Chapter 14: Java Code Generation and Reverse Engineering

Java package	Component package
Java Bean	Attribute
EJB (Enterprise Java Bean)	Class
Servlet	Class
Inner class	Nested class
Implements relationship	Realization relationship
Extends relationship	Generalization relationship
Import statement	Association, dependency, or generalization

Beginning a Java Project

When first creating a Java model, there are four steps you may want to follow. First, when working on a project that will be primarily implemented in Java, you always want to set the default language to Java. This is done through the Tools → Options menu. Click the Notation tab and set the default language to Java.

Next, select the framework you would like to use for your project. This is an optional step, but can provide you with the foundation you need to model your application. We will discuss specific frameworks shortly.

Third, if you are using either Microsoft Visual J++ or IBM VisualAge for Java, you should enable the links between Rose and these tools. Once you enable the links, you can generate code and reverse engineer VisualAge or Visual J++ projects directly from Rose.

Finally, be sure that the ClassPath environment variable is set. The ClassPath is used by Rose J to determine the location of class libraries and other files while generating code and reverse engineering. To view the ClassPath settings, select Tools → Java → Project Specification. The ClassPath entries will be displayed, and you can add or remove entries using this dialog box.

Selecting a Java Framework

When you first create a Rational Rose model, you are given the option to base your model on an existing framework. Create a new Rose model, and you will see the window shown in Figure 14.1.

Figure 14.1: Rose frameworks

Note

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If you do not see the frameworks window, select Add−Ins → Add−In Manager, and be sure Framework Wizard is checked.

There are several Java frameworks available: J2EE, J2SE 1.2, J2SE 1.3, jdk−116, jdk−12, and jfc−11. (The last three are, respectively, Java Development Kit version 1.1.6, Java Development Kit version 1.2, and the Java Foundation Classes version 1.1.)

Simply select whichever framework you will be using for your project. Rose will automatically load classes, relationships, attributes, operations, and components from the selected framework into your new model. You can then use these elements as a foundation to create your own project.

Figure 14.2 is an example of a new Rose model using the J2EE framework. No new information has yet been added to the model. The figure shows only what is imported with the J2EE framework. Note that, for readability, many of the packages in Figure 14.2 are not expanded; however, classes and other model elements are inside each one.

Figure 14.2: Rose model with J2EE framework

You can also use a framework on an existing Rose model. To do so, you need to load the appropriate controlled units. Each package in the frameworks is stored as controlled units. Select File → Units → Load, and then navigate to the Rose 2000\framework\frameworks\shared components directory. The .cat files in this directory are the controlled units for the frameworks. Each .cat file begins with the name of the framework, such as j2ee or j2se12, so you know which files to import for which framework. Select the .cat files appropriate for your framework, and Rose will import them into your model.

Linking to IBM VisualAge for Java

Establishing a link between Rational Rose and IBM's VisualAge will allow you to update a VisualAge project directly from within Rose or to reverse engineer a VisualAge project into Rose.

To set up the link between the two tools, first start VisualAge. Select File and then Quick Start. On the dialog box, select Basic and then RoseLink Plug−In Toggle. This will establish the link from the VisualAge side.

To complete the process, start Rose. Select Tools → Java → Project Specification. On the Detail tab, set the Virtual Machine setting to IBM, as shown in Figure 14.3.

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Figure 14.3: Java Virtual Machine setting

Select Tools → Java → IBM VisualAge for Java Project. Select the appropriate VisualAge project. The link between the two tools is now set.

Linking to Microsoft Visual J++

Similar to the link with IBM's VisualAge, the link to Microsoft Visual J++ will allow you to generate code and to reverse engineer using Rose and Visual J++. Once the link has been established, Rose can launch Visual J++ or Visual J++ can launch Rose in order to generate code or reverse engineer.

To set up the link to Visual J++, select Tools → Java → Project Specification. On the Detail tab, set the Virtual Machine setting to Microsoft.

You are now ready to work with Rose and Visual J++. From Rose, select Tools → Java → Generate Java to launch Visual J++ and generate code. From Visual J++, select the elements you wish to reverse engineer and select Tools → Update Rose Model. Rose will be launched, and the elements will be reverse engineered into the Rose model.

Java Code−Generation Properties

The Java code−generation properties can be set in two places. The defaults are set by using the Tools → Options menu item and then selecting the Java tab, as shown in Figure 14.4. You can set properties for the following items:

∙

	Attributes
∙
	Classes
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Module bodies

∙

Module specifications

∙

Operations

∙

Projects

∙

Roles

Figure 14.4: Java code−generation properties window

We'll discuss using these various properties throughout this chapter. We'll begin with a brief description of the available code−generation properties, then cover projects, modules, classes, attributes, operations, and roles.

Project Properties

The project properties affect all aspects of Java code generation in Rose. This section provides a listing of the properties and their common settings.

The project properties are code−generation properties that apply more to the whole project than to any specific model element, such as a class or relationship. The options in this section include things like the default directory to use when generating code, the file extensions to use, and whether or not to stop generation if an error occurs. The project properties are listed in Table 14.2, along with their purposes and default value. (In this and subsequent code−generation property tables, we list the most commonly used properties.)

Table 14.2: Java Project Properties

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Property	Purpose	Default
RootDir	Directory to hold the Java project.	<blank>
CreateMissingDirectories	If True, creates any directories that are	True
	required if they do not exist.
StopOnError	If True, Rose will stop code generation at the	False
	first error.
UsePrefixes	If True, Rose will add user−defined prefixes to	False
	the variable names.
AutoSync	Automatically begins the code−generation	False
	process when a Java element changes in the
	Rose model.
ShowCodeGenDlg	Shows a progress dialog box while generating	False
	code.
JavadocDefaultAuthor	Sets the value of the Javadoc @author tag.	<blank>
JavadocDefaultVersion	Sets the value of the Javadoc @version tag.	<blank>
JavadocDefaultSince	Sets the value of the Javadoc @since tag.	<blank>
JavadocNumAsterisks	Number of asterisks to use with the Javadoc	0
	comments.
MaxNumChars	Maximum number of characters in a line of	80
	generated Java code.
Editor	Select the editor to use while browsing code.	Rose's built−in editor
VM	Select the version of the Java Virtual Machine	Sun
	(Sun, IBM, or Microsoft).
ClassPath	Specifies the directory where code will be	<blank> (use current
	generated.	directory)
InstanceVariablePrefix	If UsePrefixes is True, then this prefix will be	m_
	added to all instance variables.
ClassVariablePrefix	If UsePrefixes is True, then this prefix will be	s_
	added to all class variables.
DefaultAttributeDataType	If no type is selected for an attribute, this type	Integer
	will be used.
DefaultOperationReturnType	If no return type is selected for an operation,	Void
	this type will be used.
NoClassCustomDlg	Determines whether the custom specification	False
	window will be suppressed for Java classes
	and other elements.
GlobalImports	Sets import statements to be generated. Each	<blank>
	class or package listed will generate an import
	statement.
OpenBraceClassStyle	Sets whether an opening brace will start on a	True
	new line.
OpenBraceMethodStyle	Sets whether an opening brace for a method	True
	will start on a new line.
UseTabs	Determines whether to use tabs (as opposed to	False
	spaces) to indent the generated Java code.

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UseSpaces	Determines whether to use spaces (as opposed	True
	to tabs) to indent the generated Java code.
SpacingItems	Number of tabs or spaces (depending on the	3
	values of UseTabs and UseSpaces) to use to
	indent the generated Java code.
RoseDefaultCommentStyle	Use the default Rose comment style in	True
	generated code.
AsteriskCommentStyle	Use asterisk comment style in generated code.	False
JavaCommentStyle	Use Javadoc tags for comments in generated	False
	code.
JavadocAuthor	Controls whether the Javadoc @author tag is	True
	enabled.
JavadocSince	Controls whether the Javadoc @since tag is	False
	enabled.
JavadocVersion	Controls whether the Javadoc @version tag is	False
	enabled.

Most of these project properties can also be set in the Project Specification window. To open the Project Specification window, select Tools → Java → Project Specification. On the Class Path tab, you can set the ClassPath project property.

Figure 14.5 shows the Style tab of the Java Project Specification window. On this tab, you can set the values of the following properties:

∙

UseTabs

∙

UseSpaces

∙

SpacingItems (Number to Use)

∙

OpenBraceClassStyle (On New Line for Classes)

∙

OpenBraceMethodStyle (On New Line for Methods)

∙

RoseDefaultCommentStyle (Rose Default)

∙

AsteriskCommentStyle (Asterisk Style)

∙

JavaCommentStyle (Javadoc Style)

∙

MaxNumChars (Maximum Number of Characters in a Line)

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JavadocAuthor, JavadocDefaultAuthor (@Author)

∙

JavadocVersion, JavadocDefaultVersion (@Version)

∙

JavadocSince, JavadocDefaultSince (@Since)

∙

JavadocNumAsterisks (Number of Asterisks)

Refer to Table 14.2 for a description of each of these properties.

Figure 14.5: Style tab of the Java Project Specification window

On the Detail tab of the Project Specification window, you can set additional project properties. Figure 14.6 shows the Detail tab. It includes the following properties:

∙

Editor

∙

VM (Virtual Machine)

∙

RootDir (Root Directory)

∙

DefaultAttributeDataType (Attribute)

∙

DefaultOperationReturnType (Method Return)

∙

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