I develop a simple plugin for netbeans platform. I wonder how can i get a classpath of specify java project (for example i have opened two WebJavaProject) and now i dont know how can i get a classsLoader for specify project.
Im trying something like but this dosent work:
FileObject f = this.project.getProjectDirectory();
ClassPath cpCompile = ClassPath.getClassPath(f, ClassPath.COMPILE);
cpCompile.getClassLoader(true);
can any body know how can i get it?
You need to look for a more specific classpath. One project will usually contain classpath for sources and classpath for tests. If you start from a project you probably want to access its Sources or SourceGroups (check ProjectUtils.getSources(org.netbeans.api.project.Project) and JavaProjectConstants.SOURCES_TYPE_JAVA). This will give you source roots and there will be classpath associated with them.
Related
I am building a desktop application with NetBeans 8.0.2. For my application, I have to manage 3 differents projects : The main project, and two "tool" projects that are linked to the main.
When I run the main project, it will check the JARs present in his classpath in order to retrieve the Manifest files and do some work with.
In order to have my application run correctly, it has to see the two linked projects' JARs but it doesn't, because NetBeans deals with the compiled classes of the project instead of the JAR (for debugging purposes I presume).
I found nothing about it on the Oracle documentation, and the only thing looking a bit like what I search is to create a big-fat-JAR by using another component.
Is there a way to tell NetBeans to "compile the linked projects and use the JARs instead of the .class" files ? Thanks in advance
EDIT : Here is an example when I add the project with "Add Project .." option
/C:/Users/xxxxx/Documents/GuiceProjectsRD/xxxReaderRef/build/classes/
And here is an example when I add the JAR
/C:/Users/xxxxx/Documents/JavaLib/xxxReaderRef.jar
When I add the JAR, I have the ".jar" extension which helps me identify a JAR and then look into it for a Manifest. When I add the Project, there is no path to the JAR but only to the compiled classes, and I can't work with that.
I would not depend on the Manifests in Jars since you then get this kind of issues.
Have a look at the Typesafe Config library. It's a small 100% pure Java library to work with Json/Hokon configuration.
Instead of relying on a Manifest, create a 'reference.conf' in each tool project. In your application, create an 'application.conf' (if needed). Load the config via 'ConfigFactory.load()'. It will automatically search all available reference.conf's, and application.conf, on the classpath, whether in a jar or not, and merge those configs into a single configuration.
I use this approach in project to be able to plugin extension. Have for example in tool A a configuration like
tool.A.class = 'my-tool-A.class'
or used nested structures like
tool {
A {
class = 'my-tool-A.class'
}
}
Do something similar voor tool B.
Then in your application, from the Config, you can get a list of 'tool' configs and detect the available tools like that.
I'm having trouble adding a .jar file I downloaded for my Java project. This is really the first time I've used eclipse, so please bear with me and for some reason (I have no clue why), I just find it somewhat confusing.
I know that in order reference different class files you simply need to create a class library and add it to the build path. From there, all which needs to be done (unless I'm misunderstanding this for whatever reason) is use the "import" keyword to import whatever .jar, .java, or .class/.interface file necessary into the project.
I've tried that with my .jar. I have it referenced in the build path (all I did was just copy the jar to the project directory, and then use the build path option to add it externally), but when ever try to call the object "Delegator", which obviously is a part of the .jar file, it won't read.
Am I missing something here? Seriously, anyone who knows the answer to this - you're relieving a mother of a headache. And before anyone asks - yes, I've searched this one to death. I've found similar questions, but nothing which quite hit what I was looking for. Either that, or I really just lack the common sense.
Right click on project->BuildPath->Libraries->Addexternaljar and then press ok and if it doesnot worked then you should go to the Order and Export tab and checked the jar you have just added in your project. It will solved your problem.
There are several possible reasons, for the question hasn't mentioned the specific failure, and where it has occurred. The following is a list of possible reasons I could think of, but this may not be exhaustive:
You can import a class, in a different package only if the class is public. The only exception is when you are using the class in the same package. If the class is an inner class marked as private, then you're well and truly out of luck. The Delegator class in question might not be public, and that's why you may be unable to use it. This issue ought to be caught by the compiler.
The directory structure within the JAR might not match your package import statements in your classes. This might not be necessary, for Eclipse ought to provide possible fixes, but it is better to verify that nevertheless. Again, the compiler should complain if this is the case.
If the issue is at runtime, then, it is most likely that the JAR is not available in the runtime classpath. You'll need to configure the Runtime configuration, to add the JAR to the runtime classpath. Refer to the Eclipse documentation on run configurations, if you need to know how to change the runtime classpath.
Note:
Exporting the build classpath entries would matter to other projects that depend on the pertinent project; unexported entries will have to be re-imported if required in other projects. This would not apply to a run configuration.
Update
Every Java application needs a main(String[] args] method to start execution. This is the entrypoint for the application. From the comment, it appears that the main method is in a different class. If so, the said class ought to be used to start the application. In Eclipse, a "Run configuration" might be used for the class that lacks this entrypoint, resulting in the described error. One can rectify this by creating a new Run configuration for the class with the said entrypoint. This may be done by one of the following:
editing the existing Run configuration to use the desired Class (the one with the main method). See the above link, in the third bullet point. Edit the value of the class to be launched.
creating a new Run configuration for the desired Class. Usually, you'll need to traverse to the desired class, and run your application (using the Alt+Shift+X+J shortcut) from the said class.
i was facing similar issue with spring jar files but then tried with different jar files and it work so I think , classes defined in jar files were private and not available outside of jar hence you were not able to access the file .
thanks ,
Raju Rathi
Right click on the project--->Build Path--->Configure Build Path...--->In left side you have to choose Java Build Path--->Libraries--->Add External JARs--->ok--->ok
Steps to add jar file in eclipse
1. right click on project
2. click on Bulid Path->configure path
3. click on java Build path
4. Click on libraries tab
5. click on add external jar tab
6. choose jar file
7 click on ok
Copy the .jar file in libs folder which you want to add in your project.
Right click on .jar file -> Add Build Path
Done.
we have downloaded jar files for lambdaj and its dependencies which are again jar files.
we do not know how to go about it. we have copied these files in the
C:\Program Files\Java\jre6\lib\ext
have set the class path in environment variales as:
variable: classpath
path: C:\Program Files\Java\jre6\lib\ext
but we do not know how to go further. we want to run some lambdaj programs.
can anyone suggest how to run lambdaj programs?
You would run a Java program that requires lambdaj in exactly the same way you'd run any other java program with an external dependency, i.e. by invoking the java executable passing in the fully-qualified name of the Main class, or the JAR with an appropriate manifest, or by deploying it in a servlet container, etc. Additionally you should be putting the LambdaJ JAR on the classpath for this invocation, not in the lib folder for your entire JVM.
What have you tried so far and why/how is it not working? Your question at the moment is a bit analogous to "I want to use Microsoft Word to view some Word documents, how do I do this?".
Update for comment 1: You said "it's not working". That doesn't help anyone address your problem as it gives no clue what you expected to happen and what you observed, only that they were different. As for where JAR files can be stored - you can put them in any directory, so long as that directory is on the classpath (or you add it to the classpath) of the Java application that runs. The canonical place to put external dependencies is in a folder called lib below the root of your project, but the important thing is that you choose somewhere consistent and sensible.
It sounds like you don't quite grok Java and classpaths yet. If you have followed some tutorials and are still stuck, ask for help to let you understand. Adding more detail to your question, including the layout of your files, the commands you issued, and the response that came back would be useful too.
If you are using Netbeans create a project and right click on the Libraries folder within the desired project. Click Add JAR/Folder...
Basically let me first explain what I am aiming to do. I have a dynamic ETL transformer app written in JAVA. Due to the dynamic nature of this app I have to be able to add plugins jars to the app in a location outside of the apps jar file.
Basically would like to have the following directory structure:
AppFolder
|- plugins/
|- configs/
|- mainApp.jar
If possible I would like to be able to use wildcards in my manifest to dynamically add jars located in the plugins folder.
Unfortunately all I have tried so far has failed. I have tried to use both relative paths and absolute paths neither have worked (with or without wildcard).
If I however include the plugins folder in the main app's jar file itself it works fine given that I don't use wildcards.
So my question is, is it actually possible to have dependencies outside of a jar or do they always have to be contained within.
The other question is regarding the usage of wildcards. i have looked at [the java documentation] (http://java.sun.com/javase/6/docs/technotes/tools/windows/classpath.html) to no prevail unfortunately.
some examples of what I have tried so far:
../plugins/*
../plugins/plugin.jar
/abolute/path/to/plugins/*
/abolute/path/to/plugins/plugin.jar
and unfortunately none of them have done the trick so any help would be very much appreciated...
Yes you can have dependencies outside the jar. But wildcards are not supported for specify dependant jars.
The jars need to be explicitly specified in your manifest, and the location needs to be relative to where the application is run from
A better option for you may be to use the Extension Mechanism
java -Djava.ext.dirs=/abolute/path/to/plugins/ ......
If you have control of the code you could always add a JarClassLoader and load the jars dynamically.
http://java.sun.com/docs/books/tutorial/deployment/jar/jarclassloader.html
I'm currently working on a Java project which uses Tibco rendezvous control.
I have the tibrvj.jar file on my build path. But I'm not able to see the classes which are there in the package "com.tibco.tibrv".
This package is in the jar which is on my build path.
When I try to open the class in that package , the message displayed on class editor is : "Source not found. the jar file tibrvj.jar has no source attachment".
Is there anything that could be done to set it right ?
This looks like an IDE specific message. Which IDE are you using?
The jar in your classpath only contains the java classes (bytecode) and not the source files (.java files). It looks like you are trying to open the class in your IDE/editor. Since you do not have the java files corrsponding to these classes, the editor is comlaining.
As these are Tibco specific classes, the only option is to "decompile" the classes to see the corresponding java code. Consider using a decompiler like DJ Java Decompiler
It depends on what you mean by "I'm not able to see the classes." If you mean you're getting build failures, that's possibly a matter of not actually having it properly in your build path (how are you building?) or maybe not having the right imports.
If you mean you can't see the source code, you'll need to get hold of it somehow (is Tibco open source?) and then configure your IDE so that it knows where the source is. Of course you don't need to source just to be able to build your app which uses Tibco.
If you could give more information about exactly which problem you're facing, along with what IDE you're using (if any) we could probably help more.