I have installed an Eclipse plugin called PMD and I want to use only one of its feature (extracting Abstract Syntax Tree). The main problem is, instead of right clicking on each Java source code and then clicking on the AST feature, I want to fully automatize it without clicking on anything.
Therefore, the question is is there a way or method to call that plugin's feature from the source code that I have written.
I have tried to import PMD's maven project, however I have encountered some errors and there are many features that I won't be using (supporting other languages etc.). Thereby, I'm trying to find a more lightweighted approach. PMD is a quite big project to integrate it into my own project.
Thanks in advance.
Apparently, PMD Plugin has its source code open. Therefore, when the relevant classes and methods are converted into a standard Java desktop application (rather than Plugin), it is possible to create AST files without and UI interactions.
The conversion part is quite simple and easy. Since PMD Plugin requires UI, it uses classes such as IFile, IProject etc. Thereby, these classes could be changed equivalent classes such as; File, Project etc.
After giving the path of the project and by adding a simple code that recursively traverses its sub-directories will help you find all of the Java source files. Then by sending each of the Java source files into the AST generator method will do all the trick.
Related
I have an eclipse Java project and want to get information like project source dir, classpaths, etc. My current implementation parses the .project file. But as I didn't find any official documentation describing the structure of the .project file, I have some concerns for the robustness of this approach.
A more convenient and robust way would be to use JDT (headlessly) to load the project and get the relevant information from the IJavaProject object.
Although the developer guide of JDT says
JDT Core packages give you access to the Java model objects and headless Java IDE infrastructure.
all the examples I can find opening an existing Java project get the IJavaProject object from projects within a workspace or use an IProject object. But I couldn't find the way to add a project to the workspace or to construct a IProject/IJavaProject from a path to .project file.
Could anyone please help?
Yes, and can all be done through clear and stable API. org.eclipse.jdt.core is a plug-in, just like org.eclipse.core.resources (which is where you would get an IWorkspace instance), and they both expect to be running within an Eclipse runtime, which can be headless if that's how you write your Eclipse Application. JDT uses the .classpath file to record where sources, libraries, and build output are, and what abstracted references to libraries to use, while the .project file is what records what kind of project it is in general--Java, PHP, Web, some combination of those or others--and a little more information about what builders to execute.
So make yourself a headless Eclipse Application, or package your end-goal functionality inside of one.
https://wiki.eclipse.org/FAQ_What_is_an_Eclipse_application%3F
https://wiki.eclipse.org/FAQ_What_are_extensions_and_extension_points%3F
http://help.eclipse.org/mars/topic/org.eclipse.platform.doc.isv/reference/extension-points/org_eclipse_core_runtime_applications.html?cp=2_1_1_27
http://help.eclipse.org/mars/topic/org.eclipse.platform.doc.isv/reference/api/org/eclipse/core/resources/ResourcesPlugin.html#getWorkspace--
http://help.eclipse.org/mars/topic/org.eclipse.jdt.doc.isv/reference/api/org/eclipse/jdt/core/JavaCore.html#getJavaCore--
http://help.eclipse.org/mars/topic/org.eclipse.jdt.doc.isv/reference/api/org/eclipse/jdt/core/IJavaProject.html#getResolvedClasspath-boolean-
See http://www.ant4eclipse.org/ for a project which allows you to work inside Eclipse projects.
I used it for a bit some years back, and found that this is too brittle for long term usage and build scripts. I would recommend against relying on internal Eclipse things. They break! Typically when mixing releases.
Instead I would suggest you move to Maven. This is a bit more work, but allows you to use the whole maven infrastructure and API's to do things. What you want to achieve here, may be possible already using a Maven plugin.
I'm trying to learn project automation and I'm using the book Pragmatic Project Automation as a guide. It's examples are in Java so I find it easier to follow it along in Java. I don't have any experience using Java or any of its IDEs. However, I've learned some C# using Visual Studio (although I'm still a beginner).
I'm having trouble understanding some parts of setting up a Java project. I'm using Netbeans IDE 7.0 on Windows 7. With Visual Studio, I have a solution with projects underneath. With Netbeans, I appear to just have a project with directories determining the rest of the structure (and the IDE to some degree)? The equivalent to Add Reference appears to be adding a source to the Classpath. There also seems to be a degree of separation between the compiler and the IDE. I'm currently in a situation where I can compile my project just fine while the IDE tells me I still have errors (and I assume this is because I have the project set up incorrectly).
I'm basically looking for analogies that will help me better understand Java project structure.
Lots of similarities between the two languages and IDEs. I spent many years in both. For starters the equivalent to 'add reference' in VS is adding a library or jar in netbeans. In respect to a reference - a jar is pretty much the same thing as a module or .dll in VS. A jar is a compiled reference. To add a reference just go to the project menu and then properties then to the libraries menu from there you can add either pre-assembled netbeans libraries, which are collections of .jar's, or a single .jar, or even a project. Once you add a reference you can import them into your class just like you would in C#.
Netbeans doesn't really have a 'solution' as VS does. You deal with individual projects. It does however have the capability to add a project as a reference so you don't have to continually re-build the references when you change something between multiple projects. It also has project groups to group similar projects.
Lastly Apache ANT is responsible for tying everything together in the background. Netbeans creates a build.xml and build-impl.xml file in the background to tell ANT how to assemble the project into a .jar.
There are my other things to cover but I thing this answers most of your questions. Does this help?
I can't speak for NetBeans, as I use Eclipse, but you are on the right track with classpath being roughly equivalent to references in the Visual Studio world. Libraries (usually .jar files) are placed on the classpath and must be there both at compile time and runtime (you specify the classpath to the compiler at compile time, and to the JVM at runtime). The classpath can contain many different entries, and they can be anywhere in the project structure (or outside of it entirely).
Java itself doesn't impose many restrictions on your project structure, although various IDEs and build tools do. The one thing that is a universal restriction in all Java environments is that source files (and class files) are placed in a directory named after the package name. So if your package name is com.test.something, then your source files will be in SRC_DIR/com/test/something, and your class files in OUT_DIR/com/test/something (note: SRC_DIR and OUT_DIR are not special variables; each IDE will have a different way to specify those directories).
Java libraires tend to heavily build-on one-another, so at some point, you'll find that the classpath entries are too many to manage manually. Before you get there, you'll want to take a look at Apache Maven or Apache Ivy which are dependency management tools. You'll need to understand how they work (either one, not both) and how to integrate them with your IDE. If you use Eclipse and Maven, m2eclipse offers fairly complete integration between the IDE and the dependency management tool.
With Netbeans, I appear to just have a
project with directories determining
the rest of the structure (and the IDE
to some degree)?
Visual Studio dictates a particular project layout and since the compiler is so tightly integrated into the IDE there's no real concept of a build script. In contrast, Java has no such structure (although certain 'best practices' have emerged such as having a 'src' directory for source files, 'lib' for libraries, 'test' for test source, etc.) and a build script is usually required to tell the compiler were to find source files and libraries, what artefacts to produce and a miscellany of other chores (running tests, deployment, creating code metrics and so forth).
In simple cases, the IDE will take care of this for you (if you follow the convention for that particular IDE) but ultimately you will probably want to take a look at a build tool to understand what's going on behind the scenes. Apache Ant and Apache Maven are both prominent offerings. Ant is very flexible whereas Maven attempts to dictate a common layout. I suggest you investigate both and see which suits.
There also seems to be a degree of
separation between the compiler and
the IDE. I'm currently in a situation
where I can compile my project just
fine while the IDE tells me I still
have errors
If your code compiles, it is correct. The IDE is simply acting in an advisory capacity (and will highlight issues beyond compiler errors, such as warning you of potential code mistakes or bad practice).
and I assume this is because I have
the project set up incorrectly
This is a possibility although, as stated above, there are many other explanations.
I am new to java and to netbeans so my apologies if this is a simple question.
I made a 'Java Class Library' Project in Netbeans 6.9.1
I added a few classes to it and hit 'Build'. It builds with no errors. However the problem is I know there are errors.
It seems as though I can make up class names and hit build and it doesnt provide me with any feedback.
How can I make it so that netbeans validates my code when buildling a class library?
I am unable to 'run' the project becuase there is no Main. However this is a class library and I dont want to make test applications in my library.
Edit:
For example I can write the following and a 'clean & build' still works
MadeUpName x = new MadeUpName();
This will build even though I have no class or reference to a class that contains
MadeUpName
I also have no 'Import' statments as of yet and it still builds....
Thanks, stephanie
1) To test a Java Class Library project you should create another project and add your "Java Class Library" project as project dependency. In this new testing project you can write class with main method to test features of the class library. When you will build the test project NetBeans IDE will also build the class library project and will add the JAR file in the class path of the testing project.
2) If the Java Class Library projects compiles through "Clean & Build" that means the project has no syntax errors. That means your code may have logical errors which are not detected by the Java compiler. Usually class library developers create JUnit test cases to find out logical errors, and you are also strongly advised to use JUnit tests for your project.
with regards
Tushar Joshi, Nagpur
Ideally you should test a class library by writing unit tests (rather than test applications) that exercise the classes in your library. There are several unit-testing frameworks available that can help you write the unit tests. The most popular is JUnit.
The test cases should be placed in a different source folder in the same project as the code they are testing. When you build the project you should ensure that the test classes are not included in the JAR file. If you use a build tool like Maven it will do this for you as long as you follow it's project conventions.
Update
Based on your comments, and the fact that you tagged your question with Groovy, I'm guessing that the library is written in Groovy? Your problem seems to be that Netbeans doesn't perform the kind of type-checking that you get with Java (or other statically-typed languages)?
Because Groovy is a dynamic language, it's not possible for the compiler to perform the same rigorous type-checking that you get with Java, but at the very least the Netbeans Groovy editor should provide some hints/warnings if you're referencing classes that don't exist (for example). Are you sure you're opening the code in the correct editor (you may need to install a Groovy plugin first).
You should use GroovyTestCase, rather than JUnit directly to test a Groovy library.
In Visual Studio land, I used to be able to define a structure in an XSD file and add a special attribute to it which would cause it to be dynamically compiled and available to use with intellisense in the other C# files in the application. I am not sure exactly what the term for this is, perhaps "dynamic code generation."
I am trying to accomplish the same in Java using Eclipse IDE. Basically what I am looking for is a tool that will allow me to specify some template and generate Java code from it in a "hot folder" that will allow me code complete in the other static Java files.
Does anyone know of a solution for this? I know it is possible in Visual Studio, but I can't seem to find anything for Eclipse.
Ok, here is exactly what I want to do.
Step 1. I create a folder called templates
Step 2. I create a file called HelloWord.ibes
Step 3. Code it automatically generated in my src folder HelloWorld.java
I want to be able to do this in eclipse easily.
You may create an ant build file that does the source generation for you. Then you are free to use any code generator you like. Ant support is part of the eclipse IDE. If you prefer maven, there's a nice eclipse pluging available (that's what I actually use for source code generation based on jaxb, javacc and xdoclet...).
Technically spoken, you just add another eclipse builder which is invoked anytime eclipse detects a change in your code base.
If you already have a code generator in mind, just 'ask' the internet if there's a plugin available.
Edit
On how to install a builder: This is done automatically. For maven, you just install the maven plugin (m2eclipse) and enable maven dependencies for a project. Then if you look at the projects properties pages (Builder section), you find a second entry in the list of builders.
It's similiar with ant, even easier, because ant is already integrated. "enable" ant for a project and the builder is added to the list of builders for the project. You can deselect it at any time if it kills performance or switch of automatic building (I don't know by heart how to enable ant builds for a project, but I remember that the eclipse help had sufficiant informations).
All about ant can be found here: Apache Ant
Creating a new builder is difficult, as it has to be coded in java and added to eclipse as a plugin. I bet you don't want to follow that track ;)
I'm not sure whether you have seen the code template option?
Preferences.Java, Code Style then Code Templates
How
to add code templates
Useful
code templates
I've trying to use Eclipse JDT AST parsing classes. After including the initial JAR, and sorting out a couple more dependencies, it is with 7+ JARs and I still having NoClassDefFoundError exceptions. This situation arises whenever I'm trying to test libraries with little or no documentation. Trial and error seems a very dumb (and annoying) approach to solve this problem.
Is there a way to automatically sort this out using Eclipse?
Update: Later I found that adding all the JARs you have, and using Ctrl-T (to view/locate types), lets you manually locate the JAR. That was the solution that Google provided so far. Is there a better way?
If you refer to this SO question Finding unused jars used in an eclipse project, you also have:
ClassPathHelper, which can quickly focus on unresolved classes:
It automatically identifies orphan jars, blocked (obscured) classes, and much more.
The only limit is dependencies that are not defined in classes, e.g. in dependency injection framework configuration files.
I have found setting up a workspace exclusively for browsing the eclipse source code incredibly useful. In this manner, you can use PDE tools like the Plug-in Spy, bundle dependency analysis, browsing the documentation, etc much like you would your own plugin projects. I found this article at Vogella a very useful guide.
If you know which bundle your desired class is you can generate the transitive closure of dependencies by creating a new OSGi launch configuration, with just the single bundle selected. By hitting the Add Required button, you can see all bundles necessary to use the one you're interested in.
Edit:
From your question it wasn't clear as to the environment you want to run the compiler in. If you're interested in an embeddable Java compiler to be run outside of an OSGi environment, may I suggest Janino.
You could use a dependency analyzer like:
JarAnalyzer
This will parse a directory full of Jars and give you an XML output dependency map, for which there are several tools for displaying in either graphical or text form.