How to generate XMI file for the java source code? - java

I'm writing a program in java language which takes the java source code as an input and the output is xmi file which contains the class diagram of the source code.
I have researched for xmi structure but I was not able to find an adequate resource which explain the structure and order of tags.
First question is how can I found out what is the order of the tags and definition of each tag? for instance, what is the meaning of "isActive = false" etc?
Secondly, is there any suggestion of libraries or anything in java language which can help me to finish this project?

I think the tag order doesn't matter in XMI. In general, XMI just defines how to map MOF to XML. So basically you build the M2 model (=UML) from Java and and then map this to XML with XMI if I understand this correctly (and I think the double indirection is why you don't find good resources for the mapping from UML to XMI directly).
For many people, examples may be more accessible than the chain of transformation rules defined by the various OMG standards. So I'd just draw a minimal UML example diagram in my favorite UML tool for the export aspect I am interested in and look at the exported XMI. Then add features as needed...
P.S.: You may want to use the Java reflection classes (package java.lang.reflect) instead of parsing the the Java source yourself to generate XMI (if you don't need to preserve method argument names).

Related

AST for UML Activity diagram

I am currently doing a project to convert uml diagrams to java code,in one of the step I have to create an ast for general activity diagram and write a java code for the ast. The problem is I am not sure how to represent it in java code to accept any activity diagram as an input. Please need some help.
This is the meta-model of a general activity diagram, I want to represent this diagram as a java code to accept inputs.
Activity Diagram Metamodel
The first diagram on the second page of the pdf
What tool are you using to create your activity diagrams? Most will provide an API to query models and/or an XMI export*. In either case you don't get an AST as such, more an Object structure of your model. But it's still pretty easy to iterate that structure and generate code.
One option worth considering is the Eclipse Modeling Framework (EMF). There are tools available for both creating diagrams (e.g. Papyrus) and a multitude of options for generating code from models (e.g. Acceleo) - have a look at the 'Model to Text' (M2T) sub-project.
Even if you decide to use another tool for diagram creation, it's possible to use Eclipse M2T for code generation; most tools will export XMI in the eclipse dialect.
hth.
--
*XMI is the 'standard' for UML model interchange. It was plagued with inconsistency in interpretation originally, and there are still some problems among tools today. However: it is an XML dialect so even if tool B can't directly import XMI from tool A, it's usually possible to convert between the two.

Java library to assist in XSD creation?

Is anyone aware of a library that makes the process of creating XSDs in Java a little easier than using something like a DocumentBuilder? Something like a helper or utility class. I came across the org.eclipse.xsd maven jar but I'm having ClassNotFoundException issues when working with it in Eclipse and I'm not entirely sure it's meant to be used as a standalone kind of thing. This is a bit difficult to Google for as well since there are lot of search results around automatic generation/translation from Java to XSD and vice versa.
Essentially what I need to do is to programmatically create an XSD from a certain source of data -- not Java classes.
Apache XMLSchema is a lightweight Java object model that can be used to manipulate and generate XML schema representations. You can use it to read XML Schema (xsd) files into memory and analyze or modify them, or to create entirely new schemas from scratch.
The fact that with this API one can create an XSD from scratch, it sounds as a starting point to achieve the ask; as to the fitness, it depends on what that "certain source of data" is.

Automatically build resource class based of XML in Java

In Android applications, resources are specified in xml documents, which automatically are built into the R class, readily accessible within the source code as strongly typed.
Is there any way I could use a similar approach for a regular Java desktop application?
What I'd like to accomplish, is both the removal of strings from the code (as a separation of "layers", more or less) and to make it easy to add support for localization, by simply telling the program to choose the xml file corresponding to the desired language.
I've googled around a bit, but the things I'm looking for seem to be drowning in results about parsing or outputting xml, rather than tools utilizing xml to generate code.
Eclipse's message bundle implementation (used by plugins for example) integrates with the Externalize Strings feature and generates both a static class and a resource properties file for your strings:
http://www.eclipse.org/eclipse/platform-core/documents/3.1/message_bundles.html
For this integration to work Eclipse needs to see org.eclipse.osgi.util.NLS on the class path. From memory, the dependencies of the libraries it was available in were a little tricky for the project I used this approach in, so I just got the source and have it as a stand-alone class in my core module (see the comments for more on that).
It provides the type safety you're looking for and the IDE features save a lot of time. I've found no downsides to the approach so far.
Edit: this is actually what ghostbust555 mentioned in the comments, but not clear in that article that this isn't limited to Eclipse plugins and you refer to your resources via static members of a messages class.
I haven't seen any mention of others using this approach with their own applications, but to me it makes complete sense given the IDE integration and type safety.
I'm not sure if this is what you mean but check out internationalization- http://netbeans.org/kb/docs/java/gui-automatic-i18n.html
Are you looking for something that parses XML files and generates Java instances of similar "struct-like" objects, like JAXP, and JAXB?
I came across ResGen which, given resource bundle XML files generates Java files that can be used to access the resources in a type-safe way.
http://eigenbase.sourceforge.net/resgen/

Automatically generating Java source code

I'm looking for a way to automatically generate source code for new methods within an existing Java source code file, based on the fields defined within the class.
In essence, I'm looking to execute the following steps:
Read and parse SomeClass.java
Iterate through all fields defined in the source code
Add source code method someMethod()
Save SomeClass.java (Ideally, preserving the formatting of the existing code)
What tools and techniques are best suited to accomplish this?
EDIT
I don't want to generate code at runtime; I want to augment existing Java source code
What you want is a Program Transformation system.
Good ones have parsers for the language you care about, build ASTs representing the program for the parsed code, provide you with access to the AST for analaysis and modification, and can regenerate source text from the AST. Your remark about "scanning the fields" is just a kind of traversal of the AST representing the program. For each interesting analysis result you produce, you want to make a change to the AST, perhaps somewhere else, but nonetheless in the AST.
And after all the chagnes are made, you want to regenerate text with comments (as originally entered, or as you have constructed in your new code).
There are several tools that do this specifically for Java.
Jackpot provides a parser, builds ASTs, and lets you code Java procedures to do what you want with the trees. Upside: easy conceptually. Downside: you write a lot more Java code to climb around/hack at trees than you'd expect. Jackpot only works with Java.
Stratego and TXL parse your code, build ASTs, and let you write "surce-to-source" transformations (using the syntax of the target language, e.g., Java in this case) to express patterns and fixes. Additional good news: you can define any programming language you like, as the target language to be processed, and both of these have Java definitions.
But they are weak on analysis: often you need symbol tables, and data flow analysis, to really make analyses and changes you need. And they insist that everything is a rewrite rule, whether that helps you or not; this is a little like insisting you only need a hammer in toolbox; after all, everything can be treated like a nail, right?
Our DMS Software Reengineering Toolkit allows the definition of an abitrary target language (and has many predefined langauges including Java), includes all the source-to-source transformation capabilities of Stratego, TXL, the procedural capability of Jackpot,
and additionally provides symbol tables, control and data flow analysis information. The compiler guys taught us these things were necessary to build strong compilers (= "analysis + optimizations + refinement") and it is true of code generation systems too, for exactly the same reasons. Using this approach you can generate code and optimize it to the extent you have the knowledge to do so. One example, similar to your serialization ideas, is to generate fast XML readers and writers for specified XML DTDs; we've done that with DMS for Java and COBOL.
DMS has been used to read/modify/write many kinds of source files. A nice example that will make the ideas clear can be found in this technical paper, which shows how to modify code to insert instrumentation probes: Branch Coverage Made Easy.
A simpler, but more complete example of defining an arbitrary lanauges and transformations to apply to it can be found at How to transform Algebra using the same ideas.
Have a look at Java Emitter Templates. They allow you to create java source files by using a mark up language. It is similar to how you can use a scripting language to spit out HTML except you spit out compilable source code. The syntax for JET is very similar to JSP and so isn't too tricky to pick up. However this may be an overkill for what you're trying to accomplish. Here are some resources if you decide to go down that path:
http://www.eclipse.org/articles/Article-JET/jet_tutorial1.html
http://www.ibm.com/developerworks/library/os-ecemf2
http://www.vogella.de/articles/EclipseJET/article.html
Modifying the same java source file with auto-generated code is maintenance nightmare. Consider generating a new class that extends you current class and adds the desired method. Use reflection to read from user-defined class and create velocity templates for the auto-generating classes. Then for each user-defined class generate its extending class. Integrate the code generation phase in your build lifecycle.
Or you may use 'bytecode enhancement' techniques to enhance the classes without having to modify the source code.
Updates:
mixing auto-generated code always pose a risk of someone modifying it in future to just to tweak a small behavior. It's just the matter of next build, when this changes will be lost.
you will have to solely rely on the comments on top of auto-generated source to prevent developers from doing so.
version-controlling - Lets say you update the template of someMethod(), now all of your source file's version will be updated, even if the source updates is auto-generated. you will see redundant history.
You can use cglib to generate code at runtime.
Iterating through the fields and defining someMethod is a pretty vague problem statement, so it's hard to give you a very useful answer, but Eclipse's refactoring support provides some excellent tools. It'll give you constructors which initialize a selected set of the defined members, and it'll also define a toString method for you.
I don't know what other someMethod()'s you'd want to consider, but there's a start for you.
I'd be very wary of injecting generated code into files containing hand-written code. Hand-written code should be checked into revision control, but generated code should not be; the code generation should be done as part of the build process. You'd have to structure your build process so that for each file you make a temporary copy, inject the generated source code into it, and compile the result, without touching the original source file that the developers work on.
Antlr is really a great tool that can be used very easily for transforming Java source code to Java source code.

Creating Java Classes from Ontology

I have an ontology file (in RDF) which expresses the entities in the app that I am writing. I am using Jena, and can access the Concepts and create/access the resources by directly manipulating triples.
To make things easier, I created a set of Java classes, one for each type of resource in my ontology, keeping in mind their inheritances, and properties. E.g.
public class Agent{
}
and
public class Person extends Agent{
private String name;
}
If the ontology contains two types of resources, Agent and Person, with the latter being a subclass of the former.
I realized that the process of creating these classes (and the methods to extract them) are very monotonous. If I was writing an application on databases, I would have used a config file for Hibernate and let it take care of the details.
My question is: Is there a tool available that will take an ontology (in an RDF file) as input, and create a set of Java files representing the Concepts in the ontology, as in the example above? (or if Jena itself can do this, and I am missing something)
Thanks.
There are tools such as Bouml and Andromda with which you may generate Java from XMI UML serialization.
Furthermore, work has been done towards integrating UML with RDF: http://infolab.stanford.edu/~melnik/rdf/uml/.
So I guess you could find a way to transform your RDF to XMI then to generate Java from XMI, given you first map your initial RDF schema to RDF/UML.
Also I just found this paper: Automatic Mapping of OWL Ontologies into Java which I did not read so I cannot comment.
Protege supports RDF import and java export. I've used it in the past for getting ontology data into java programs and it's worked reasonably.
While going through the links provided above, I chanced upon the Trispresso Project, which provides a nice summary of the relevant tools and their features, including multiple inheritance and code generation. Thought it would make a good answer to my own question.
Did u checked JRDF? There are other code generation tools available too.. Check here.

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