This is honestly a tiny problem but it's keeping me from proceeding with my small Java practice app.
I'm currently practicing making an API call in Java. I was trying to create a simple class file called "Film". However, when I try to create it as a class-file, Intelli-J keeps telling me that it is unable to create a class-file. I'm trying to set this file up in a folder called "models". All of these class files are going to be utilized as part of an app that performs API calls.
Is there some naming convention I haven't followed? I've been Googling but haven't really found anything.
More directly, based on what #Vishal Jumani touched on, you need to tell IntelliJ what directories are 'source' or 'test' directories.
A directory structure you can use as an example, but you can use whatever you wish.
Right click on the directory you wish to mark as 'root' --> find 'Mark Directory As' --> Select 'Sources Root'
Now you should be able to add java classes in the directory without IntelliJ interrupting you!
This would usually be because of the way your project is setup. It may not be setup correctly to indicate where your source code is.
To setup your project, in the Project Tab, click on the top most folder and select F4. This should bring up the Project Settings dialog window.
Now click on Modules in the LHS, and then select the Sources Tab on the RHS
Select your src folder and click on the Sources button, to indicate this is your source folder. Now IntelliJ is aware that this is where your code is.
Click on Apply and OK. This should close the Dialog Window.
Now right click on the src folder and then select New -> Java Class to create your Java class
Related
I need some help with IntelliJ. I am fairly new to programming, and I have some experience with the IDE but I am by no means a know-it-all when it comes to IntelliJ.
I have 3 Java files (without their respective class files). When I open intelliJ it asks me:
Create New Project
Import Project
Open
Check out from Version Control
I click on open, IntelliJ opens up a file location, I click on one of the three Java files to open, and I drag the other two one by one (they open in their separate tab).
I cannot figure out how to run them. It is likely that I need to create run configuration and I don't know how to do it. I know how to create a new project and get everything working, but I don't know how I can get the files working if I just open them. Can someone tell me how to create the run configurations to run the files? Please and thank you.
IntelliJ IDEA is a great IDE!
This is what I would do:
Select File/New/Project... in the menu. You will get a new modal window.
Then select Java on the left, make sure that you have your JDK selected (top right), it not there, create it right from the window. Click 'Next'.
Just go 'Next' on the 'create project from template' step.
Then type your project name and select a folder for it. It will create a new project.
After that, copy your java files into /src folder using drag-and-drop in IDEA or just a file manager you like.
Now you have an IDEA project with your source code in it. You might need to sync your IDEA project, use File/Synchronize for that.
Finally, you can right click on you java file and 'Run' it from IDEA.
It the project fails on compilation you might need to add required imports and libraries, but that depends on your code. IDEA will highlight all the errors.
I'm a Java beginner and came from JGrasp where I could simply open up a class anywhere and be able to run it without any problems. When I open a class in Intellij it says the configuration isn't correct. Is there a way to set up Intellij by default to automatically set up the SDK for everything to default and allow me to open up any class without setting up configuration for each one. I attached an image that shows the edit configuration popup for a directory I opened. I am aware how to set up a project from scratch but I'd like to be able to open up code from anywhere without too much hassle setting up SDKs and configurations every time.
Here is the code :
To be able to run a class, you first need that class to have a "psvm" (public static void main, which can be easily generated for you by simply writing "psvm" when you're coding a new method in a class).
Once that's done, you head over to the left, in your project's folder-tree, right-click your class, and press the "Run" button.
The green arrow on top of the class' blue circle indicates that this class has a "psvm" and that you thus can "Run" it.
After having done this once, IntelliJ will remember that you have ran this class and the "Edit confirguration" dropdown should usually always allow you to select it. Once the class you want to Run from that dropdown is selected, you can simply press the green triangle next to it.
You should place the source code (that is file with .java extension) to a separate directory (from the compiled classes (that is file with .class extension) and set it as a source root in IDEA: right click on the folder which server as a root package directory and select -> Mark As -> Source Root.
I've tried adding .jar files to the Global Libraries section in settings, but whenever I create a new project, those libraries still have to be manually added to the project.
I've consulted the documentation on Jetbrains's site (https://www.jetbrains.com/idea/help/configuring-project-and-global-libraries.html) and I seem to be doing everything correctly.
With only the Welcome to IntelliJ IDEA window open, I've performed the following steps:
Open Default Project Structure options with CMD+;
Select Global Libraries from the left pane.
Click the + in the second pane and select Java.
Navigate to and select the jsoup-1.8.2.jar file which is the library I am attempting to make global and then select OK.
Click OK to close the Default Project Structure options window.
Select Create new Project
Select Java from the left panel and then select Next.
Select Next again.
Name the project and select Finish.
At this point the only External Libraries added is <1.6>.
So I have to proceed by manually adding the library to the project.
How do I set IntelliJ IDEA to load specific libraries automatically when creating new Projects?
Global libs are "global", so it can be used in multiple projects, so the real question is How does IJ know if you want to use this global lib in to "this" project ?
b/c the way "global libs" woks is you could have python virtual-env as global lib, you could have django libs there.. any named-custom set of jars could be a global lib etc..
so how does ij know-- you need python or django etc in this project? that's why you have to tell/add it manually deciding which one is needed for this project.
I'm posting this query after doing lots of googling and trying out different options for last few days. Is there an easy way to attach source in Eclipse? is the closest answer I found to my question.
From above post, I tried all solutions but each time Eclipse is opening .class file instead of .java file.
Eclipse Details:
Kepler Service Release 2
Build id:20140224-0627
Please let me know if this is a bug with Eclipse or if I am missing something.
If you are using Maven, try this:
Double click on your project in eclipse -> Maven -> Enable Workspace Resolution
This is most likely because Eclipse actually use the class file for declaring the item you have requested the declaration for, and not the source file you think it should be using.
The typical reason for this is if you have a jar file containing previously compiled classes on your build path before (or instead) of the project containing the source you want. This is very rarely desirable as it can take quite a while to discover that your edits do not take effect.
Examine your build path carefully and ensure it is as you want it to be.
Maven is likely supplying a Classpath Container to your project, and generating entries for the Java Build Path based on the pom.xml contents (the JRE System Library is another example of this). Its entries will not have source attachment unless the container decides it will, which is why the Installed JREs preference page offers to let you set Source Attachments. If the pom.xml has something like that, see if you can use it. If not, see if you can configure the Maven container from its context menu. Otherwise, you may simply be stuck.
I had this same problem: when I pressed F3 or tried to open Declaration (after right click) for any element, it took me to the bytecode .class file.
My solution:
I went to the project in Project Explorer:
right click on project name->Properties
Then in Porject Properties window,
Java Build Path->"Order and Export" tab
There I selected the folder with the .java files (source code), which was below the folder having the .class files -in my case "JRE System Library [java-11-openjdk-amd64]", and pressed 'Top' button on the right frame. Then the folder with source files moved to the top.
Finally, pressed "Apply and Close" button.
That solved my problem forever and ever.
The folder
I installed a plug-in which allows me to download the sources for a maven project.
I'm not by my develop machine right now, but I think it was this:
http://marketplace.eclipse.org/content/m2e-dynamic-sources-lookup#.U8gjGWIaySM
With this, you can select a project an have maven download the sources and make then available when you navigate the code in Eclipse. All without "leaving" Eclipse.
Check into your project modules the Java Build Path, look inside the Source tab and verify if you have "Allow output folders for source folders" checkbox flagged; in this case you just need to uncheck it and you will be able to see again the right source from java files.
This is related to the Call Hierarchy in Eclipse IDE.
If you are in a situation, where you're seeing duplicate methods inside the call hierarchy showing Members calling 'myMethod(...)', double-clicking on one of the listed methods may open the .class file instead of the .java file.
When this happens, the solution is to set the search scope in the call hierarchy to Project instead of Workspace.
After setting the search scope, you won't be seeing duplicate methods listed in the call hierarchy, and double-clicking on the listed methods will only open the .java files.
(Using Eclipse DevStyle Dark Theme)
Now that I've learned a bit more, I can ask a more direct question.
Scenario:
I have a Java project in IntelliJ Idea, with the end goal of making a standalone .jar capable of running on Windows or Linux, either run from the command line with java -jar jarname.jar or simply by being double-clicked like any normal, simple jar.
I've written a handful of classes, located in my src/package/name directory. However, one of my classes requires the use of an external class, i.e. a class not located in my source directory or is not part of Java's default set of .jar's in the JDK.
How do I go about configuring IntelliJ to build the .jar artifact AND include the necessary resources inside of it, with everything needed put in the proper place, so that my class can use the resource by an ordinary import statement? An answer given in example form would be awesome; I've almost figured it out, but there must be just one thing I'm not doing correctly.
Thanks for your time,
Yankee
Sources:
http://tukaani.org/xz/java.html
Viewing the directory structure of that source gives a better idea:
http://git.tukaani.org/?p=xz-java.git;a=tree
One does not simply package Mordor into their jar.
After much experimentation, I found a solution that, while maybe not the right way to do it, definitely works. The key is to:
Define your external library (a .jar in my case) as a module dependency.
Add your external resources as (what IntelliJ calls) an "Extracted Directory."
For the first item, go to File -> Project Structure. Click "Modules" in the Project Settings list on the left. In the list just to the right, you will see a list of modules (whatever they are) which belong to your project. Leave that alone, but make sure that it is highlighted/selected as the current module. What you want is the settings for that module, which will show in the window on the right. Go to the "Dependencies" tab. On the rightmost part of the screen will be a little green plus sign. Click that, choose "Jars or directories" and navigate to your relevant resource you want to bring along with your finished jar.
Note: don't be fooled by the check box that says "Export." Its only purpose is to cause endless pain and suffering as you wonder why the dependency isn't exported along with your jar. Always remember, the export box is trying to get you to click on it. It wants to be ticked :3
Next, add that resource as an extracted directory by going to File -> Project Structure. Then "Artifacts" in the Project Settings list on the left. Click the green plus sign at the top to make a new "Jar" artifact "From modules with dependencies." In the right hand window, under the "Output Layout" tab, click the little green plus sign and choose "Extracted Directory." Once again, browse to your precious jar.
You should now be able to successfully build a jar artifact that contains all the resources it needs to run as you designed it.
Here is a reference section on configuring external libraries as module dependencies - link. Regarding artifacts construction - it's possible to precisely specify its content (including dependency libraries content) - link.
Read How classes are found...
It is OK (expected that you) to ship your program in your own jar, and dependent 'libraries' as separate jars
You are expected to provide a way to run your program with the correct -classpath argument to the java command so that java can find both your jar, and the dependent jars... there are multiple ways to do that... see the link above.
Rolf