Java compiler. A traditional JRE JVM does not includea Java compiler and is thus insufficient to properly validate JSP files. Note that future versions of MyEclipse will relax this requirement andprovide additional preferences to improve the configurability of this behavior.
2. Enable the Build Automatically setting found under the Project menubar. See Figure 12 for the location of this setting.
3. Enable the project-specific validation from the project properties dialog. To access this dialog select the HelloWorld project in the Package Explorerview. Then from the context menu (right-click menu) select Properties>MyEclipse-Validation and check the JSP Validation checkbox . SeeFigure 13 for an example.
Let's begin by introducing a simple syntax error in our helloworld.jsp to see how automatic validation works. On line 29 insert the following text:
<% out.println("Hello World") %>
Note, the ';' to terminate the statement is intentional omitted to illustrate error detection and marking.
Next save the file using Ctl-S or the system menu, File->Save . During the save operation the internal MyEclipse JSP compiler analyzes the JSP file forsyntax and Java type correctness by compiling the JSP. Detected errors and warning are presented in a manner similar to that of the Java editor. Figure 14illustrates the various error/warning identifiers.
Figure 14. JSP validation and error marking
Now add the ';' to the end of println statement and save the helloWorld.jsp file. The error should be resolved and all error related markers eliminated.6.4.3 Manual Validation
At anytime you may manually invoke the JSP validation. Select any file or directory in the Package Explorer view of your Web Project and then from thecontext-menu select MyEclipse > Run Validation. This will cause JSP validation to be performed on the target resource(s). In the case of a selecteddirectory or project, validation will be performed recursively on all of its files and subdirectories.
You may enable/disable MyEclipse automatic JSP validation at either a system-wide level by modifying the MyEclipse validation preferences or at theindividual project level using the Web Project's MyEclipse-Validation properties. Figure 10 depicts the MyEclipse default validation preferences. To accessthese preferences using the menubar path, Window > Preferences > MyEclipse > Validation .
MyEclipse validation preferences can be overridden at the project level by modifying the validation properties of each Web Project. To access theseproperties select the Web Project. Then from the context-menu (right-click menu) select Properties > MyEclipse-Validation . The project validationsettings will take precedent over the MyEclipse system-wide validation preferences.
Figure 17. MyEclipse Web Project validation properties
7. Deploying, Testing, and Debugging a Web Application
7.1 Deploy Web Project
In this step we will deploy the HelloWorld Web Project to a Tomcat 5 server. For application server configuration details please review the ApplicationServers Tutorial document. From the Java Package Explorer view, select the HelloWorld project. Then use either the MyEclipse deploy icon on the toolbar(Figure 18) or the Web Project context-menu (Figure 19) to launch the Deploymentment Management Dialog.
Figure 19. Accessing the Deployment Management Dialog from a context menu
From the Deployment Wizard shown in Figure 20a & 20b, select Add followed by Tomcat 5 as the target server followed by Finish . This will deploy theHello World project under the Tomcat-5 work area in exploded WAR format. The context-root under which the project is deployed is"/HelloWorld" and is accessible at http://localhost:8080/HelloWorld . Recall that the context-root is a user-defined Web Project property,see MyEclipse-Web properties available from the Web Project context-menu>Properties>MyEclipse-Web.
Figure 20a. Deploying to the Tomcat Server - Selecting the Project
Figure 20b. Deploying to the Tomcat Server - Selecting the Server
The Exploded Archive deployment mode utilizes the MyEclipse "Sync-on-Demand" technology to continuously synchronize projects with their respectivedeployments. Thus when you add, modify, or remove files in your project the deployed instance(s) will be automatically synchronized at the time of thechange. Therefore you do not need to worry about inconsistent state between your project and the application servers to which an application is deployed.
At any time that you wish to discontinue "Sync-on-Demand" deployment for a project, simply undeploy the project using the Deployment Wizard again.
To undeploy the HelloWorld web application, access the Manage Deployments dialog from the toolbar. Select the project and server you wish to undeploy.Complete the undeployment operation by selecting the Remove button.
Figure 21. Undeploying HelloWorld from the Tomcat Server
7.2 Testing a Deployed Web Project
We need to launch Tomcat in order to test the HelloWorld application. A properly configured the Tomcat 5 Application Server Connector is a prerequisitefor completion of this section. Please see the Application Server Tutorial for details on how to configure the connector properly. Once the server isconfigured, from the MyEclipse Server toolbar select Tomcat > Start (see Figure 22). Monitor Tomcat's startup progress in the console.
Figure 22. Starting Tomcat
Verify that the output includes a message similar to the following:
INFO: Installing web application at context path /HelloWorld from URL file:C:\dev\webservers\Tomcat5.0\webapps\HelloWorld
Open a web-browser to the URL location: http://localhost:8080/HelloWorld/helloworld.jsp. It will take several seconds to open this page as Tomcat mustfirst compile the helloWorld.jsp page before it can be presented. Your output should be similar to that of Figure 23.
Figure 23. Invoking helloworld.jsp from a web browser
7.3 JSP Debugging
Open the JSP editor on the helloWorld.jsp file created earlier. If you corrected the errors we intentionally introduced in Section 6.4.2 there should be noerror markers on any line of this file. Now, inside the scriplet code starting on line 29 add a breakpoint by double-clicking in the left margin of the editor onthe scriplet line (See Figure 24).
Next, from your web-browser refresh or revisit the http://localhost:8080/HelloWorld/helloworld.jsp page. This time you should observe the Eclipseworkbench activate the Debug perspective and the execution suspended at the helloWorld.jsp breakpoint (see Figure 25). The suspended line is markedwith inverted color background and foreground colors. All Java variables and constructs are visible and available for modification in the Variables View. Additionally you can select a parent stack-frame in the stack view and invoke "Drop to frame" to rollback the stack and reenter the JSP. Doing so will allowyou to step through execution of the JSP line by line.
Note: if execution continues past the breakpoint without suspending, check the breakpoint marker. If it does not include a checkmark then it has notbeen registered and activated with the Tomcat JVM. This typically occurs when your server does not support the JSR045 specification to enable native JSPdebugging or your project. In such cases review the server provider's release notes, e.g., Tomcat 4.X does not support JSP debugging natively.
If you have an existing Eclipse Java project you may enable it for use with MyEclipse Web Tools by adding MyEclipse Web Capabilities to the project. Thecentral requirement of the "Add Web Capabilities..." action is that the resulting Web Project must include a web-root folder who's contents are patternedafter the "web archive" subdirectory structure described in Section 2 . If the Java project does not originally support this web-root directory structure theWeb Capabilities wizard will create it as part of its actions.
Note that while most of the MyEclipse Web Tool editors will operate with limited functionality on Eclipse web resources that are notpart of a MyEclipse Web Project you are encouraged to upgrade your Java projects to MyEclipse Web Projects for maximumconvenience and support.
Following is the upgrade process for adding MyEclipse Web capabilities to a Java project:
Step 1: Select the Java project followed by MyEclipse > Add Web Capabilities... from the context-menu or the MyEclipse menubar entry. Thiswill open the "Add Web Capabilities" wizard. See Figures 26 and 27.
Step 2: Enter the folder that will serve as the web-root. Use the Advanced button to create a new folder if needed.
Step 3: Select Finish to update the project. The key changes you will notice to the Java project in the upgrade is the output location of the project'sJava Builder Properties is set to <web-root location>/WEB-INF/classes. Also, all <web-root location>/WEB-INF/lib JAR files are added to theproject's Java build path.
Step 4: Lastly relocate all project resources that are not already under the designated web-root folder to their respective web-root subdirectorylocation.
Figure 28. Upgraded Java project with Web capabilities
9. Customizing Web Project Preferences
MyEclipse provides a number of customizable preferences. You are encouraged to familiarize yourself with each of these. We have already seen severalWeb Project wizards and dialogs with prepopulated fields. The value of many prepopulated dialog fields is frequently derived from the MyEclipse systempreferences. Two MyEclipse preferences that you should be aware of are the Web Project folder template and deployment policies. See the AdvancedFeatures section for a description of the later preferences.
To access the MyEclipse preferences do the following:
From the menubar select Window > Preferences > MyEclipse > J2EE Project > Web Project (See Figure 29).
Figure 29. MyEclipse Web Project Template preferences
Set the "Web root folder name" to "/" if you don't want an explicit web root folder.
Note: changing the Web Project template will only affect new projects, not exising projects.
10. Advanced Features
10.1 Dependent Java Project Setup and Deployment Policy Configuration
Frequently the codebase of a web application may be partitioned between a primary MyEclipse Web Project and 1 or more Java projects upon which theweb project depends. Typically the role of these dependent Java projects is to localize common or shared code that has other uses beyond that of the webproject. MyEclipse can be configured to package and weave dependent Java projects into the deployment of a Web Project. In this section we introducethe procedure for establishing a project dependency and configuring Web Project deployment policies for dependent projects.
10.1.1 Establishing a Java Project dependency
A dependent Java project is defined through the Web Project's Build Path properties . To access the Build Path properties dialog from the target WebProject's context-menu select Properties > Java Build Path > Projects. See Figure 30 for an example of establishing the example Logging Java projectas a dependent project of the HelloWorld Web Project. Doing this enables HelloWorld to have access to the services defined by an example Logging Javaproject. Code completion, validation, and other tools are able to reference Logging project resources.
Figure 30. Making the Logging Java project a dependent of the HelloWorld Web Project
10.1.2 Configuring the Deployment Policy of Dependent Java Projects
The MyEclipse Web Project Deployment Service provides 3 policies that define how dependent Java projects are processed during Web Project deployment.Table 3 describes each of these policies.
Always Jar dependent Javaprojects and merge into thedeployment
This deployment policy instructs the Deployment Serviceto create JAR archives of each dependent Java project'soutput locations. The resulting JAR files are then mergedinto the deployment's WEB-INF/lib directory. JAR files arecreated with the name of the dependent project in lower-case text and a ".jar" extension. Example: the Jar filecreated for a dependent Java project named "Foo" will befoo.jar.
Use of this mode requires theundeployment/redeployment of a Web Project in orderfor changes in a dependent project to be made availableto it. The naming pattern for all
Use Smart Deployment fordependent Java projects
A) When the principal web project is deployed inpackaged WAR format its dependent projectsare packaged JARs similar to the previous policy and thenmerged with the web project's WEB-INF/lib folder.
B) When the web project is deployed in exploded WARformat the compiled output of each dependent project ismerged with the compiled output of the principal webproject. This later configuration enables the Deployer's"Sync-on-Demand" feature to detect changes to sourcecontent in any dependent project and to dynamciallysynchronize that change with the deployed state of theweb project. For application servers that support smart
application reloading such as Tomcat 5, JBoss, andWeblogic, this capability can be very beneficial for hot-reloading of updated classes to your deployment.
Ignore dependent Javaprojects
This deployment mode instructs the DeploymentService to disregard dependent projects during thedeployment process. A consequence of this policy is thatyour deployed application may experienceClassNotFoundExceptions yet within your MyEclipseworkspace the project may compile cleanly.
The default deployment behavior for all Web Projects is defined by the MyEclipse system preferences (See Figure 31).
Figure 32. MyEclipse Web Project deployment properties.
10.2 Library Deployment Policy Configuration
All Eclipse Java projects including MyEclipse Web Projects maintain a build-path that consists of a collection of Java resources similar to the Java classpath.During the build process the Eclipse compiler searches the project's build-path seeking Java classes referenced by the project's source files. A Web Project'sbuild-path typically includes all Jar libraries contained in the project's WEB-INF/lib folder. Additionally, a Web Project's build-path may be configured toinclude:
1. Jar files that reside in a different location within the project2. External Jar files that reside outside the Eclipse workspace3. User libraries assigned to the4. Jars exported by dependent Java projects5. User libraries exported by dependent Java projects
To learn more about the managing Jar libraries within Eclipse see the following Eclipse help topic: Java Development UserGuide>Tasks>Building>Working With Build-Paths>Adding a JAR file to the build path .
When a Web Project is deployed it typically requires non-system resources such as the Jar libraries defined on the project build-path to be included as partof the deployment. The Deployer employs 4 library deployment policies that enable it identify the relevant build-path Jar files to be copied into the WEB-INF/lib folder of the deployment. Table 4 describes each of these library deployment policies. If the Web Project's deployment mode is "packaged" then therelevant Jar libraries are included in the resulting WAR file that is copied to the target application server's automatic deployment area. If the Web Project'sdeployment mode is "exploded" then the relevant Jar libraries are copied into the expanded WAR file structure in the target application server's automaticdeployment area.
Table 4. Library Deployment Policy descriptions
LibraryDeploymentPolicy
Description
Include Jars onProject build-path
Deployer merges the local and external Jar libraries onthe project's build-path into the WEB-INF/lib folder ofthe deployment.
Include Jars inProject user-
Deployer merges the user library Jar files on theproject's build-path into the WEB-INF/lib folder of the
Deployer merges the Jar libraries of dependent Javaprojects that have been explicitly exported. Thelibraries are copied into the WEB-INF/lib folder of thedeployment.
Deployer merges the user libraryJar files of dependentJava projects that have been explicitly exported. Thelibraries aer copied into the WEB-INF/lib folder of thedeployment.
The default deployment behavior for all external libraries is defined by the MyEclipse system preferences (see Figure 33).
To add support for one of these technologies to your web project use its corresponding "Add Capabilities" wizard. Each technology addition wizard isaccessible by selecting the target Web Project and then invoking the wizard from either the MyEclipse context-menu (i.e., right-click menu) or the MyEclipsemenubar entry.
The use for each of these technologies and their associate MyEclipse prod__%%__uctivity tools is beyond the scope of this document. For moreinformation visit the MyEclipse Tutorial library.
11. Summary
This concludes the introduction to working with MyEclipse Web Projects. Additional Tutorial documents are available that into editing, application serverconfiguration, enterprise application and EJB project development, and database development. For more information visit the MyEclipse Tutorial library.
