I want to run a particular class in Ecplise called 'RunCreateNetwork'.
However, when I choose Run as and create new Application Config, it doesn't allow me to choose project, where this class is located.
Give me an advice how to run it, if you can, please.
As Som noticed correctly, your project doesn't seem to be a Java project (for whatever reason). A Java project would have a 'J' in the upper right corner of the Icon.
Check your project configuration if it has a Java nature. How you do this is alread described here.
Related
I don't understand exactly what is the way of working with maven projects in Eclipse.
The problems I have are often with projects I download from github. If I set the project myself it usually work, so I think I'm doing something different from the majority of people.
I'll try to detail a specific case:
I clone a repo, let's say: https://github.com/spring-guides/tut-spring-boot-oauth2
In Eclipse I import "existing maven project"
The project has a "Maven nature" as indicated by M on the folder icon
I try to run java class with main from Eclipse. First strange thins is that the "Run As" menu doesn't have "Run as a Java application"
I have to configure the configuration manually. Now it runs, but strange things happens, like I can't edit the file as the "content assist" throw errors instead of giving the normal assists.
I notice that the project has no "source folder". So my first instinct is to add a Java nature or select src as source folder
So I add Java nature to the project. This is a disaster. It can compile anymore as it can find packages. All classes have errors. I try to play around setting source folders on /src or /src/main/java. Sometimes I fix the errors but I can't run (and now I have run as Java application) but when I run it can't load the class
So in the end, I'm a bit confused and I don't know if I explained clearly what I'm doing.
I think I would like to know in a simple way how people are doing it, rather than trying to correct my steps as I'm probably creating a mess myself.
Any help or suggestion welcome.
I'm using the last version of eclipse. I don't know which other tool's versions are relevant.
P.S. I also refresh,restart,clean rebuild the project often after touching things...but it doesn't get better
Maven is a build (management) tool. Simply spoken, its task is to create a JAR that can be used as a dependency/library by other projects or when running java -jar ....
Running a project's code isn't part of it (apart from unit and integration tests code and by using non-default plugins for special situations). Running code is part of Eclipse (or any other IDE) with its Run Configurations.
As stated in the title: I want to run an Eclipse-Plugin, more specifically a GEF-Editor, without starting an Eclipse instance before.
I've tried to use the export functionality provided in the MANIFEST.MF file:
However, running the generated JAR (call it editor.jar) by executing java -jar editor.jar on the command line fails with the message no main manifest attribute, in plugins editor.jar.
I'm aware of the fact, that this is because my MANIFEST.MF file is missing the following line
Main-Class: <packagename>.<classname>
which defines an entry point for my application. However, I've no idea what exactly I need to do here (in the case of an Eclipse-Plugin), cause I don't have something like a main method. I assume Eclipse is running some magic code it doesn't show to me, when I start my project as an Eclipse Application.
So, what do I need to do?
You could try running a GEF editor as a Java application. See Draw2D examples to understand how it can be done. You could probably re-use your GraphicalViewer and PaletteViewer, which means that mouse based interactions with the diagram and palette will be preserved.
However, your editor class would probably have to be incorporated into an SWT shell. Also, all actions contributed to by your editor into Eclipse toolbars, popup menus etc. would be gone. Outline and Tree view would have to be incorporated into your java app somehow if needed.
Think you'd be better off with an RCP application.
Wrap your GEF editor in a simple RCP. You can create one via the Plug-in wizard, setting "Would you create a rich client application?" to "Yes" in the process. This gives you the option to create a minimal application via the Hello World template in the next step. Once you have this, you can either embed your GEF editor in this plugin, or declare a dependency from the new RCP application to your GEF editor plugin, and start the editor from the Application class' start method.
For an overview of resources about RCP development, cf. Getting started with the Eclipse RCP.
It really doesn't add that much overhead to your editor but gives you the opportunity to work with the platform's workbench and workspace metaphors and create easy-to-deploy-and-use application bundles.
Once you have that in place, you can test your RCP from plugin.xml > Overview > Testing > Launch an Eclipse application. This will not run a whole new instance of the IDE, but just the RCP application itself.
Rather than exporting from the MANIFEST.MF, look into creating a product (you can do it via the wizard: New > Product Configuration), and building it via the Maven Tycho plugin(s) (have a look at the respective - really worthwhile - tutorial from EclipseCon Europe 2012: http://eclipsecon.org/europe2012/sessions/building-eclipse-plugins-and-rcp-applications-tycho.html, this includes a section on creating a product as well). Tycho gives true cross-platform builds, as long as you're not on Windows.
No magic code there :).
Question
Given a Classpath Container I've written as a plugin/extension, how do I add it to the classpath, automatically?
Background
Ok so I'm an experienced Java Developer but extremely new to writing Eclipse Plugins. I've been googling, following tutorials and reading source code of other plugins for a couple days. I know exactly what I want to do but not exactly how to do it.
Right now, in Eclipse, when I click a resource and choose "Run as JUnit test" as in:
Behind the scenes, the m2eclipse plugin somehow generates a run configuration that contains the "Maven Dependencies" classpath container, like the following:
My best guess is that the "Maven Dependencies" classpath container is added through some extension point being used by the M2Eclipse plugin. Similarly, I want to add my classpath container, automatically, whenever a user runs a JUnit test--so it shows up under "User Entries." What extension point(s) can I use to make something like that happen? I've been looking at org.eclipse.jdt.core.classpathContainerInitializer but I'm not sure that's going to do what I need.
Ideal Result
Ideally, I'd like to write a plugin that takes every entry in the project's build path and adds it to the classpath of a run configuration (whenever a new launch configuration is created via: Run As > JUnit test). This should be the default behavior of Eclipse but it's not!
My next-best solution would be to simply add my custom classpath container to the run configuration's build path, automatically. At the end of the day, I just want one classpath for any java code our team runs/launches. This shouldn't be so hard!
Any advise on how to achieve any of this would be appreciated! Even basic pointers on where to look to understand how particular Extension Points are intended to be used (the basic JavaDocs APIs are terrible). Thanks,
gMale
Roostergx provides part of the answer (i.e., how to create the classpath container). The second part, as you admit, is how to add it automatically.
I would recommend using an extension point called org.eclipse.ui.startup. This allows you to contribute code that runs (pretty much) as early as possible when Eclipse starts up. On every startup, you can iterate through all projects and see if any existing projects require the classpath container that you created.
The article at http://www.ibm.com/developerworks/opensource/tutorials/os-eclipse-classpath/index.html provides an exellent description and source for a plugin that defines a project specific classpath container that includes all the jar files in a specified directory.
I'm going to try to give as much detail as possible here, pardon me if some is irrelevant.
I have two projects in eclipse. Project 1: com.myworkplace.parent, with code in the package of the same name. Project 2: com.myworkplace.child, with code in package of the same name (I moved my code to that package, from the default package, if that makes a difference). Both are located in my workspace folder and structured the way you'd expect them to be, as far as I can tell.
I've added child to the build path of parent in eclipse using Java Build Path -> Projects -> Add. Parent's .classpath file contains the entry:
<classpathentry combineaccessrules="false" kind="src" path="/com.myworkplace.child"/>
I add a reference to a com.myworkplace.child.Child class in parent, import it, compile it with no errors, run and get:
java.lang.NoClassDefFoundError: com/myworkplace/child/Child
What gives?
Edit: The parent application is an RCP app, maybe OSGI (I really don't know much about RCP and related stuff.) Some googling leads me to believe it might have something to do with this.
Since your application is an RCP app there is a difference between the eclipse classpath that is used while you are editing code and the OSGi classpath that is used at runtime. It sounds like you need to add the com.myworkplace.child plugin to the list of dependencies of the com.myworkplace.parent plugin.
Open either plugin.xml or META-INF/manifest.mf in the parent project. Eclipse should open the PDE plugin editor (a form based editor for the underlying config files). Click the Dependencies tab at the bottom and add your child plugin to the "Required Plug-ins" list on the left hand section of the form. Alternately you could add the com.myworkplace.child package to the "Imported Package" list on the right. The difference between the two is beyond the scope of this answer, but you can read about that in the eclipse docs now that you (hopefully) are moving in the right direction.
We found that even doing all the proper things in the eclipse rcp project, we were still getting such errors. The solution was to delete the application's workspace directory (by default it would store workspace settings under .eclipse, but we've tweaked our code to use another dir that is not shared with other eclipse stuff).
When we removed this dir after a rebuild, our app worked. Apparently it was storing the classpath somehow along with other settings, but we didn't investigate the exact details.
(NOTE: This applies only if you've called the IWorkbenchConfigurer.setSaveAndRestore method passing a boolean value of 'true' - which means that your application will save and restore various rcp settings after a shutdown of the application and subsequent relaunch.)
If your code is running in an application server, you need to configure the Classpath correctly for that application server.
To do that, find your Servers tab, double-click it, click Open Launch Configuration in the new tab that appears in the main editing area, click the Classpath tab and ensure the Classpath there is correct.
Netbeans, indeed any Java compiler and
executor, needs to know the classpath
to compile and run a file. When you
just open a file in Netbeans, you do
not tell it any of that information.
When you set up a project, that
process tells Netbeans where the Java
resources are.
Yet other IDEs can easily do this. It's not good practice, but it's simple and quick for "fooling around".
Is there any way to compile & run a file, that doesn't belong to a project, in Netbeans?
edit: The options are greyed out if the file doesn't belong to a project.
Your best option with NetBeans is just to create a dummy "try stuff" project that you know will never contain a shipping product but will allow you to experiment without having to create a new project every time.
You could even collect code snippets in different classes this way. If you add a main() method to each experimental class, you have a way to run them all in the IDE just by changing what you have set for the main project class. This is what I do and it works pretty well.
Why not using 'create new project with existing sources' which can be done for Java, Ruby, ... projects?
You can do so and netbeans will create only a nbproject folder within your project's dir and all should be fine.
This solution doesn't work great because projects are also "typed" and I work in 4 languages. I'd hate to have a "rubystuff" project, a "pythonstuff" project, "javastuff", etc, etc...