MoDisco/ModelFilter

The goal of the ModelFilter plug-in is to extract specific information from java projects, and to show it as UML models.

• First application is to initialize a graph of dependencies from one selected element, with the level of recursion provided as a parameter.
• Second application is to show method calls as a pseudo sequence diagram using dependencies between methods, numbered from 1 to n to indicate the order.
• Third application is to represent the real type of properties when an interface has been used in java code.

Description

To discover an application, you may use SimpleTransformationsChain to obtain a UML model which represents the whole application structure. Or you may use the ModelFilter plug-in to focus on different aspects. It could be represented by little models dedicated to one element, or a complete model but with added information. Depending on the complexity of the application and resulting UML model, you will have to select a different kind of model.

The dependencies graph is clearly well fitted to show how several little models could be useful. Representation of method calls as a pseudo sequence could be done by little models or by one complete model; it has been implemented as one model to show how different diagrams have to be used to mask complexity of model elements. And representation of real type for properties show how a complete model could be improved with a few details.

Dependencies graph

From a selected class in a java application, you choose the recursion level of the search for dependencies and you will get a UML model which represents a dependencies graph from the selected class. Structural links, like association, inheritance, etc. are of course available, but we have added UML dependencies to show local uses of a type, or method parameters. It is very useful to detect usage of qualified types or usage of a type in the same package.

Sample dependencies graph with local and method parameter dependencies.

Method calls

To represent method calls as pseudo sequence, we use UML dependencies from one method (caller) to other methods (callee). Each dependency is named with the name of the called method suffixed by a number which represents its order in the sequence of method calls.

Sample method calls graph

Real type of properties

When the type of a property is an interface, it is interesting to represent its real type as a dependency in a UML model:

User manual

To illustrate the ModelFilter plugin and its features, we will use a sample inspired from the Pet Store Application.

Get and install use case

The models are available from the MoDisco SVN in subdirectory "examples/trunk/org.eclipse.gmt.modisco.usecase.modelfilter.sample" or from a downloadable archive. If you use a SVN client in Eclipse (Subversive or Subclipse), the project will be immediately available in your Eclipse workspace.

Sources of the Pet Store application are available here: http://www.oracle.com/technetwork/java/petstore1-3-1-02-139690.html

You may have to download several libraries to obtain an eclipse project without errors (JPA, JTA, JSF-apis and Servlets-jsp-apis). A complete bundle is also available from Mia-Software... To view this application in your Eclipse workspace, you will have to extract the content of this archive, and use the "import" wizard (import project in workspace).

Dependencies graph

To get the dependencies graph of a particular class, you have to right-click on the class in the Package Explorer, and select Discovery > Actions > Display Dependencies

Contextual menu entry for Display Dependencies

Then, a graph displaying the dependencies will open:

Dependencies graph

Method calls

Right-click on a project and select Discovery > Actions > Display Method Calls. A graph displaying all the method calls will open:

All method calls

You will have a better look if we focus on a particular method. For example, the method

public List<SelectItem> getCategories()

in class MapBean located in package com.sun.javaee.blueprints.petstore.mapviewer.

    public List<SelectItem> getCategories() {
        // return categories for a JSF radio button
        ArrayList<SelectItem> arCats=new ArrayList<SelectItem>();
 
        // get the CatalogFacade for the app
        FacesContext context=FacesContext.getCurrentInstance();
        Map<String,Object> contextMap=context.getExternalContext().getApplicationMap();
        CatalogFacade cf=(CatalogFacade)contextMap.get("CatalogFacade");
 
        // get the categories from the database
        List<Category> catsx=cf.getCategories();
        for(Category catx : catsx) {
            // add categories to be displayed in a radio button
            arCats.add(new SelectItem(catx.getCategoryID(), catx.getName()));
        }
        return arCats;
    }

Right-click on the method in the Package Explorer, and select Discovery > Actions > Display Method Calls:

Displaying method calls from a single method

Real type of properties

To get the UML model with real type of properties, right-click on the java project you would like to inspect, and select Discovery > Discoverers > Create UML model with real types information on associations:

Context menu item

Then, you will have a complete UML model with the real types of Associations:

UML model with real types of Associations

You will have a better look if we focus on a particular association. For example, the properties

private Collection<Item> items

in class Tag and

private Collection<Tag> tags

in class Item both located in package com.sun.javaee.blueprints.petstore.model.

Current limitations

Dependencies graph

• The dependencies gaph does not reflect some implicit dependencies, for example with nested method calls:

String entryPagesParam = filterConfig.getServletContext().getInitParameter("entryPages");

Method calls

• Diagrams have to be built manually with Papyrus
• Method calls should be represented with a uml sequence diagram

Real type of properties

• Diagrams have to be built manually with Papyrus
• Initializations through parameters or local variable are not managed
• Initializations through method calls are not managed

Team

Gabriel Barbier (Mia-Software)

Install

You can install the discoverer from the MoDisco update site.

As part of the "Use cases layer" which is not embedded in MoDisco SDK, you cannot install it from eclipse or modeling update site. Please use MoDisco release update site.