Java – UML Class diagram, how to show a Class extends thread

class-diagramjavarelationshipuml

I have a class called ServerSide in which another class resides called Cserver. The following code fragment should explain what I am talking about:

public static void main (String [] args) throws Exception 
{
    System.out.println("The server is running.");
    int clientnumber = 1;
    ServerSocket server = new ServerSocket(9090);
    try
    {
        while (true)
        {
            new cserver(server.accept(), clientnumber++).start();

        }

    }finally
    {
        server.close();
    }

}

private static class cserver extends Thread
{
    private Socket socket;
    private int clientnumber;
    private ConnectionHandler c_handler;
    private Protocol protocol;

    public cserver(Socket socket, int clientnumber)
    {
        this.socket = socket;
        this.clientnumber = clientnumber;
          log("New connection with Client: " + clientnumber + " at " + socket);
    }

I want to make a class diagram in UML which shows the relationship between the two classes, as I am unsure as how this can be drawn in UML. Will it be an association?
Thanks

Best Answer

This would be the diagram, it's an inheritance relation (IS-A):

enter image description here

Related Solutions

Java – How to test a class that has private methods, fields or inner classes

Update:

Some 10 years later perhaps the best way to test a private method, or any inaccessible member, is via @Jailbreak from the Manifold framework.
@Jailbreak Foo foo = new Foo();
// Direct, *type-safe* access to *all* foo's members
foo.privateMethod(x, y, z);
foo.privateField = value;
This way your code remains type-safe and readable. No design compromises, no overexposing methods and fields for the sake of tests.

If you have somewhat of a legacy Java application, and you're not allowed to change the visibility of your methods, the best way to test private methods is to use reflection.

Internally we're using helpers to get/set private and private static variables as well as invoke private and private static methods. The following patterns will let you do pretty much anything related to the private methods and fields. Of course, you can't change private static final variables through reflection.

Method method = TargetClass.getDeclaredMethod(methodName, argClasses);
method.setAccessible(true);
return method.invoke(targetObject, argObjects);

And for fields:

Field field = TargetClass.getDeclaredField(fieldName);
field.setAccessible(true);
field.set(object, value);

Notes:
1. TargetClass.getDeclaredMethod(methodName, argClasses) lets you look into private methods. The same thing applies for getDeclaredField.
2. The setAccessible(true) is required to play around with privates.

Java – How to generate UML diagrams (especially sequence diagrams) from Java code

ObjectAid UML Explorer

Is what I used. It is easily installed from the repository:

Name:     ObjectAid UML Explorer
Location: http://www.objectaid.com/update/current

And produces quite nice UML diagrams:

Screenshot

Description from the website:

The ObjectAid UML Explorer is different from other UML tools. It uses the UML notation to show a graphical representation of existing code that is as accurate and up-to-date as your text editor, while being very easy to use. Several unique features make this possible:

Your source code and libraries are the model that is displayed, they are not reverse engineered into a different format.

If you update your code in Eclipse, your diagram is updated as well; there is no need to reverse engineer source code.

Refactoring updates your diagram as well as your source code. When you rename a field or move a class, your diagram simply reflects the changes without going out of sync.

All diagrams in your Eclipse workspace are updated with refactoring changes as appropriate. If necessary, they are checked out of your version control system.

Diagrams are fully integrated into the Eclipse IDE. You can drag Java classes from any other view onto the diagram, and diagram-related information is shown in other views wherever applicable.