Does anyone knows a tool for Java (something like codedom for C#) that provides a way to generate Java code to a .java file?
EDIT:
I'm building a platform the main objective of which is to automate an operation. Giving some input, I want to generate code for an external tool. So it isn't generation on runtime. I want to generate and output that to an actual file.
JET maybe outdated (I didn't use it) JET Tutorial Part 1
More Plugins for Eclipse Plugins in Code Generation
EDIT:
Sorry I don't know codedom and what features this tool implies.
Standalone is Freemarker
and Velocity see also this example
I have had some success using ASM to both modify existing classes at the bytecode level or to generate completely new classes on the fly. The tutorial walks you through this in a very understandable fashion.
ASM like most such tools generates bytecode not source. The reason for this is if you want to dynamically generate and execute new code from with a program, historically it was not straight forward to invoke the Java compiler. Therefore it was generally easier to generate and use bytecode than source.
If you need to generate and run the code immediately within your program I recommend you use bytecode manipulation tool. If all you need is Java source, I would roll my own code generator that takes my input format and generates the code. You may want to look for a framework to help you with this but since a source file is just text, usually it is just as easy to create this yourself especially if you have a custom input format.
ABSE and AtomWeaver form a code generation and model-driven-development framework where you can easily implement what you want. ABSE is a new methodology where you compose your code generator from smaller bits (called Atoms) and AtomWaver is an straightforward IDE that lets you implement, manipulate and use your generator models.
It also allows non-programmers to build programs/configurations/whatever, made from already-built parts (Atoms you have previously prepared).
This project is just being publicly launched now, and an alpha version is being made available now. ABSE is open, and AtomWeaver is free for personal and commercial use.
Get more info here : http://www.abse.info (Disclaimer: I am the project lead)
What you could try is to use an existing grammar (e.g. from ANTLR) and build the AST. Then from the AST generate the code. That should be much more robust than simple templating. For something in the middle I suggest the (eye-opening) talk from Terence Parr about StringTemplate. (Sorry, don't have the link for the talk at hand)
I am not sure what you really need, but take a look at javassist. Is it the thing you are looking for?
Related
I'm trying to figure out how to use Soot in an existing project (a metacircular interpreter). Specifically, I want to use Soot to convert java bytecode into a convenient 3-address code (either Jimple or Shimple) that I can interpret. I may want to do more things later, but for now I just want the conversion.
What's the best way to perform this translation? Soot seems like a ginormous project which as tons of functionality, but I really only need a single method
compileClass: Byte[] -> ShimpleClass
Preferably as pure as possible (i.e. no setup/teardown required, everything packaged within that method). I've spent hours going over the javadoc/papers/presentations, but most of them seem focused on usage as a command line tool or an eclipse plugin. Could anyone give me some pointers as to where to start?
This is probably easiest answered on the Soot mailing list.
Soot is set up to load .class files from the file system but it should not be that hard to instruct it to load something from a ByteArrayInputStream as well. I guess that should help you in your case.
Is there an eclipse based solution to refactor Java code using scripts?
I've read about the Eclipse Language toolkit, but it seems that it implies the creation of a plugin, which sounds like overkill for a one-off operation.
Are there some kind of bindings to a scripting language, or at least a way to call refactoring code from java but without a plugin?
Sample use case : I have a project which uses castor generated classes, and I want to migrate to JAXB 2. It implies a lot of refactoring in the existing code, which cannot be done by search and replace, nor regular expressions, because of the context-sensitveness.
When the refactoring is complex, I usually write a transformation pipeline with Recoder. The only drawback of this tool is that it sometimes breaks the code format (e.g. moving comments around, or adding/deleting whitespace), but so far it has been enough for my requirements.
Eclipse provides some refactoring help. For eg if you select the portion of code you want to refactor and right click, you get an option for Refactor. From which you can extract to a method(the one i commonly use while refactoring), extract interface, superclass etc.
You can also check these:
http://www.eclipse.org/articles/article.php?file=Article-Unleashing-the-Power-of-Refactoring/index.html
Eclipse: Most useful refactorings
Working on a code generation tool to help creating boiler code for our project.
The generator is written in ruby with erb templates, the project itself is in Java.
Now I am looking for a ruby gem/library for parsing java source files, given a string from a .java files, get the imports, methods, fields, class name etc etc, that would enable me to navigate to a certain method and appending code to it etc (kinda like jQuery selector).
I am wondering if there are already solutions that I can use, kinda like the javaclass-rb library, but that is for parsing bytecodes from .class files.
I know I could use ANTLR and a ruby adapter, but I hope there are existing solutions.
Thanks!
JRuby is a Ruby implementation on top of the JVM that make interaction between Ruby and Java objects trivial. If you decide to use this, you can use any Java library to solve the task, like javaparser.
Basically, I do lots of one-off code generation, large-scale refactorings, etc. etc. in Java.
My tool language of choice is Python, but I'll take whatever solutions you can offer.
Here is a simplified illustration of what I would like, in a pseudocode
Generating an implementation for an interface
search within my project:
for each Interface as iName:
write class(name=iName+"Impl", implements=iName)
search within the body of iName:
for each Method as mName:
write method(name=mName, body="// TODO implement this...")
Basically, the tool I'm searching for would allow me to:
parse files according to their Java structure ("search for interfaces")
search for words contextualized by language elements and types ("variables of type SomeClass", "doStuff() method calls on SomeClass instances")
to run searches with structural context ("within the body of the current result")
easily replace or generate code (with helpers to generate, as above, or functions for replacing, "rename the interface to Foo", "insert the line Blah.Blah()", etc.)
The point is, I don't want to spend a lot of time writing these things, as they are usually throwaway. But sometimes I need something just a little smarter than what grep offers. It wouldn't be too hard to write up a simplistic version of this, but if I'm going to use something like this at all, I'd expect it to be robust.
Any suggestions of a tool/library that will help me accomplish this?
Edit to add some clarification
Python is definitely not necessary; I'll take whatever is that. I merely suggest it incase there are choices.
This is to be used in combination with IDE refactoring; sometimes it just doesn't do everything I want.
In instances where I'm using for code generation (as above), it's for augmenting the output of other code generators. e.g. a library we use outputs a tonne of interfaces, and we need to make standard implementations of each one to mesh it to our codebase.
First, I am not aware of any tool or libraries implemented in Python that specifically designed for refactoring Java code, and a Google search did not give me any leads.
Second, I would posit that writing such a decent tool or library for refactoring Java in Python would be a large task. You would have to implement a Java compiler front-end (lexer/parser, AST builder and type analyser) in Python, then figure out how to integrate this with a program editor. I'm not surprised that nobody has done this ... given that mature alternatives already exist.
Thirdly, doing refactoring without a full analysis of the source code (but uses pattern matching for example) will be incapable of doing complex refactoring, and will is likely to make mistakes in edge cases that the implementor did not think of. I expect that is the level at which the OP is currently operating ...
Given that bleak outlook, what are the alternatives:
One alternative is to use one of the existing Java IDEs (e.g. NetBeans, Eclipse, IDEA. etc) as a refactoring tool. The OP won't be able to extend the capabilities of such a tool in Python code, but the chances are that he won't really need to. I expect that at least one of these IDEs does 95% of what he needs, and (if he is realistic) that should be good enough. Especially when you consider that IDEs have lots of incidental features that help make refactoring easier; e.g. structured editing, undo/redo, incremental compilation, intelligent code completion, intelligent searching, type and call hierarchy views, and so on.
(Aside ... if existing IDEs are not good enough (#WizardOfOdds - only the OP can make that call!!), it would make more sense to try to extend the refactoring capability of an existing IDE than start again in a different implementation language.)
Depending on what he is actually doing, model-driven code generation may be another alternative. For instance, if the refactoring is happening because he is frequently creating and recreating his object model(s), then an alternative is to code the models in some modeling language and generate his code from those models. My tool of choice when doing this kind of thing is Eclipse EMF and related technologies. The EMF technologies include generation of editors, XML serialization, persistence, queries, model to model transformation and so on. I have used EMF to implement and roll out projects with object models consisting of 50 to 100 distinct classes with complex relationships and validation requirements. EMF's support for merging source code edits when you regenerate from an updated model is a key feature.
If you are coding in Java, I strongly recommend that you use NetBeans IDE. It has this kind of refactoring support builtin. Eclipse also supports this kind of thing (although I prefer NetBeans). Both projects are open source, so if you want to see how they perform this refactoring, you can look at their source code.
Java has its fair share of criticism these days but in the area of tooling - it isn't justified.
We are spoiled for choice; Eclipse, Netbeans, Intellij are the big three IDEs. All of them offer excellent levels of searching and Refactoring. Eclipse has the edge on Netbeans I think and Intellij is often ahead of Eclipse
You can also use static analysis tools such as FindBugs, CheckTyle etc to find issues - i.e. excessively long methods and classes, overly complex code.
If you really want to leverage your Python skills - take a look at Jython. Its a Python interpreter written in Java.
I'm looking for a tool that will reverse engineer Java into a sequence diagram BUT also provides the ability to filter out calls to certain libraries.
For example, the Netbeans IDE does a fantastic job of this but it includes all calls to String or Integer which clutter up the diagram to the point it is unusable.
Any help is greatly appreciated!!!!!!!
I think jtracert is what you are looking for. It generates a sequence diagram from a running Java program. Also, because its output is a text description of the diagram (in the formats of several popular SD tools), you can use grep to filter for only the classes you are interested in.
I believe the perfect tool to solve your problem is Diver: Dynamic Interactive Views For Reverse Engineering. It provides both static and dynamic sequence diagrams and looks to solve all your requirements from your question.
It is a plugin for Eclipse and lets you:
Easily trace your Java programs
Visualize your program’s runtime functionality
Filter your traces to make them more compact
Filter your IDE based on what occurs at runtime
See what code ran in your source code editors
It's on Github and there is also a project web site
Full Disclosure: I am the current project lead for Diver
Try MaintainJ. MaintainJ generates sequence diagrams at runtime for a use case. It provides multiple ways to filter out unwanted calls. Yes, filtering out unwanted calls is the most important feature needed in sequence diagram generating tools. Besides, MaintainJ provides a neat interface to explore the diagram and search for calls in one use case or across use cases.
Check the demo video to get a quick overview.
I am the author of MaintainJ, by the way.
JTracert is now discontinued. In place, they recommend http://www.jsonde.com/
I have a tool that meets your requirements exactly. Check it out
http://sourceforge.net/projects/javacalltracer/
In addition to being a reverse engineering tool for java it is also very lightweight. You can control the what you want to record from your java program.
Enterprise architect from Sparx claims to be able to reverse engineer java code including generating sequence diagrams - see this section of the user guide
It looks like it can record a debugging session and then you generate the sequence diagram from that
I've not tried it (though have used EA as a modelling tool) so ymmv!
There is a free 30day evaluation download available
Take a look at http://www.maintainj.com
It don't know, whether it can filter library calls, but it has a reasonable graphical front end and seems to trace even very large applications.
MaintainJ is really wonderful tool, Recently i was started to use with MaintainJ with my application it is giving more comfort with my entire usage to understand my system based on Maintainj sequence & UML diagrams.
I am sure for the above question MaintainJ is will give better idea.
Thanks,
Krishna MM
I have just started using the sequence diagram recording feature in Sparx Systems Enterprise Architect. It works very well for C#. You can create filters by class and by method. I'm actually trying to find out if it's possible to filter out an entire package. There is a checkbox for automatically excluding external modules (like the .NET Framework) which aids in declutter. YMMV for Java, but I think their support (and documentation) for Java is generally better (more examples) than for .NET.
Heatlamp (http://www.jmolly.com/heatlamp/) was designed for exactly this purpose.
It generates interactive (and printable) diagrams from running Java code. You can specify filters to describe which classes, packages, and methods to trace. You can also search, filter, and collapse invocations after the diagram is rendered to further reduce the sequence diagram.
Disclaimer: I'm the author of Heatlamp.
This looks like a really nice tool:
http://www.architexa.com/learn-more/sequence-diagrams
But it looks like it's only free for a year, then its $250 a year. Bummer.
I found the ModelGoon plugin to be helpful. It's a bit limited because you choose a single method as the starting point for the sequence diagram, and it only shows the calls that method makes (so to go a level deeper you need to generate another diagram.)
http://www.modelgoon.org/?page_id=53
JIVE (www.cse.buffalo.edu/jive) will construct a sequence diagram from the execution of a Java program. It has an Exclusion Filter capability will allow you to exclude objects belonging to designated classes or packages. JIVE can draw sequence diagrams for multi-threaded Java program execution. It also has the ability compact large diagrams in both the horizontal and vertical dimension, under user guidance.
Here's and add-on to Asgeir's answer. Here's the link that I found.
http://www.java2s.com/Code/Jar/s/sequence.htm
Run from the command line ... "java -jar sequence.jar" ... this is a Java application with a GUI.
The help section says:
SEQUENCE is a program for producing UML Sequence Diagrams. In contrast to most similar programs you don't actually draw the diagram. Instead you write a textual description of the method calls you want to diagram and the layout is calculated and drawn automatically.
So this tool doesn't reverse engineer anything, but I can see how it might be helpful if you wanted to quickly diagram things from scratch. Looks like it was built in 2002 and I think there are probably better tools out there now.
Here's another similar tool here:
http://sdedit.sourceforge.net/example/index.html